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
Methods and materials
CTPA protocol
No written informed consent was required as scans were performed as per routine protocol:
- All patients underwent SDCT on Phillips iQOn Elite
- Tube voltages were set to 120kVp
- Vessel enhancement via injection of 50-75 ml of 350 mg/ml iodinated contrast material
- Bolus tracking performed at the level of pulmonary trunk with manual triggering
- All CTPA studies routinely contained a polyenergetic (120 kVP) and VMI (45keV) image set archived to PACS
Image and data analysis
A retrospective chart review was conducted via PACS for all CTPA examinations performed from March 2020 – May 2020. In the axial sections, circular regions of interests (ROIs) were placed at the main pulmonary trunk and attenuation (mean HU) was measured on both the VMI and polyenergetic data sets by a radiology registrar with 3 years of experience (Figure 1).
A nondiagnostic threshold of 250 HU for main pulmonary trunk attenuation was utilised, a value widely used in the literature [9].