Keywords:
Pulmonary vessels, CT-Angiography, Contrast agent-intravenous, Imaging sequences, Technical aspects, Embolism / Thrombosis
Authors:
S. Do, K. Dobeli, C. Hacking; Herston, QLD/AU
DOI:
10.26044/ranzcr2021/R-0515
Conclusion
Multiple factors can lead to nondiagnostic CTPA, for example technical factors such as injection timing and patient factors such as cardiac output. This may lead to additional radiation from repeat CTPA or delayed diagnosis with further V/Q scan.
Our preliminary experience with SDCT demonstrates that despite nearly 20% nondiagnostic opacification on polyenergetic CTPA, less than 2% of all examinations had repeat CTPA or subsequent V/Q scan performed. In our experience this is likely due to the demonstrated increased pulmonary vasculature opacification on VMI which is routinely reviewed side by side with the polyenergetic series when assessing for PE. These results of increased VMI contrast opacification appear aligned with a similar study by Murphy et. al [10].
In summary, the use of SDCT and VMI to increase pulmonary arterial vascular opacification practically eliminates nondiagnostic CTPA examinations. Further studies into the diagnostic accuracy of 45 keV VMI compared to other monoenergetic levels and resultant patient outcomes for PE would be useful to further this research.