Melanie Morrison, Medical Biophysics
Student’s Full Name: Melanie A. Morrison, Ph.D. Postdoctoral Scholar
Department of Radiology & Biomedical Imaging, University of California San Francisco
Supervisor’s Full Name and Title: Simon J. Graham, Ph.D., P Eng. Senior Scientist
Department of Medical Biophysics, University of Toronto
Physical Sciences Department, Sunnybrook Research Institute
PhD thesis (Title and Brief Overview):
Pre-Operative Functional MRI: Application to Tumor Resection by Awake Craniotomy
In the surgical management of brain tumors in eloquent areas, the surgeon has the competing goals of attempting to maximize tumor resection while simultaneously sparing healthy cortex. Pre-operative and intra-operative brain mapping techniques are capable of localizing eloquent cortex, and are thus employed to facilitate the surgical decisions. Although direct cortical stimulation (DCS) remains the gold standard intra-operative brain mapping technique, non-invasive imaging tools like functional magnetic resonance imaging (fMRI) have become increasingly popular at the pre-operative planning stage. In this thesis project technical work was done to improve, characterize, and provide perspective on appropriate usage of pre-operative fMRI in brain tumor surgery. A standardized intra-operative behavioral testing platform was developed, demonstrating improved language mapping capabilities over current practice. The impact of disease and technical factors on the reproducibility of fMRI activation maps was shown; fMRI reliability was comparable in low-grade glioma patients and healthy controls, but poorer in high-grade patients. Last sources of variation influencing concordance between fMRI and DCS were explored, demonstrating a substantial extent of false positive activations in fMRI results compared to DCS, as well as improved concordance when behavioral tasks are standardized across fMRI and DCS. Though concordance is generally good, it is directly related to the quality of fMRI activation maps. Collectively this work supports that pre-operative fMRI is a suitable adjunct to DCS for surgical decision- making. Recommendations for neurosurgeons interpreting the reliability of fMRI activation maps is provided in the corresponding publications.
Morrison, M. A., Tam, F., Garavaglia, M. M., Hare, G. M. T., Cusimano, M. D., Schweizer, T. A., Graham, S. J. 2016. Sources of Variation Influencing Concordance between Functional MRI and Direct Cortical Stimulation in Brain Tumor Surgery.
Morrison, M. A., Churchill, N. W., & Cusimano, M. D. 2016. Reliability of Task-Based fMRI for Preoperative Planning: A Test-Retest Study in Brain Tumor Patients and Healthy Controls. PLoS ONE. 11(2): e0149547
Morrison, M. A., Tam, F., Garavaglia, M. M., Golestanirad, L., Hare, G. M. T., Cusimano, M. D., Graham, S. J. 2015. A novel tablet computer platform for advanced language mapping during awake craniotomy procedures. 124(4):938-944.
Saving Cyla: http://www.theglobeandmail.com/life/health-and-fitness/health/video-saving-cyla-inside-the-operating-room-as-a-young-ontario-woman-undergoes-brain-surgery-while-awake/article20895176/
A few paragraphs about the student’s PhD research, scholarship and/or awards, publications; current position; future education plans and/or career goals.
I can recall as early as 10th grade, my profound interests in science and desire to become a cancer researcher. Much of my undergraduate career was spent exploring the various branches of science only to discover mid-way that: a) I was a terrible biologist and b) there was more to physics than endless equations and quantum theory. I discovered the field of medical physics, one where physics concepts and methods could be applied to medicine. I was sold.
Before joining the Department of Medical Biophysics (MBP) at UofT as a graduate student, I first found the department after browsing online and applied to their summer research program. The summer of my 3rd undergraduate year was spent investigating the late-effects of radiation therapy in oral cancer patients at Princess Margaret Hospital. I had no experience and mediocre grades, but good work ethics and a whole lot of passion. I earned my first publication that summer and found myself a year later at Sunnybrook Hospital accepting an offer to join Dr. Simon Graham’s lab for graduate studies. Within three years, I had earned myself multiple first-author publications and my greatest accomplishment to date, a doctorate degree.
My doctorate research was primarily focused on the application of functional magnetic resonance imaging (MRI) to awake brain tumor surgery. Functional MRI is a non-invasive imaging technique that, in the absence of radiation, is capable of measuring brain function. In medicine, this tool holds great promise for improving brain tumor surgery. More specifically, it can aid neurosurgeons in neurosurgical planning when faced with the competing goals of trying to maximize tumor resection and preserve healthy brain tissue. In order to validate the clinical usage of fMRI, I spent a lot of my time either at the MRI scanner or in the operating room working closely with neurosurgeon, Dr. Sunit Das, his patients, and his surgical team. I thoroughly enjoyed every moment of this work. My time with MBP has brought me and continues to deliver incredible amounts of opportunity, reward, happiness, and purpose. I am both humbled and grateful to have been repeatedly awarded in recognition of my academic achievements and involvement in graduate student life. Having recently returned to Canada to accept the 2016 Walker-Marshall award was truly a great honor.
Today, I am postdoctoral researcher in the Radiology department at UCSF (University of California San Francisco). It is nothing far from a dream to be working here at one of the nations leading institutions in clinical brain tumor research. With access to cutting edge technology, namely an ultra high-field MRI scanner, I am utilizing imaging techniques to investigate the long-term effect of radiation therapy on the brain. Over the next years, I will be refining my research interests and begin to take on more responsibilities as I transition into an independent academic scientist position. I am excited to continue learning and growing, and see where the future takes me.