This procedure involves injecting a radioactive isotope (typically thallium or cardiolyte) into the patient’s vein after which an image of the patient’s heart becomes visible with a special camera. The radioactive isotopes are absorbed by the normal heart muscle. Nuclear images are obtained in the resting condition, and again immediately following exercise. The two sets of images are then compared.
During exercise, if a blockage in a coronary artery results in diminished blood flow to a part of the cardiac muscle, this region of the heart will appear as a relative “cold spot” on the nuclear scan. This cold spot is not visible on the images that are taken while the patient is at rest (when coronary flow is adequate).
Radionucleide stress testing, while more time-consuming and expensive than a simple exercise cardiac stress test, greatly enhances the accuracy in diagnosing coronary artery disease.
- Test, rapid plasma reagin
A screening blood test for syphilis. Rapid plasma reagin is commonly abbreviated RPR. A negative (“nonreactive”) RPR test result is compatible with a person not having syphilis. However, a person may have a negative RPR test and still have syphilis since, in the early stages of the disease, the RPR often gives negative results. This […]
- Test, rapid strep
A diagnostic test commonly used to demonstrate whether streptococcus bacteria (“strep”) are present in the throat. A throat infection with strep needs to be treated with an antibiotic. The traditional test for a strep throat has been a throat culture; the major drawback is that the results of the throat culture take 2 to 3 […]
- Test, Rorschach
A psychological test involving inkblots. The inkblots are used to determine what a person perceives (reads into) in the enigmatic and highly ambiguous shapes. Ten standardized blots are shown one at a time to a subject and their responses are recorded. The Rorschach test became a common psychological test and is still in use in […]
- Test, stool occult blood
A test to check for microscopic blood in stool. (Fecal refers to stool. Occult means hidden.) Abbreviated stool OB.
- Test, stress echocardiography
A supplement to the routine exercise cardiac stress test. During stress echocardiography, the sound waves of ultrasound are used to produce images of the heart at rest and at the peak of exercise. In a heart with normal blood supply, all segments of the left ventricle (the major pumping chamber of the heart) exhibit enhanced […]