Week 2: MRI,US,CT and IR plus project intro

This week I had the opportunity to shadow a doctor performing lumbar puncture(LP) to collect fluid sample to test for presence of lymphoma in the nervous system. This was typical Intervention Radiology(IR), where live imaging is used to aid in a medical procedure, usually not an open surgery. In LP, the doctor used live X-ray imaging (fluoroscopy) guidance to position the needle accurately in position on the patient spine, without touching the bone, to collect the fluid sample.

I also shadowed doctors in Ultrasound reading room, where I was able to see MRI, CT and Ultrasound(US)images taken from the body, (other than head neck and spine). Among many US images I saw, US was used to test presence of kidney stones, and also check status of the uterus of a bleeding pregnant patient. Contrary to MRI and CT, US can’t image deep in tissue, neither can it image through a bone tissue but it is also the cheapest and least radioactive imaging modality of all.

Back to Neuro reading room some of the new things I have seen this week include the use of diffusion contrast MRI to analyze brain stroke. I learned about two types of Edema, vasogenic and cytotoxic. Vasogenic edema is when cells are surrounded by water such as in a tumor case, while cytotoxic is when cells become filled with water and swell as they are about to die, such as in a stroke case. Using diffusion contrast enables radiologists to identify area of stroke in the brain since the water diffusion in the stroke area is limited, being only inside the cells, in contrast to non-stroke areas.

This week I also got introduced to the project which I will be working on. This involves assessing probability of low grade tumors developing into high grade (malignant tumors).  This is because, it has been a challenge to decide how to deal with low grade tumors. Treating them while at low grade, which involves use of chemo and radio therapy, usually had other unwanted side effects. On the hand, waiting to see if they advance to high grade tumors is risky because once they become high grade, tumors are malignant and more difficult to treat. Therefore, knowing the likelihood of a low grade tumor developing into a high grade tumor will help in deciding best course of action to take.