NYC Chronicles (Week 1): What the Heck is Radiology?!

Prior to the start of this summer immersion program at Weill Cornell, I knew very little about magnetic resonance imaging (MRI). In fact, I only knew that MRI was a technique used by physicians in order to diagnose patients, but I wasn’t quite sure how to interpret an MR image, how MRI works, or what the limitations of MRI were. As a young and naive scientist strictly interested in musculoskeletal tissue engineering, radiology was far beyond my scope of curiosity, but that quickly changed after spending that last 48 hours with my clinician, Dr. Martin Prince.

First, it should be noted that Dr. Prince frequently runs to catch buses and taxicabs, like many New Yorkers, and takes very few breaks during the day to actually eat because he’s just so passionate about his work. So it didn’t take me long to realize that (1) I will always need to have a pair of running shoes with me in order to keep up with him and (2) that my BMI may slightly decrease by the end of this program due to all the running and the fast-paced nature of Dr. Prince’s schedule. But back to the science. Yes! MRI is, in fact, a technique used by radiologist to generate clear images of a patient’s anatomy in order to appropriately diagnose a patient, to help physicians understand the best treatment options for their patients, and to aid surgical procedures by locating the patient’s anatomical regions of interest for the surgeons.  So how does it work?  In short, conventional MR imaging relies on the parallel or antiparallel alignment of ¹H-nuclei spins, predominantly found in water or fat, within a magnetic field, the application of a radiofrequency (RF) pulse, and proton spin relaxation that generates heat (T1 relaxation) and a small, measurable RF signals (T2 relaxation), which can be detected by a coil of wires and thus converted into an image that will be contrasted (dark- and light-grayscale assignments) based on the rigidity or free-flowing nature of a specific region in the tissue of interest.  

During my nascent career in radiology thus far, I find that the most fascinating aspect of MRI is observing the many variations of the human anatomy by looking at the MR images of different patients, which was extremely difficult initially. In fact, I had the opportunity to attend a liver transplantation meeting with Dr. Prince at Columbia University Medical Center, where the physicians of the Center of Liver Disease and Transplantation surgical team collaborated to interpret the MR images of their patients who they felt were potential candidates for a liver transplant. Since this was my first time looking at MR images, I found it very difficult to follow along and to understand how the physicians were actually interpreting these images. To me, they were just pictures with darker and lighter regions; and in an effort to stay awake during the 7:00AM meeting, I took notes and pretended that I knew what they were talking about. However, when I finally got the chance to look at more cases individually with Dr. Prince later that day, my “eye” for interpreting MR images slowly began to develop as I can now identify specific organs in the abdomen and pelvic areas, and differentiate between healthy and abnormal tissue. 

Another aspect of MRI that I find interesting is that it can reveal the medical history of a patient, such as someone who acquired severe injuries or received invasive surgeries, based on the scare tissue or lesions that can be detected on an MR image. During my two days of actively shadowing Dr. Prince, we looked at the MR images of several patients with polycystic kidney disease (PKD) and breast cancer. In regards to the former disease, we saw many severe cases of PKD where patients developed hundreds of cysts on their kidneys and liver, resulting in organs that were 2-15 times larger in volume than the standard range of healthy tissues. I also had the opportunity to shadow Dr. Prince as he interacted with breast cancer patients to interpret their MRI scans and to discuss their results with them. An interesting procedure that I learned from Dr. Prince at this time regarded a relatively new reconstructive surgical technique, called the deep inferior epigastric artery perforator (DIEP), which is available for breast cancer patients who intend to receive unilateral or bilateral mastectomy. This technique involves the replacement of cancerous breast tissue with healthy subcutaneous fat, typically removed from the abdomen or pelvic regions of the body, and requires the rerouting of vasculature to the chest for appropriate breast reconstruction. Although this procedure can take surgeons up to 10 hours to perform in the operating room, with the help of MRI, it can decrease the amount time spent in the OR, and revolutionize the field of breast oncology and reconstructive surgery as it would not only prevent immune rejection from bio-incompatible implants, but also cure patients from the disease itself.

As the weekend approaches, I can finally sleep in. I enjoyed every moment of the past two days learning about MRI and running up and down York Avenue trying to keep up with Dr. Prince. My short time in the program has already exposed me to an exciting field of medicine that I was initially terrified of, because who really wanted to learn about magnetic resonance in organic chemistry or physics in undergraduate school? Not me! Nevertheless, I’m thankful to be shadowing Dr. Prince this summer and I look forward to learning more about radiology and MRI in the near future.

(Fun Fact: Although MR imaging relies on the use of protons to generate an accurate depiction of the anatomy, there are some regions of the body that have scarce proton density (e.g. lungs) and will require more advanced methods of MR imaging to make a full diagnosis of patients suffering from relevant diseases, such as asthma, COPD, or emphysema. However, this issue can be overcome by the use of diffusion weight imaging of a hyper-polarized noble gas, such as helium-3, which requires the inhalation and diffusion of ³He into the lungs to calculate relevant parameters, such as the apparent diffusion coefficient (mm²s^-1) which is indicative of the diffusion capability of helium -3 within a specific region of the lung, providing insight on additional parametric information about the lung, such as the alveolar diameter of healthy and emphysematous patients.)