Posts Tagged ‘tracking’

Brain and behavior

Larry H. Bernstein, MD, FCAP, Curator



Behavior Brief

A round-up of recent discoveries in behavior research

By Catherine Offord | March 25, 2016

Manta in the mirror

The mirror self-recognition (MSR) test is commonly used to evaluate nonhuman animals’ self-awareness, and has been reportedly passed by several mammals and birds including apes, elephants, dolphins, and magpies. According to a study published earlier this month (March 11) in The Journal of Ethology, there’s now evidence to add manta rays to that list.

Contingency checking and self-directed behaviors in giant manta rays: Do elasmobranchs have self-awareness?

Csilla Ari  , Dominic P. D’Agostino     Journal of Ethology   11 March 2016: 1-8    doi:10.​1007/​s10164-016-0462-z

Elaborate cognitive skills arose independently in different taxonomic groups. Self-recognition is conventionally identified by the understanding that one’s own mirror reflection does not represent another individual but oneself, which has never been proven in any elasmobranch species to date. Manta rays have a high encephalization quotient, similar to those species that have passed the mirror self-recognition test, and possess the largest brain of all fish species. In this study, mirror exposure experiments were conducted on two captive giant manta rays to document their response to their mirror image. The manta rays did not show signs of social interaction with their mirror image. However, frequent unusual and repetitive movements in front of the mirror suggested contingency checking; in addition, unusual self-directed behaviors could be identified when the manta rays were exposed to the mirror. The present study shows evidence for behavioral responses to a mirror that are prerequisite of self-awareness and which has been used to confirm self-recognition in apes.

X-RAY MAG: How did you become interested in studying the behavior of manta rays?

CA: I knew that I wanted to dedicate my life to study and protect marine life since I was 13 years old. It was during a family vacation in Croatia when I first had the chance to try scuba diving. I was so mesmerized by the experience that when I surfaced I decided to try to find out more about this magical world. I became especially fascinated by the majestic and mysterious manta rays after watching a nature documentary, soon after this first dive. It described how little we know about them and how vulnerable they are.

But growing up in Hungary, a landlocked country, I did not have much option to pursue my dream as a marine biologist, so I got my master’s degree in zoology and my doctorate in neurobiology, while volunteering at oceanography institutes in different countries during the summers. During my PhD studies, I worked on the neuroanatomy and neurohistology of several shark and ray species, including mobulids (mantas and mobulas). During these years, I had the chance to explore the brain structures of mantas and mobulas, which reflected some very unique and surprising features. It was the unusual enlargement of some of their brain parts that got me interested in focusing on their behavior.

“Manta rays are likely the first fish species found to exhibit self-awareness, which implies higher order brain function, as well as sophisticated cognitive and social skills,” study coauthor Csilla Ari told X-Ray Mag.


Observing two rays in a tank at the Atlantis Aquarium in the Bahamas, the researchers noticed that the animals changed their behavior when a mirror was placed on one of the walls. New behaviors included apparently checking out their fins (see this video) and blowing bubbles at their reflections.

X-RAY MAG: What were the findings that caused you to conclude that these animals are using cognition?

CA: Animal cognition, often referred to as animal intelligence, is an exciting scientific field that attempts to describe the mental capacity of an animal. It developed from the field of comparative psychology and it includes exciting research questions, such as perception, attention, selective learning, memory, spatial cognition, tool use, problem solving or consciousness.

There are no easy ways to test these on manta rays, but I found a widely-used and well-established test that can give us insight on their cognitive abilities. The mirror self-recognition (MSR) test is considered to be a reliable behavioral index to show the animal’s ability for self-recognition/self-awareness. Recognizing oneself in a mirror is a very rare capacity among animals. Only a few, large-brained species have passed this test so far, including Asian elephants, bottlenose dolphins and great apes, but no fish species so far.

So, employing a protocol adapted from primates and bottlenose dolphin MSR studies, I exposed captive manta rays to a large mirror and recorded their behavior. The manta rays showed significantly higher frequency of repetitive behavior, such as circling at the mirror or high frequency cephalic fin movements when the mirror was placed in the tank. Contingency checking and self-directed behavior included body turns into a vertical direction, exposing the ventral side of the body to the mirror while staying visually oriented to the mirror. Most surprisingly, such self-directed behaviors were sometimes accompanied with bubble blowing front of the mirror and sharp downward swims.

“This new discovery is incredibly important,” Marc Bekoff of the University of Colorado in Boulder who was not involved in the study told New Scientist. “It shows that we really need to expand the range of animals we study.”

But the MSR test’s developer, Gordon Gallup of the State University of New York at Albany, told New Scientist that the observed movements might reflect curious, rather than self-aware, behavior. “Humans, chimpanzees, and orangutans are the only species for which there is compelling, reproducible evidence for mirror self-recognition,” he said.

Manta rays are first fish to recognise themselves in a mirror

Manta Ray (Manta birostris) feeding on plankton in current, Sangalakki Island, Borneo

Manta ray hears the dinner bell    Norbert Wu/Minden Pictures/FLPA

Giant manta rays have been filmed checking out their reflections in a way that suggests they are self-aware.

Harmless but zippy

Rattlesnakes and other vipers are well-known for their lightning-quick bites, but nonvenomous snakes may be just as speedy, according to a study published this month (March 15) in Biology Letters.

Debunking the viper’s strike: harmless snakes kill a common assumption

David A. Penning, Baxter Sawvel, Brad R. Moon

“There’s this kind of pre-emptive discussion that [vipers] are faster,” study coauthor David Penning of the University of Louisiana, Lafayette, told Smithsonian. But, he added, “as sexy as the topic sounds, there’s not that much research on it.”

To Scientists’ Surprise, Even Nonvenomous Snakes Can Strike at Ridiculous Speeds  By Marcus Woo

The Texas rat snake was just as much of a speed demon as deadly vipers, challenging long-held notions about snake adaptations

Texas Rat Snake

Read more:

To put the assumption to the test, Penning and his colleagues used a high-speed camera to film strikes from three snake species—the western cottonmouth and the western diamond-backed rattlesnake (both vipers), and a relatively harmless Texas rat snake that kills its prey using constriction.

When a snake strikes, it literally moves faster than the blink of an eye, whipping its head forward so quickly that it can experience accelerations of more than 20 Gs. “It’s the lynchpin of their strategy as predators,” says Rulon Clark at San Diego State University. “Natural selection has optimized a series of adaptations around striking and using venom that really helps them be effective predators.”

When Penning and his colleagues compared strike speeds in three types of snakes, they found that at least one nonvenomous species was just as quick as the vipers. The results hint that serpents’ need for speed may be much more widespread than thought, which raises questions about snake evolution and physiology.  They compared the western cottonmouth and the western diamond-backed rattlesnake, which are both vipers, and the nonvenomous Texas rat snake. They put each snake inside a container and inserted a stuffed glove on the end of a stick. They waved the glove around until the animal struck, recording the whole thing with a high-speed camera. The team tested 14 rat snakes, 6 cottonmouths and 12 rattlesnakes, recording several strikes for each individual.

The recordings revealed that although the highest head acceleration—279 meters per second squared, or nearly 29 g—did indeed come from a rattlesnake, one of the rat snakes followed close behind, accelerating its head at 274 meters per second squared.   All the snakes turned out to be speed demons, the team reports this week in Biology Letters. The rattlesnake scored the highest measured acceleration, at 279 meters per second squared. But to their surprise, the nonvenomous rat snake came in a close second at 274 meters per second squared. That’s lightning-quick, considering that a Formula One race car accelerates at less than 27 meters per second squared to go from 0 to 60 in just one second.

“I was really surprised, because this comparison hadn’t been made before,” Rulon Clark of San Diego Statue University who was not involved in the work told Smithsonian. “It’s not that the vipers are slow, it’s that this very high-speed striking ability is something that seems common to a lot of snake species—or a wider array than people might’ve expected.”

Penning told Discover Magazine that the results make sense, since even nonvenomous snakes have to catch their food. “Prey are not passively waiting to be eaten by snakes,” he said.

Even Harmless Snakes Strike at Deadly Speed

Rather than offering the snakes some sacrificial prey animals, the researchers baited the snakes into striking in self-defense. They used a stuffed glove on a stick. The glove would move around the snake until the animal realized the glove was “clearly not going away,” Penning says, and struck at it. High-speed cameras and mirrors captured these attacks, which happened in the blink of an eye.

Early learning

Emerging evidence suggests that both humans and superb fairywrens begin learning the vocal patterns of their mothers even before birth. Now, a study published this month (March 16) in The Auk: Ornithological Advances indicates that the same is true of the red-backed fairywren, offering the possibility of studying the phenomenon across related species.

“Fairywrens have become a new model system in which to test new dimensions in the ontogeny of parent-offspring communication in vertebrates,” study coauthor Mark Hauber of New York City’s Hunter College said in a statement.

Following on their previous discovery of prenatal learning in superb fairywrens, the researchers compared the structure of nestling calls in the red-backed fairywren to the calls of the birds’ mothers. The team found that the more calls per hour that nestlings received when in the egg, the higher the similarity to maternal calls after hatching. (The number of calls received during the nestling period had no effect on call similarity.)

“Prenatal vocal learning has rarely been described in any animal, with the exception of humans and Australian superb fairywrens,” William Feeney of the University of Queensland, Australia, who was not involved in the work said in the statement. “This result is exciting as it opens the door to investigating the taxonomic diversity of this ability, which could provide insights into why it evolves.”

Vocal imitation of mother’s calls by begging Red-backed Fairywren nestlings increases parental provisioning

Red-backed fairywren (Malurus melanocephalus)  J WELKIN


Prenatal imitative learning is an emerging research area in both human and non-human animals. Previous studies in Superb Fairywrens (Malurus cyaneus) showed that mothers are vocal tutors to their embryos and that better imitation of maternal calls yields more parental provisions after hatching. To begin to test if such adaptive behavior is widespread amongst Australasian wrens in Maluridae, we investigated maternal in-nest calling patterns in Red-backed Fairywrens (Malurus melanocephalus). We first compared the structure of maternal and nestling call elements. Next, we examined how in-nest calling behavior varied with parental behaviors and ecological contexts (i.e. prevalence of brood parasitism and nest predation). All Red-backed Fairywren females called to their eggs during incubation and they continued to do so for several days after hatching at a lower rate. Embryos that received more calls per hour during the incubation period (but not the nestling period) developed into hatchlings with higher call element similarity between mother and young. Female call rate was mostly independent of nest predation but in years with more interspecific brood parasitism, nestling element similarity was greater and female call rates tended to be higher. Playback experiments showed that broods with higher element similarity to their mother received more successful feeds. The potential for prenatal tutoring and imitative begging calls in 2 related fairywren taxa sets the stage for a full-scale comparative analysis of the evolution and function of these behaviors across Maluridae and in other vocal-learning lineages.


Traveling junk-foodies

White storks may be addicted to junk food, in some cases making migratory trips of tens of kilometers to landfill sites during the breeding season, according to a study published earlier this month (March 15) in Movement Ecology.

“We found that the continuous availability of junk food from landfill has influenced nest use, daily travel distances, and foraging ranges,” study coauthor Aldina Franco of the University of East Anglia said in a statement. “Storks now rely on landfill sites for food—especially during the non-breeding season when other food sources are more scarce.”

Using GPS tracking, the researchers focused on 17 storks traveling between nesting and feeding areas over the course of a year. They found that most long-distance trips were made to landfill sites, and that “having a nest close to a guaranteed food supply also means that the storks are less inclined to leave for the winter,” Franco explained in the statement. “They instead spend their non-breeding season defending their highly desirable nest locations.”

“It’s clear migratory behaviors are quite plastic, in that the [storks] are adaptable and can change quickly,” Andrew Farnsworth of the Cornell Lab of Ornithology who was not involved in the work told National Geographic. He added that the new, detailed dataset will help scientists “consider how such changes in behavior may affect the future population of these birds.”

Are white storks addicted to junk food? Impacts of landfill use on the movement and behaviour of resident white storks (Ciconia ciconia) from a partially migratory population

Nathalie I. Gilbert Email authorRicardo A. CorreiaJoão Paulo Silva,…, Jenny A. Gill and Aldina M. A. Franco

Movement Ecology 2016; 4:7

The migratory patterns of animals are changing in response to global environmental change with many species forming resident populations in areas where they were once migratory. The white stork (Ciconia ciconia) was wholly migratory in Europe but recently guaranteed, year-round food from landfill sites has facilitated the establishment of resident populations in Iberia. In this study 17 resident white storks were fitted with GPS/GSM data loggers (including accelerometer) and tracked for 9.1 ± 3.7 months to quantify the extent and consistency of landfill attendance by individuals during the non-breeding and breeding seasons and to assess the influence of landfill use on daily distances travelled, percentage of GPS fixes spent foraging and non-landfill foraging ranges.   Results   Resident white storks used landfill more during non-breeding (20.1 % ± 2.3 of foraging GPS fixes) than during breeding (14.9 % ± 2.2). Landfill attendance declined with increasing distance between nest and landfill in both seasons. During non-breeding a large percentage of GPS fixes occurred on the nest throughout the day (27 % ± 3.0 of fixes) in the majority of tagged storks. This study provides first confirmation of year-round nest use by resident white storks. The percentage of GPS fixes on the nest was not influenced by the distance between nest and the landfill site. Storks travelled up to 48.2 km to visit landfills during non-breeding and a maximum of 28.1 km during breeding, notably further than previous estimates. Storks nesting close to landfill sites used landfill more and had smaller foraging ranges in non-landfill habitat indicating higher reliance on landfill. The majority of non-landfill foraging occurred around the nest and long distance trips were made specifically to visit landfill.  Conclusions   The continuous availability of food resources on landfill has facilitated year-round nest use in white storks and is influencing their home ranges and movement behaviour. White storks rely on landfill sites for foraging especially during the non-breeding season when other food resources are scarcer and this artificial food supplementation probably facilitated the establishment of resident populations. The closure of landfills, as required by EU Landfill Directives, will likely cause dramatic impacts on white stork populations.

WEIRD & WILD   Junk Food-Loving Birds Diss Migration, Live on Landfill    By Brian Handwerk

Spain and Portugal’s white storks are forgoing their annual journeys to African wintering grounds, a new study says

You’ve heard of the staycation. Some white storks in Europe are now opting for the staygration. 

The big birds are skipping their annual trip to African wintering grounds to remain year-round in Spain and Portugal, a new study shows.

Why? They’ve developed an addiction to junk food at landfills.

“White storks used to be wholly migratory. Before the 1980s, there were no white storks staying in” Spain and Portugal, says study leader Aldina Franco, a conservation ecologist at the University of East Anglia in the U.K.

“During the 1980s, the first individuals started staying, and now we see those numbers increasing exponentially.” (Related: “Beloved Storks, Emblems of Fertility, Rebounding in France.”)


Unlikely allies

Israel’s barren Negev desert is home to striped hyenas and gray wolves—two large scavenger species with considerably overlapping diets. But although such conditions might be expected to create fierce competition, researchers in Israel and the U.S. have now presented evidence that—at least in some cases—these animals form alliances and may even hunt collaboratively for food. The findings were published last month (February 10) in Zoology in the Middle East.

Wolves and hyenas in the desert might “just need each other to survive, because food is so, so limited,” study coauthor Vladimir Dinets of the University of Tennessee in Knoxville told The Washington Post.

Collating observations made over the past two decades (including reports of overlapping paw prints, and sightings of hyenas among packs of wolves), the researchers note that the findings could reflect the behavior of a few, oddly behaving hyenas, or a more widespread commensal, or even cooperative, relationship between the species.

“Animal behavior is often more flexible than described in textbooks,” Dinets said in a press release. “When necessary, animals can abandon their usual strategies and learn something completely new and unexpected. It’s a very useful skill for people, too.”


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The unfortunate ending of the Tower of Babel construction project and its effect on modern imaging-based cancer patients’ management

The story of the city of Babel is recorded in the book of Genesis 11 1-9. At that time, everyone on earth spoke the same language.

Picture: Pieter Bruegel the Elder: The Tower of Babel_(Vienna)

It is probably safe to assume that medical practitioners at that time were reporting the status of their patients in a standard manner. Although not mentioned, one might imagine that, at that time, ultrasound or MRI scans were also reported in a standard and transferrable manner. The people of Babel noticed the potential in uniform communication and tried to build a tower so high that it would  reach the gods. Unfortunately, God did not like that, so he went down (in person) and confounded people’s speech, so that they could not understand each another. Genesis 11:7–8.

This must be the explanation for our inability to come to a consensus on reporting of patients’ imaging-outcome. Progress in development of efficient imaging protocols and in clinical management of patients is withheld due to high variability and subjectivity of clinicians’ approach to this issue.

Clearly, a justification could be found for not reaching a consensus on imaging protocols: since the way imaging is performed affects the outcome, (i.e. the image and its interpretation) it takes a long process of trial-and-error to come up with the best protocol.  But, one might wonder, wouldn’t the search for the ultimate protocol converge faster if all practitioners around the world, who are conducting hundreds of clinical studies related to imaging-based management of cancer patients, report their results in a standardized and comparable manner?

Is there a reason for not reaching a consensus on imaging reporting? And I’m not referring only to intra-modality consensus, e.g. standardizing all MRI reports. I’m referring also to inter-modality consensus to enable comparison and matching of reports generated from scans of the same organ by different modalities, e.g. MRI, CT and ultrasound.

As developer of new imaging-based technologies, my personal contribution to promoting standardized and objective reporting was the implementation of preset reporting as part of the prostate-HistoScanning product design. For use-cases, as demonstrated below, in which prostate cancer patients were also scanned by MRI a dedicated reporting scheme enabled matching of the HistoScanning scan results with the prostate’s MRI results.

The MRI reporting scheme used as a reference is one of the schemes offered in a report by Miss Louise Dickinson on the following European consensus meeting : Magnetic Resonance Imaging for the Detection, Localisation, and Characterisation of Prostate Cancer: Recommendations from a European Consensus Meeting, Louise Dickinson a,b,c,*, Hashim U. Ahmed a,b, Clare Allen d, Jelle O. Barentsz e, Brendan Careyf, Jurgen J. Futterer e, Stijn W. Heijmink e, Peter J. Hoskin g, Alex Kirkham d, Anwar R. Padhani h, Raj Persad i, Philippe Puech j, Shonit Punwani d, Aslam S. Sohaib k, Bertrand Tomball,Arnauld Villers m, Jan van der Meulen c,n, Mark Emberton a,b,c,

Image of MRI reporting scheme taken from the report by Miss Louise Dickinson

The corresponding HistoScanning report is following the same prostate segmentation and the same analysis plans:

Preset reporting enabling matching of HistoScanning and MRI reporting of the same case.

It is my wish that already in the near-future, the main radiology societies (RSNA, ESR, etc..) will join together to build the clinical Imaging’s “Tower of Babel” to effectively address the issue of standardizing reporting of imaging procedures. This time it will not be destroyed…:-)

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Knowing the tumor’s size and location, could we target treatment to THE ROI by applying imaging-guided intervention?

Knowing the tumor’s size and location, could we target treatment to THE ROI by applying imaging-guided intervention?

Author: Dror Nir, PhD


Advances in techniques for cancer lesions’ detection and localisation [1-6] opened the road to methods of localised (“focused”) cancer treatment [7-10].  An obvious challenge on the road is reassuring that the imaging-guided treatment device indeed treats the region of interest and preferably, only it.

A step in that direction was taken by a group of investigators from Sunnybrook Health Sciences Centre, University of Toronto, Ontario, Canada who evaluate the feasibility and safety of magnetic resonance (MR) imaging–controlled transurethral ultrasound therapy for prostate cancer in humans [7]. Their study’s objective was to prove that using real-time MRI guidance of HIFU treatment is possible and it guarantees that the location of ablated tissue indeed corresponds to the locations planned for treatment. Eight eligible patients were recruited.


The setup


Treatment protocol


The result


“There was excellent agreement between the zone targeted for treatment and the zone of thermal injury, with a targeting accuracy of ±2.6 mm. In addition, the temporal evolution of heating was very consistent across all patients, in part because of the ability of the system to adapt to changes in perfusion or absorption properties according to the temperature measurements along the target boundary.”


Technological problems to be resolved in the future:

“Future device designs could incorporate urinary drainage during the procedure, given the accumulation of urine in the bladder during treatment.”

“Sufficient temperature resolution could be achieved only by using 10-mm-thick sections. Our numeric studies suggest that 5-mm-thick sections are necessary for optimal three-dimensional conformal heating and are achievable by using endorectal imaging coils or by performing the treatment with a 3.0-T platform.”

Major limitation: “One of the limitations of the study was the inability to evaluate the efficacy of this treatment; however, because this represents, to our knowledge, the first use of this technology in human prostate, feasibility and safety were emphasized. In addition, the ability to target the entire prostate gland was not assessed, again for safety considerations. We have not attempted to evaluate the effectiveness of this treatment for eradicating cancer or achieving durable biochemical non-evidence of disease status.”


  1. SIMMONS (L.A.M.), AUTIER (P.), ZATURA (F.), BRAECKMAN (J.G.), PELTIER (A.), ROMICS (I.), STENZL (A.), TREURNICHT (K.), WALKER (T.), NIR (D.), MOORE (C.M.), EMBERTON (M.). Detection, localisation and characterisation of prostate cancer by Prostate HistoScanning.. British Journal of Urology International (BJUI). Issue 1 (July). Vol. 110, Page(s): 28-35
  2. WILKINSON (L.S.), COLEMAN (C.), SKIPPAGE (P.), GIVEN-WILSON (R.), THOMAS (V.). Breast HistoScanning: The development of a novel technique to improve tissue characterization during breast ultrasound. European Congress of Radiology (ECR), A.4030, C-0596, 03-07/03/2011.
  3. Hebert Alberto Vargas, MD, Tobias Franiel, MD,Yousef Mazaheri, PhD, Junting Zheng, MS, Chaya Moskowitz, PhD, Kazuma Udo, MD, James Eastham, MD and Hedvig Hricak, MD, PhD, Dr(hc) Diffusion-weighted Endorectal MR Imaging at 3 T for Prostate Cancer: Tumor Detection and Assessment of Aggressiveness. June 2011 Radiology, 259,775-784.
  4. Wendie A. Berg, Kathleen S. Madsen, Kathy Schilling, Marie Tartar, Etta D. Pisano, Linda Hovanessian Larsen, Deepa Narayanan, Al Ozonoff, Joel P. Miller, and Judith E. Kalinyak Breast Cancer: Comparative Effectiveness of Positron Emission Mammography and MR Imaging in Presurgical Planning for the Ipsilateral Breast Radiology January 2011 258:1 59-72.
  5. Anwar R. Padhani, Dow-Mu Koh, and David J. Collins Reviews and Commentary – State of the Art: Whole-Body Diffusion-weighted MR Imaging in Cancer: Current Status and Research Directions Radiology December 2011 261:3 700-718
  6. Eggener S, Salomon G, Scardino PT, De la Rosette J, Polascik TJ, Brewster S. Focal therapy for prostate cancer: possibilities and limitations. Eur Urol 2010;58(1):57–64).
  7. Rajiv Chopra, PhD, Alexandra Colquhoun, MD, Mathieu Burtnyk, PhD, William A. N’djin, PhD, Ilya Kobelevskiy, MSc, Aaron Boyes, BSc, Kashif Siddiqui, MD, Harry Foster, MD, Linda Sugar, MD, Masoom A. Haider, MD, Michael Bronskill, PhD and Laurence Klotz, MD. MR Imaging–controlled Transurethral Ultrasound Therapy for Conformal Treatment of Prostate Tissue: Initial Feasibility in Humans. October 2012 Radiology, 265,303-313.
  8. Black, Peter McL. M.D., Ph.D.; Alexander, Eben III M.D.; Martin, Claudia M.D.; Moriarty, Thomas M.D., Ph.D.; Nabavi, Arya M.D.; Wong, Terence Z. M.D., Ph.D.; Schwartz, Richard B. M.D., Ph.D.; Jolesz, Ferenc M.D.  Craniotomy for Tumor Treatment in an Intraoperative Magnetic Resonance Imaging Unit. Neurosurgery: September 1999 – Volume 45 – Issue 3 – p 423
  9. Medel, Ricky MD,  Monteith, Stephen J. MD, Elias, W. Jeffrey MD, Eames, Matthew PhD, Snell, John PhD, Sheehan, Jason P. MD, PhD, Wintermark, Max MD, MAS, Jolesz, Ferenc A. MD, Kassell, Neal F. MD. Neurosurgery: Magnetic Resonance–Guided Focused Ultrasound Surgery: Part 2: A Review of Current and Future Applications. October 2012 – Volume 71 – Issue 4 – p 755–763
  10. Bruno Quesson PhD, Jacco A. de Zwart PhD, Chrit T.W. Moonen PhD. Magnetic resonance temperature imaging for guidance of thermotherapy. Journal of Magnetic Resonance Imaging, Special Issue: Interventional MRI, Part 1, Volume 12, Issue 4, pages 525–533, October 2000

Writer: Dror Nir, PhD


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Radiology congresses are all about imaging in medicine. Interestingly, radiology originates from radiation. It was the discovery of X-ray radiation at the beginning of the 20th century that opened the road to “seeing” the inside of the human body without harming it (at that time that meant cutting into the body).

Radiology meetings are about sharing experience and knowhow on imaging-based management patients. The main topic is always image-interpretation: the bottom line of clinical radiology! This year’s European Congress of Radiology (ECR) dedicated few of its sessions to recent developments in image-interpretation tools. I chose to discuss the one that I consider contributing the most to the future of cancer patients’ management.

In the refresher course dedicated to computer application the discussion was aimed at understanding the question “How do image processing and CAD impact radiological daily practice?” Experts’ reviews gave the audience some background information on the following subjects:

  1. A.     The link between image reconstruction and image analysis.
  2. B.     Semantic web technologies for sharing and reusing imaging-related information
  3. C.     Image processing and CAD: workflow in clinical practice.

I find item A to be a fundamental education item. Not once did I hear a radiologist saying: “I know this is the lesion because it’s different on the image”.  Being aware of the computational concepts behind image rendering, even if it is at a very high level and lacking deep understanding of the computational processes,  will contribute to more balanced interpretations.

Item B is addressing the dream of investigators worldwide. Imagine that we could perform a web search and find educating, curated materials linking visuals and related clinical information, including standardized pathology reporting. We would only need to remember that search engines used certain search methods and agree, worldwide, on the method and language to be used when describing things. Having such tools is a pre-requisite to successful pharmaceutical and bio-tech development.

I find item C strongly linked to A, as all methods for better image interpretation must fit into a workflow. This is a design goal that is not trivial to achieve. To understand what I mean by that, try to think about how you could integrate the following examples in your daily workflow: i.e. what kind of expertise is needed for execution, how much time it will take, do you have the infrastructure?

In the rest of this post, I would like to highlight, through examples that were discussed during ECR 2012, the aspect of improving cancer patients’ clinical assessment by using information fusion to support better image interpretation.

  • Adding up quantitative information from MR spectroscopy (quantifies biochemical property of a target lesion) and Dynamic Contrast Enhanced MR imaging (highlights lesion vasculature).

Image provided by: Dr. Pascal Baltzer, director of mammography at the centre for radiology at Friedrich Schiller University in Jena, Germany

  • Registration of images generated by different imaging modalities (Multi-modal imaging registration).

The following examples: Fig 2 demonstrates registration of a mammography image of a breast lesion to an MRI image of this lesion. Fig3 demonstrates registration of an ultrasound image of a breast lesion scanned by an Automatic Breast Ultrasound (ABUS) system and an MRI image of the same lesion.

Images provided by members of the HAMAM project (an EU, FP7 funded research project: Highly Accurate Breast Cancer Diagnosis through Integration of Biological Knowledge, Novel Imaging Modalities, and Modelling):


 Multi-modality image registration is usually based on the alignment of image-features apparent in the scanned regions. For ABUS-MRI matching these were: the location of the nipple and the breast thickness; the posterior of the nipple in both modalities; the medial-lateral distance of the nipple to the breast edge on ultrasound; and an approximation of the rib­cage using a cylinder on the MRI. A mean accuracy of 14mm was achieved.

Also from the HAMAM project, registration of ABUS image to a mammography image:

registration of ABUS image to a mammography image, Image provided by members of the HAMAM project (an EU, FP7 funded research project: Highly Accurate Breast Cancer Diagnosis through Integration of Biological Knowledge, Novel Imaging Modalities, and Modelling):

  • Automatic segmentation of suspicious regions of interest seen in breast MRI images

Segmentation of suspicious the lesions on the image is the preliminary step in tumor evaluation; e.g. finding its size and location. Since lesions have different signal/image character­istics to the rest of the breast tissue, it gives hope for the development of computerized segmentation techniques. If successful, such techniques bear the promise of enhancing standardization in the reporting of lesions size and location: Very important information for the success of the treatment step.

Roberta Fusco of the National Cancer Institute of Naples Pascal Foundation, Naples/IT suggested the following automatic method for suspi­cious ROI selection within the breast using dynamic-derived information from DCE-MRI data.


Automatic segmentation of suspicious ROI in breast MRI images, image provided by Roberta Fusco of the National Cancer Institute of Naples Pascal Foundation, Naples/IT


 Her algorithm includes three steps (Figure 2): (i) breast mask extraction by means of automatic intensity threshold estimation (Otsu Thresh-holding) on the par­ametric map obtained through the sum of intensity differences (SOD) calculated pixel by pixel; (ii) hole-filling and leakage repair by means of morphological operators: closing is required to fill the holes on the boundaries of breast mask, filling is required to fill the holes within the breasts, erosion is required to reduce the dilation obtained by the closing operation; (iii) suspicious ROIs extraction: a pixel is assigned to a suspicious ROI if it satisfies two conditions: the maximum of its normalized time-intensity curve should be greater than 0.3 and the maximum signal intensity should be reached before the end of the scan time. The first condition assures that the pixels within the ROI have a significant contrast agent uptake (thus excluding type I and type II curves) and the second condition is required for the time-intensity pattern to be of type IV or V (thus excluding type III curves).


Written by: Dror Nir, PhD

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Author: Dror Nir, PhD


The most stressful period in a cancer patients’ pathway is from the moment they fail a screening test or present with suspicious symptoms to the moment they are diagnosed. Today’s medical guidelines require histopathology findings as the only acceptable proof: positive results  mean you are a cancer patient, negative results mean, well…maybe you are and maybe you are not. You now enter into what might be a very long period, sometime years, of uncertainty regarding your health and prospects. And why?

Because the substance for histopathology is acquired by biopsies, and biopsies are known to be inaccurate. For example, breast and prostate biopsies  fail to find 25% to 35% of the cancer lesions at the first biopsy session.

Therefore, it is not surprising that from the beginning of this procedure,  medical practitioners look for ways to incorporate imaging into the workflow. In the last decade, significant progress has been made in the introduction of imaging-guided biopsies. The most common modalities were ultrasound and CT/mammography. Recently, as the industry solved the issues of magnetic field compatibility for biopsy needles and the introduction of open MRI systems, MRI-guided biopsies were also made  possible.

Ultrasound-guided biopsies are  by far the most commonly used procedure. Why? Because they  can be often performed as an office-based procedure. Here are some interesting links to YouTube videos describing such procedures:

  • Prostate

Prostate Ultrasound and Prostate Biopsy by Dr. Neil Baum

Transrectal ultrasound (Trus) Biopsy of the prostate

  • Breast

Ultrasound-Guided Breast Biopsy

Breast Tissue Biopsy

The main advantages: they are easily accessible, low cost and quick. The disadvantages of these procedures are  that they are very much operator dependent, rather than standardized, and there are no quality assurance guidelines attached. Efforts to standardize ultrasound-based biopsies and increase their efficiency are evident by recent introductions of ultrasound systems into the market ,  which support real-time guided biopsies and ultrasound applications that perform real-time biopsy tracking. But these systems are still far from being widely available. I will touch on this issue in my upcoming posts as I am part of these efforts.

CT and Mammography guided biopsies require more sophisticated equipment and well-trained operators. As an example:

Breast Biopsy – What To Expect

The main advantage: if you return to the same operator, the process is likely to be reproducible. The disadvantages are identical to that of ultrasound-based biopsies. It is worthwhile to note that, recently, radiologists who perform biopsies are required to go through a certification process. Still, such certification demands vary between the various radiology societies.

MRI-guided biopsies are an even more sophisticate and complex procedure:

  • Prostate:

DynaTRIM Video

DynaTRIM Intervention

An interesting quote from Dr. Hashim U. Ahmed, M.D., MRCS, Division of Urology  Department of Surgery, University College of London ( “Advocating the widespread use of MRI before biopsy in a population of men with risk parameters for harboring prostate cancer has a number of advantages, which might ultimately benefit the care these men undergo. Increasing the detection of prostate cancer that requires treatment while avoiding biopsy – and hence unnecessary treatment – in those with insignificant or no cancer are compelling arguments for this approach.”

  • Breast

MRI Breast Biopsy – Diagnostic and Biopsy Services for Breast Evaluation

I recommend reading the following article regarding the use of Open MRI to guide freehand biopsies of breast lesions. Especially interesting is the discussion where the authors give a good description of the difficulties in breast biopsies they are trying to overcome in order to achieve good lesion sampling.

MR-guided Freehand Biopsy of Breast Lesions in a 1.0-T Open MR Imager with a Near-Real-time Interactive Platform: Preliminary Experience Frank Fischbach, MD, et. al

The question remains: which biopsy procedure is the best? And does this question have one coherent answer, i.e. one that will satisfy the patients, the doctors and the health-care insurers?  Will the answer to this question remain the subject of endless uncoordinated clinical studies?

If anyone who reads this post knows on methodological scientific or regulatory initiatives aimed at answering this question on a level of global guide lines  I would appreciate his comment.

Written by: Dror Nir, PhD.


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