How a Perfusion CT Works

A perfusion computed tomography, or CT, scan is a specialized form of CT scan used to measure the blood volume and flow rates in the brain. A variety of medical conditions can be identified by using this diagnostic tool.

Administration

• In perfusion CT scanning, the patient's brain is scanned both with and without contrast. After initial scans without contrast, the patient is given an iodinated contrast material by IV administration and additional scans are taken as the contrast travels through the patient's veins. A third series of scans is taken after the contrast has passed through the veins. The test lasts from 10 to 25 minutes.

Indications

• The primary indication for perfusion CT scan is stroke, but the study may also be used to detect and locate blood clots, to locate possible brain tumors, and to assess blood flow, rate of flow and blood volume in the brain.

Contraindications

• Perfusion CT scans are not recommended for women who are pregnant because the radioactive material in the contrast dye can harm the fetus. Women who are breastfeeding should wait 24 hours after having the test before continuing to breastfeed. Perfusion CT is contraindicated in persons who are allergic to iodine. The test is also contraindicated in patients with diabetes and those with renal failure.