Reproducibility of a Dynamic CT Pulmonary Perfusion Technique Using Only Two Volume Scans
Presentations
TH-B-207-5 (Thursday, 7/14/2022) 8:30 AM - 9:30 AM [Eastern Time (GMT-4)]
Room 207
Purpose: Existing dynamic CT perfusion (CTP) techniques are limited by their high radiation dose and lack of reproducibility. The purpose of this study is to investigate the reproducibility of a low-dose CTP technique using only two volume scans.
Methods: Seven Yorkshire swine (52.0±6.8kg) were used in the study with 40 independent CTP acquisitions using a 320-slice CT scanner. Dynamic CTP scans were performed twice with the same scan parameters. For each dynamic CTP acquisition, two volume scans were prospectively acquired. The first volume scan (50mA) was acquired before contrast injection. The second volume scan (full-dose) was acquired after intravenous contrast administration (370 mg/ml iodine, 0.5ml/kg, 5ml/s) with bolus-tracking within the main pulmonary artery and a time-to-peak delay. Two scan modes were used for the CTP acquisition: the volume scan mode (16 cm z-coverage, 0.35 s rotation time, 300mA) and a fast helical scan mode (23.6 cm z-coverage, ~2.5 s scan time, 200mA). Each pair of the prospective CTP measurements were quantitatively compared to each other by linear regression, Bland-Altman analysis and t-test. The CT dose index (CTDI) of the two-volume CTP using volume and helical scan modes were calculated to be 9.3mGy and 4.8mGy, respectively.
Results: The repeated CTP measurements using the volume scan mode were correlated by PVOL1=1.03PVOL2 - 0.82 mL/min/g (r=0.97, RMSE = 1.04, p =0.21). The repeated CTP measurements using the helical scan mode were correlated by PHEL1=0.93PHEL2 +1.07 (r = 0.98, RMSE = 1.00, p = 0.04).
Conclusion: The results show excellent reproducibility of the two CTP measurements using both volume and helical scan modes. The two-volume CTP using the helical scan mode enables the whole-lung dynamic CTP measurement.
Funding Support, Disclosures, and Conflict of Interest: Partially funded through a grant from Canon Medical Systems
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