Medical Tests & Procedures Archive

Ask the doctor

Q. A friend recently had what his doctor called a "3D echocardiogram." How is that different from a standard echocardiogram?

A. All echocardiograms use high-frequency sound waves (ultrasound) to create still and video images of your heart. But there are two different procedures for getting the images and several variations of this common test, which doctors often refer to simply as an echo.

Research we're watching

An increasing number of Americans have a blood abnormality that indicates autoimmunity, which means their immune system has created antibodies that could work against the body's own cells, according to a study published April 7, 2020, in Arthritis and Rheumatology. Autoimmunity can lead to autoimmune diseases such as rheumatoid arthritis or lupus, although the study authors said they didn't look to see whether the prevalence of diagnosed autoimmune diseases also rose during the same period of time.

The researchers found a rise over two decades in the number of people who had positive antinuclear antibody (ANA) blood tests, a signal of autoimmunity. They used blood samples taken from 14,211 people ages 12 and older, as part of the U.S. National Health and Nutrition Examination Survey. In samples taken in the period 1988 to 1991, ANA prevalence was 11%. It rose slightly to 11.5% for the 1999–2004 time period, and to 15.9% in the 2011–2012 period. Comparing differences in gender, race and age, the largest increases in positive ANA tests occurred in men, non-Hispanic whites, adolescents, and adults ages 50 and older.

In the journals

Combining two kinds of biopsies may lead to a more accurate diagnosis of prostate cancer, suggests a study in the March 5, 2020, issue of The New England Journal of Medicine. Researchers from the National Cancer Institute enrolled 2,103 men with prostate abnormalities. Each man had a standard 12-point biopsy and an MRI-targeted biopsy.

With a 12-point biopsy, tissue samples are taken from 12 systematically placed spots on the prostate. An MRI-targeted biopsy uses an MRI image of the prostate to help doctors locate areas where cancer is most highly suspected. Previous research has shown that MRI-targeted biopsies are more accurate than 12-point biopsies. However, even MRIs can miss some tumors.

Ask the doctors

Q. A friend told me that I should be screened for hepatitis C. I'm not in a high-risk group. Is this really necessary?

A. If you're an adult younger than 80 years old, the answer is yes. In March, a government health advisory group, the U.S. Preventive Services Task Force (USPSTF), revised its earlier position and now recommends that all people ages 18 to 79 be screened for this "silent" virus. Prior to this change, the USPSTF recommended only that only high-risk individuals or adults born between the years 1945 and 1965 be screened. Hepatitis C can attack the liver and lead to serious liver damage and liver cancer. The condition is curable if detected. But people often don't consider themselves at risk and are unaware that they are infected, because they typically don't have symptoms.

There's no easy answer to this question. Rather, women should make the decision based on their individual needs.

Most women don't look forward to their routine mammogram, which can be uncomfortable and stressful. You may wonder: Is there an age when can you dispense with this regular chore? 75, 80, 85?

The truth is that experts haven't determined a magic age when women no longer need breast cancer screening — largely because scientific evidence in this area is lacking, says Dr. Kathryn Rexrode, associate professor of medicine at Harvard Medical School and chief of the Division of Women's Health at Brigham and Women's Hospital. But many experts also agree that continuing mammography might not be the right choice beyond age 75. The real question, they say, is what is the right age for you to stop based on your individual needs? To decide, you need to understand both the potential risks and benefits of breast cancer screening.

Research we're watching

Could a single blood test one day enable doctors to diagnose Alzheimer's disease? Researchers writing in the March 2 issue of Nature Medicine say they've made advances in this area. The blood test they developed measures the concentration of pTau181 — a form of the tau protein associated with brain changes in Alzheimer's disease — in the body's blood plasma. They used the test on samples collected from more than 400 people who were part of an ongoing -memory study.

The researchers found that the blood test was able to accurately detect which patients had Alzheimer's, which were healthy, and which had a different type of dementia caused by a neurodegenerative disease. Today, doctors typically diagnose Alzheimer's using a series of tests designed to rule out other causes, but the process is time-consuming and costly. The researchers are now aiming to refine the test further, in hopes that it will someday make it easier to detect Alzheimer's at an early stage, when the disease may be easier to treat.

On call

Q. When should I worry about changes in the color of my urine? What color is considered healthy?

A. If a person is well hydrated, the normal color of urine is a pale yellow. Someone who drinks large amounts of fluid or takes diuretics (water pills) can have almost clear-looking urine. A dark yellow color may indicate a need to increase your fluid intake.

News briefs

The guidelines are changing when it comes to screening for hepatitis C, a silent viral infection that attacks the liver and can cause cirrhosis, liver cancer, or liver failure. Back in 2012, the CDC recommended a one-time hepatitis C screening for the so-called baby boomer generation (anyone born between 1945 and 1965), a group that made up about 75% of all hepatitis C cases at that time. The following year, the U.S. Preventive Services Task Force (USPSTF) agreed. Now the USPSTF is expanding the screening age to all adults ages 18 to 79. The move is meant to identify more people in early stages of infection and comes as hepatitis C cases have increased almost fourfold since 2010. The USPSTF also advises screening for people outside of the recommended age range if they have ever used injected drugs. The recommendations were published online March 2, 2020, by JAMA. The CDC is in the process of developing similar recommendations. The screening requires only a simple blood test.

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If you or someone else suspects early signs of memory loss, here's how you can find out if there's a problem.

There's no cure for dementia, and you cannot substantially reverse its effects, but there are ways to possibly slow its progression. But first, you need to know if you — or a loved one — may have a memory disorder. "Unfortunately, there is not one single test that confirms dementia while you are alive," says Dr. Julie Brody Magid, clinical director of the Harvard-affiliated McLean Hospital Memory Disorders Assessment Clinic. "The testing process is multilayered and takes many things into consideration. Going through this evaluation may help identify memory problems before they get worse."

Know the symptoms

Symptoms of dementia include memory loss, problem-solving difficulties, and language issues. Behavior and emotions also can be affected. Symptoms are often subtle early on, and then get progressively worse. They can increasingly interfere with daily life tasks, like remembering to attend appointments, take medication, or pay bills. People also may have trouble preparing meals or driving safely.

Most people don't need an electrocardiogram before a minor, low-risk procedure. Major surgery is different.

If you've ever had surgery, you may recall having a preoperative evaluation, sometimes referred to as "clearance" for surgery. These check-ups often occur days or weeks prior to a planned, non-cardiac surgery and typically involve a physical exam. You also may get blood tests, x-rays, and an electrocardiogram (ECG) — a quick, painless test that records your heart's electrical activity.

"These evaluations are designed to assess your chances of experiencing a heart-related problem during the surgery," says Dr. Brendan Everett, director of the general cardiology inpatient service at Harvard-affiliated Brigham and Women's Hospital. The term "clearance" is misleading, as there is no way to guarantee you won't have complications. Still, knowing ahead of time about any heart-related risks you may have enables the surgeon to better prepare for possible complications and have a backup plan available, says Dr. Everett.