Abhishek Keraliya

To quantify the radiation dose reduction achievable by minimizing z-axis coverage in 320-detector coronary computed tomography angiography (CCTA). We retrospectively reviewed 130 CCTAs performed on 320-detector CT that offers up to 16cm z-axis coverage (adjustable in 2cm increments), allowing complete coverage of the heart in a single gantry rotation. For each CT we obtained the radiation dose (CTDI_vol and DLP), measured the z-axis field of view and measured the craniocaudal cardiac size (distance from the left main coronary artery to the cardiac apex).We calculated the radiation dose savings achievable by reducing the z-axis coverage to the minimum necessary to cover the heart using 320 X 0.5mm (max 16cm) and 256 X 0.5mm (max 12.8cm) detector collimations. Results are expressed as mean ± standard deviation. The mean craniocaudal cardiac size was 10.5±1.0cm, with 85% (n=112) of CCTAs performed with 16cm of z-axis coverage. The mean dose length product (DLP) was 417.6±182.4mGy.cm, with the mean DLP saving achievable using the minimum z-axis coverage required to completely image the heart is 96.2±47.4mGy.cm, an average dose reduction of 26.9±7.0%. Z-axis coverage of ≤12cm was adequate for 92% and 12.8cm for 98% of subjects Using the minimal z-axis coverage to adequately image the heart is a simple step that can reduce in DLP in 320-detector CCTA by approximately 27%. Z-axis coverage of ≤12cm is adequate for 92%, 12.8cm for 98% and 14cm for 100% of patients undergoing CCTA Reducing z-axis coverage in 320-detector CCTA can reduce DLP by approximately 27%.

Aortic infections are uncommon clinical entities, but are associated with high rates of morbidity and mortality. In this review, we focus on the cross-sectional imaging appearance of aortic infections, including aortic valve endocarditis, pyogenic aortitis, mycotic aneurysm and aortic graft infections, with an emphasis on CT, MRI and PET/CT appearance. Teaching Points • Aortic infections are associated with high morbidity and mortality. • CT, MRI and FDG PET/CT play complementary roles in aortic infection imaging. • Radiologists should be vigilant for aortic infection manifestations to ensure timely diagnosis.

The identification of characteristic genetic alteration in gynaecologic malignancies has opened the door for molecular targeted therapy. The purpose of this review is to provide a primer for the radiologist on these agents with emphasis on the role of imaging in treatment response assessment and drug toxicities. The use of targeted therapy in gynaecological malignancies will likely increase in the future and make the role of radiologist critical in response assessment and detection of toxicities.