Contrast agents used in CT scans are mainly water-soluble contrast agents and are administered intravascularly. Unlike contrast agents used in conventional X-rays, which can be non-water-soluble, they are mainly administered orally or by enema through natural cavities.

Contrast agents are often used in some imaging diagnostic methods such as: X-ray, CT to help improve images, distinguish between normal and pathological images or help narrow down the diagnosis based on the contrast agent absorption characteristics of normal and pathological tissues. So when is it necessary to use contrast agents?

Ulcerative colitis is a chronic inflammatory bowel disease affecting the colon with an unclear pathogenesis. The disease can be diagnosed and evaluated by many methods, including X-ray and CT Scan.

Computed tomography colonography, also known as virtual colonoscopy (VC), was introduced in 1994 by Vining et al. They were the first to describe this modified computed tomography (CT) scan of the large intestine as a diagnostic test for colorectal carcinoma and polyps. Since then, virtual colonoscopy has become an essential test in the imaging of polyps and occult colorectal cancer in patients who are not candidates for optical colonoscopy.

Acute subdural hematoma is a blood clot that forms under the dura mater within 72 hours of injury. Treatment of acute subdural hematoma requires aggressive treatment, sometimes requiring emergency surgery because the disease has a high mortality rate and can leave serious sequelae.

Liver abscess is a condition in which liver cell tissue is destroyed, forming a pus pocket. With the advancement of science and technology today, diagnosing liver abscess has become easier. In particular, abdominal and pelvic scans are often prescribed for hepatobiliary diseases, including liver abscess.

Epiploic appendagitis is a rare inflammatory condition that affects the small fat-filled sacs (epiploic appendages) of the colon. Today, with the use of ultrasound and CT scanning in the evaluation of acute abdominal pain, epiploic appendagitis can be detected by its characteristic imaging features.