Lymphoscintigraphy:
For assessment of lymphatic flow from peripheries of upper or lower limb, to the central part of the body. The exam consists of sequential images acquired every 2 hrs, usually up to 6 hrs.
MUGA Scan:
To determine how efficiently the heart is working to pump blood in various part of the body. The exam requires about one hour.
Parathyroid Scan:
Used in patients having high PTH hormone and calcium levels in blood (primary hyperparathyroidism), to identify / localize the parathyroid adenoma, before the surgery. No preparation is required. The test usually takes around 2-3 hrs.
Renal Scan:
This is of various types, namely, DTPA scan, DMSA scan, EC or MAG3 scan. These tests are used to diagnose urinary tract obstruction, urinary tract infections, renal artery stenosis etc. Patients are asked to drink plenty of water prior to the scan. They are then injected with tracer, and scanned for approximately 30 minutes followed by sequential images taken with a gap of one minute each, every 2 hrs, for up to 6-8 hrs. In some cases, extra procedures, such as injection of a diuretic or return for a second scan on next day are needed. In DMSA scan, there is a waiting period of 3 hrs between injection of the tracer and imaging which takes approximately 15 minutes. For some scans, the patient should not take ACE inhibiting medication for 48 hours and all blood pressure medication for 24 hours prior to the scan.
Tc99m Thyroid Uptake and Scan:
To diagnose hyperthyroidism, hypothyroidism, or thyroid nodules or enlargement. Tracer is administered intravenously followed by imaging of neck after 20 minutes. Patients must be off thyroxin (for at least 6 weeks) / antithyroid drugs (for at least 7 days) before the thyroid scan. Iodinated contrast media, used in radiological diagnostic imaging, should be avoided before this test.
Whole Body Iodine Scan: This test is done to evaluate thyroid cancer patients after surgical removal of entire thyroid gland, to identify any residual thyroid tissue in neck or metastatic disease anywhere in the body. Patient should be off Thyroxin for at least 4-6 weeks before this test. Serum TSH levels should be checked before this test and should be more than 30. The tracer is given orally in form of a capsule followed by whole body imaging after 48 hrs.
ECD brain perfusion Scan: This is done to assess blood supply (perfusion) in various areas of brain, especially used to evaluate patients with dementia. No preparation is required. The tracer is injected intravenously followed by imaging of brain after 1 hr. The imaging takes approximately 20 minutes. Stress myocardial perfusion test: This is done to assess the blood supply (perfusion) to the muscles of the heart, during resting state and during physical stress. It is useful to assess the functional significance of plaque / obstruction in coronary arteries. This is very useful study to follow up patients after coronary interventions like angioplasty / bypass surgery. Patients should stop taking beta blockers for at least 2 days prior to this test. The test usually takes around 4-5 hrs.
Gastroesophageal reflux scan (Milk Scan): This is usually done in pediatric population to demonstrate reflux of gastric contents into the esophagus. If the patient cannot swallow a capsule, a nasogastric tube needs to be inserted through the nasal cavity to administer the tracer directly into the stomach. The test usually takes approximately 30-45 minutes.
Meckel’s scan: This is usually done in pediatric population. Patients complain of bleeding through rectum. This test is useful to rule out ectopic gastric mucosa /Meckel’s diverticulum as the cause of this complaint. The test usually takes 30 minutes. Usually no preparation is required.