Pulmonary angiography using 16 slice multidetector computed tomography in normal dogs.

We report a canine computed tomography (CT) pulmonary angiography technique using multidetector CT (MDCT). CT pulmonary angiography using a 16 slice MDCT was performed on five healthy, anesthetized beagles. A helical acquisition with pitch of 1.4 was used. The time delay for the angiographic study was determined using a bolus-tracking program. A dose of 400mg I/kg of nonionic contrast medium (Iohexol 300mgI/ml) was administered to each dog via a cephalic catheter using an angiographic power injector at a rate of 5ml/s. In two dogs a second study, using a contrast medium dose of 200 and 600mg I/kg was performed. Arterial enhancement of transverse and reformatted images was classified subjectively as excellent, good, or poor, and assessed objectively by measuring Hounsfield units at the right main pulmonary artery. Angiographic studies were evaluated by two radiologists to determine the number of subsegmental arterial branches visualized. The median number of subsegmental arterial branches identified was five (range: 2-7). Based on the time attenuation curve obtained by the bolus-tracking program, there was consistent enhancement of the right main pulmonary artery beginning at 6 s and peaking at 8 s in 4/5 dogs. The contrast medium dose of 400mg I/kg produced good to excellent vascular enhancement in the same 4/5 dogs. A dose of 200mg I/kg resulted in poor enhancement. CT pulmonary angiography using MDCT and an automated bolus-tracking program allows rapid, consistent evaluation of the pulmonary vasculature using a single dose of 400mg I/kg of contrast medium. (C) 2010 Veterinary Radiology & Ultrasound, Vol. 52, No. 2, 2011, pp 173-178.