Objective evaluation of vessel attenuation in multidetector-row computed tomographic pulmonary angiography using high-density contrast material for the detection of pulmonary embolism.

Objective: The purpose of this study was to analyze the pulmonary vessel enhancement obtainable using high-density contrast material and saline flushing with automated bolus tracking for multidetector-row computed tomographic (MDCT) pulmonary angiography in a routine clinical setting.

Methods: Attenuation values of pulmonary vessels were retrospectively measured in 51 CT scans performed on a 40-channel MDCT for unselected emergency patients with clinically suspected pulmonary embolism.

Results: Mean vascular attenuation measured 326.7 +/- 104 Hounsfield units (HU) in the pulmonary trunk and 299.1 +/- 102 HU in the left distal lower lobe artery. Mean vascular attenuation values in the distal lower lobe artery were equal or higher than 150 HU for 94.1% (48/51) of patients.

Conclusions: In conclusion, the combination of high-density contrast media and saline flushing with automated bolus tracking on a fast CT scanner reliably results in a homogenously high attenuation of pulmonary vessels, allowing precise delineation of clots down to the subsegmental level in MDCT pulmonary angiography.