CT and MRI scans are anatomic imaging modalities, which means they look at the size and shape of organs and body structures. A PET scan is a metabolic imaging modality, which means it looks at function. The information collected from a PET scan is different from any other test that is available.

The studies are read shortly after the PET scan is completed and patients can expect verbal reports to be available to their physicians on the day of the study. Most insurance companies pay for clinically indicated PET procedures. To be clinically indicated, the PET scan must be potentially beneficial in providing information supportive of a diagnosis or monitoring certain conditions.

Intravenous contrast material is often, but not always, used in today's CT and MRI studies to help with diagnosis. An iodine based material is used for CT and gadolinium is used for MRI. The purpose is to “enhance” the tissues and organs of the body in such a way as to make them better stand out from each other, and to allow better visualization of abnormal areas within normal areas. This ability to differentiate normal from abnormal is important to make the correct diagnosis.

Both MRI and CT scans make cross-sectional images (slices) of almost any area of the body using a sophisticated computer system. The major difference is that an MRI uses a large magnet and radio waves to produce images while a CT scanner uses x-rays. Therefore, with the MRI studies, there is no exposure to x-rays.

Computed Tomography (CT) uses x-rays to create a cross-sectional image of the body part being examined. Magnetic Resonance Imaging (MRI) uses a high field strength magnet and radio waves to generate a cross-sectional image.

A PET scan produces images of metabolic activity as opposed to images of the body's physical structures that are derived from these other imaging tests. This is important because functional changes often predates structural changes in tissues. PET images may therefore demonstrate changes long before they would be revealed by modalities like CT and MRI.

MRI is more sensitive to subtle changes in soft tissues, particularly the brain and spinal cord. It is the primary imaging method for evaluation of joints, especially the knee, ankle, shoulder, and wrist.

MRI scan is excellent at showing soft tissue such as spinal cord, nerve roots and herniated discs. A CT scan shows bone detail and some soft tissue. When looking for herniated discs or tumors, an MRI image will usually reveal much more detail.

Instead of relying on X-rays like CT scans and conventional X-ray exams, MRI uses radio waves, a computer and a powerful magnet approximately 7,000-times stronger than the magnetic force of the earth. MRI produces better images of soft tissue than CT scans or X-ray exams. Back to top.

MRI stands for Magnetic Resonance Imaging and does not utilize radiation. Instead, a strong magnetic field and radio waves are combined to create high-quality images of soft tissue which cannot be detected by an X-ray.

actual CT scan typically takes 5-15 minutes. However, patients who are scheduled for abdomen/pelvis CT scans will be required to drink an Oral Contrast Drink up to 2 hours prior. These patients must allow for this 2-hour prep time when scheduling this procedure. For your convenience, patients may can pick up the cral contrast drink prior to the scan rather than drinking it and waiting at the hospital.

CT and MRI differ in two basic ways.CT uses x-rays to detect and record the radiation absorbed by different tissues, and sends the data to a computer to transform into images. MRI does not use x-rays. Instead, MRI employs a powerful magnetic field to monitor the nuclei of hydrogen atoms in water, the most abundant element in the body.

All four are useful for non-invasive medical imaging. X-rays Conventional X-ray images are usually on photographic film or a fluorescent screen. X-rays from an X-ray tube pass through the body and the difference in absorption by different structures in the body is what produces contrast in the images. The images are 2D projections of a 3D object so they contain overlapping structures.

The more information that our radiologist has when reviewing your exam, the more specific the interpretation will be. Correlations with other studies are often helpful.

CT imaging itself is painless. The patient is required to remain motionless during the examination (which is difficult for some people), but the actual scan causes no bodily sensation.