Computed tomography pulmonary angiography using high-pitch dual-source scanner technology

OBJECTIVES: To compare use of ultra-fast high-pitch dual-source free-breathing computed tomography pulmonary angiogram (CTPA) with conventional standard-pitch single-source breath-hold CTPA. METHODS: This retrospective comparative study was conducted in Radiology Department at King Fahad Military Medical Complex Dhahran, Saudi Arabia from July 2016 to December 2017. Patients (N=130) were divided into 2 groups, each having 65 consecutive patients; Group-1 (single-source CT) and Group-2 (dual-source CT). Previously treated pulmonary embolism cases, pregnant patients and those with incomplete data were excluded. Image quality was subjectively assessed by 2 readers for adequacy of contrast opacification and pulmonary vessel outline, and presence of artifacts (breathing motion, cardiac pulsation, and contrast related). Scan acquisition times and radiation doses were also compared. Chi-square and t-test were used to determine association. RESULTS: Improved image quality (optimal studies without artifacts 91%) was seen in Group-2 compared to Group-1 (optimal studies without artifacts 75.4%). Also, reduced scan time (1-2 sec.) and radiation dose (mean dose length product (DLP)-248 mGy-cm) were observed in Group-2 compared to Group-1 (scan time- 6.5 sec, mean DLP-375). Results were found significant (p<0.05). CONCLUSION: High-pitch dual-source CT with free-breathing yields better image quality, reduces image acquisition time and radiation doses.