Labs & Radiology

How to prepare for your blood test

If Dr. Karam or his staff asks you to fast for your blood test, please make sure not to eat any food for 8 to 10 hours before your blood test. We DO want you to drink water and you may also have black (no cream, sugar or artificial sweetener) coffee or tea.

Effects of water on blood test results

Although eating food or consuming drinks containing nutrients, calories or sugar will affect the results of your fasting blood test, drinking water will have no measurable impact because it contains no calories, fats or sugars. Drinking water is actually beneficial prior to having your blood drawn.

Dehydration and drawing blood

If you have not had enough water to drink prior to having your blood drawn, you may be dehydrated. Dehydration can make it difficult for the technician to draw your blood sample or collect an adequate supply of urine.

Dehydration and Triglycerides

Triglycerides are measured as part of a routine cholesterol screening. Dehydration can also affect your triglyceride level and cause it to be deceptively high.

Cholesterol

Cholesterol is different from most tests in that it is not used to diagnose or monitor a disease but is used to estimate risk of developing a disease — specifically heart disease. Because high blood cholesterol has been associated with hardening of the arteries (arteriosclerosis), heart disease, and a increased risk of death from heart attacks, cholesterol testing is considered a routine part of preventive health care.

Liver Panel

A liver panel, also known as liver (hepatic) function tests or LFT, is used to detect, evaluate, and monitor liver disease or damage. It usually consists of seven tests that are run at the same time on a blood sample. These include:

Alanine aminotransferase (ALT) – an enzyme mainly found in the liver; the best test for detecting hepatitis

Alkaline phosphates (ALP) – an enzyme related to the bile ducts; often increased when they are blocked

Aspartate aminotransferase (AST) – an enzyme found in the liver and a few other places, particularly the heart and other muscles in the body

Bilirubin – two different tests of bilirubin often used together (especially if a person has jaundice): total bilirubin measures all the bilirubin in the blood; direct bilirubin measures a form that is conjugated (combined with another compound) in the liver

Albumin – measures the main protein made by the liver and tells whether or not the liver is making an adequate amount of this protein

Total Protein – measures albumin and all other proteins in blood, including antibodies made to help fight off infections.

Hemoglobin A1c

The A1c test and eAG calculation are used primarily to monitor the glucose control of diabetics over time. The goal of those with diabetes is to keep their blood glucose levels as close to normal as possible. This helps to minimize the complications caused by chronically elevated glucose levels, such as progressive damage to body organs like the kidneys, eyes, cardiovascular system, and nerves. The A1c test and eAG result give a picture of the average amount of glucose in the blood over the last few months. They can help you and your doctor know if the measures you are taking to control your diabetes are successful or need to be adjusted. The A1c test is frequently used to help newly diagnosed diabetics determine how elevated their uncontrolled blood glucose levels have been. It may be ordered several times while control is being achieved, and then several times a year to verify that good control is being maintained.

Before your MRI

Some imaging facilities advertise an "open" MRI scanner, which can help some patients who are extremely claustrophobic, while others utilize conscious sedation to completely "knock" a patient out. The skilled technologist has many techniques to help put patients at ease, and even very claustrophobic patients have done well in high field (more tubular shaped) MRI scanners. One tip is to have a damp washcloth to cover the eyes. Another is to have a friend drive you to and from your appointment, and receive a small dose of oral sedation like Xanax, which taken appropriately beforehand will relax you.

Can I get images of my MRI on a CD?

A CD of your entire exam is available at many facilities. If it is created shortly after your scan, it will not have the radiologist's report on it. Be sure that the facility provides the images in a standard format called DICOM, which means the images can be viewed in the correct, original format no matter where you travel for healthcare. Typically, CDs will only be viewable on PCs, not Apple computers.

What information do CT and MRI scans provide?

Both tests provide detailed pictures of areas of the body that used to be inaccessible by conventional X-Rays. The development of non-invasive imaging techniques reduces invasive, exploratory surgeries and allows detailed views of the anatomic structures in normal and diseased states. CT scans give us excellent information on anatomical (bony) features and tissue density that allows for the detection of tumors, and sometimes the ability to distinguish between malignant and benign tumors. CT scans are useful in sensitive detection of calcification (calcium deposits), cysts, abscesses, and hemorrhaging. CT is also widely used due to short imaging times, widespread availability, and ease of access.