Question

A gradient echo image of a patient is acquired with an MRI scanner operating at 3T with the following parameters: TR = 10ms, TE=15ms, flip angle = 10°. The radiologist identified a dark spot on the image (darker than its surroundings) and suspects a pathological process. Among the various possibilities, four potential explanations were given for the finding:

(a) Focal inflammation leading to edema;

(b) Calcification of tissue;

(c) Local accumulation of iron;

(d) Vascular leakage of Gadolinium-based contrast agent injected earlier during the scan session.

Answer the following questions:

1. (a) Which explanation is least likely to be true? Why?
2. (b) What physical quantity responsible for contrast in MRI is associated with each of the three remaining explanations?
3. (c) What other scans are needed to resolve the responsible pathological mechanism, if it is indeed one of the three remaining explanations?

Answer 1