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AI System Used to Detect Lung Cancer

Reporter: Irina Robu, PhD

Lung cancer is characterized by uncontrolled cell growth in tissues of the lung. The growth spreads beyond the lung by metastasis into nearby tissues. The most common symptoms are coughing (including coughing up blood), weight loss, shortness of breath, and chest pains. The two main types of lung cancer are small-cell lung carcinoma(SCLC) and non-small-cell lung carcinoma (NSCLC). Lung cancer may be seen on chest radiographs and computed tomography(CT) scans. However, computers seem to be as good or better than regular doctors at detecting tiny lung cancers on CT scans according to scientists from Google.

The AI designed by Google was able to interpret images using the same skills as humans to read microscope slides, X-rays, M.R.I.s and other medical scans by feeding huge amounts of data from medical imaging into the systems. It seems that the researchers were able to train computers to recognize patterns linked to a specific condition.
In a new Google study, the scientists applied artificial intelligence to CT scans used to screen people for lung cancer. Current studies have shown that screening can reduce the risk of dying from lung cancer and can also identify spots that might later become malignant.

The researchers created a neural network with multiple layers of processing and trained the AI by giving it many CT scans from patients whose diagnoses were known. This allows radiologists to sort patients into risk groups and decide whether biopsies are needed or follow up to keep track of the suspected regions. Even though the technology seems promising, but it can have pitfalls such as missing tumors, mistaken benign spots for malignancies and push patients into risky procedures.

Yet, the ability to process vast amounts of data may make it imaginable for artificial intelligence to recognize subtle patterns that humans simply cannot see. It is well understood that the systems should be studied extensively before using them for general public use. The lung-screening neural network is not ready for the clinic yet.

SOURCE

A.I. Took Test To Detect Lung Cancer And Smashed It

 

 

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3D Imaging of Cancer Cells

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

3D Imaging of Cancer Cells Could Lead to Improved Ability of Pathologists and Radiologists to Plan Cancer Treatments and Monitor Cell Interactions

Dark Daily Apr 8th 2016        Jon Stone

https://www.linkedin.com/pulse/3d-imaging-cancer-cells-could-lead-improved-ability-plan-joseph-colao

 

3D Imaging of Cancer Cells Could Lead to Improved Ability of Pathologists and Radiologists to Plan Cancer Treatments and Monitor Cell Interactions.

New technology from researchers at the University of Texas Southwestern Medical Center enables the ability to study cancer cells in their native microenvironments.

Imaging research is one step closer to giving clinicians a way to do high-resolution scans of malignant cells in order to diagnose cancer and help identify useful therapies. If this technology were to prove successful in clinical studies, it might change how anatomic pathologists and radiologists diagnose and treat cancer.

Researchers at the University of Texas Southwestern Medical Center developed a way to create near-isotropic, high-resolution scans of cells within their microenvironments. The process involves utilizing a combination of two-photonBessel beams and specialized filtering.

New Imaging Approach Could be Useful to Both Pathologists and Radiologists

In a recent press release, senior author Reto Fiolka, PhD, said “there is clear evidence that the environment strongly affects cellular behavior—thus, the value of cell culture experiments on glass must at least be questioned. Our microscope is one tool that may bring us a deeper understanding of the molecular mechanisms that drive cancer cell behavior, since it enables high-resolution imaging in more realistic tumor.”

In a study in Developmental Cell, Erik S. Welf, PhD, et al, described the new microenvironmental selective plane illumination microscopy (meSPIM). When developing the technology, the team outlined three goals:

1. The microscope design must not prohibitively constrain microenvironmental properties.

2. Spatial and temporal resolution must match the cellular features of interest.

3. Spatial resolution must be isotropic to avoid spatial bias in quantitative measurements.

This new technology offers pathologists and medical laboratory scientists a new look at cancer cells and other diseases. The study notes that meSPIM eliminates the influence of stiff barriers, such as glass slide covers, while also allowing a level of control over both mechanical and chemical influences that was previously impossible.

Early meSPIM Research Reveals New Cell Behaviors

Early use of meSPIM in observing melanoma cells is already offering new insights into the relationship between the cell behavior of cellular- and subcellular-scale mechanisms and the microenvironment in which these cells exist. The study notes, “The ability to image fine cellular details in controllable microenvironments revealed morphodynamic features not commonly observed in the narrow range of mechanical environments usually studied in vitro.”

One such difference is the appearance of blebbing. Created by melanoma cells and lines, these small protrusions are thought to aid in cell mobility and survival. Using meSPIM, observers could follow the blebbing process in real-time. Formation of blebs on slides and within an extracellular matrix (ECM) showed significant differences in both formation and manipulation of the surrounding microenvironment.

The team is also using meSPIM to take a look at membrane-associated biosensor and cytosolic biosensor signals in 3D. They hope that investigation of proteins such as phosphatidylinositol 3-kinase (PI3K) and protein kinase C will help to further clarify the roles these signals play in reorientation of fibroblasts.

meSPIM combined with computer vision enables imaging, visualization, and quantification of how cells alter collagen fibers over large distances within an image volume measuring 100 mm on each side. (Photo Copyright: Welf and Driscoll et al.)

The research team believes this opens new possibilities for studying diseases at a subcellular level, saying, “Cell biology is necessarily restricted to studying what we can measure. Accordingly, while the last hundred years have yielded incredible insight into cellular processes, unfortunately most of these studies have involved cells plated onto flat, stiff surfaces that are drastically different from the in vivo microenvironment …

“Here, we introduce an imaging platform that enables detailed subcellular observations without compromising microenvironmental control and thus should open a window for addressing these fundamental questions of cell biology.”

Limitations of meSPIM

One significant issue associated with the use of meSPIM is the need to process the large quantity of data into useful information. Algorithms currently allow for automatic bleb detection. However, manual marking, while time consuming, still provides increased accuracy. Researchers believe the next step in improving the quality of meSPIM scans lie in computer platforms designed to extract and process the scan data.

Until this process is automated, user bias, sample mounting, and data handling will remain risks for introducing errors into the collected data. Yet, even in its early stages, meSPIM offers new options for assessing the state of cancer cells and may eventually provide pathologists and radiologists with additional information when creating treatment plans or assessments.

 

Seeing cancer cells in 3-D (w/ Video)

http://phys.org/news/2016-02-cancer-cells-d-video.html

 

Cancer in 3-D

http://cdn.phys.org/newman/csz/news/800/2016/cancerin3d.png

Extracted surfaces of two cancer cells. (Left) A lung cancer cell colored by actin intensity near the cell surface. Actin is a structural molecule that is integral to cell movement. (Right) A melanoma cell colored by PI3-kinase activity near the cell surface. PI3K is a signaling molecule that is key to many cell processes. Credit: Welf and Driscoll et al.

Cancer cells don’t live on glass slides, yet the vast majority of images related to cancer biology come from the cells being photographed on flat, two-dimensional surfaces—images that are sometimes used to make conclusions about the behaviour of cells that normally reside in a more complex environment. But a new high-resolution microscope, presented February 22 in Developmental Cell, now makes it possible to visualize cancer cells in 3D and record how they are signaling to other parts of their environment, revealing previously unappreciated biology of how cancer cells survive and disperse within living things.

“There is clear evidence that the environment strongly affects cellular behavior—thus, the value of cell culture experiments on glass must at least be questioned,” says senior author Reto Fiolka, an optical scientist at the University of Texas Southwestern Medical Center. “Our is one tool that may bring us a deeper understanding of the molecular mechanisms that drive cancer cell behavior, since it enables high-resolution imaging in more realistic tumor environments.”

Read more at: http://phys.org/news/2016-02-cancer-cells-d-video.html#jCp

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A step forward in diagnostics

Larry H. Bernstein, MD, FCAP, Curator

LPBI

 

3D Imaging of Cancer Cells Could Lead to Improved Ability of Pathologists and Radiologists to Plan Cancer Treatments and Monitor Cell Interactions

DARK DAILY   4/8/2016   info@DarkDaily.com  http://www.darkdaily.com/#axzz45En6Xbfr

 

Imaging research is one step closer to giving clinicians a way to do high-resolution scans of malignant cells in order to diagnose cancer and help identify useful therapies. If this technology were to prove successful in clinical studies, it might change how anatomic pathologists and radiologists diagnose and treat cancer.

Researchers at the University of Texas Southwestern Medical Center developed a way to create near-isotropic, high-resolution scans of cells within their microenvironments. The process involves utilizing a combination of two-photonBessel beams and specialized filtering.

New Imaging Approach Could be Useful to Both Pathologists and Radiologists

In a recent press release, senior author Reto Fiolka, PhD, said “there is clear evidence that the environment strongly affects cellular behavior—thus, the value of cell culture experiments on glass must at least be questioned. Our microscope is one tool that may bring us a deeper understanding of the molecular mechanisms that drive cancer cell behavior, since it enables high-resolution imaging in more realistic tumor.”

In a study in Developmental Cell, Erik S. Welf, PhD, et al, described the new microenvironmental selective plane illumination microscopy (meSPIM). When developing the technology, the team outlined three goals:

1. The microscope design must not prohibitively constrain microenvironmental properties.

2. Spatial and temporal resolution must match the cellular features of interest.

3. Spatial resolution must be isotropic to avoid spatial bias in quantitative measurements.

This new technology offers pathologists and medical laboratory scientists a new look at cancer cells and other diseases. The study notes that meSPIM eliminates the influence of stiff barriers, such as glass slide covers, while also allowing a level of control over both mechanical and chemical influences that was previously impossible.

Early meSPIM Research Reveals New Cell Behaviors

Early use of meSPIM in observing melanoma cells is already offering new insights into the relationship between the cell behavior of cellular- and subcellular-scale mechanisms and the microenvironment in which these cells exist. The study notes, “The ability to image fine cellular details in controllable microenvironments revealedmorphodynamic features not commonly observed in the narrow range of mechanical environments usually studied in vitro.”

One such difference is the appearance of blebbing. Created by melanoma cells and lines, these small protrusions are thought to aid in cell mobility and survival. Using meSPIM, observers could follow the blebbing process in real-time. Formation of blebs on slides and within an extracellular matrix (ECM) showed significant differences in both formation and manipulation of the surrounding microenvironment.

The team is also using meSPIM to take a look at membrane-associated biosensorand cytosolic biosensor signals in 3D. They hope that investigation of proteins such as phosphatidylinositol 3-kinase (PI3K) and protein kinase C will help to further clarify the roles these signals play in reorientation of fibroblasts.

 

meSPIM-500ppi

meSPIM combined with computer vision enables imaging, visualization, and quantification of how cells alter collagen fibers over large distances within an image volume measuring 100 mm on each side. (Photo Copyright: Welf and Driscoll et al.)   http://www.darkdaily.com/wp-content/uploads/meSPIM-500ppi-220×300.jpg

 

Seeing cancer cells in 3-D (w/ Video)

February 22, 2016

Cancer in 3-D

Extracted surfaces of two cancer cells. (Left) A lung cancer cell colored by actin intensity near the cell surface. Actin is a structural molecule that is integral to cell movement. (Right) A melanoma cell colored by PI3-kinase activity near the cell surface. PI3K is a signaling molecule that is key to many cell processes. Credit: Welf and Driscoll et al.  http://cdn.phys.org/newman/csz/news/800/2016/cancerin3d.png

Cancer cells don’t live on glass slides, yet the vast majority of images related to cancer biology come from the cells being photographed on flat, two-dimensional surfaces—images that are sometimes used to make conclusions about the behaviour of cells that normally reside in a more complex environment. But a new high-resolution microscope, presented February 22 in Developmental Cell, now makes it possible to visualize cancer cells in 3D and record how they are signaling to other parts of their environment, revealing previously unappreciated biology of how cancer cells survive and disperse within living things.

“There is clear evidence that the environment strongly affects cellular behavior—thus, the value of cell culture experiments on glass must at least be questioned,” says senior author Reto Fiolka, an optical scientist at the University of Texas Southwestern Medical Center. “Our is one tool that may bring us a deeper understanding of the molecular mechanisms that drive cancer cell behavior, since it enables high-resolution imaging in more realistic tumor environments.”

In their study, Fiolka and colleagues, including co-senior author Gaudenz Danuser, and co-first authors Meghan Driscoll and Erik Welf, also of UT Southwestern, used their microscope to image different kinds of skin cancer cells from patients. They found that in a 3D environment (where cells normally reside), unlike a glass slide, multiple melanoma cell lines and primary melanoma cells (from patients with varied genetic mutations) form many small protrusions called blebs. One hypothesis is that this blebbing may help the survive or move around and could thus play a role in skin cancer cell invasiveness or drug resistance in patients.

The researchers say that this is a first step toward understanding 3D biology in tumor microenvironments. And since these kinds of images may be too complicated to interpret by the naked eye alone, the next step will be to develop powerful computer platforms to extract and process the information.

“When we conceived of this project, we first asked what we wanted to measure and then designed a microscope and analytical platform to achieve this goal,” says co-first author Erik Welf, a cell biologist. “We hope that now instead of asking what we can measure, scientists will ask what we must measure in order to make meaningful contributions to cancer cell biology.”

The microscope control software and image analytical code are freely available to the scientific community.

More information: Developmental Cell, Welf and Driscoll et al.: “Quantitative Multiscale Cell Imaging in Controlled 3D Microenvironments” dx.doi.org/10.1016/j.devcel.2016.01.022

Read more at: http://phys.org/news/2016-02-cancer-cells-d-video.html#jCp

Quantitative Multiscale Cell Imaging in Controlled 3D Microenvironments

Erik S. Welf4, Meghan K. Driscoll4, Kevin M. Dean, Claudia Schäfer, Jun Chu, Michael W. Davidson, Michael Z. Lin, Gaudenz Danusercorrespondence , Reto Fiolkacorrespondence
Dev Cell  22 Feb 2016;  Volume 36, Issue 4:462–475     DOI: http://dx.doi.org/10.1016/j.devcel.2016.01.022
Highlights
  • meSPIM allows microenvironmentally conscious 3D imaging/analysis of subcellular biology
  • Precisely controlled microenvironments reveal diverse morphological phenotypes
  • Isotropic resolution and high speed enable the quantification of 3D cell signaling and morphodynamics
  • Multiscale quantification of microenvironmental reorganization by cells

Summary

The microenvironment determines cell behavior, but the underlying molecular mechanisms are poorly understood because quantitative studies of cell signaling and behavior have been challenging due to insufficient spatial and/or temporal resolution and limitations on microenvironmental control. Here we introduce microenvironmental selective plane illumination microscopy (meSPIM) for imaging and quantification of intracellular signaling and submicrometer cellular structures as well as large-scale cell morphological and environmental features. We demonstrate the utility of this approach by showing that the mechanical properties of the microenvironment regulate the transition of melanoma cells from actin-driven protrusion to blebbing, and we present tools to quantify how cells manipulate individual collagen fibers. We leverage the nearly isotropic resolution of meSPIM to quantify the local concentration of actin and phosphatidylinositol 3-kinase signaling on the surfaces of cells deep within 3D collagen matrices and track the many small membrane protrusions that appear in these more physiologically relevant environments.

Read more: 3D Imaging of Cancer Cells Could Lead to Improved Ability of Pathologists and Radiologists to Plan Cancer Treatments and Monitor Cell Interactions | Dark Daily http://www.darkdaily.com/3d-imaging-of-cancer-cells-could-lead-to-improved-ability-of-pathologists-and-radiologists-to-plan-cancer-treatments-and-monitor-cell-interactions-301#ixzz45Enp2yT0

The research team believes this opens new possibilities for studying diseases at a subcellular level, saying, “Cell biology is necessarily restricted to studying what we can measure. Accordingly, while the last hundred years have yielded incredible insight into cellular processes, unfortunately most of these studies have involved cells plated onto flat, stiff surfaces that are drastically different from the in vivo microenvironment …

“Here, we introduce an imaging platform that enables detailed subcellular observations without compromising microenvironmental control and thus should open a window for addressing these fundamental questions of cell biology.”

Limitations of meSPIM

One significant issue associated with the use of meSPIM is the need to process the large quantity of data into useful information. Algorithms currently allow for automatic bleb detection. However, manual marking, while time consuming, still provides increased accuracy. Researchers believe the next step in improving the quality of meSPIM scans lie in computer platforms designed to extract and process the scan data.

Until this process is automated, user bias, sample mounting, and data handling will remain risks for introducing errors into the collected data. Yet, even in its early stages, meSPIM offers new options for assessing the state of cancer cells and may eventually provide pathologists and radiologists with additional information when creating treatment plans or assessments.

 

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Ultrasound in Radiology – Results of a European Survey

Reporter and Curator; Dror Nir, PhD

Ultrasound is by far, the most frequently used imaging modality in patient’s pathway being used by office-based clinicians and in most of hospitals’ departments. This is also true for cancer patients. As the contribution of imaging to the clinical assessment of patients becomes more substantial, the argument around “who is qualified” to perform such assessment is becoming louder and definitely more relevant!

Both the European and the North America Radiology societies are pushing towards establishment of centralized ultrasound services within the hospitals radiology department, still most ultrasound machines are spread between the different departments and being used by all practitioners. ESR’s working group on ultrasound published a report on the status of ultrasound-practice in European hospitals. Quite a shame; only 13% of the hospital addressed for participation in the survey reacted positively. I would like to highlight the most relevant conclusion from this survey, which is valid no matter which hand is holding the probe: Technique-oriented teaching, time and examinations are necessary to learn how to use Ultrasound properly within the framework of organ-oriented and disease training. Personally, I would support the idea that when it comes to management of cancer patients, this will become a “quality requirement” by law, similar to rules applicable to using radio-active substances.

 Here below is the full report:

Organisation and practice of radiological ultrasound in Europe: a survey by the ESR Working Group on Ultrasound

European Society of Radiology (ESR) 

Neutorgasse 9/2, AT-1010 Vienna, Austria

European Society of Radiology (ESR)

Email: communications@myesr.org

URL: http://www.myESR.org

Received: 25 April 2013Accepted: 26 April 2013Published online: 29 May 2013

Abstract

Objectives

To gather information from radiological departments in Europe assessing the organisation and practice of radiological ultrasound and the diagnostic practice and training in ultrasound.

Methods

A survey containing 38 questions and divided into four groups was developed and made available online. The questionnaire was sent to over 1,000 heads of radiology departments in Europe.

Results

Of the 1,038 radiologists asked to participate in this survey, 123 responded. Excluding the 125 invitations to the survey that could not be delivered, the response rate was 13 %.

Conclusion

Although there was a low response rate, the results of this survey show that ultrasound still plays a major role in radiology departments in Europe: most departments have the technical capabilities to provide patients with up-to-date ultrasound examinations. Although having a centralised ultrasound laboratory seems to be the way forward, most ultrasound machines are spread between different departments. Ninety-one per cent of answers came from teaching hospitals reporting that training is regarded as an art and is needed in order to learn the basics of scanning techniques, after which working in an organ-oriented manner is the best way to learn how to integrate diagnostic US within the clinical context and with all other imaging techniques.

Main Messages

• Hospitals should introduce centralised ultrasound laboratories to allow for different competencies in US under the same roof, share human and technological resources and reduce the amount of equipment needed within the hospital.

• Technique-oriented teaching, time and examinations are necessary to learn how to use US properly within the framework of organ-oriented training.

• A time period of about 6 months dedicated solely to learning US scanning techniques is deemed sufficient in most cases.

INTRODUCTION

The Working Group on ultrasound (US) of the European Society of Radiology was founded in 2009 with the aim of supporting increased quality and visibility of US within radiological departments as well as strengthening the position of US within the radiology community.

Among the many practical goals assigned to the group, one of the most important has been to gather information about the organisation and practice of radiological US in Europe.

This article reports the results of a survey assessing how diagnostic US is practiced and how training in US is organised in radiological departments of European hospitals. Questions were also aimed at evaluating the practice of US within both radiology and other hospital departments in order to understand the relationships among the different users of this technique. A comparison with the results of a previous survey on the US activities within 17 academic radiological departments throughout Europe published in 1999 by Schnyder et al. [1] was also attempted.

MATERIALS AND METHODS

A questionnaire was developed to obtain data about the practice of diagnostic US within radiology departments in Europe.

The survey contained 38 questions that were divided into four groups:

(1)

Related to the hospital: location; dimensions; presence or absence of teaching duties.

(2)

Related to the workload of US: number of US examinations/year, amount of US equipment available; state of available technology; types of most frequent examinations; organisation of the US laboratory; presence of sonographers; methods of reporting and archiving US examinations.

(3)

Related to the teaching of US to radiology residents: organisation and duration of training programmes; number of examinations to be performed before completion of the training period; presence of training programmes dedicated to sonographers or other non-radiology residents.

(4)

Related to the US examinations performed outside radiology in each hospital; clinical specialists most often involved in performing directly US; availability of special techniques, such as contrast-enhanced ultrasound (CEUS); methods of reporting and archiving US examinations.

The questionnaire was made available online and an invitation to fill it in was sent to all 1,038 heads of radiology departments throughout Europe within the database of the European Society of Radiology. The invitation was repeated three times over a period of 3 months, between June and August 2011.

RESULTS

There were 123 responses to the questionnaire. Considering that 125/1,038 e-mail messages were reported as “undelivered”, the response rate to the invitation was 13 %. Many responders did not answer all the questions presented in the questionnaire, and some answers and comments were somewhat difficult to understand and evaluate.

First group of questions

Answers were gathered from different parts of Europe; 63.4 % were from five nations (Germany, Austria, France, Spain and Italy). The distribution according to countries is presented in Table 1.

Table 1

Nationality of responders

Germany (DE)

19

Austria (AT)

18

France (FR)

16

Spain (ES)

14

Italy (IT)

11

Hungary (HU)

7

Switzerland (CH)

5

The Netherlands (NL)

4

Turkey (TR)

3

UUK

3

Czech Rep (CZ)

3

Poland (PL)

2

Denmark (DK)

2

Romania (RO)

2

Norway (NO)

2

Croatia (HR)

2

Portugal (PT)

2

Belgium (BE)

2

Greece (GR)

1

Montenegro (ME)

1

Lithuania (LT)

1

Ireland (IE)

1

Serbia (RS)

1

Sweden (SE)

1

There were 25 responses (20.3 %) from hospitals with fewer than 400 beds, 52 (42.3 %) from hospitals with between 400 and 1,000 beds and 46 (37.4 %) from hospitals with more than 1,000 beds. Most answers were from teaching hospitals (91.1 %).

Second group of questions

Most radiology departments (77 %) have fewer than 10 working US units; 22 % have between 10 and 20 US machines; only 0.8 % have more than 20 machines. Small, portable units are available in 64.5 % of departments, 3D/4D capabilities are present in 52 % and elastography in 48.2 %, and 67.3 % have the possibility to perform CEUS examinations.

Up to 57.6 % of radiology departments perform more than 10,000 examinations per year; between 3,000 and 10,000 examinations per year are performed in 33.1 % of cases; only 9.3 % of departments perform fewer than 3,000 examinations.

Abdominal US is the most frequent exam (51.51 %), followed by breast (14.46 %), musculoskeletal (11.59 %), pelvic (10.88 %) and vascular (10.42 %) US examinations. Contrast-enhanced US (CEUS) studies constitute about 4.39 %. US is used by radiologists in emergency in 96.6 % of cases and in paediatrics in 74.6 %. Comments indicate that most of those who answered “no” did not have a paediatric section in their hospital.

Transvaginal US is used in obstetric examinations by 15.8 % of responders and in gynaecological studies by 50.7 %. Endoscopic US is used by radiologists in 13.4 % and intravascular US in 14.6 %; radiologists are called by surgeons for intraoperative US in 64.2 % of cases.

There were 49 responders who indicated the actual number of US examinations performed/year. The characteristics of hospitals in which the radiology department performs more than 20,000 ultrasound examinations/year are presented in Table 2.

Table 2

Characteristics of the hospitals in which the radiology department performs more than 20,000 US examinations/year (nationality, presence/absence of teaching duties, number of inpatients, number of US machines available, ratio between number of US examinations performed by non-radiology specialists vs. radiologists)

t2

Those who reported fewer than 5,000 US examinations/year are reported in Table 3.

Table 3

Characteristics of the hospitals in which the radiology department performs less than 5,000 US examinations/year (nationality, presence/absence of teaching duties, number of inpatients, number of US machines available, ratio between number of US examinations performed by non-radiology specialists vs. radiologists)

t3

Third group of questions

The first question in this group was whether the hospital was organised with a centralised US laboratory where physicians from all specialties work together.

There were 13/110 positive answers (11.8 %) from Germany (5), Spain (3), Austria (2), Hungary (2) and Croatia (1). All other hospitals have US machines scattered throughout the different radiological and non-radiological departments. The centralised US laboratory is organised together by the radiology and the internal medicine departments in three cases; it is truly multidisciplinary, with all specialties concurring, in three others; it is run by radiology in two. The remaining two positive answers did not provide further detail about their organisation.

The second question related to the role of sonographers. Only 15/110 (13.6 %) department heads stated they work with sonographers. They are located in Spain (3), Germany (2), UK (2), The Netherlands (2), Austria (1), Belgium (1), Ireland (1), Lithuania (1) and Montenegro (1). In all others, US examinations are done directly by the radiologists. There were 12 comments describing how the work of sonographers is organised. Sonographers do both the examination and the report, with the radiologist checking difficult cases only in four hospitals; sonographers do the studies and the radiologist takes a final look and writes the reports in six; two departments state they use sonographers for vascular examinations only.

The third question related to the organisation of training programmes in US. Radiology residents are trained in 91.1 % of responders. Some centres organise a theoretical course on basic principles of US before starting practical activity. Then, clinical practice is usually performed according to organ/systems training schemes. Residents work under close supervision of a senior radiologist: they approach the patient, perform a preliminary examination and issue a first report, which is then checked by the expert. The aim is to obtain progressive growth of competences: from scanning capabilities, to reporting capabilities, to complete independence.

The length of the period of training within the US laboratory in the various teaching hospitals and the minimum number of US examinations required before the end of the residency period are summarised in Tables 4 and5.

Table 4

Length of the period of training within the US laboratory in the 84 teaching hospitals that reported it

No. of teaching hospitals

Length of training

13

<4 months

38

4–6 months

26

6–12 months

7

>1 year

Table 5

Minimum number of US examinations to be performed before the end of the residency period in the 75 teaching hospitals that reported it

No. of teaching hospitals

Minimum no. of US examination

20

<500

16

500–1,000

17

1,000–2,000

22

>2,000

There was a direct correlation between the number of US exams performed in the department and the depth of US involvement during training: training programmes in the two hospitals where the lowest number of US examinations/year is performed indicate a period of 3 months and 250 and 500 examinations. However, a hospital with a workload of 45,000 US studies per year (in which, however, the examinations are performed by sonographers) suggested only 2–3 months of training and 100 exams before the end of the residency period.

Training is also provided for non-radiology residents in 37 hospitals. It is most frequently offered to internal medicine, gastroenterology, surgery, anesthesiology, vascular surgery and paediatrics. Comments indicate that these radiology courses allow only theoretical teaching, since observation, but not direct contact with patient, is provided for non-radiologists.

All 15 departments working with sonographers provide, or are planning to provide, starting in 2012, training courses for these professionals. These include both theory and practice; the theoretical part is done, in some cases, together with radiology residents.

As an important technical point, it must be noted that US images performed by radiologists are recorded into PACS systems in 85.6 % of cases. Comments on this question indicated that not all equipment is linked to PACS and that only selected images or videos are often archived; furthermore, technical problems in archiving videos have been reported.

A final group of questions pertained to the US examinations performed outside the radiology department in each hospital.

One question asked about the proportion of US examinations performed by radiologists vs. those performed by non-radiologists. European radiologists, as a whole, still perform a higher number of examinations (61.27 %) than non-radiologists (38.32 %). Differences in the percentage of studies performed in the different hospitals are presented in Table 6.

Table 6

Proportion of US examinations performed by radiologists vs. non-radiologists. Although radiologists, as a whole, perform more US examinations than non-radiologists, the table shows there are differences among different departments, with slightly more than 50 % performing more than 70 % of the studies

% of hospital US exams performed by radiologists

No. of radiology departments

≥90 %

25 (20.32 %)

70–90 %

37 (30.08 %)

10–70 %

57 (46.35 %)

<10 %

4 (3.25 %)

Comments indicate that most OB/GYN, neurology, vascular, urology, internal medicine, anaesthesiology and gastroenterology departments run their own US units in their wards. CEUS is used in 35.1 % of gastroenterology departments, in 15.1 % of internal medicine, in 10.6 % of transplant units and in 10.4 % of nephrology departments.

The examinations performed out of the radiology department are formally reported in 64.4 % of cases only. Comments indicate that reports are fully stored within the Hospital Information System (HIS) in 31 cases; storage is only partial in 24; no HIS storage is used in 5 cases.

US images obtained outside of the radiology department are recorded into the PACS system of the hospital in 18.3 % of cases only.

DISCUSSION

Several considerations are raised from the results of this survey.

First, there was a low response rate to the survey itself. There were only 123 answers to the 913 received messages asking for information from radiology department heads (a mere 13 %). It is hoped that this low response rate relates to the many committments on their side and not to low interest in the role of US within radiology [23].

Second, most responders indicated that US is still an important part of the activities of the radiology department. Only 9.3 % report fewer than 3,000 examinations/year. It must be noted that there may be a bias in these figures, since it is conceivable that responders were more interested in US than those who did not answer the questionnaire (even if there were responders who indicated that, in their hospital, US is done mostly outside of the radiology department). Most of the workload is due to abdomino-pelvic exams, followed by breast, musculoskeletal and vascular applications. Furthermore, state-of-the-art equipment is used in about 50 % and CEUS can be performed in 64.2 %. Portable machines are available in 64.5 %, transvaginal US examinations of the pelvis are used in 50.7 %, and radiologists are still involved in intraoperative US examinations in 64.2 % of cases. Most departments still have the technical capabilities to provide up-to-date US answers to the requests they receive.

Another consideration relates to the organisation of US within the hospital. In most cases US machines are scattered throughout the different departments, and only 13 hospitals have organised a centralised US laboratory where all physicians from different specialities come to examine their patients. Although centralisation seems the best way to run a US service, there are several factors that can explain why this is not the case, many of which stem from tradition. US laboratories, in fact, commonly arose separately from one another, following the initiatives of the different specialists who started introducing this technique in their practice. Then, there is a disposition to maintain independence and separate departmental income from the activities as well as the desire to control all aspects of patients’ care.

Only 15 departments reported they are working with sonographers. Although it is known that in Europe most radiologists perform US examinations directly, it is believed that this figure underestimates the real contribution of these professionals. A possible explanation is that only three hospitals from the UK answered the questionnaire; in the UK sonographers play a major role in dealing with the US workload.

Most answers to the questionnaire came from teaching hospitals (91.1 %). Comments on how training is organised state that US scanning is commonly regarded as an art, taught from maestro to pupil, with progressive growth in scanning and reporting capabilities. In addition, most report that US is taught within an organ-/system-oriented training system. The “art” of US is highly dependent on the operator’s dedication and technical ability, and this has to be properly taught. Additionally, a period of training within a dedicated US laboratory is probably needed to learn the basics of scanning techniques. After learning the technique, working in an organ-oriented manner is surely the best way to learn how to integrate diagnostic US within the clinical context and with all other imaging techniques.

There were 13 teaching hospitals in which fewer than 4 months is deemed sufficient, and in 20 cases having fewer than 500 examinations before the end of the residency is regarded as complete training.

The low number of US examinations performed in some training centres can jeopardise teaching. The recruitment of patients for adequate training can be impossibile to obtain in low-volume practices, leading to a further decrease of radiological US for future generations of radiologists. Furthermore, the use of sonographers can make teaching the practical skills of US scanning difficult. In a hospital with high-volume US practice (45,000 cases/year) in which the examinations are performed by sonographers, residents are asked to remain in the US laboratory only for 2–3 months and to perform only 100 examinations before the end of training. When in clinical practice in a hospital without sonographers, these radiologists would not be able to carry out even routine diagnostic US examinations. On the contrary, the role of expert sonographers as a resource to provide practical training to radiology residents has not been considered and can be explored.

The results of this survey show a large heterogeneity in the use of US within radiology throughout Europe. There are hospitals in which the majority of US examinations are still performed by radiologists, and others in which radiologists are left with only a small proportions of studies.

Similar findings were observed by Schnyder et al. in 1999 [1]. From their survey in 17 academic radiology departments throughout Europe, these authors reported that in some nations radiologists had full control of US, while this was not the case in Germany, Austria and Switzerland. The situation seems somewhat worse today, since there are 22 hospitals (18.2 %) in different nations (Austria, Poland, Germany, France, UK, Norway, Switzerland and Italy) in which radiologists perform less than 70 % of all US examinations and 5 (4 %) who answered they do less than 10 % of the studies. Since the answers to the questionnaire were provided by radiology departments, the figures for radiological activity can be considered as precise. On the contrary, it is possible that those answers on the US activities out of radiology can be regarded as an estimate. However, to the best of our knowledge, the data in the survey of Schnyder et al. were also obtained in a similar way, and a comparison can thus be made.

The percent decrease in the number of US examinations done in radiology vs. those performed outside radiology is probably related to a marked increase of the use of US by non-radiology clinicians rather than to a decreased attention to this technique by radiologists. In fact, new specialists, such as emergency physicians and anesthesiologists, are now using this technique as a complement to their visit or as a guide to therapeutic manoeuvres, and the so-called “point-of-care US” philosophy, in which US equipment accompanies the physician at the patient’s bedside to guide his/her therapeutic decision making, is gaining popularity.

An additional point to be considered relates to the recording of US reports and images into the hospital informations system and PACS. US examinations performed by radiologists are archived within the PACS system in 85.6 %, while those performed by non-radiologists are stored in only 18.3 % of cases. Furthermore, radiologists provide a formal report in virtually all cases, while examinations performed out of radiology are formally reported in 64.4 %. Costs and technical difficulties in connecting all equipment to PACS and RIS are described as reasons for not recording US images, and this is especially the case for recording of video clips. The use of “point-of-care US” is a further difficulty for connecting equipment to PACS, and, within this framework, the US exam is not regarded as a separate study but as part of the physician visit. However, to have all US images and reports of the patient recorded and available for consultation could greatly help during subsequent studies, and efforts have to be made to develop consensus with clinical colleagues to increase connectivity and to report all US studies, at least as a description within the patients’ charts. Within the framework of the relationships established by the ESR WG in US with the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), it has been agreed to prepare and publish a recommendation about the necessity, for all US examinations, of a formal report and proper archiving of both report and images.

ACTION POINTS

Two points of action can be suggested.

The first relates to the centralisation of the US laboratory. Although at the moment only a small number of hospitals are working according to this model, radiologists should take the lead in proposing such organisation [4]. This would allow the gathering of all the different competencies in US under the same roof, to share human and technological resources and to reduce the amount of equipment needed within the hospital. In an era of cost containments, a centralised US laboratory can allow each US scanner operate for longer hours and with higher numbers of examinations, resulting in an optimisation of resources. Furthermore, requests to upgrade and/or renovate equipment would possibly be easier if coming from a large laboratory and shared by different hospital departments. Another advantage would be having people with different backgrounds work in the same environment, thus promoting exchange and integration of their knowledge and possibly resulting in better patient care. It would be easier, in this respect, to prepare institutional guidelines and protocols that place US in the correct perspective towards all other imaging modalities and, most importantly, towards patients’ needs. It is not clear from the survey how this way of working is organised on a day-to-day basis, and especially how emergency services are provided (i.e. if all specialists concur in the emergency or if this is left to radiologists only), but an integrated management and organisational infrastructure bears numerous advantages for cost containment, quality standards and efficiency.

The second point of action relates to training in US within radiology residency programmes. In the opinion of the ESR Working Group on US, radiologists need to develop consensus on how many examinations under tutorship residents have to perform and on how much time they have to spend in ultrasound before the end of the training period. The results of the survey vary widely. However, out of 75 training centres that reported on the number of examinations, there were 39 (52 %) providing figures between 1,000 and 2,000 or higher. Therefore, approximately 2,000 seems to be a figure on which consensus can be reached. This figure also complies with what is suggested by the EFSUMB [5]. This federation provides recommendations about the number of examinations for training in the different subspeciality areas of US: the sum of studies for abdomen, breast, musculoskeletal and vascular training is 1,500, while figures for head and neck are not provided. The length of training is more complex to decide. A distinction has to be made here between the time needed to learn the technique of US scanning and the time needed to learn how to use US properly, to integrate it with other imaging techniques and to provide useful reports. In order to perform US, both approaches are needed. Technique-oriented teaching is necessary to learn how to perform the studies and to identify anatomy and pathology. Time and exams are needed to learn how to use US properly within the framework of organ-oriented training. A period of time of about 6 months dedicated solely to learning the US scanning technique can possibly be considered sufficient, as suggested by 76.2 % of responders. The capabilities of residents to perform US examinations have to be assessed during the training period, especially during and at the end of the technique-oriented part. It is known that the learning curve can vary widely among trainees, and longer times and higher numbers of examinations may be needed in some cases [6]. Additional time should be spent, and exams taken, during organ-oriented training. It must be underlined that organ-oriented teaching needs to include the proper role of US in each subspeciality and also take into account technical advances such as CEUS, 3D/4D and elastography and to use them when needed.

Acknowledgment

This article was kindly prepared by the ESR Working Group on US (M. Bachmann-Nielsen, M. Claudon, L. E. Derchi, S. Elliott, G. Mostbeck, C. Nicolau, S. Yarmenitis, A. Zubarev, Y. Menu–Chair of the ESR Professional Organisation Committee and J.A. Reekers–Chair of the ESR Subspecialty Societies Committee) on behalf of the European Society of Radiology. It was approved by the ESR Executive Council in April 2013.

Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.

References

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Schnyder P, Capasso P, Meuwly I-Y (1999) Turf battles in radiology: how to avoid/how to fight/how to win. Eur Radiol 9:741–748PubMedCrossRef

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Lockhart ME (2008) The role of radiology in the future of sonography. AJR 190:841–842PubMedCrossRef

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Derchi LE, Claudon M (2009) Ultrasound: a strategic issue for radiology? Eur Radiol 19:1–6PubMedCrossRef

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Krestin GP (2009) Maintaining identity in a changing environment: the professional and organizational future of radiology. Radiology 250:612–617PubMedCrossRef

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Minimum training recommendations for the practice of medical ultrasond in Europe. http://www.org/guidelines/guidelines01.asp

6.

Hertzberg BS, Kliewer MA, Bowie JD, Carroll BA, DeLong DH, Gray L, Nelson RC (2000) Physician training requirements in sonography: how many cases are needed for competence? AJR 174:1221–1227PubMedCrossRef

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Acute and Chronic Myocardial Infarction: Quantification of Myocardial Perfusion Viability – FDG-PET/MRI vs. MRI or PET alone

Author, and Content Consultant to e-SERIES A: Cardiovascular Diseases: Justin Pearlman, MD, PhD, FACC

and

Reporter: Aviva Lev-Ari, PhD, RN

The Voice of  Justin Pearlman, MD, PhD, FACC

While working on angiogenesis imaging support at Harvard, the author discovered that injured heart muscle retains gadolinium-based contrast used for perfusion testing (1992). Whereas the gadolinium passes through normal tissue in less than 20 minutes and redistributes mostly to body fat, it stays where cell membranes are damaged, even if the damage is old. The gadolinium then “lights up” the damaged zone when normal heart muscle tissues appear dark by magnetic resonance imaging (MRI). Thus “scar mapping” was born. Prior to that discovery, the standard test for “viability” was a positron emission tomography (PET) scan reporting the presents of absence of normal sugar metabolism in damaged or ischemic heart muscle. PET relies on detection of a pair of gamma rays emitted by a radioactive label in a metabolite. The pair are emitted simultaneously at nearly 180 degrees apart, with a small angulation offset from the momentum of the emitter. The emission event requires a positron finds an electron, so it does not occur precisely where the metabolite sits, and thus has inherently a poor “resolution” (minimal distance where two distinct sources are identifiable as distinct).  The protocol for PET assessment of heart muscle viability utilized by the author and other investigators required intravenous infusion of glucose, insulin, and potassium, to assure good delivery of sugar to the healthy viable heart muscle, coupled to repeat blood tests to make sure the blood sugar and serum potassium levels were adequately maintained (otherwise the patient could suffer from low sugar or a potassium-related arrhythmia). Numerous investigatores followed up on this discovery, and determined that a gadolinium demarcated defect less than half the heart wall thickness corresponded clinically to viable myocardium (meaning one could expect improved function after revascularization of a blocked blood supply) whereas a defect more than half the wall thickness corresponded clinically to non-viable myocardium (no expected significant functional gain from revascularizing that region). Subsequently, a third option for assessment of viability was developed: combined PET and MRI.

PET/MRI device produced “high-quality cardiac MR imaging acquisitions,” overcoming any technical issues of having the PET detector within the MRI’s 3-tesla magnet field, Nensa and colleagues concluded.

“No negative side effects from the integrated imaging system design were observed,” they noted.

The researchers were able to show “a close match” between FDG-PET and MRI in assessing myocardial viability and infarct quantification among patients with acute and chronic myocardial infarction.

“These findings demonstrate the feasibility of clinical cardiac MR imaging with an integrated PET/MRI device,” they added. “However, to prove that the integrated design does not interfere with the performance of the device, a systematic intraindividual comparison with a comparable 3-tesla MRI system and identical sequence parameters is still needed.”

Future studies should investigate whether hybrid FDG-PET/MRI of myocardial infarction can provide additional information compared with MRI or PET alone, according to the authors.

http://www.auntminnie.com/index.aspx?sec=sup&sub=mri&pag=dis&ItemID=103390&wf=1236

Study shows feasibility of cardiac PET/MRI — with caveats

By Wayne Forrest, AuntMinnie.com staff writer
May 9, 2013

Cardiac FDG-PET/MRI is feasible on an integrated whole-body PET/MRI system, but the hybrid modality still must prove it adds clinical relevance to cases of ischemic heart disease, according to a study published online May 7 in Radiology.

The study from University Hospital Essen in Germany found good concordance with the simultaneous acquisition of FDG-PET and MR images regarding both cine and late gadolinium-enhanced imaging in patients with myocardial infarction.

However, despite the simultaneous MRI and PET acquisition, “consolidated cardiac PET/MRI protocols need to be established, as long examination times associated with fasting seem to compromise patient compliance” with the exams, wrote lead author Dr. Felix Nensa, from the department of diagnostic and interventional radiology and neuroradiology, and colleaguesRadiology, May 7, 2013).

Cardiac feasibility study

The purpose of the study was to determine the feasibility of simultaneous acquisition of cardiac images on an integrated 3-tesla PET/MRI system, and to determine if the placement of the PET detector within the MRI’s field of magnet strength would adversely affect clinical results.

The researchers evaluated 20 consecutive patients with ischemic heart disease who were referred for FDG-PET/MRI between May and December 2012. Among the 20 patients, 14 had confirmed acute ST-elevation myocardial infarction within four to 15 days after interventional revascularization, one had suspected non-ST-elevation myocardial infarction, and five had chronic myocardial infarction.

Ten of the 20 patients underwent additional cardiac PET/CT before their PET/MRI scan.

Individuals with contraindications for gadolinium-based contrast agents and general MRI conditions, such as claustrophobia, were excluded from the study. All patients were asked to detail any personal discomfort or side effects that occurred during the PET/MRI exam.

All imaging studies were performed with an integrated whole-body PET/MRI system with 3-tesla field strength (Biograph mMR, Siemens Healthcare) and the PET insert inside the MRI scanner. All MRI sequences were performed with phased-array body surface coils designed for the PET/MRI system.

For late gadolinium-enhanced qualitative imaging, patients received gadobutrol (GadovistBayer HealthCare Pharmaceuticals) based on a dosage of 0.2 mmol/kg of body weight.

FDG-PET/MRI studies were performed after a fasting period of at least six hours, with FDG administered one hour before imaging with a mean of 202 (± 21) MBq. The scans began at a mean of 129 (± 41) minutes after FDG injection and included an electrocardiographically gated cardiac PET scan with one bed position and 3D image reconstruction.

For the FDG-PET/CT scans, an electrocardiographically gated cardiac PET/CT study was performed with a 128-slice CT unit (Biograph mCT, Siemens). PET scans began approximately 70 (± 12) minutes after FDG injection, with a mean of 211 (± 55) MBq.

Image comparisons

To compare the identification and characteristics of the infarcts between the two hybrid modalities, the researchers mapped the left ventricle with a 17-segment model, as recommended by the American Heart Association. Two-point scoring systems were used to assess myocardial tracer uptake, myocardial wall motion, and myocardial late enhancement in each segment.

In addition, the researchers measured the size of a patient’s infarct zone by drawing regions on the late gadolinium-enhanced MR images and PET images, and it was expressed as a percentage of the entire left ventricular myocardium.

Nensa and colleagues were able to complete 19 of 20 cardiac PET/MRI scans. One patient with ST-elevation myocardial infarction did not finish due to claustrophobia. Total PET/MRI scan time without patient preparation and positioning was 53 (± 3) minutes, and all cardiac MR images were rated as diagnostic in quality.

The analysis of FDG-PET and MRI with the 17-segment model found “good concordance” of the left ventricle with both cine imaging and late gadolinium-enhanced imaging in 18 of the 19 patients.

Of the 306 segments evaluated, 97 (32%) were rated as infarcted on PET images, compared with 93 (30%) rated as infarcted on late gadolinium-enhanced images and 90 (29%) on cine images.

Two-chamber views show “stunned myocardium” in a 66-year-old patient with ST-elevation myocardial infarction and acute occlusion of the left anterior descending artery. Cardiac PET/MRI was performed seven days after intervention. Late gadolinium-enhanced image (top left) shows no infarction zone. Fused late gadolinium-enhanced and PET images (top right) show that tracer uptake was reduced in segments 13-15 and 17. T2-weighted MR image (bottom left) shows myocardial edema (arrows) that corresponded well with the area of reduced tracer uptake on the bottom right image. All images courtesy of Radiology.

The size of the infarct zones averaged 22% of the entire left ventricular myocardium on PET images, compared with an average of 20% on late gadolinium-enhanced images.

Among the subgroup of 10 patients with an additional PET/CT scan, no significant difference in myocardial tracer uptake between PET/CT and PET/MR images was found.

In patient exit interviews, 16 patients cited long examination times (including patient preparation) as a source of discomfort. In addition, 11 patients cited the PET/MRI exam itself, i.e., noise, narrowness, and immobility, while 15 patients did not like having to fast.

Final conclusions

In summary, the PET/MRI device produced “high-quality cardiac MR imaging acquisitions,” overcoming any technical issues of having the PET detector within the MRI’s 3-tesla magnet field, Nensa and colleagues concluded.

“No negative side effects from the integrated imaging system design were observed,” they noted.

The researchers were able to show “a close match” between FDG-PET and MRI in assessing myocardial viability and infarct quantification among patients with acute and chronic myocardial infarction.

“These findings demonstrate the feasibility of clinical cardiac MR imaging with an integrated PET/MRI device,” they added. “However, to prove that the integrated design does not interfere with the performance of the device, a systematic intraindividual comparison with a comparable 3-tesla MRI system and identical sequence parameters is still needed.”

Future studies should investigate whether hybrid FDG-PET/MRI of myocardial infarction can provide additional information compared with MRI or PET alone, according to the authors.

Related Reading

MRI motion correction improves PET/MR image quality, July 6, 2012

SNM: PET/MRI for myocardial perfusion feasible but challenging, June 11, 2012

SNM: Hybrid PET/MRI study among top 5 research papers, June 7, 2011

Copyright © 2013 AuntMinnie.com

SOURCE:

http://www.auntminnie.com/index.aspx?sec=sup&sub=mri&pag=dis&ItemID=103390&wf=1236

SNM: Hybrid PET/MRI study among top 5 research papers

By Wayne Forrest, AuntMinnie.com staff writer

June 7, 2011 — SAN ANTONIO – The first-ever study on the clinical use of PET/MRI and a breakthrough on the use of FDG-PET to detect fevers of unknown origin were among the top research papers outlined Monday at this week’s Society of Nuclear Medicine (SNM) annual meeting.

More than 1,000 papers were submitted for consideration and presentation at this year’s meeting, with many studies showing how molecular imaging is gaining influence in the early detection of Alzheimer’s disease. Other submissions included a first-of-its-kind study on the use of near-infrared fluorescence and a new synthesized imaging agent to discover hidden blood clots in veins and arteries.

Hybrid PET/MRI

Early results from the clinical use of PET/MRI indicate that the hybrid modality can provide important diagnostic information about soft tissues and physiological functions throughout a patient’s body. The technology’s ability to find suspicious lesions and potential cancer already appears comparable to that of conventional molecular imaging methods.

In a German study, 11 patients with cancer underwent single-injection PET/CT followed by PET/MRI (Biograph mMR, Siemens Healthcare). Simultaneous PET/MRI acquisition was feasible and offered good-quality PET and MRI diagnostic data.

The analysis found that all 13 lesions detected at PET/CT were also identified by PET/MRI, with no significant difference between PET/CT and PET/MRI regarding the uptake ratios.

The study “demonstrates for the first time that newly introduced integrated whole-body MR/PET technology allows simultaneous acquisition of high-quality MR and PET data in a clinical setting within an acceptable time frame,” wrote lead study author Dr. Alexander Drzezga from TU München.

The hybrid technology could result in the development of new imaging agents that combine the diagnostic prowess of PET and MRI, Drzezga said. With the ability to image physiologic and pathophysiologic processes at the same time, the technology could open a new imaging discipline within nuclear medicine.

Carcinoma is compared in a patient who received a PET/CT scan 80 minutes after contrast injection (above), followed by a PET/MRI scan 160 minutes after contrast injection (below). All images courtesy of SNM.

FDG-PET and fever of unknown origin

Japanese researchers broke new ground in their study, which concluded that FDG-PET provided additional diagnostic information in cases of fever of unknown origin. The use of FDG-PET also had a high clinical impact, especially among patients with infectious diseases.

The retrospective study evaluated 81 consecutive patients with fever of unknown origin. They underwent FDG-PET at six Japanese institutions between July 2006 and December 2007.

Results were divided into four groups for final diagnoses: infection, arthritis/vasculitis/autoimmune/collagen disease, tumor/granuloma, and other/unknown.

The analysis found that sensitivity was highest in the tumor/granuloma group at 100% (seven of seven cases), followed by infection at 89% (24 of 27 cases) and arthritis/vasculitis/autoimmune/collagen disease at 65% (11 of 17 cases). Sensitivity was 0% (zero of one case) in the other/unknown category. Overall sensitivity was 81% and overall specificity was 75%.

Additional information provided by FDG-PET was highest in the infection group, at 76% of the cases (22 of 29), followed by tumor/granuloma at 75% (six of eight), arthritis/vasculitis/autoimmune/collagen disease at 43% (nine of 21), and other/unknown at 23% (five of 22).

The other/unknown group showed a high specificity of 84% (16 of 19 cases) and accurately excluded active focal inflammatory diseases and malignancy.

Lead study author Dr. Kozuo Kubota, PhD, chief of nuclear medicine at the National Center for Global Health and Medicine in Tokyo, said that until now, conventional modalities have produced low imaging resolution and very poor detectability for the fever’s cause.

“If the CT scan, ultrasound, or other conventional imaging technique fails, it is very difficult to find ways to find the focus of the fever,” Kubota said. “If we use FDG-PET, we can scan from head to thigh in only one scan to detect where the truly active lesion is. FDG is very sensitive both for inflammation and the tumor.”

With the addition of FDG-PET, physicians discovered a graft infection in a 50-year-old male with kidney failure and fever of unknown origin, with high FDG uptake illustrating the malady.

“I view this [study] as extraordinary,” said Dr. Michael Graham, PhD, director of nuclear medicine at the University of Iowa, who announced the top five papers. “This is in a setting where modern medicine is unable to come up with the answer, even after weeks. In about an hour-and-a-half, an FDG-PET scan came up with the answer with excellent sensitivity. We don’t get it every single time, but if it weren’t done, it would be mysterious what the patient had. It would be treated with antibiotics and hope for the best.”

“This is a huge step forward and I think it will change how we approach this problem,” he said.

PET and Alzheimer’s detection

Three studies presented at SNM 2011 added to the growing evidence that PET is an effective method to detect Alzheimer’s disease in its early stages, and that it provides a pathway to future clinical screening and treatments.

One lead study author, Dr. Kevin Ong, research scientist at Austin Hospital in Heidelberg, Australia, said that amyloid imaging with PET scans can help ascertain the likelihood that individuals will deteriorate cognitively within a few years, enabling more efficient channeling of healthcare resources.

Molecular imaging of Alzheimer’s disease has focused on detecting and analyzing the formation of the protein beta amyloid in the brain, which researchers say is directly involved in the pathology of Alzheimer’s. The presence of significant amyloid buildup is also linked to more rapid memory decline and brain atrophy.

Increased amyloid is bad for cognition even in the healthy elderly, noted lead study author Michael Devous Sr., PhD, director of neuroimaging for the Alzheimer’s Disease Center at the University of Texas Southwestern Medical Center.

The three ongoing studies involve several years of research based on hundreds of participants ranging widely in age, cognitive ability, and stage of disease.

Collective results showed that amyloid plaques build up at an estimated rate of 2% to 3% per year, and they often are already present in healthy older individuals. Amyloid plaque was present in 12% of people in their 60s, 30% of those in their 70s, and 55% of those older than 80.

In one study, approximately 25% of subjects older than 60 had amyloid plaques.

For individuals who have already developed a measurable memory decline, a positive scan for amyloid is the most accurate predictor of progression to Alzheimer’s disease, said Dr. Christopher Rowe, a lead investigator for the Australian Imaging, Biomarkers, and Lifestyle study of aging and professor of nuclear medicine at Austin Hospital.

Amyloid imaging with PET scans, he added, will be an important new tool in the assessment of cognitive decline.

Several studies have used carbon-11-labeled Pittsburgh Compound B (C-11 PIB), a PET imaging agent that binds to beta amyloid in brain tissue, but two of the current studies are assessing the benefit of F-18 florbetaben and F-18 florbetapir, which are designed for routine clinical use.

Both F-18 florbetaben and F-18 florbetapir are showing promise as reliable predictors of progression to Alzheimer’s disease, and F-18 amyloid imaging agents are considered most likely to move into clinical practice in the near future, perhaps as soon as next year.

NIRF for blood clot detection

In another novel study at SNM 2011, researchers from Massachusetts General Hospital are using near-infrared fluorescence (NIRF) and a new synthesized imaging agent to detect blood clots inside elusive veins, often within the deep tissues of the thighs and pelvis.

The agent uses a biomarker that seeks out a peptide — called fibrin — that is actively involved in the formation of blood clots. Combined with NIRF, which uses light energy to gather information from cells and tissues, the technique could also be used for coronary arteries. The fibrin peptide agent (EP-2104R) has already been tested in phase II clinical trials.

Lead study author Dr. Tetsuya Hara, PhD, noted that the availability of a high-resolution fibrin sensor is important for two reasons: intravascular NIRF imaging of coronary-sized arteries is now possible, and coupling the fibrin peptide with this technique may allow researchers to study coronary artery plaques and stents, which could potentially help identify patients at increased risk of heart attack.

The researchers were able to successfully detect fibrin-rich deep vein thrombosis with both intravital fluorescence microscopy and noninvasive fluorescence molecular tomography, allowing information to be acquired about tissues by analyzing how light is absorbed and scattered.

By coupling the fibrin peptide agent with intravascular NIRF imaging, researchers can now study microthrombi on coronary artery plaques and coronary stents that are at high risk for thrombosis and vessel occlusion.

This advance could help clinicians predict potential heart attacks and other major cardiovascular events, potentially saving more patients’ lives.

Related Reading

SNM exceeds fundraising goal, June 6, 2011

SNM: PET/MRI must prove its worth to ensure clinical adoption, June 6, 2011

PET/CT with NaF bone agent takes SNM’s Image of the Year, June 6, 2011

SNM proposes name change, May 3, 2011

SNM’s Clinical Trials Network: Progress despite growing pains, April 29, 2011

SOURCE:

http://www.auntminnie.com/index.aspx?sec=sup&sub=mol&pag=dis&ItemID=95494

Copyright © 2011 AuntMinnie.com

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Sudden Cardiac Death invisible at Autopsy: Forensic Power of Postmortem MRI

Aviva Lev-Ari, PhD, RN 4/18/2013

https://pharmaceuticalintelligence.com/2013/04/18/sudden-cardiac-death-invisible-at-autopsy-forensic-power-of-postmortem-mri/

Hypervascular Hepatocellular Carcinoma: Important clues from Gadoxetic acid-based MRI imaging

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MRI Cortical Thickness Biomarker Predicts AD-like CSF and Cognitive Decline in Normal Adults

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Early Detection of Prostate Cancer: American Urological Association (AUA) Guideline

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Reporter: Aviva Lev-Ari, PhD, RN

A radiologist reflects on the Boston Marathon bombings

 

By Wayne Forrest, AuntMinnie.com staff writer

May 16, 2013 — Monday, April 15 — Patriots’ Day in Boston — started much like any other day for radiologist Dr. Robert Ward of Tufts Medical Center. But it turned out to be anything but normal after two bombs exploded at the end of the Boston Marathon, sending dozens of injured people to Tufts with battlefield-like injuries.

Ward is chief of musculoskeletal imaging and has been on the job at Tufts for more than five years. He’d finished his administrative duties for the day and was reading routine imaging studies when he received a text from his wife shortly before 3 p.m. A friend, who is a gastroenterology fellow at Boston University and was running in the marathon, told Mrs. Ward there had been explosions heard near the race’s finish line.
Dr. Robert Ward

Dr. Robert Ward from Tufts Medical Center.

“My first inclination was that there was some sort of minor mischief; maybe someone dropped some firecrackers or something like that into a garbage can,” Ward said. “Then a colleague poked his head into the reading room and said there were explosions, limbs were lost, and there were several people dead. At that point, it became an entirely different matter.”

Marathon bombings

Soon thereafter, Ward, the city, the nation, and the rest of world would come to learn that two homemade bombs had been detonated within seconds of each other about 200 yards apart along the path to the finish line. In the end, three people died and more than 260 bystanders and runners were injured, some hurt so severely that they lost limbs.

On a normal Boston Marathon day, most patients at Tufts present with dehydration, or a couple of days after the race, people arrive with extremity abnormalities. There are 22 radiologists and 22 residents at the medical center, with 16 or 17 staff members onsite at any given time.

Word spread quickly that bombing victims were on their way to the level I trauma center.

“I elected to go down to the ER,” Ward recalled. “Patients were starting to come in, probably five times the normal number of people who are in the emergency department [at that time of day]. That place was really in a chaotic manner.”

He estimated there were 13 marathon patients in the emergency room, most of whom were young and probably runners. Most injuries were isolated to the lower extremities; a fair number of patients had skin ripped away from their bodies. What’s more, the limbs of many patients were embedded with the “strangest foreign bodies [and] shrapnel like we have never seen before.”

Some patients had BBs lodged in their extremities, as well as what Ward described as twisted, metallic items that must have been 2 to 4 inches in size. “Generally, those [objects] don’t make it deep into tissue unless there is a substantial explosion, which was obviously the case,” he said.

Onsite care

For the marathon, medical personnel and physicians often take the day off and donate their time to treat race-related injuries and other ailments at a makeshift facility near the finish line. On this day, having that kind of medical expertise so close to the bombings “made for an extraordinary rapid response,” Ward said. “It was almost like battlefield medicine in a sense.”

Under normal circumstances, Tufts’ protocol is to acquire two right-angle x-rays of leg and ankle injuries to determine their extent and location.

“Because of the emergent nature of the injuries, we would get one x-ray and [patients] would go straight to the operating room,” Ward explained. “It is purely a time issue. With some of the bizarre shrapnel fragments that we were seeing, it was hard to believe they were actually inside people.”

Patients with injuries above the waist received a CT scan of the chest, abdomen, and pelvis.

Ward stayed in the emergency department for about 30 minutes, collaborating with a fellow radiologist in the reading room. He later joined the rest of his colleagues, all of whom stayed late into the evening to process all the image interpretations that needed to be done.

Radiology was one of several departments at Tufts that rallied additional personnel to respond to the emergency conditions. The orthopedic department, for example, called in its entire staff to assist in the operating room.

Ward described the coordination between the radiologists and the surgeons as “seamless,” adding that communication between caregivers functioned the same as during any other day at the medical center.

“We have a very well-patterned response, and we were doing our job the same way we do every day, except with a little bit more intensity, given the experience,” he added. “When consultations were necessary, the lines of communication were open.”

Lessons learned

In the wake of the Boston Marathon bombings, Tufts will likely review its emergency response to the event and modify its disaster protocol, if needed, just as it regularly assesses its preparedness through periodic drills.

Within the past 18 months, Tufts was upgraded from a level II to a level I trauma center, which included the implementation of protocols for trauma and potential disaster scenarios.

“In the global sense, we are in the business of helping people, and every day you wake up and have to be aware that you never know what’s going to come your way,” Ward reflected. “You have to be ready, and vigilance is key in every aspect, whether it’s homeland security or taking care of patients who are victims of dramatic, unforeseen events. It brings an urgency to the importance of quality care and making sure that everyone in the department is ready to go at any moment.”

A few days after the tragedy, Ward and a colleague dined at a Boston restaurant while still wearing scrubs, as they had come straight from work. At the end of their dinner, the server insisted that they allow the restaurant to pay for their meal in gratitude for their service. The server told them his friend was treated in the neuro intensive care unit at Tufts during that week and had recently been discharged.

“We were both speechless,” Ward recalled. “That’s just us doing our jobs. The real tragedy is the people who wanted to go see a race, were running in the marathon, and were victims of this tragic incident. We are in the business of helping people. Whatever we can do to help is why we went into this endeavor to begin with.”

Related Reading

Haiti after the earthquake: A radiologist’s story, January 22, 2010

Is your department prepared for disaster? You might be surprised, September 5, 2007
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