Typical computed tomography protocol for assessing the arteries
Unenhanced precontrast images are often, but not always, obtained. Some indications for obtaining unenhanced precontrast images include: suspected hemorrhage, penetrating trauma, evaluation of the aorta following stent or surgical repair, and suspected acute aortic syndrome.
Arterial phase images are obtained after the injection of 100 ml of iodinated contrast material mixed with saline at a rate of 4 to 5 ml per second, using bolus tracking, with a monitoring delay of 12 seconds and a scan delay of 6 seconds.
Venous phase images are not routinely obtained. Some indications for venous phase imaging include: suspected mesenteric ischemia, suspected hemorrhage, evaluation of an indwelling stent graft to detect an endoleak, and suspected venous thrombus.
