Accurate diagnosis can depend upon the equipment used.
By Kevin R.R. Williams
HEALTH What's the difference between a CT scan and an MRI? Each resembles a donut hole that encircles a patent. But which is better suited for locating cancers within the body? This can depend upon where tumors may be located. Multiple Myeloma, for example is a bone cancer that shows up better in a CT (or CAT) scan since, much like a high-resolution x‑ray, it is best suited for bone injuries, lung or chest imaging, and detecting cancers. CT scans are widely used in emergency rooms because the procedure takes less than 5 minutes.
An MRI, on the other hand, can take up to 30 minutes. It excels in distinguishing soft tissues (i.e. ligament and tendon injury, spinal cord injury, brain tumors etc.). One advantage of an MRI is that it does not use radiation while CT scans do. This radiation is harmful if there is repeated exposure, so MRIs may be used to evaluate progress during a course of cancer treatment.
A PET scan uses nuclear medicine imaging to produce a three-dimensional picture of functional processes in the body. PET scans provide metabolic information and are increasingly read alongside CT or MRI (magnetic resonance imaging) scans, which provide anatomic information.
Radiology Comparison Chart
Not all equipment is created equally. CT scanners range from 4‑slice to 16- or 64‑slice units. MRI machines are available in 1.5‑T (Tesla) and 3‑T with higher image quality and shorter scanning times. An experienced oncologist is more likely to be familiar with and have access to better equipment. A diagnosing factor that is equally as important as the equipment is the skill of the one interpreting the images. For critical decisions, a second radiologist reading may be warranted.