PET scans require dietary preparation, sometimes up to 24 hours before your test, so it's important that you know what foods to eat before a PET scan.

A contrast dye is sometimes injected into a vein during an MRI to improve the ability to see certain structures. All dyes used for MRIs contain a metal called gadolinium. These dyes -- called gadolinium-based contrast agents -- are generally very safe, but side effects are possible.

CAT or CT scanning is a highly accurate medical test that combines x-ray with computerized technology.

Therapeutic ultrasound is a modality commonly used by physical therapists. Ultrasound therapy works by driving sound waves into the tissue to help alleviate pain, inflammation and muscles spasms while increasing range of motion.

A bone scan is a radiologic technique in which a small amount of a radioactive chemical, also known as a tracer, is injected into the veins. This tracer is used to help visualize how fast bones are being broken down and reformed.

A computerized tomography, or CT, scan is a diagnostic testing procedure that involves taking X-rays to create cross-sectional images of an area of the body. For many CT scans, a contrast material, or dye, is swallowed or injected to emphasize certain structures on the X-rays.

Located behind the thigh, the hamstrings are a group of muscles associated with the movement of the hip and knee joints. Athletes participating in sports such as soccer, basketball and tennis or other activities involving sprinting are more prone to hamstring injuries, reports the Mayo Clinic.

Bone scans serve several medical diagnostic purposes, according to Drugs.com. They can diagnose bone tumors or cancer, detect if a patient’s cancer has spread, diagnose bone fractures and bone infections, determine the source of bone pain, and assess metabolic disorders.

A muscle tear, as defined by the American Academy of Orthopedic Surgeons, is a medical condition that is graded according to its severity. When you push yourself further than your body is accustomed to, you may feel your muscles protest as it pulls away from your tendons.

Electrocardiogram, abbreviated as either EKG or ECG, is used to record the heart's electrical activity. The EKG is a valuable tool for doctors, as it can help diagnose heart problems, like heart attacks, arrhythmia and heart failure.