A dye is usually a coloring agent. In medical imaging the term dye refers to radiopaque material used during x-ray examinations to provide or increase contrast in the different tissues and organs. Dye usually refers to intravenous contrast agents.

See also Contrast Agents.

See Dye, Contrast Agents.

See Contrast Agents and Dye.

A computed tomography (CT) of the abdomen images the region from the thoracic diaphragm to the pelvic groin. The computed tomography technique uses x-rays to differentiate tissues by their different radiation absorption rates.
Oral contrast material can be given to opacify the bowel before scanning. An i.v. injection of a contrast agent (x-ray dye) improves the visualization of organs like liver, spleen, pancreas and kidneys and provides additional information about the blood supply.
Spiral- or helical CT, including improvements in detector technology support faster image acquisition with higher quality. Advanced CT systems can usually obtain a CT scan of the whole abdomen during a single breath hold. This speed increases the detection of small lesions (caused by differences in breathing on consecutive scans) and is beneficial especially in pediatric, elderly or critically-ill patients.
Changes in patient weight require variations in x-ray tube potential to maintain constant detector energy fluence. An increased x-ray tube potential improves the contrast to noise resolution (CNR).

An abdominal CT is typically used to help diagnose the cause of abdominal pain and diseases such as:
Other indications for CT scanning of the abdomen/pelvis include planning radiation treatments, guide biopsies and other minimally invasive procedures. Advanced techniques include for example 3D CT angiography, multiphasic contrast-enhanced imaging, virtual cystoscopy, virtual colonoscopy, CT urography and CT densitometry.

See also Contrast Enhanced Computed Tomography.

Administration in medical imaging refers to the administration of contrast agent (dye) or radioactive material (radiopharmaceutical) into the body by injection, oral administration or by other route.