Imaging

An X-ray is a picture of the inside of your body. Depending on the part of your body to be X-rayed, the image may show bones, organs, foreign objects, or pockets of air or fluid. Any part of your body can safely  be X-rayed, including your head, chest, belly, arms, and legs.

Fluoroscopy is a test that uses a steady beam of X-ray to look at parts of the body and movement within the body, such as blood moving through a blood vessel. Fluoroscopy also can be used to help find a foreign object in the body, position a needle for a medical procedure, or realign a broken bone. A dye (contrast material) that shows up on fluoroscopy can be put in a vein (I.V.) or swallowed so vessels or organs show up clearly.

Dual-energy X-ray absorptiometry (DEXA) is a test that uses two different X-ray beams to check bone thickness (density). This information is used to estimate the strength of your bones.

A computed tomography (CT) scan uses X-rays to make detailed pictures of structures inside of the body.

During a CT scan, you lie on a table that is attached to the CT scanner, which is a large doughnut-shaped machine. The CT scanner sends X-ray pulses through your  body. Each pulse lasts less than a second and takes a picture of a thin slice of the organ or area being studied. One part of the scanning machine can tilt to take pictures from different positions. 

A CT scan can be used to study any body organ, such as the liver, pancreas, intestines, kidneys, adrenal glands, lungs, and heart. It also can study blood vessels, bones, and the spinal cord.

An iodine dye (contrast material) is often used to make structures and organs easier to see on the CT pictures. The dye may be used to check blood flow, find tumors, and look for other problems. Dye can be put in a vein (I.V.) in your arm. Or, for some tests, you may drink the dye. CT pictures may be taken before and after the dye is used.

A coronary computed tomography angiogram (CCTA) is a test that uses X-rays to provide detailed pictures of the heart and the blood vessels that go to the heart, lung, brain, kidneys, head, neck, legs, and arms. The test uses a special dye that is put into a vein (I.V.) to make very detailed pictures of the blood vessels.

A CT angiogram can show whether a blood vessel is narrowed or blocked. The test can also show whether there is a bulge (aneurysm) or a buildup of fatty material called plaque in a blood vessel.

Magnetic resonance imaging (MRI) is a test that uses a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body.

In many cases, an  MRI gives different information about structures in the body than can be seen with an X-ray, ultrasound, or computed tomography (CT) scan. An MRI also may show problems that cannot be seen with other imaging methods.

For an MRI test, the area of the body being studied is placed inside a special machine that has a strong magnet. In some cases, a dye (contrast material) may be used during the MRI to show pictures of organs or structures more clearly.

Photographs or films of certain views can also be made. Information from an MRI can be saved and stored on a computer for more study.

An MRI can be used to look for problems such as bleeding, tumors, infection, blockage, or injury in the brain, organs and glands, blood vessels, and joints.

Ultrasound is a test that uses reflected sound waves to produce an image of organs and other structures in the body. It does not use X-rays or other types of possibly harmful radiation.

For ultrasound testing, gel or oil is applied to the skin to help transmit the sound waves. A small, handheld instrument called a transducer is passed back and forth over the area of the body that is being examined. The transducer sends out high-pitched sound waves (above the range of human hearing) that are reflected back to the transducer. A computer analyzes the reflected sound waves and converts them into a picture that is displayed on a TV screen. The picture produced by ultrasound is called a sonogram, echogram, or ultrasound scan. Pictures or videos of the ultrasound images may be made for a permanent record.

Ultrasound is most useful for looking at organs and structures that are either uniform and solid (such as the liver) or fluid-filled (such as the gallbladder). Mineralized structures (such as bones) or air-filled organs (such as the lungs) do not show up well on a sonogram.

A mammogram is an X-ray of the breast. It can be done to screen for breast cancer. It can also be done to check lumps and other changes in the breast. It can show tumors or abnormal areas that are too small for you or your doctor to feel.

Thyroid Scan

A thyroid scan uses a radioactive tracer and a special camera. The tracer can be swallowed or can be injected into a vein. It travels through your body, giving off radiation signals. The camera “sees” the signals and can measure how much tracer the thyroid absorbs from the blood.

Bone Scan

During a bone scan, a small amount of radioactive substance (radionuclide) is injected into the bloodstream. A camera takes pictures of the location of the radioactive substance in the bone. Areas that absorb little or no amount of tracer appear as dark or "cold" spots. This could show a lack of blood supply to the bone or certain types of cancer. Areas of abnormal bone collect a lot of the radioactive substance and show up as "hot" spots on the picture. Hot spots may mean problems such as arthritis, a tumor, a fracture, or an infection. A bone scan can often detect a problem days to months earlier than a regular X-ray test.

Nuclear Stress Test

A nuclear stress test measures the amount of blood in your heart muscle at rest and after your heart has been made to work hard. Medicine or exercise can be used to increase the amount of blood that your heart needs.

During the scan, a camera takes pictures of your heart after a radioactive tracer is put into a vein in your arm. The tracer travels through the blood and into your heart. As the tracer moves through your heart, areas that have good blood flow absorb the tracer. Areas that don't absorb the tracer may not be getting enough blood or may have been damaged by a heart attack. The pictures show the difference.

Two sets of pictures may be made during the test. One set is taken while you are resting. Another set is taken after your heart has been made to work harder (called a stress test).

An echocardiogram (echo) is a type of ultrasound examination that uses high-pitched sound waves sent through a device called a transducer to produce an image of the heart and sometimes the aorta.

Transesophageal echocardiogram

In a transesophageal echocardiogram, a transducer is inserted through the mouth and down the throat into the esophagus. High-pitched sound waves (ultrasound) are sent through the transducer to produce an image of the heart and sometimes the aorta.

Stress Test - Treadmill and  Echocardiogram

A stress test using a treadmill and echocardiogram checks for changes in your heart while you exercise. Sometimes EKG abnormalities can be seen only during exercise or while you have symptoms. This test is sometimes called a "stress test" or a "treadmill test." During an exercise EKG, you may either walk on a motor-driven treadmill or pedal a stationary bicycle.

The heart is a muscular pump made up of four chambers. The two upper chambers are called atria, and the two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract and pump blood through the heart to the lungs and the rest of the body.

An exercise EKG translates the heart's electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.

A resting EKG is always done before an exercise EKG test. Then results of the resting EKG are compared to the results of the exercise EKG. A resting EKG may also show a heart problem that would make an exercise EKG unsafe.