Endocrine Testing Technology

Testing and Technology

Endocrine Testing Technology

Medical College of Wisconsin endocrinologists use the latest tests and technology to diagnose a wide range of endocrine disorders.

ACTH (cortrosyn) stimulation test

Measures the adrenal glands’ stress response to adrenocorticotropic hormone (ACTH). This hormone is produced in the pituitary gland and stimulates the adrenal glands to release cortisol. During the test, a small amount of synthetic ACTH is injected, and the amount of cortisol the adrenals produce in response is measured. This test is used to diagnose or rule out primary and secondary adrenal insufficiency, Addison's disease and related conditions.

Adrenal vein sampling

A minimally invasive procedure to collect blood samples from the adrenal glands to determine how active the adrenal glands are and if one gland is more active than the other. A catheter is inserted into a vein in the groin and advanced into the main blood vessel in the abdomen. Small amounts of X-ray dye are injected to help locate each adrenal vein. The catheter is advanced into each adrenal vein and blood samples are collected. Blood samples are also collected from an arm.

CRH stimulation test

A test to determine the cause of a drop or rise in a patient’s adrenal hormones (caused by Cushing’s syndrome). This test measures levels of cortisol in the blood before and after a patient is given a synthetic form of CRH (corticotropin-releasing hormone), a naturally occurring hormone which causes the pituitary gland to secrete the hormone ACTH. The way a patient’s cortisol levels respond to the test can tell if the problem is with the pituitary glands, the hypothalamus or the adrenal glands.

Dexamethasone suppression test

A test to measure the response of the adrenal glands to adrenocorticotropic hormone (ACTH). This test is done when it is suspected that the body is producing too much cortisol. There are two types of dexamethasone suppression tests: the low-dose test and the high-dose test. During the test, a patient receives dexamethasone, and the patient’s cortisol levels are measured.

Dual energy X-ray (DEXA)

A technique for scanning bones and measuring bone mineral density. Two X-ray beams with different energy levels are aimed at the patient’s bones.

Inferior petrosal sinus sampling (IPSS)

A minimally invasive test that involves inserting a catheter into a vein and advancing it to the inferior petrosal sinuses at the base of the skull. Blood samples are collected from the sinuses and an arm vein. Next, corticotrophin-releasing hormone is given through the arm vein, and repeat blood samples are drawn at intervals. The level of ACTH (a hormone secreted by the pituitary gland) is measured in the blood samples. The ratios between the petrosal sinus blood samples and the arm vein blood samples are compared to determine if ACTH production is related to a pituitary or a non-pituitary source. Medical College of Wisconsin endocrinologist James Findling, MD, FACP, developed this test in the late 1970s/early 1980s. Today, the test is used across the United States to help diagnose Cushing’s syndrome.

Salivary cortisol test

A screening test for Cushing’s syndrome that involves measuring levels of cortisol in saliva between 11:00 pm and midnight (people with Cushing’s have an elevated level of cortisol late in the evening, when it should otherwise decrease). A person simply places an absorbing material in the mouth to collect saliva for testing. The material is then placed in a small vial and mailed to the lab for analysis. If the test is positive, it is repeated and other tests are done to confirm a Cushing’s diagnosis. Medical College of Wisconsin James Findling, MD, FACP, helped develop this important test in the 1990s.

Supervised fast for hypoglycemia in the non-diabetic patient

Some people have hypoglycemia due to inappropriate insulin secretion. This is usually caused by insulin producing tumor of the pancreas. To diagnose this disorder, the person will undergo supervised fast. During a period of up to 72 hours, patients fast while being closely monitored. Period blood tests look for a blood glucose level below 45 mg/dL associated with evidence of high insulin production.

Measurement of plasma metanephrines and catecholamines

Tests to help diagnose or rule out the presence of a pheochromocytoma, a tumor that causes excess production of epinephrine (adrenaline) and norepinephrine and usually occurs in one or both adrenal glands. The plasma metanephrines test uses a blood sample, and the catecholamines test uses a urine sample.

Ultrasound

A noninvasive imaging test used to help diagnose and treat medical conditions. An ultrasound test involves exposing part of the body to high-frequency sound waves to produce pictures of the inside of the body. Ultrasound images are captured in real-time and show the structure and movement of the internal organs.

Ultrasound-guided fine needle aspiration

A method for evaluating a suspicious thyroid nodule. A very thin needle is inserted into the thyroid nodule or mass to aspirate (suction) cells and/or fluid. The sample is then evaluated for the presence of cancerous cells.

Vertebral fracture assessment (VFA)

An established, low-radiation method for detecting vertebral fractures (vertebrae are the bony segments of the spinal column). Vertebral fractures, which are often not recognized when they occur, indicate a substantial risk for subsequent fractures, independent of bone mineral density.

Last Review Date: Aug. 21, 2009