alberta imaging symposium 2011

222111 aaappprrriiilll 222000111111 * HOPEWELL PROFESSORSHIP ALBERTA IMAGING SYMPOSIUM 2011 A Celebration of Excellence in Provincial Medical Imaging Research

Health Science Centre G500 University of Calgary 10h30-‐18h00

Hopewell Professorship Alberta Imaging Symposium 2011

April 2011 -1- *

Thursday 21 April 2011, 10h30-18h00 Registration Desk opens at 10h00 University of Calgary Meeting Location .............................................................................................................................................................................. 1 Symposium Program ...................................................................................................................................................................... 2 Welcome Letter ................................................................................................................................................................................. 4 Abstracts .............................................................................................................................................................................................. 5 Hongmei Zhu, PhD -‐ Mathematics & Statistics, York University ................................................................................................5 Robert Kosior, PhD -‐ Biomedical Engineering, University of Calgary.....................................................................................6 Hing Cheng, BSc -‐ Radiology, University of Calgary .........................................................................................................................7 Yunyan Zhang, MD, PhD -‐ Radiology and Clinical Neurosciences, University of Calgary ................................................8 Nathan Becker, MSc -‐ Physics and Astronomy, University of Calgary .....................................................................................9 Kelvin Chow, BSc -‐ Biomedical Engineering, University of Alberta .......................................................................................10 Karla Ponjavic, MSc – Neuroscience, University of Lethbridge ...............................................................................................11 Rebecca Feldman, PhD -‐ Biomedical Engineering, University of Alberta............................................................................12 Shantanu Banik, MSc -‐ Electrical and Computer Engineering, University of Calgary ....................................................13 Stefanie Hassel, PhD – Psychiatry, University of Calgary ...........................................................................................................14 Robert Stobbe, PhD -‐ Biomedical Engineering, University of Alberta ..................................................................................15 Amber Doiron, PhD -‐ Chemical Engineering and Radiology, University of Calgary........................................................16 Francois Moreau, MD -‐ Clinical Neurosciences, University of Calgary .................................................................................17 Mirza Faisal Beg, PhD -‐ School of Engineering Science, Simon Fraser University...........................................................18 Yue Wang, MD -‐ Faculty of Rehabilitation Medicine, University of Alberta .......................................................................19 Jodi Harker, MBBS -‐ Stephenson CMR Centre, Libin Cardiovascular Institute .................................................................20 Dongming Zhou, PhD -‐ Biomedical Engineering, University of Alberta ...............................................................................21 Alison King, PhD – Radiology, University of Calgary ....................................................................................................................22 Lisa Marie Langevin, PhD -‐ Behavioural Research Unit, Alberta Children’s Hospital....................................................23 Stefano Peca, MSc -‐ Seaman Family MR Centre, University of Calgary.................................................................................24

Invited Speakers and Registered Attendees...................................................................................................................... 25 Additional Imaging Meeting of Interest............................................................................................................................... 27 Meeting Location Foothills Campus – 3330 Hospital Drive NW, Cal-gary Registration – outside Health Sciences Centre -‐ Room G500 Sessions -‐ Health Sciences Centre -‐ Room G500 Lunch – Health Medical Research Bldg -‐ West Atrium Paid parking available in Lot 6 Parkade located imme-‐diately to the north of the Health Sciences complex. Lunch provided to delegates with paid registration.


April 2011 -2- *

Symposium Program

Time Speaker Title

10:30 Dr Richard Frayne University of Calgary

Welcome

Session 1 – Chair: Dr Cheryl McCreary, University of Calgary

10:40 Dr Hong-mei Zhu York University

Time-frequency analysis and its application in under-standing brain functional connectivity

11:20 Dr Rob Kosior University of Calgary

Elucidating Seizure Foci with Voxel-Based Relaxome-try

11:35 Mr Hing Cheng University of Calgary

Automatic Identification of Abnormalities in Medical Images via Fast Deformable Co-Registration

11:50 Dr Yunyan Zhang University of Calgary

MRI Texture Analysis Differentiates Persistent and Transient T1 ‘Black holes’ in Multiple Sclerosis

12:05 Mr Nathan Becker University of Calgary

Cone-Beam CT Based Lung Tumour Motion Estima-tion

12:20 Mr Kelvin Chow University of Alberta

Myocardial Tissue T1 Mapping

12:35 Ms Karla Ponjavic University of Lehtbridge

Electrophysiological Correlates of Auditory Distrac-tion as Manifested in Post-secondary Adults with and without Attention Deficit Hyperactivity Disorder

Session 2 – Chair: Dr Richard Thompson, University of Alberta

13:45 Dr Rebecca Feldman University of Alberta

Fluid Suppressed Sodium Magnetic Resonance Imag-ing of the Human Knee

14:00 Mr Shantanu Banik University of Calgary

Detection of Architectural Distortion in Prior Mam-mograms of Interval-cancer Cases

14:15 Dr Stefanie Hassel University of Calgary

Differential Activation during an Affective Go-NoGo Task in Bipolar Disorder

14:30 Dr Robert Stobbe University of Alberta

Exploring New Ways to Get A-round in 3D k-Space

14:45 Dr Amber Dorion University of Calgary

The Design of a MR Molecular Imaging Agent for De-tection of Atherosclerotic Plaques


April 2011 -3- *

Time Speaker Title

15:00 Dr Francois Moreau University of Calgary

Absolute Oxygen Measurements in Stroke, Prelimi-nary Findings

15:15 Dr Mizra Faisal Beg Simon Fraser University

Computational Anatomy – Tools for mapping brain structure and applications to differential discrimina-tion in dementia

Session 3 – Chair: Dr Robert Kosior, University of Calgary

16:15 Dr Yue Wang University of Alberta

Quantitative Measures of Modic Changes on Lumbar Spine MRI: Intra- and Inter-rater Reliability

16:30 Dr Jodi Harker University of Calgary

Assessment of Significant Coronary Artery Stenosis using Blood Oxygen Level Dependent Cardiovascular Magnetic Resonance (BOLD-CMR)

16:45 Dr Dongming Zhou University of Alberta

Regional Cortical Thickness and Asymmetry Differ-ences from Children to Older Adults

17:00 Dr Alison King University of Calgary

Quite a stretch: Deep knee bends studied with low-field MRI

17:15 Dr Lisa-Marie Langevin University of Calgary

Examining the Common Neurobiological Basis of Mo-tor and Attention Deficits in Neurodevelopmental Disorders

17:30 Mr Stefano Peca University of Calgary

The Hemodynamic Response in fMRI: Applications in Cerebral Amyloid Angiopathy

17:45 Dr Richard Frayne University of Calgary

Wrap-up and Acknowledgements


April 2011 -4- *

1430 29 t h S t reet NW, Calgary , Alber ta , Canada T2N 2T9 • mrcentre.ca

Thursday 21 April 2011 Dear Invited Speakers and Symposium Attendees:

Thank you very much for attending the inaugural Hopewell Professorship Alberta Imaging Symposium.

Today’s program will highlight achievements from across Alberta in the field of medical imaging that were accomplished during 2010. The focus will be on invited research updates given by senior research trainees, fellows and staff. These individuals were selected from a group of distinguished individuals nominated by faculty at the Universities of Alberta, Calgary, and Lethbridge. They represent a unique cross-section of the exciting imaging research happening across our province.

A special thank you is also due to Drs Faisal Beg (from Simon Fraser University) and Hong-mei Zhu (York University, Toronto) for coming to and presenting at our Symposium. We not only look forward to their presentations, but to the opportunity to engage with them during the day.

Finally, special recognition is due to the Hopewell Group of Companies for funding the Professorship that has helped support this Symposium.

I hope you have an enjoyable day listening to our achievements.

Sincerely,

Richard Frayne, PhD Canada Research Chair in Image Science Hopewell Professor of Brain Imaging

hi Faculty of Medicine

Departments of Radiology and Clinical Neurosciences Seaman Family MR Research Centre, MRG013 Telephone: 403 944 8321 Fax: 403 270 7907 Email: [email protected]

Welcome Letter


April 2011 -5- *

Abstracts

Presentation 1.1 – 10:40

Hongmei Zhu, PhD -‐ Mathematics & Statistics, York University Dr Zhu is an Associate Professor at the Department of Mathematics and Statistics, York University. She holds a PhD in Applied Mathematics at the University of Wa-‐terloo and worked as a postdoctoral fellowship with Dr Ross Mitchell at the Sea-‐man MR Centre at Foothills Hospital, University of Calgary between 2001 and 2004. Her research interests are in the areas of time-‐frequency analysis, data analysis, numerical computations and their applications in real-‐world problems arisen from biomedicine and other industries.

Time-‐frequency Analysis and its Application in Understanding Brain Functional Connectivity

C Liu, W Gaetz, TPL Roberts, H Zhu Time-‐frequency analysis is a powerful tool for understanding non-‐stationary characteristics of data such as brain signals. It can not only reveal brain activities occurred in a single brain region but also be used to derive statistical measures, such as coherence, to describe functional dynamics between different brain regions. In this talk, we address the use of time-‐frequency analysis to estimate time-‐varying statistical measures and then apply them to investigate motor cortex activities under the multisource interference task.


April 2011 -6- *


Robert Kosior, PhD -‐ Biomedical Engineering, University of Calgary Robert Kosior is a researcher at the Seaman Family MR Research Centre, located in the Foothills Medical Centre in Calgary, Alberta. This past December, he defended his PhD thesis in Biomedical Engineering at the University of Calgary where he also obtained a BSc in Mechanical Engineering in 2005. His PhD thesis was focused on quantitative MR imag-‐ing for stroke and epilepsy under the supervision of imaging expert Dr Richard Frayne at the Seaman Family MR Centre. His research involves close collaboration with other scien-‐tists and clinicians including experts from the Hotchkiss Brain Institute. A key contribu-‐tion of his graduate work for stroke imaging was the development of an MR topographical score using a digital brain atlas, based on a stroke scoring scale called the Alberta Stroke Program Early CT Score, or AS-‐PECTS scale. By using MR scans and automated processing methods, Kosior has developed a more objective way of apply-‐ing the topographical score. He is currently working in close collaboration with Dr Paolo Federico, an epileptologist, on voxel-‐based quantitative MR imaging of epileptic patients. The goal of this work is to improve how abnormal tissue, or sei-‐zure foci, may be identified in the brain using statistical mapping techniques.

Elucidating Seizure Foci with Voxel-‐Based Relaxometry

RK Kosior, RJ Sharkey, R Frayne, P Federico Purpose: Voxel-‐Based Relaxometry (VBR) is a technique in which a voxel-‐level statistical comparison of quantitative MR T2 maps is performed to identify regions with significantly elevated T2 relaxation time. In cases of an indeterminate diagnosis, single-‐subject VBR may provide important information to corroborate, refute, or substitute indeterminate information from the other sources. Our objective was to assess the performance of single-‐subject VBR at 3 T as a diagnostic tool for patients whose diagnosis of epilepsy or seizure focus location is uncertain. Methods: Fifty-‐nine patients with possible epilepsy or known epilepsy, but an unknown focus were selected for assessment. All subjects were scanned at 3 T using a modified Carr-‐Purcell-‐Meiboom-‐Gill MR sequence. Forty-‐two healthy subjects were used as controls. VBR was performed on a single-‐subject basis at a significance level of α = 0.001. The diagnosis of each pa-‐tient was determined based on history, neuropsychological testing, EEG, conventional structural MR and in some cases, video-‐EEG monitoring (VEM) and/or single photon emission computerized tomography. Patients were grouped based on whether the diagnosis of epilepsy was in question and whether there was a suspected focus. VBR detections were assessed across the brain, and a VBR severity score was determined based on the presence of VBR significance in any of 13 prede-‐fined regions per hemisphere. Results: All patient groupings exhibited more median VBR abnormalities than controls. This difference was significant (p < 0.05) between all patients and controls, and between patients with known epilepsy and controls. Eighteen of the 27 pa-‐tients with a suspected focus (67%) exhibited a VBR abnormality in the suspected focus, with additional regions of in-‐volvement being elucidated. At least one VBR detection was seen in 45 of the 59 patients (76%), versus 18 of the 42 control subjects (43%). In 34 of the patients, the structural MR was completely normal, with 27 of these patients still showing at least one VBR detection (79%). Patients with the most precisely localized seizure focus (i.e. with a suspected lobe and side) also had the highest likelihood of having at least one VBR detection (86%). Clinical follow-‐up was available for 54 of 59 pa-‐tients (92%), where new clinical, imaging, or EEG information was obtained and re-‐evaluated. In seven of these patients, further investigations or clinical information allowed reclassification from their original groupings to have a suspected fo-‐cus or confirmed focus. With reclassification, four of the seven patients had VBR findings that were predictive of their sub-‐sequent clinical reclassification of their epilepsy. Conclusions: Single-‐subject VBR confirmed the seizure focus in patients with suspected seizure foci but with an unremark-‐able MR scan and it identified potential seizure foci in patients with unknown seizure foci. Because it is possible for VBR maps to be generated in a semi-‐automated fashion with minimal user interaction, VBR should be considered in patients with epilepsy in whom conventional structural MR imaging is not informative. An algebraic T2 estimation approach is being investigated for improved detection sensitivity of seizure-‐related abnormalities


April 2011 -7- *


Hing Cheng, BSc -‐ Radiology, University of Calgary Hing received B.Sc. in Math and Physics in 1970, and was MPhil. and PhD candi-‐dates in Applied Math from 1990 to 1995 in Hong Kong, (candidacy terminated due to immigration). He had done research in stock cutting, scheduling, plastic in-‐jection moulding, multi-‐agent system (University of Calgary), prosthetics, orthotics & scoliosis imaging (National Research Council, University of C), steelmaking (Pre-‐carn, University of Alberta), rail transportation, radiotherapy patient positioning (University of Toronto), as well as 3D imaging and image processing for reverse engineering, weapon excavation, baby skull deformation, and 3D movies, etc. From January 2009, he is Research Associate in Imaging Informatics Lab, University of Calgary, where he has completed the following projects: Fast, accurate computa-‐tion of 1D S-‐Transform amplitudes for long time series, with localized filtering; Real-‐time, accurate computation of 2D S-‐Transform amplitudes for medical images; Fast, accurate computation of 2D S-‐Transform statistics for regions of interest in medical images; Deformable co-‐registration of highly dissimilar medical images, and fast, automatic identification of abnormalities. His future work will be in texture-‐based region growing, segmenta-‐tion, classification and image search.

Automatic Identification of Abnormalities in Medical Images via Fast Deformable Co-‐Registration

H Cheng We present a method to perform fast deformable co-‐registration between two dissimilar medical images. We employ several techniques to improve the efficiency and effectiveness of the co-‐registration. We then compare the co-‐registered images to identify prominent outliers. In particular, if one image is normal and the other has disease, then we are able to identify the abnormalities in the latter. We can also find asymmetries in a single im-‐age by co-‐registering it with its mirror image. This may be useful for detecting lesions in brain images.


April 2011 -8- *


Yunyan Zhang, MD, PhD -‐ Radiology and Clinical Neurosciences, Uni-‐versity of Calgary Dr Zhang is a Radiologist and a scientist in medical image processing and analysis. She completed her PhD, with the support of Studentships from NSERC and the De-‐partment of Medical Sciences, in 2007 in Biomedical Engineering at the University of Calgary following her medical studies in China. She then went on to complete post-‐doctoral studies at the Universities of Calgary and British Columbia, supported by Fellowships from Teva Neuroscience, MS Society of Canada, and The Network of mul-‐tiple sclerosis (MS) Clinics, Canada. In the meantime, she has completed a mini Fel-‐lowship in Neuroradiology, University of Calgary. Currently, Dr Zhang is finishing a Clinical Fellowship in Neurology specializing in MR imaging in MS, and taking on a research assistant professor posi-‐tion in the Departments of Radiology & Clinical Neurosciences, University of Calgary, where she is also a primary member of the HBI MS Program.

MRI Texture Analysis Differentiates Persistent and Transient T1 ‘Black Holes’ in Multiple Sclerosis

Y Zhang, A Traboulsee, Y Zhao, L Metz, DK Li Introduction: New contrast-‐enhancing lesions (CELs) in multiple sclerosis (MS) are frequently accompanied by hypointen-‐sity on T1-‐weighted MRI, namely acute black holes (ABHs). An ABH may persist (pABH) or resolve (transient ABH, tABH) over time. While a pABH is thought to represent irreversible tissue destruction, the conversion of tABH parallels remyelina-‐tion. Remyelinated lesions may help to ensheath the denuded axon and thereby assist to restore compromised CNS func-‐tion. However, pABHs cannot be distinguished from tABHs on conventional images. MRI texture analysis shows promise for detecting subtle abnormalities in signal intensity and pattern. Pilot data suggests that increased texture heterogeneity cor-‐responds to inflammation and demyelination in murine mice. The goal was to compare texture characteristics in pABH and tABH on T1-‐weighted MRI in MS. Method: Twenty RRMS patients were scanned at months 1, 3, 8 and 9. Pre-‐ and post-‐contrast T1-‐weighted and T2-‐weighted images were acquired at 3T. New CELs that appeared simultaneously T1 hypointense at month 1 or 3 (onset) were identi-‐fied. An ABH was classified as a pABH or a tABH based on its visual appearance at month 8 or 9 (followup) pre-‐contrast T1-‐weighted MRI. NAWM from the same patient was evaluated for control. T1-‐weighted images were corrected for non-‐uniformity and 3D co-‐registered serially. Regions of interest (ROIs) were drawn around each ABH at onset and were super-‐imposed to the registered MRI at followup to ensure evaluation of the same region over time. MRI texture was calculated using a spatial frequency based technique for each pixel in a ROI. Texture difference was assessed using multivariate re-‐gression analysis. The p ≤ 0.05 was set as significant. Results: There were 15 ABHs (8 pABHs and 7 tABHs) identified from 9 patients. Nine NAWM regions were studied. Differ-‐ent local spectra were found between ABHs and NAWM (p = 0.02) particularly over low frequency ranges. Unlike the smooth pattern in NAWM, focal amplitude increases were observed in ABHs, which span broader and of higher energy in pABHs than in tABHs. Furthermore, the spectral energy over low frequencies was significantly greater in the pABHs than that in the tABHs (p < 0.05), which was both larger than that in the NAWM. High frequency spectrum did not differ (p > 0.05). Discussion: This preliminary study showed that low frequency energy representing coarse texture was greater in the pABHs than that in the tABHs several months before visible evolution. It may indicate that pABHs contain more severe tis-‐sue damage and therefore higher structural heterogeneity than the tABHs, which is minimal in the plaque-‐free NAWM. Sub-‐sequently, increased complexity at the initiation of lesion formation in pABHs may have confounded repair compared to tABHs. This is consistent with previous results showing that greater coarse texture at lesion onset related to less recovery 8 months later. This texture analysis approach may have the potential to predict the fate of ABHs, which could be very useful for a precise quantification of disease activity and evaluation of therapeutic efficacy aimed at neuroprotection or repair.


April 2011 -9- *


Nathan Becker, MSc -‐ Physics and Astronomy, University of Calgary Nathan completed a BSc Degree with Honours in Physics from the University of the Fraser Valley in Abbotsford, BC. In 2006, he began a Masters degree at the University of Calgary in the Physics and Astronomy Department, specializing in Radiation Oncology Physics. In 2008, he directly transferred to the PhD program, and is currently in the final year of the program, with future plans to complete a residency in medical physics. His research involves lung tumour motion man-‐agement for radiation therapy. He has developed a novel technique to measure the internal motion of lung tumours, using a new imaging modality called cone-‐beam computed tomography (CT).

Cone-‐Beam CT Based Lung Tumour Motion Estimation

N Becker, I Kay, S Quirk, H Lau, W Smith When a lung cancer patient is treated with radiation therapy, the respiratory induced motion of the tumour can change from day to day. Conventional cone-‐beam CT (CBCT) imaging provides a static 3D image that is used to precisely localize the tumour prior to treatment, but tumour motion can cause imaging artifacts. We present a novel algorithm to estimate the trajectory of an implanted fiducial marker from the raw CBCT projection data . During a CBCT scan, approximately 600 projection images are captured as the onboard X-‐ray imager (OBI) com-‐pletes a revolution around the patient. The lung tumour may be difficult to identify in these projection images, so a fiducial marker implanted near the tumour can act as a surrogate for tumour motion. Our algorithm works by binning the images according to the motion of the marker in them. For a given image, the true position of the marker lies along a ray from the imager source to the position of the seed projection on the detector. This true position can be estimated using the projections from other images in the same bin. We can build an entire 4D trajectory of the fiducial marker by repeating this process for each image in the CBCT dataset. We first used computer simulations to show that this algorithm is capable of reconstructing realistic lung tumour motion with sub-‐millimeter accuracy. We also verified it is feasible to implement at the treatment unit, by imaging and re-‐constructing the motion of a programmable moving platform. Lastly, we demonstrated a reconstruction using this algorithm for a clinical case study. This research has provided a new way to reconstruct CBCT data that can provide additional information about the daily changes in the motion of the tumour, without increasing the im-‐aging dose to the patient.


April 2011 -10- *


Kelvin Chow, BSc -‐ Biomedical Engineering, University of Alberta After graduating from the University of Alberta in 2006 with a bachelor’s degree with distinction in Engineering Physics, Kelvin is furthering his studies in the PhD program in Biomedical Engineering under the supervision of Dr Richard Thomp-‐son. Initially focusing on functional lung imaging using MRI, his research program has expanded to include various aspects of cardiopulmonary MRI, particularly myocardial tissue characterization with quantitative T1 and T2 mapping. Kelvin’s involvement includes programming and implementing novel MRI pulse se-‐quences, development of post-‐process analysis software, and participation in numerous clinical research studies, with over 200 patient exams performed during his program. He is currently in the 5th year of his PhD program.

Myocardial Tissue T1 Mapping

K Chow, M Friedrich, R Thompson Myocardial fibrosis is a condition where myocytes, the functional unit of the heart muscle, are replaced by collagen. Its presence has been associated with various heart diseases, such as myocardial infarction [1], heart failure [2], and dilated cardiomyopathy [3], and it is associated with a worsening in various measures of overall heart function. Measurement of myocardial T1 values following an intravenous injection of a gadolinium based contrast agent can identify regions of fibro-‐sis, as the greater volume of contrast agent in fibrotic tissue results in a shorter T1 than healthy tissue.

Late Gadolinium Enhancement (LGE) imaging is a T1 weighted sequence that is part of the common clinical routine when assessing tissue viability with ischemic heart disease, particularly following myocardial infarction. At 7 minutes fol-‐lowing the injection of gadolinium, an inversion recovery turbo spin echo sequence is used with an experimentally deter-‐mined inversion time selected to null healthy myocardium. This sequence generates image contrast that highlights regions of scarred tissue as bright relative to a dark myocardium, and provides the clinician information about whether a particular region of tissue is scarred (non-‐viable) or may still be salvageable through intervention. However, LGE fails to identify global diffuse fibrosis, where the entire myocardium may have a shortened T1.

Quantitative T1 mapping approaches are sensitive not only to global changes in tissue cellular structure, but the amount of T1 shortening also reflects the degree of fibrosis present, as more heavily fibrosed tissue retains a larger volume of gado-‐linium contrast. The most common imaging sequence for this technique is the MOdified Look-‐Locker Inversion recovery (MOLLI) sequence, which combines multiple images with varied inversion recovery times to determine T1 values. Image acquisitions before and after contrast injection can be combined with the relaxivity equation, R1post = R1pre + R*[Gd], where R1=1/T1, to determine the gadolinium concentration in the tissue. However, post-‐gadolinium T1 measurements are known to vary as a function of time after injection as the contrast is cleared from the body.

Measurements of blood T1 values pre and post-‐contrast (in addition to myocardial T1 values) can be used derive the blood-‐tissue partition coefficient, lambda: {lambda=[R1(myocardium,post) -‐ R1(myocardium,pre)]/[R1(blood,post) -‐ R1(blood,pre)]}. This value is normalized to the gadolinium concentration in the blood and is expected to be a more time-‐insensitive measure of fibrosis.

In this work, the blood and myocardial T1 values are measured prior to gadolinium contrast injection and at one minute intervals afterwards in a population of healthy subjects (n=9). A custom saturation recovery single-‐shot steady state free precession sequence is used to obtain T1 measurements at each time point during a single breath-‐hold. Quantitative T1 imaging is likely to be added to a clinical exam during the 10-‐15 minute post-‐contrast window, where myocardial T1 values were found to increase by 6%, while lambda increased by only 1%. [1] Flacke SJ et al. Radiol 2001; 218: 703-‐710. [2] Iles L et al. J Am Coll Cardiol 2008; 52: 1574-‐80. [3] Jerosch-‐Herold M et al. Am J Physiol Heart Circ Physiol 2008; 295: H1234-‐H1242.


April 2011 -11- *


Karla Ponjavic, MSc – Neuroscience, University of Lethbridge Karla’s interest primarily lies in cognitive disorders and mental health. While pursuing an undergraduate degree in Neuroscience at the University of Leth-‐bridge she worked as a behavioural therapist with children and young adults with autism and associative disorders. After completion of her degree, she worked as a research assistant at the Canadian Centre for Behavioural Neuroscience (CCBN) before beginning graduate school at the University of Lethbridge in September 2010. In her graduate work, Karla studies the electrophysiological correlates of auditory distraction in post-‐secondary adults with and without Attention Deficit Hyperactivity Disorder (ADHD) using dense-‐array electroencephalography (EEG). Karla hopes to continue her educational endeavors by pursuing a PhD in Clinical Neuropsychology.

Electrophysiological Correlates of Auditory Distraction as Manifested in Post-‐Secondary Adults with and without Attention Deficit Hyperactivity Disorder

KD Ponjavic, JR Dowdall, MS Tata The auditory Event-‐Related Potential (ERP) has been used to investigate focused attention. In classic cue-‐target paradigms the N1 amplitude of the ERP waveform is greater when the target is validly cued and smaller when invalidly cued. This suggests that early auditory mechanisms handle task-‐relevant and task-‐irrelevant input dif-‐ferently. We tested the hypothesis that N1 amplitude evoked by task-‐relevant (i.e. attended) stimuli would be modulated by different levels of distraction, despite a constant endogenous attentional instruction to maintain focus on the target. We further hypothesized that susceptibility to distraction would be severe in subjects with Attention Deficit Hyperactivity Disorder (ADHD). Healthy controls and adults with a prior diagnosis of ADHD were recruited for this study. The ADHD group was split into individuals taking stimulant medication (e.g. Rita-‐lin) and those who were un-‐medicated. Participants focused their attention on a stream of long and short noise bursts presented to one ear while simultaneously ignoring a pre-‐recorded story (high distraction) or amplitude matched broadband noise (low distraction) presented to the other ear. Behavioral data showed significantly higher sensitivity to detect targets (d’) under low distraction relative to high distraction conditions across all groups. N1 amplitude was greater when evoked by targets in the low distraction relative to high distraction conditions across all groups. These results suggest that modulations of N1 amplitude indicate the degree of dis-‐traction in healthy controls and in individuals with ADHD. Since the magnitude of a peak in the ERP waveform can be modulated by differences in inter-‐trial amplitude (i.e. sensory gain) or inter-‐trial phase coherence (i.e. jitter in the time-‐locking of brain responses to the events that trigger them), we further characterized the effect of distraction on inter-‐trial amplitude and phase coherence. We also sought to visualize intracranial generators of brain electrical activity under varying conditions of auditory distraction.


April 2011 -12- *


Rebecca Feldman, PhD -‐ Biomedical Engineering, University of Alberta In 2003 Rebecca Feldman graduated from the University of Toronto with a de-‐gree in Engineering Science (Electrical Option) as well as avocado, yellow, light blue, orange, and gold hard hats. In 2005 she obtained a MSc degree from Medi-‐cal Biophysics at the University of Western Ontario. One can only assume that this was unintentional as she turned around and reenrolled in the same depart-‐ment with the same supervisor in an attempt to remedy the mistake. Four years later, she graduated from the University of Western Ontario again, this time with a PhD from Medical Biophysics, and then fled the province. Despite only medio-‐cre skill in the sports of ice skating, yukigassen, and skiing, Rebecca is currently a Post Doctoral fellow in the Department of Biomedical Engineering at the University of Alberta. Her most recent work involves 23NA magnetic resonance imaging development with a focus applications involving cartilage as-‐sessment in the knee. Her most recent procrastination techniques involve writing about herself in the third per-‐son, executing back-‐handsprings, and experimenting with profile pictures. Rebecca typically utilizes the Oxford comma when writing, C++ when coding, and the word ‘utilizes’ whenever I could use ‘uses’.

Fluid Suppressed Sodium Magnetic Resonance Imaging of the Human Knee

R Feldman, C Beaulieu Osteoarthritis is a degenerative disease affecting more than 3 million Canadians; it is the second leading cause of chronic disability in Canada. More than 40% of people over 70 years of age suffer from osteoarthritis and degeneration due to this disease is the most common reason for total hip and knee replacements. The progression of osteoarthritis is typically asso-‐ciated with the loss of articular cartilage, but early indicators also involve changes in the cartilage matrix. Standard imaging modalities, including proton magnetic resonance imaging (1H-‐MRI), have been unable to effectively visualize the initial progression; however, sodium concentration has been show to correlate well with cartilage health. So, sodium magnetic resonance imaging (23Na-‐MRI) could be useful as a non-‐invasive way to evaluate of articular cartilage. If sodium content proves to be a good metric of cartilage health, 23Na-‐MRI could be used track both the progression of the disease and the efficacy of potential drug or preventative therapies.

Sodium imaging can be a technical challenge, at least when compared to more common 1H-‐MRI. In part because of the lower gyromagetic ratio of sodium, signal from a nucleus is less than 35% of the signal from a hydrogen nucleus. Addition-‐ally, although sodium is prevalent in the body, the biological abundance of sodium is still over 1000 times less than that of hydrogen. To make matters even more interesting, sodium relaxes very quickly after excitation, making rapid acquisition of data essential. Finally, the knee physiology itself presents some challenges, as the knee cartilage is in close proximity to fluid. This fluid produces a very bright sodium signal that makes the quantification of cartilage in sodium images difficult.

Since the relaxation rates, specifically the longitudinal relaxation component T1, of tissue and fluid are significantly dif-‐ferent, it should be possible to suppress the fluid signal using an inversion-‐recovery pulse sequence. In order implement that sequence effectively, we need to be fairly certain of the various tissue relaxation rates in the knee. This presentation will discuss the results of our characterization of the T1 in knee tissues and how we used those values to implement a fluid suppression sequence.

As long as we are looking at fluid suppression using inversion recovery, it becomes possible to turn some of the difficul-‐ties in sodium imaging to an advantage. The rapid relaxation rate of sodium means that the application of a ‘soft’ inversion pulse can be used to incompletely invert cartilage with respect to fluid. This technique results in a stronger cartilage signal, as well as permits more rapid repetition times, all of which leads to better image quality (a better image signal to noise ra-‐tio).

Using a soft inversion recovery fluid suppression pulse sequence, and the experimentally determined T1 relaxation times were used to optimize the cartilage signal to noise ratio.


April 2011 -13- *


Shantanu Banik, MSc -‐ Electrical and Computer Engineering, University of Calgary Shantanu Banik is currently a PhD candidate at the University of Calgary, Calgary, Alberta, Canada. He received his MSc degree in 2008 in Electrical and Computer Engineering from the University of Calgary, Calgary, Alberta, Canada and his BSc degree in 2005 in Electrical and Electronic Engineering from the Bangladesh Uni-‐versity of Engineering and Technology (BUET), Dhaka, Bangladesh. He is working on the problem of detection of architectural distortion in prior mammograms to aid the process of early detection of breast cancer. His research interests include medical signal and image processing and analysis, machine learning, developing computer-‐aided diagnosis (CAD) techniques for the detection of breast cancer, landmarking and segmentation of pediatric computed tomographic (CT) images, and automatic segmentation of the primary tumor mass in children with neuroblastoma. He has coauthored several journal papers, conference papers, a few book chapters, and a book (monograph) on Landmarking and Segmentation of 3D CT Images.

Detection of Architectural Distortion in Prior Mammograms of Interval-‐cancer Cases

S Banik Architectural distortion is an important early sign of breast cancer, but because of its subtlety, it is a common cause of false-‐negative findings on screening mammograms. We hypothesize that screening mammograms ob-‐tained prior to the detection of cancer could contain subtle signs of early stages of breast cancer, in particular, architectural distortion. The methods are based upon Gabor filters, phase portrait analysis, a novel method for the analysis of the angular spread of power, fractal analysis, Laws’ texture energy measures derived from geo-‐metrically transformed regions of interest (ROIs), and Haralick’s texture features. With Gabor filters and phase portrait analysis, 4,224 ROIs were automatically obtained from 106 prior mammograms of 56 interval-‐cancer cases, including 301 true-‐positive ROIs related to architectural distortion, and from 52 mammograms of 13 normal cases. For each ROI, the fractal dimension, the entropy of the angular spread of power, 10 Laws’ meas-‐ures, and Haralick’s 14 features were computed. The areas under the receiver operating characteristic (ROC) curves obtained using the features selected by stepwise logistic regression and the leave-‐one-‐image-‐out method are 0.77 with the Bayesian classifier, 0.76 with Fisher linear discriminant analysis, and 0.79 with a single-‐layer feed-‐forward neural network. Free-‐response receiver operating characteristics indicated sensitivities of 0.80 and 0.90 at 5.8 and 8.1 false positives per image, respectively, with the Bayesian classifier and the leave-‐one-‐image-‐out method. The study demonstrated the ability to detect early signs of breast cancer 15 months ahead of the time of clinical diagnosis, on the average, for interval-‐cancer cases, with a sensitivity of 0.8 at 5.8 FP/image. The proposed computer-‐aided detection (CAD) techniques, dedicated to accurate detection and localization of architectural distortion, could lead to efficient detection of early and subtle signs of breast cancer at pre-‐mass-‐formation stages.


April 2011 -14- *


Stefanie Hassel, PhD – Psychiatry, University of Calgary My research interests focus on the combination of neuroimaging methodologies and their application to investigate and characterize the neurophysiological cor-‐relates of emotion perception, emotion regulation and social cognition in mood disorders, specifically bipolar disorder and unipolar depression. We are employ-‐ing functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to investigate the interactions between prefrontal cortical and subcorti-‐cal/temporal regions which have been shown to underlie mood-‐regulation, to gain a better understanding of potentially aberrant neural processes that underlie emotion processing and emotion regulation in mood disorders, because each modality reveals unique aspects of brain activity. In order to fully understand bipolar disorder, marked by extreme mood swings between mania and depression, patients have to be examined across the different phases of their illness. In addition to cross-‐sectional studies we are therefore also interested in following patients in longitudinal studies.

Differential Activation during an Affective Go-‐NoGo Task in Bipolar Disorder.

S Hassel Increased accuracy in diagnosing bipolar disorder (BD) is a long-‐term goal. Identifying biomarkers, which re-‐flect underlying pathophysiologic neural mechanisms in BD, may facilitate achieving this goal. A first aim there-‐fore is to find disease specific markers by examining functional neural abnormalities in BD during neuropsy-‐chological tasks related to its core clinical features, e.g. impaired emotion regulation and social cognition. Using functional magnetic resonance imaging (fMRI), we measured neural activity in response to an Affective

Go-‐NoGo Task, consisting of emotional stimuli (fear, happy, anger faces) and non-‐emotional control stimuli (neutral female and male faces) in euthymic BD and healthy individuals (HI). FMRI data were preprocessed and analysed using Statistical Parametric Mapping (SPM8) software. In whole-‐brain analyses (p(uncorrected)=0.001) we compared patterns of neural activity in BD and HI. Preliminary results comparing emotional Go versus emotional NoGo trials yielded differential patterns of ac-‐

tivation in BD and HC within the right ventro-‐medial prefrontal areas (BA11/10), the left insula and cingulate gyrus (BA24). HI showed increases in activation in the right cingulate gyrus. Comparing all Go (emotional and control) versus all NoGo trials revealed increased activation within the right cingulate gyrus (BA24) and dorso-‐lateral PFC (BA9) in BD to Go trials, but to NoGo trials in HI. Preliminary findings point to cognition-‐emotion interference in BD and observed neural differences indicate

a possibly altered emotion modulation of cognitive processing in BD. Increased activation in brain regions pre-‐viously shown in emotion regulation and response inhibition tasks could represent a disease-‐specific marker for BD.


April 2011 -15- *


Robert Stobbe, PhD -‐ Biomedical Engineering, University of Alberta Rob has a degree in Electrical Engineering from the University of Victoria and a joint PhD in Electrical and Biomedical Engineering from the University of Alberta. He has industrial experience with both Nortel, as a co-‐op student (including 4 months in Calgary), and Vecima Networks in Victoria, as a co-‐op student and then as a full-‐time microwave communication circuit design research engineer. Rob is currently employed as a post-‐doctoral fellow at the University of Alberta with Dr Christian Beaulieu, and his research interests include the design and development of new non-‐Cartesian k-‐space acquisition methodologies. This summer Rob is looking forward to: coaching his oldest son in U6 soccer, chasing his second oldest son as he escapes on his tricycle, and especially the arrival of number three.

Exploring New Ways to Get A-‐round in 3D k-‐Space

R Stobbe, C Beaulieu There are many ways in which one could sample k-‐space to create an MR image, and in this presentation further emergence from simple back-‐and-‐forth Cartesian methodology (i.e. k-‐space acquisition as one may mow their lawn) will be explored. In particular this presentation will describe a logical development of 3D projection imag-‐ing (3DPI – a class of acquisition methodologies in which sampling projects from the centre of k-‐space) leading to two very new, and as yet unpublished, 3DPI k-‐space acquisition proposals. 3DPI has proven to be highly bene-‐ficial for 23Na MRI (the development playground of my PhD), but I will suggest that 3DPI may have value, be-‐yond its facilitation of ultra-‐short TE, in the context of some (potentially unexpected) 1H imaging scenarios as well. The two new 3DPI techniques to be presented are ones in which sampling trajectories wind through 3D k-‐

space such that each trajectory samples a large portion of k-‐space. The development of these techniques was sparked by the hope that the winding of trajectories through 3D k-‐space would lead to sampling less inhibited by the maximum rate of change permissible for gradient fields, a maximum constrained by peripheral nervous system stimulation. In essence, the hope was that more of 3D k-‐space could be sampled with each trajectory than is possible with back-‐and-‐forth Cartesian methodology in the same time allotted for k-‐space acquisition, and thus reduce the time required for MR image formation in certain circumstances. Whether or not I have ‘hoped well’ remains to be fully determined. This presentation will be predominantly theoretical, building from the introduction of 3DPI and prior devel-‐

opment (which has benefited 23Na MRI) to the development of my two new techniques. The first technique was created to fully sample k-‐space to a spherical extent in a single shot as one may wind a ball of yarn, and was christened Yarn-‐Ball. The second technique was created for multi-‐shot 3D k-‐space acquisition and has been christened Wind-‐Spinner. An evaluation of these techniques, using custom-‐built GPU-‐based direct Fourier trans-‐form software which samples the k-‐space values of known 3D image objects at the non-‐Cartesian k-‐space loca-‐tions specified by each trajectory and facilitates comparison of reconstructed images with the original image, will be described. This evaluation allows initial analysis of the sampling techniques themselves without the added influences of off-‐resonant and eddy-‐current (etc.) effects. Preliminary images acquired at 4.7T will also be shown. Yarn-‐Ball will be theoretically compared with echo-‐volume imaging (EVI), which has recently been con-‐sidered for ‘ultra-‐rapid’ fMRI. Wind-‐spinner will be theoretically considered for utility in the context of rapidly-‐acquired magnetization prepared gradient echo (MP-‐RAGE), dynamic contrast enhanced imaging (DCE-‐MRI), as well as the contexts of diffusion tensor imaging (DTI) and fMRI.


April 2011 -16- *


Amber Doiron, PhD -‐ Chemical Engineering and Radiology, University of Calgary Dr Doiron has been a postdoctoral fellow in the departments of chemical engi-‐neering and radiology at the University of Calgary since 2009. She conducts re-‐search in the areas of molecular imaging, nanotechnology, and fluid dynamics. Her current research is directed towards the development of a molecular imaging agent for detection of atherosclerosis as well as investigating the interactions of endothelial cells with nanoparticles. She received her BS degree in chemistry at Colorado State University (2003), and received a MS (2007) and PhD (2008) from the University of Texas at Austin in biomedical engineering. Her honors include the T Chen Fong Postdoctoral Fellowship in Medical Imaging, the National Science Foundation Integrative Graduate Education and Research Traineeship (2004-‐2006), the Thrust 2000 fellowship (2004-‐2008), and the Lucent Technologies Academic Award (1999-‐2003).

The Design of a MR Molecular Imaging Agent for Detection of Atherosclerotic Plaques

AL Doiron Despite recent advances in medicine and imaging, complications arising from atherosclerosis remain the leading causes of morbidity and mortality in the developed Western world. Medical imaging of atherosclerotic plaque is vital in assessing the likelihood of the plaque to cause a stroke or heart attack and determining how detrimental that event may be. Magnetic resonance (MR) imaging is an exciting technology for plaque imaging due to its abil-‐ity to characterize plaque components, lack of ionizing radiation, and repeatability over time. Current clinical techniques for atherosclerosis imaging focus largely on the luminal space of the vessel; how-‐

ever, the vulnerability of the plaque to rupture is better characterized by its biochemical, biomechanical, and cellular composition. We have used nanotechnology to create a molecularly-‐specific MR contrast agent to target atherosclerotic plaques based on cellular composition in order to augment medical imaging and identification of plaques at risk for rupture. The molecular imaging agent consists of a gadolinium-‐linked polymeric nanoparticle that incorporates tar-‐

geting to activated macrophages via a folic acid moiety. Activated macrophages over express folate receptors and are integral to inflammatory diseases such as atherosclerosis. To initially study this agent in vitro, a fluoro-‐phore was also attached to the particle to enable visualization with fluorescent microscopy. Successful particle creation was confirmed chemically with FTIR and NMR, as well as morphologically with transmission electron microscopy. The agent has been further characterized in terms of cytotoxicity to human endothelial cells, zeta potential, gadolinium content and release over time, and relaxivity (MR contrast enhancement). The efficiency of targeting of the conjugate in vitro was studied using a human cell line expressing the folate receptor compared to a cell line without folate receptor. The agent is currently being studied in an in vitro flow chamber model as well as a mouse model of athero-‐

sclerosis. In order to study cellular attachment and distribution of the particles in the flow chamber, particles are introduced into circulating media that flows over a monolayer of cells, mimicking the physiological vascular environment. As demonstrated previously by our laboratory with commercially available contrast agents, this flow chamber model can be used to determine the localization and retention of contrast agent as imaged with MR, and the cells can also be imaged using microscopy to localize particles on a cellular level.


April 2011 -17- *


Francois Moreau, MD -‐ Clinical Neurosciences, University of Calgary Francois Moreau is a neurology professor at Université de Sherbrooke, Quebec doing a 2-‐year felllowship in Stroke in Calgary. His main research focus is in transient ischemic attack (TIA) but he also entertains interests in Near-‐Infrared Spectroscopy and vascular ultrasound

Absolute Oxygenation Measurements in Stroke using Near-‐infrared Spectroscopy: Preliminary Findings

F Moreau, A Demchuk, JF Dunn Background: Brain oxygen levels are an important unmeasured parameter in stroke. Frequency domain Near-‐Infrared Spectroscopy (NIRS) is a relatively new spectroscopy technique with the potential to measure absolute oxygenated hemoglobin levels in the microvasculature of brain. Absolute levels are required in order to com-‐pare oxygenation between patients and healthy subjects, for both diagnosis and monitoring purposes. Methods: Oxiplex TS (ISS) was used to quantify oxygenated hemoglobin, deoxygenated hemoglobin and related calculated parameters on various sites over the scalp in 5 healthy volunteers, 5 cadavers, 3 large middle cere-‐bral artery (MCA) subacute stroke patients and one large MCA subacute stroke patient with hemicraniectomy. Results: There were no side to side difference and normal values for all parameter in both healthy volunteers and large MCA stroke patients. Cadavers had near 0 levels of oxygenated hemoglobin, which is significantly dif-‐erent. In the hemicraniectomy patient, Total hemoglobin and oxygen saturation levels were much higher on the side of the stroke without bone covering. This patient had hemorrhagic transformation within the infarcted area. Conclusion: These preliminary results show that it is possible to measure oxygen levels in healthy volunteers and patients. More patient data is required before making conclusions about the oxygen levels to expect at the various stages of stroke.


April 2011 -18- *


Mirza Faisal Beg, PhD -‐ School of Engineering Science, Simon Fraser University Faisal Beg got his PhD from the Johns Hopkins School of Medicine in 2003. He is currently an Associate Professor at the Simon Fraser University, School of Engi-‐neering Science. His interests are in computational anatomy, registration, segmen-‐tation and multimodal image analysis.

Computational Anatomy – Tools for Mapping Brain Structure and Applications to Differential Discrimination in Dementia

MF Beg Quantification of neuroanatomical structure is an extremely challenging problem in the general setting. The human brain consists of functionally specific neuroanatomical regions at the level of cortical and subcortical re-‐gions and the white matter pathways. However, there is considerable variation observed in MRI-‐visible neuro-‐anatomy across individuals. Thus, the computerized identification of neuroanatomical changes from MR images that occur due to disease and distinguishing those from those that occur due to normal variation in the popula-‐tion is a difficult problem that is the goal of Computational Anatomy (CA). I will discuss a few tools from the Computational Anatomy toolbox for tasks such as measuring cortical thick-‐

ness, and performing whole brain registration and segmentation. I will then show a few results of applying these tools towards the problem of discrimination between structural changes in the brain in dementias such as Alz-‐heimer’s and frontotemporal dementias.


April 2011 -19- *


Yue Wang, MD -‐ Faculty of Rehabilitation Medicine, University of Al-‐berta I am an orthopedic surgeon from China. Finished resident training in 2001, I prac-‐ticed orthopedic surgery in Hangzhou (a city in eastern China) for over 6 years. I won the China-‐Canada Norman Bethune Health research scholarship (a collabo-‐rating program supported by the China Scholarship Council and CIHR) and come to Canada studied as a PhD student since 2008. Under the supervision of Profes-‐sor Michele Crites Battié at the University of Alberta, currently I am in the forth year of my PhD program. With great enthusiasm in spine surgery and spine re-‐search, my main research interests are: 1) the vertebral endplate: morphomet-‐rics, lesions, and the role it may play in back pain and disc degeneration; 2) Modic changes: etiology, epidemiological characteristics, and associations with disc degeneration and back pain.

Quantitative Measures of Modic Changes on Lumbar Spine MRI: Intra-‐ and Inter-‐rater Reliability

Y Wang Objective: To develop quantitative measures for Modic changes (MCs) on magnetic resonance (MR) images and evaluate measurement reliability. Summary of Background Data: MCs have been studied for over 20 years but the clinical significance remains controversial. Little effort has been made to improve the measurement of MCs. Materials and Methods: The study was approved by the responsible institutional review board. Based on Modic classification, a series of quantitative dimension and signal intensity measures were developed for assessing MCs. Mid-‐sagittal T1 and T2-‐weighted MR images from 83 lumbar spines were then qualitatively and quantita-‐tively assessed by two observers independently. Kappa and intra-‐class correlation coefficient (ICC) were used to examine intra-‐ and inter-‐rater reliability. Pearson correlation coefficient was used to assess the relationships between the quantitative measurements of MCs. Mean absolute deviation (MAD) and Bland-‐Altman Plots also were used to evaluate measurement errors and limits of agreement for selected measures. Results: For Modic classification, intra-‐rater agreement was excellent (κ=0.88) and inter-‐rater agreement was substantial (κ=0.79). Intra-‐rater agreement also was excellent when obtaining dimension measurements (ICC=0.82 to 0.96) from T1 or T2-‐weighted images and inter-‐rater agreement was slightly greater using T1-‐weighted images (ICC=0.73 to 0.88) than T2-‐weighted images (ICC=0.66 to 0.82). Signal intensity measurements on T2-‐weighted images were found to have almost perfect intra-‐ and inter-‐rater reliability (ICC=0.92 to 0.99). The correlation analysis demonstrated that the quantitative measures represent different constructs. The MAD and Bland-‐Altman Plots further confirmed the high reliability of the area ratio, MCs mean signal intensity and MCs total signal intensity measurements. Conclusions: Three quantitative measures are suggested to assess the severity of MCs, which provide reliable, precise measurements for research on the etiology, pathogenesis and clinical relevance of MCs.


April 2011 -20- *


Jodi Harker, MBBS -‐ Stephenson CMR Centre, Libin Cardiovascular Institute I am a cardiologist from Brisbane, Australia. I have previously undertaken a fellowship in multi-‐modality cardiac imaging at the Prince Charles Hospital in Brisbane. I am currently a Post-‐Doctoral Research Fellow at the Ste-‐phenson CMR Centre. My current research interest is BOLD CMR in ischaemic heart disease.

Assessment of Significant Coronary Artery Stenosis using Blood Oxygen Level Dependent Cardiovascular Magnetic Resonance (BOLD-‐CMR).

J Harker, J Luu, DP Guensch, J Hare, MG Friedrich Background: Changes in myocardial tissue oxygenation can be detected with blood oxygen level–dependent (BOLD) cardiovascular MRI (CMR) using the magnetic properties of haemoglobin. The objective of this study was to validate whether BOLD-‐sensitive CMR images can detect an abnormal myocardial tissue response to adenosine infusion in patients with CAD, when compared to fractional flow reserve (FFR). Methods: Patients undergoing clinically indicated coronary angiography underwent BOLD CMR scans using a clinical 1.5T scanner. Three short axis BOLD cine images were captured during baseline and during adenosine-‐induced coronary hyperaemia. The mean segmental percent signal intensity (SI) changes were calculated be-‐tween baseline and hyperaemia in the subendocardial myocardium at basal, mid, and apical regions using the 16-‐segment model. Segments were defined as ischaemic (using a cut-‐off of <0.80) or non-‐ischaemic by FFR. Results: 30 patients were enrolled in the study, 5 patients were excluded (3 as they were unable to tolerate CMR, 1 patient due to being unable to breath hold during adenosine and 1 patient due to significant artifact from an abdominal surgical clip) leaving 25 patients (average age 61 ± 10 years) for analysis. There were 800 myo-‐cardial segments (baseline and with adenosine) available for analysis, 278 of these segments were subtended by a coronary artery with an available FFR value. Seventy-‐seven segments (28%) were excluded due to pre-‐defined criteria for poor image quality, 53 (69%) of these segments were during adenosine and 48 (62%) were apical segments. From the remaining seventy-‐five paired segments (75 segments at baseline and 75 segments during adenosine), 38 had FFR values <0.80, 37 had FFRs of ≥ 0.80. Mean SI change was significantly less in segments with abnormal FFR values (0.23% ± 9.40%), in comparison to patients with normal FFR values (8.58% ± 9.58%; p=0.0002). Conclusion: A blunted hyperemic response to adenosine detected with BOLD-‐sensitive CMR using a 1.5T scan-‐ner can identify functionally significant coronary artery stenosis. However, image quality remains a limitation of the approach. Most excluded segments were from early studies, suggesting improved acquisition quality with experience.


April 2011 -21- *


Dongming Zhou, PhD -‐ Biomedical Engineering, University of Alberta Dr Dongming Zhou is currently a Post Doctoral Fellow in the Department of Bio-‐medical Engineering, University of Alberta, Canada. His research focuses on corti-‐cal thickness analysis of MRI images in developmental and clinical profile. After received his double Bachelor Degrees of Electrical Engineering and Chinese Lan-‐guage and Literature in Tsinghua University, China, he pursued and received his PhD Degree of Biophysics in the Key Laboratory of Cognitive Science and Beijing MRI Centre, Institute of Biophysics, Chinese Academy of Sciences, China, studying the acoustic physical parameters on the sensory gating effects of Electroencepha-‐lography (EEG) in animals. He was also one of the major developers and owners of the patent: 'Dynamic Analy-‐sis with Pupilometer for Detecting Drug Abusers', which is now widely used by Chinese police in anti drug-‐abuse practices. Presently, Dr Zhou is working on understanding the brain morphology in human using novel neuroimaging methods.

Regional Cortical Thickness and Asymmetry Differences from Children to Older Adults

D Zhou The cerebral cortex is a highly convoluted structure with an extended surface area of on average 2.5 square feet, and a normal thickness of about 3 mm. Recently, technological advantages enable the quantification of cortical thickness in vivo by estimating as the distance between pial-‐cortical surface and gray-‐white interface, using 3D isotropic T1-‐weighted images with the Laplace's Equation. In a typically developed brain, the thickness varies across the cortical mantle, as well as the left-‐ and right-‐ paired regions between hemispheres. The measurement of cortical thickness also allows to relate cognitive abilities, effects of developmental, aging, gender and hemi-‐sphere to subtle structural changes in the gray matter of human brain. In the current research, we investigated the age and gender effects on cortical thickness and its asymmetry between hemispheres in 272 healthy partici-‐pants (139 females, 260 right-‐handed, 5 -‐ 67 years) with high resolution T1-‐weighted images acquired at 1.5T MRI scanner and processed with the CIVET 1.1.9 pipeline at the Montreal Neurological Institute (MNI). Al-‐most the whole cortical mantle was found thinning with age, while the inferior temporal and temporal pole ar-‐eas were thickened with age. Males’ cortex was found thinner than females’. Brain asymmetry was found in a particular way that in the frontal part of the brain, the lateral side was rightward (left < right), while the medial side was leftward, and in the posterior part of the brain, the lateral side was leftward, while the medial side was rightward. Cortical asymmetry patterns varied with age, but lacked of gender differences.


April 2011 -22- *


Alison King, PhD – Radiology, University of Calgary I have always been interested in how non-‐invasive imaging can help us under-‐stand movement and physiology inside living organisms. In January 2010, I started working on MRI and musculoskeletal research. For this project, I have been developing an open-‐bore, low-‐field magnet to investigate soft tissue move-‐ment during knee flexion. I am interested in the spectrum of physiology, from how behaviour affects it, to how molecules underpin it, and am looking forward to developing a standing 0.2T magnet to investigate moving, loaded joints, and to using a 3T magnet to look at molecular changes in musculoskeletal disease. During my PhD, I received NSERC and the Department of Fisheries and Oceans graduate scholarships to develop imaging ultrasound for monitor-‐ing invertebrate cardiovascular contractions. My findings on how these contractions change with behavioural state were published in first-‐tier international journals such as the Journal of Experimental Biology and Animal Behaviour. When I am not developing ways to use non-‐invasive imaging, I enjoy furthering my understanding of movement by skiing, dancing and backcountry backpacking.

Quite a Stretch: Deep Knee Bends Studied with Low-‐field MRI

AJ King, C Deng, R Tyson, J Sharp, JF Dunn In the study of joint function, MRI offers advantages over other imaging modalities because it can image soft tissues as well as bones. Low-‐field MRI offers particular advantages because scanners can be built with an open bore that accommodates all knee flexion angles. The normal range of daily knee motion is thought to be approximately 10-‐120° of flexion, but high-‐field scanners typically only accommodate 0-‐30°. By understanding soft tissue function during knee flexion in healthy in vivo knees, it is thought that we will better understand the etiology of knee pathology and improve surgical knee reconstructions and prostheses. As proof of concept for using open-‐bore MRI to monitor com-‐plex 3D soft tissue changes from extended (“straight”) to flexed (“bent”) knees, we undertook a study of the posterior cruciate ligament (PCL) during flexion. This ligament is critical in maintaining knee stability. While most of the poste-‐rior side of the PCL is visible in a dissected knee, the anterior side is blocked by the tibial crest when the knee is ex-‐tended, and by the patella when the knee is flexed. Therefore, the length of anterior side is difficult to measure in vivo without using MRI.

Using a 0.2 T, open-‐bore scanner, knees of 7 healthy volunteers were imaged in vivo while passively extended and while passively flexed to 120°. We used a 3D SSFP pulse sequence because, of the pulse sequences tested, it produced better contrast-‐to-‐noise-‐ratio per unit time for the ligaments. Images could be obtained in <6 min. The posterior cru-‐ciate ligament (PCL) was segmented from the MR images and reconstructed in 3D using Amira software (Visage Im-‐aging). We measured the longest path between the PCL’s femoral attachment and its tibial attachment on the PCL’s anterior side and posterior side. The anterior aspect increased 26.1±4.4% (mean ± standard deviation) in length after flexion (p<0.001, paired t-‐test, t=27.023, n=7, tcrit =2.447). The posterior side, however, did not change length (3.8±7.0%, p=n.s., paired t-‐test, t=1.467, n=7, tcrit =2.447). This is the first step in visualizing and quantifying soft tis-‐sues such as ligaments, tendons and the menisci during joint flexion.

While many soft tissues of the knee remain in similar orientations to their underlying bones during knee flexion, ligaments do not. We have demonstrated that 3D image reconstruction allows the study of knee soft tissue such as ligaments. Our initial findings suggest that there are important differences between the mechanical environment of the anterior and posterior side of the PCL, between the biomechanical properties of the anterior and posterior side of the PCL itself, or both. Using MRI, other groups have demonstrated that menisci (washer-‐like, stabilizing structures within the joint that are attached to the tibia) loose structural integrity with the onset of osteoarthritis, a disease his-‐torically thought to only be of the cartilage. Future investigations in our lab will include how the dynamics of the PCL are altered in diseased states (e.g. osteoarthritis) and after PCL reconstruction surgery.


April 2011 -23- *


Lisa Marie Langevin, PhD -‐ Behavioural Research Unit, Alberta Chil-‐dren’s Hospital Dr Lisa Marie Langevin is currently a postdoctoral research fellow in the Behav-‐ioural Research Unit at the Alberta Children’s Hospital. Dr Langevin received her undergraduate degrees in Psychology and Cellular, Molecular, Microbial Biology from the University of Calgary in 2003, and went on to complete her doctoral training in Neuroscience the lab of Dr Carol Schuurmans examining mammalian neocortical development. Deciding to apply her expertise in brain development genetics to an applied field, Dr Langevin has recently begun her postdoctoral training with Dr Deborah Dewey at the Alberta Children’s Hospital. Her current research investigates the neu-‐rophysiology and genetics related to co-‐occurring attention, motor and learning disorders in children.

Examining the Common Neurobiological Basis of Motor and Attention Deficits in Neurodevelopmental Disorders

LM Langevin, B Goodyear, C Beaulieu, S Crawford, D Dewey During early childhood, the development of motor functioning is essential for participation in play, sports and social inter-‐action. Developmental coordination disorder (DCD) impairs the acquisition of novel motor skills, and is frequently coinci-‐dent with other neurodevelopmental disorders such as Attention Deficit Hyperactivity Disorder (ADHD). Motor impair-‐ments and deficits in attentional functioning are also manifested in autism spectrum disorders (ASD). In recent investiga-‐tions of ASD and ADHD, attentional and motor symptoms have been attributed to genetic and/or environmental impacts on developmental brain anatomy. In contrast to the numerous imaging studies examining ADHD and ASD, structural imaging research on children diagnosed with DCD and comorbid conditions are extremely limited.

Response inhibition and contextual fine motor performance skills are frequently deficient in individuals with ASD, ADHD and DCD. The underlying mechanism for these impairments may involve alteration of normal white matter circuitry, leading to reduced activation of neural networks. Previous studies have shown reduced integrity and lateralization of spe-‐cific white matter tracts in individuals with ADHD and ASD. Additionally, poorer performance on attention and motor tasks has been associated with reduced activation of anterior brain regions in individuals with ASD, ADHD and DCD. Whether similar white matter abnormalities underlie both the motor and attention deficits in DCD and ADHD has not been exam-‐ined.

This study investigates the involvement of white matter circuitry in motor and attention deficits in participants with iso-‐lated or co-‐occurring DCD, ADHD and other neurodevelopmental disorders (e.g., ASD, reading disability). Using fMRI and diffusion tensor imaging (DTI) of brain structures in children (ages 8-‐17) we examined white matter associated with neu-‐rodevelopmental disorders. On the basis of a detailed neuropsychological assessment, the participants were grouped into diagnostic categories. While undergoing an MRI scan, participants completed two button-‐pressing tasks of varying com-‐plexity followed by an inhibition task. Measures of response time, accuracy, and inhibition errors were collected and com-‐pared to age-‐matched controls. DTI data was assessed in specific white matter tracts using a region of interest (ROI) tracto-‐graphy approach. We focused on tracts that comprise cortical and subcortical circuits responsible for executive functioning (frontal-‐striatal circuit), attention (prefrontal and hippocampal formations), visuospatial processing (commissural and lon-‐gitudinal fibres) and motor planning (fronto-‐striatal-‐cerebellar circuitry).

The aim of this study is to identify structural commonalities among DCD, ADHD, and other neurodevelopmental condi-‐tions. In future, this data will be used to conduct neuroimaging genetics studies that will enable identification of shared mechanisms that result in neurodevelopmental deficits. Understanding the genetic basis of structural variations in specific brain areas and the related clinical outcomes will have profound consequences with respect to earlier identification, and clinical, behavioural and academic intervention for families affected by DCD, ADHD and ASD.


April 2011 -24- *


Stefano Peca, MSc -‐ Seaman Family MR Centre, University of Calgary Stefano earned his MSc in Physics in 2004 and his Specialization in Medical Phys-‐ics in 2009, both at “La Sapienza” University in Rome, investigating epilepsy through functional MR spectroscopy. Later that year, he moved to Calgary to con-‐tinue his training in fMRI. Stefano is now in his second year investigating Cerebral Amyloid Angiopathy (CAA), supervised by Dr Brad Goodyear and Dr Eric Smith. The purpose of this study is to help identify the mechanisms by which CAA causes cognitive impairment and its biomarkers.

The Hemodynamic Response in fMRI: Applications in Cerebral Amyloid Angiopathy.

S Peca, B Goodyear, C McCreary, E Smith As a neuronal population increases its firing rate, a signaling occurs which ultimately leads to a local increase in blood flow, characterized by the so-‐called hemodynamic response function (HRF). In functional MRI, knowledge of the HRF’s shape may be crucial in setting up an adequate data-‐fitting model. Interestingly, the HRF has been shown to vary across brain regions and across subjects. In addition, alterations of the hemodynamic response may be indicative of some pathologies of the vascular system, particularly cerebral small vessel disease. In this brief talk, we will first review the basics of the hemodynamic response and its relevance to fMRI. A simple method to estimate the HRF from the fMRI data using a basis set of functions will then be introduced (from Woolrich & Smith 2004; available in FSL). Finally, results on an fMRI study involving cerebral amyloid angiopa-‐thy (CAA) patients will be presented, showing how differences in the HRF may be interpreted, and how these differences may affect fMRI results.


April 2011 -25- *

Invited Speakers and Registered Attendees Registrants as of Monday 18 April 2011

Name City Institution Email

Andersen, Linda Calgary University of Calgary [email protected]

Alto, Hilary Calgary Innervision Med Tech [email protected]

Arnold, Aiden Calgary University of Calgary [email protected]

Banik, Shantanu Calgary University of Calgary [email protected]

Baron, Corey Edmonton University of Alberta [email protected]

Bealieu, Christian Edmonton University of Alberta [email protected]

Becker, Nathan Calgary University of Calgary [email protected]

Beers, Craig Calgary University of Calgary [email protected]

Beg, Faisal Burnaby, BC Simon Fraser University [email protected]

Beladi, Somaieh Calgary University of Calgary [email protected]

Buries, Ford Calgary University of Calgary [email protected]

Changizi, Neda Calgary University of Calgary [email protected]

Chen-Baron, June Edmonton University of Alberta [email protected]

Cheng, Hing Calgary University of Calgary [email protected]

Chow, Kelvin Edmonton University of Alberta [email protected]

Crites Battie, Michele Edmonton University of Alberta [email protected]

Davies, Tim Calgary Innervision Med Tech [email protected]

Dewey, Deborah Calgary Alberta Children’s Hospital [email protected]

Doiron, Amber Calgary University of Calgary [email protected]

Dunn, Jeff Calgary University of Calgary [email protected]

Ethan, Macdonald Calgary University of Calgary [email protected]

Feldman, Rebecca Edmonton University of Alberta [email protected]

Flewit, Jacqueline Calgary Foothills Medical Centre [email protected]

Fortin, Maryse Edmonton University of Alberta [email protected]

Francois, Moreau Calgary Foothills Medical Centre [email protected]

Frayne, Richard Calgary University of Calgary [email protected]

Gauderon, Philippe Calgary University of Calgary [email protected]

Gaxiola, Ismael Calgary University of Calgary [email protected]

Gazzi-Macedo, Luciana Edmonton University of Alberta [email protected]

Goodyear, Brad Calgary University of Calgary [email protected]

Goghari, Vina Calgary University of Calgary [email protected]

Harker, Jodi Calgary Foothills Medical Centre [email protected]


April 2011 -26- *

Name City Institution Email

Hassel, Stefanie Calgary University of Calgary [email protected]

Iaria, Giuseppe Calgary University of Calgary [email protected]

King, Alison Calgary University of Calgary [email protected]

Kosior, Jayme Calgary Cybertrial Med Software [email protected]

Kosior, Rob Calgary University of Calgary [email protected]

Lama, Sanju Calgary University of Calgary [email protected]

Langevin, Lisa-Marie Calgary Alberta Children’s Hospital [email protected]

Liu, Irene Calgary University of Calgary [email protected]

Liu, Min Edmonton University of Alberta [email protected]

McLeod, Kevin Calgary University of Calgary [email protected]

McCreary, Cheryl Calgary University of Calgary [email protected]

Misik, Warren Calgary University of Calgary [email protected]

Modi, Jayesh Calgary University of Calgary [email protected]

Moreau, Francois Calgary University of Calgary [email protected]

O’Brien, Brian Calgary University of Calgary [email protected]

Peca, Stefano Calgary University of Calgary [email protected]

Patton, David Calgary University of Calgary [email protected]

Ponjavic, Karla Lethbridge University of Lethbridge [email protected]

Quirk, Sarah Calgary Foothills Medical Centre [email protected]

Rangayyan, Raj Calgary University of Calgary [email protected]

Slone, Ted Calgary University of Calgary [email protected]

Smith, Mike Calgary University of Calgary [email protected]

Stobbe, Robert Edmonton University of Alberta [email protected]

Thompson, Richard Edmonton University of Alberta [email protected]

Tsang, Adrian Edmonton University of Alberta [email protected]

Tuor, Ursula Calgary University of Calgary [email protected]

Wang, Yue Edmonton University of Alberta [email protected]

Zelinski, Erin Lethbridge University of Lethbridge [email protected]

Zhang, Yunyang Calgary University of Calgary [email protected]

Zhou, Dongming Edmonton University of Alberta [email protected]

Zhu, Hong-mei Toronto, ON York University [email protected]

Zvaigzne, Cheryl Calgary University of Calgary [email protected]


April 2011 -27- *

Additional Imaging Meeting of Interest

alberta imaging symposium 2011

Documents