Doctor-Reviewed Health Guides: Conditions, Procedures & Health News

Intravascular ultrasound (IVUS) is a minimally invasive test that uses a tiny ultrasound probe on the tip of a thin catheter to see blood vessels from the inside. It shows how much plaque has built up and how narrow the artery is. It's most often done during cardiac catheterization to plan and check stent placement.

Nephroscopy is a minimally invasive procedure that uses a nephroscope, a thin, lighted tube with a lens, to look inside the kidney and treat problems there. It's most often used to remove large kidney stones. Most people go home the next day. Compared with open surgery, it means a shorter hospital stay, faster recovery and fewer complications.

The Bravo test is a wireless esophageal pH test that measures how much stomach acid flows back into the esophagus, usually over 48 hours. During an upper endoscopy, a provider attaches a capsule to the esophagus that sends acid readings to a recorder you wear. It helps diagnose and monitor GERD. The capsule falls off on its own.

Nuclear medicine imaging uses a small amount of radioactive material, called a tracer, to show how the organs and tissues are working, not just what they look like. A gamma camera or PET scanner detects the tracer. The radiation dose is low, side effects are rare, and the tracer leaves the body within about 48 hours.

Cordocentesis, also called percutaneous umbilical blood sampling (PUBS), is a prenatal test that takes a sample of blood from the umbilical cord using a needle guided by ultrasound. It can check the fetus for anemia, infections and chromosome conditions. It's done after 17 weeks. The main risk is pregnancy loss, in about 1 to 2 of every 100 procedures.

Culdocentesis is a procedure that uses a thin needle passed through the back wall of the vagina to remove fluid from the space behind the uterus. Checking this fluid can help find the cause of pelvic pain and detect bleeding from a ruptured ectopic pregnancy. It's used less often because transvaginal ultrasound can find pelvic fluid with less risk.

A Wood's lamp examination is a quick, painless skin test that uses long-wave ultraviolet (UV) light to make certain skin, hair and scalp problems glow or change color. It helps spot fungal infections such as scalp ringworm, bacterial infections and pigment changes such as vitiligo. A glow can suggest a condition, but it doesn't always confirm it.

Contrast-enhanced ultrasound (CEUS) is an ultrasound exam that uses an IV contrast agent made of tiny gas-filled microbubbles to show blood flow in organs and blood vessels in real time. It's most often used to tell benign from cancerous liver lesions. The contrast isn't harmful to the kidneys and the test uses no radiation. Serious reactions are rare.

Electronystagmography (ENG) is a test that records eye movements to check how well the inner ear balance system and the nerves controlling the eyes are working. It looks for nystagmus, fast involuntary eye movements that can signal a balance problem. It helps evaluate dizziness, vertigo and balance problems. It takes about 90 minutes and may cause brief dizziness.

Retroperitoneal lymph node dissection (RPLND) is surgery to remove lymph nodes from the retroperitoneum, the space behind the belly organs near the large blood vessels. It's used mainly for testicular cancer, to find out how far cancer has spread, remove cancer and lower the chance it comes back. It usually means a 4- to 7-day hospital stay.

Digital breast tomosynthesis (DBT), often called 3D mammography, is an advanced mammogram that takes many low-dose X-ray pictures of the breast from different angles and combines them into a 3D image. It helps find cancers hidden by overlapping tissue and reduces false alarms. It's especially helpful for dense breasts. The appointment takes about 30 minutes.

The Amsler grid is a chart of straight lines with a dot in the center that helps you check your central vision at home. It's used mainly by people with macular degeneration. Cover one eye at a time and stare at the dot. If any lines look wavy, blurry, faded or missing, call your eye specialist right away.

Balloon-assisted enteroscopy (single or double balloon enteroscopy) is a procedure that lets a provider see and treat the small intestine, which standard endoscopes can't fully reach. A flexible scope with one or two balloons is advanced through the mouth or rectum. It's most often used to find and treat hidden bleeding. Most people go home the same day.

Microlaryngoscopy is a procedure in which a surgeon uses a microscope and a rigid tube through the mouth to examine the vocal folds (vocal cords), with no cuts on the skin. The surgeon can remove growths such as nodules, polyps or cysts or take a biopsy. It's done under general anesthesia, and most people go home the same day.

A fibrinogen test (also called a factor I activity test) is a blood test that measures fibrinogen, a clotting protein made by the liver. A typical normal range is about 200 to 400 mg/dL. Providers order it for unexplained or excessive bleeding, abnormal PT/INR or PTT results and inherited clotting disorders.

A catecholamines test measures stress hormones made by the adrenal glands and nerves: epinephrine (adrenaline), norepinephrine and dopamine. It's mainly used to look for rare tumors that make too much of them, such as pheochromocytoma. It can be done on a 24-hour urine sample or a blood sample. A high result doesn't confirm a tumor on its own.

An echocardiogram with strain (strain imaging) is a heart ultrasound that measures how much the heart muscle shortens and lengthens with each beat. It can pick up subtle heart muscle weakness before the ejection fraction drops. It's often used to monitor the heart during chemotherapy and to follow cardiomyopathy and heart failure.

Cardiac imaging is a group of tests that make pictures of the heart and nearby blood vessels. The main types are the echocardiogram, cardiac CT, cardiac MRI, nuclear stress tests, the coronary angiogram and the MUGA scan. They help screen for, diagnose and monitor problems such as coronary artery disease, heart failure and valve disease.

The quantitative sudomotor axon reflex test (QSART) checks the small nerves that control sweating. Electrodes on the leg, foot and wrist deliver a gentle electrical current, and a machine measures how much and how fast you sweat. It helps evaluate autonomic neuropathy, small fiber neuropathy and POTS. It takes about 45 minutes to an hour and isn't painful.

A loopogram is an X-ray test that checks how well urine drains through an ileal conduit, a urine pathway made from small intestine after the bladder is removed. Contrast fluid is injected through a catheter in the stoma, and X-rays help find narrowing, leaks or blockages. The test takes 15 minutes. It isn't done during pregnancy.

An ENA panel (extractable nuclear antigen antibodies panel) is a blood test that looks for specific autoantibodies, antibodies that attack proteins inside your own cells. Providers often order it after a positive ANA test to help diagnose lupus, Sjögren's syndrome, scleroderma, mixed connective tissue disease and myositis. No single result diagnoses a disease on its own.

Immunostaining is a lab method pathologists use to find a specific protein in a sample of tissue, blood or bone marrow. It uses antibodies that stick to their target and carry a label that makes it visible. It helps diagnose cancers, infections, blood disorders and autoimmune diseases. Results can take from a few hours to about 10 days.

A scoliometer is a small handheld tool that measures how much the trunk is rotated when you bend forward, helping providers screen for and track scoliosis. A reading of 0 degrees means no sign of scoliosis, while more than 10 degrees suggests scoliosis. It's painless and takes just minutes. An X-ray is often used to confirm the curve.

A T4 (thyroxine) test is a blood test that measures thyroxine, the main hormone the thyroid gland makes. A typical adult free T4 range is about 0.9 to 1.7 ng/dL. High T4 can mean an overactive thyroid, and low T4 can mean an underactive thyroid. Stop biotin supplements 3 to 5 days before, because biotin can skew results.