Are a CAT scan and a CT scan the same test?

The older name, computed axial tomography, produced the abbreviation CAT. Modern services generally use CT, but the names may be used interchangeably in appointment letters and conversation.

A CT scanner uses X-rays taken from several angles and computer processing to form cross-sectional images. These pictures can show the size and location of an abnormal area, its relationship to nearby structures, and changes seen on later scans.

Some examinations use an imaging contrast agent by mouth or through a vein to make selected tissues easier to distinguish. Whether contrast is needed depends on the body area and the clinical question.

Follow the imaging department's instructions about eating, drinking, medicines, and arrival time. Tell the team before the examination if you may be pregnant, have kidney problems, previously reacted to imaging contrast, or take medicines that the department has asked about.

Remove metal items when requested and expect to lie on a moving table while the scanner takes images. Staying still and following brief breathing instructions helps reduce blur.

Tell staff immediately if you develop trouble breathing, swelling of the face or throat, faintness, or a rapidly spreading rash during or soon after contrast. Seek urgent medical help if these symptoms begin after you leave.

Contact the imaging service if pain, redness, or swelling around the injection site is worsening rather than settling. For concerns unrelated to contrast, use the contact instructions supplied with your appointment or result.

Ask which body area will be scanned, whether contrast is planned, what preparation is required, and when and how the report will reach you. If previous images were taken elsewhere, check whether the team needs copies for comparison.