David B Hackney, professor of Radiology, Harvard Medical School, Department of Radiology Beth Israel Deaconess Medical Center, Boston, USA, and president of the American Society of Neuroradiology, tells NeuroNews that neuroradiology will have a critical future in diagnosing patients with cognitive decline and evaluating their response to therapy. He also shares his interest in economics and finance in the academic literature and the opera…
How did you come to choose medicine? What drew you to neuroradiology?
I cannot remember when I did not think I would be a doctor. It was always part of my persona since I was a small child. I loved science; I liked the idea of having a direct impact, as opposed to only doing research, so medicine seemed the natural choice. I considered being a scientist, but ultimately I viewed the ability to be effective as less certain in science. Many people who take faculty jobs in the life sciences do not achieve the early career funding or research success required to get tenure. They end up not having the academic careers they have envisioned. Physicians in the same position can justify their existence by practicing clinical medicine. I thought that getting an MD was a far less risky career choice. Once I was in medicine, radiology and then neuroradiology appealed to me because of the constant innovation, and the direct influence on patient care. Neuroradiology in particular combined increasingly high tech methods with understanding the anatomy and biology of the central nervous system.
Which innovations in interventional neuroradiology have had significant impact on patient care?
The ability to treat aneurysms has changed the demands on diagnostic neuroradiologists, as have advances in treating arteriovenous malformations. Carotid stenting, if it survives current doubts about its efficacy relative to endarterectomy, also has made accurate diagnosis and monitoring more important.
Who were your mentors in the field and what do you still remember from their wisdom?
I have been fortunate to have a number of wonderful mentors over the years.
My first mentor was not a neuroradiologist. Boris Magasanik was my undergraduate advisor in biochemistry when I was a student at Harvard and he was the head of the Biology Department at MIT. He studied microbial physiology and regulation of gene expression. I suppose the most important thing I remember learning from him was his emphasis on the importance of studying data, rather than accepting the interpretations provided to me. He frequently would have me read older papers, the primary sources for what was at the time taught in textbooks. These were well done studies whose data were completely reliable, but for which the interpretation of the results had changed dramatically over the years.
My first mentor in neuroradiology was Charles Kerber at the University of California, San Diego. He is an interventional neuroradiologist and he taught me the importance of meticulous technique in performing procedures. During my fellowship, Kenneth Davis at Massachusetts General Hospital was my most important influence. When I started on the faculty at the University of Pennsylvania, as a newly-minted assistant professor, I worked with four senior faculty members: Drs Robert Zimmerman, Larissa Bilaniuk, Herbert Goldberg, and most important for me, Robert Grossman. I learned a great deal of practical neuroradiology from all of them, but Bob Grossman probably had the greatest impact on my career. I have benefited from my relationship with other neuroradiologists, most notably Robert Quencer, at the University of Miami, and scientist collaborators Robert Lenkinski, now at the University of Texas, Southwestern, and Felix Wehrli, at the University of Pennsylvania.
Which innovations in neuroradiology have shaped your career?
The constant advances in magnetic resonance have had the most impact on my career. Diffusion imaging and derivatives such as q-space imaging were particularly important.
Can you describe a memorable case?
For the things that interest me, the most memorable insights have not been from individual cases. Perhaps the most important was the realisation that we could use various MR methods to infer structure at a spatial scale far finer than the nominal resolution of the images. Thus, even with relatively large pixel sizes, one can interpret the studies in terms of changes in tissue architecture on the order of microns, or less. This decoupling of voxel size from spatial resolution meant that we could directly relate MR results to microscopic histopathology. Since there are many known implications of the pathologic changes at this scale, MR opened the door to in vivo imaging of these effects.
What are three key questions in neuroradiology that you would like to see answered?
I will share four. This is not related to my work, but I think neuroradiology will have a critical future role in diagnosing patients with cognitive decline and evaluating their response to therapy. One might include in this goal not only the dementias, but also common and severe psychiatric disorders such as depression and schizophrenia. This work is in its infancy, but perhaps I might simply express this as a wish—I hope to see neuroradiology contribute to a far better understanding of normal and abnormal cognition.
I hope neuroradiology can characterise changes in the glia and extracellular matrix of the central nervous system. One might think of the first goal, understanding cognition, as studying neurons and their interactions. Since the glia and matrix are also fundamental to neurological function, we should be able to provide a fairly comprehensive, spatially localised, description of the status of these components of the central nervous system.
The third goal I would ask is improved ability to predict stroke risk based on the status of the central nervous system vessels, including atheromatous disease, risk of plaque rupture, collateral supply, and the resilience of the brain itself. This could include guiding revascularisation therapy in the setting of acute stroke, but hopefully it would also help reduce the incidence of stroke and prevent many strokes before they occur.
Lastly, I hope neuroradiology can help with emerging studies of central nervous system tissue regeneration and axon guidance.
You have served as a consultant at the federal Food and Drug Administration, Radiological Devices Panel and the Medical Devices Advisory Committee. In your view, are new medical devices adequately regulated?
I am a former member, and current consultant for the Medical Devices Panel, and I do not speak for the FDA. The panel reviews large numbers of new devices. From my time on the panel, the devices that come before it undergo very careful review.
The FDA looks at efficacy for the proposed use, safety, and a large number of manufacturing details. As with drugs, devices are approved for a particular application. Once they receive approval, physicians can use them for other purposes. Often concerns about such devices revolve around off-label use.
How have developments in imaging influenced your research?
My work on MR imaging of spinal cord injury has followed innovations in diffusion imaging, q-space imaging, and ultra short TE imaging. We have used these to study axon and myelin loss after trauma.
The work has been mainly in animal models, but some of these methods are starting to be applied in human subjects.
What is the research you have done that has been most rewarding?
MR of spinal cord injury. This has been endlessly interesting, and the methods first developed in small animal imaging systems have moved to clinical application.
What have you achieved in your term as president of American Society of Neuroradiology (ASNR)?
We have raised the profile of the work the ASNR does to support and enhance clinical practice, strengthened the focus on research and innovation within the society and at the annual meeting, and increased the attention to comparative effectiveness research. We have also tried to put the ASNR on a sound financial footing as changes in healthcare will put pressure on the society’s ability to deliver the services members have come to expect.
What are the new techniques/technologies that you are watching closely for the future?
MR imaging is constantly advancing. Right now I am most excited about applying things like ultrashort TE and q-space imaging for characterising white matter. Compressed sensing could be revolutionary in how we acquire images, and perhaps making practical some approaches that have been considered too slow.
Moving away from specific techniques, I think neuroradiology is still in the early stages of its contributions to evaluating cognitive deficits. Dementia is already a critical health problem and will only become more important as populations age.
What are your interests outside of medicine?
I am interested in economics and finance, particularly in the academic literature—for fun, because it is interesting, not because it influences investing. I also enjoy music, particularly opera and chamber music to listen to but do not play. I also spend time carrying out home improvement projects and exercising.
Fact File
Certification in Diagnostic Radiology and Neuroradiology
1985 Faculty in Neuroradiology, University of Pennsylvania, USA
1996 Professor of Radiology, University of Pennsylvania, USA
2001 Acting Section Chief of Neuroradiology and chaired of the Department of Radiology Committee on Appointments and Promotions. While at Penn, he served in numerous capacities in faculty governance, including Chair of the Faculty Senate.
2003–present Professor of Radiology, Department of Radiology, director of Faculty Development for the Radiology Department and chief of Neuroradiology at Beth Israel Deaconess Medical Center (BIDMC)
2003 Assistant Dean for Faculty Development and Professor of Radiology at Harvard Medical School.
Service on national boards and committees
- National Institute of Health federal advisory boards including the Trauma Task Force
- Medical Imaging Study Section (MEDI-regular member) for the Center for Scientific Review
- Training Grant and Career Development Committee for National Institute for Neurological Disorders and Stroke
- Special emphasis panels for the National Cancer Institute
- Consultant at the federal Food and Drug Administration, Radiological Devices Panel and the Medical Devices Advisory Committee, and for the Veteran’s Administration State of the Art Conference on Traumatic Brain injury.
Society positions and honours
- President of the American Society of Neuroradiology
- Fellow of the American College of Radiology
- Fellow of the International Society of Magnetic Resonance in Medicine
Publications
Over 170 original manuscripts and editorials, reviews, chapters, and several hundred abstracts.
