Communist States   The five countries that are usually referred to as Communist (a  type of Socialism) are:    China  Cuba  Vietnam  Laos  North Korea    â¦  There are disputes as to whether or not certain of these states are  actually socialist in action or only name.
Magnetic resonance imaging (MRI) provides general imaging of the inside of the body, while magnetic resonance angiography (MRA) offers a specific picture of the blood vessels. MRA scans use MRI technology, but provide a narrower focus than would be available with a regular MRI study. The key difference between MRI and MRA is their intended uses and applications, as the MRA is used for a very specific purpose, while MRIs can be employed in many different settings. Both MRI and MRA studies offer high resolution images with few risks for the patient. In an MRI study, a patient enters a tube with powerful magnets used to collect a noninvasive series of images from inside the body. This is done with a high degree of resolution, and without exposure to radiation.
CT Scan vs. MRI. A CT Scan (or CAT Scan) is best suited for viewing bone injuries, diagnosing lung and chest problems, and detecting cancers. An MRI is suited for examining soft tissue in ligament and tendon injuries, spinal cord injuries, brain tumors, etc. CT scans are widely used in emergency rooms because the scan takes fewer than 5 minutes. An MRI, on the other hand, can take up to 30 minutes. An MRI typically costs more than a CT scan. One advantage of an MRI is that it does not use radiation while CAT scans do.