High-pitch computed tomography pulmonary angiography with iterative reconstruction at 80 kVp and 20 mL contrast agent volume

Abstract

CTPA is feasible at 80 kVp using only 20 ml of contrast agent. High-pitch CTPA at 80 kVp has an effective dose under 1 mSv. This CTPA protocol can obtain sufficient image quality in normal-weight individuals.

25th Anniversary of European Radiology

“…Lu et al attempted to reduce both the radiation dose and the amount of contrast material in CT pulmonary angiography (CTPA) simultaneously [15]. Low tube voltage (80 kVp) and a high-pitch technique were employed.…”

Double-Low Dose Protocol of Computed Tomography Pulmonary Angiography (CTPA) in the Diagnosis of Pulmonary Embolism: A Feasible Approach for Reduction of Both Contrast Medium and Radiation Doses

“…This has been widely reported in cardiovascular CT imaging, such as coronary CT angiography, [21][22][23][24] abdominal aortic imaging, 25,26 and CTPA. [27][28][29][30] Similarly, CIN has been drawing more attention in the recent literature due to routine use of contrast medium injection during CT scans including CTPA. Thus, reduction of contrast medium volume is equally important as reduction of radiation dose, which is shown in some studies.…”

“…Their results showed significant improvement in the visualization of pulmonary vessels with use of low contrast medium. Another study by Lu et al 30 reported their experience of further lowering the contrast medium to 20 ml with tube voltage of 80 kVp and high-pitch protocol. Of 100 patients with suspected pulmonary embolism, 50 patients were scanned with the CTPA protocol of 100 kVp, pitch of 1.2 and 60 ml of contrast medium, while another 50 patients with the protocol of 80 kVp, pitch of 2.2 and 20 ml of contrast.…”

“…High-pitch and low kVp (80 kVp) protocol has been reported in a number of studies demonstrating the further dose reduction to less than 1 mSv without compromising diagnostic image quality. 30,37,38,41 However, lowering kVp and increasing pitch level will increase image noise, thus may impair diagnostic performance of CTPA, hence, it is not widely implemented in clinical practice. It has been reported that better image quality was achieved with a pitch of 2.0 when compared to the CTPA protocol using a pitch of 3.0.…”

“…Of these reported double lowdose CTPA studies, most of them were performed in patients with normal BMI (mean value <25 kg/m 2 ). 30,35 In contrast, Boos and colleagues presented diagnostic quality images in large patients as well, although they did not include extremely obese patients. The limitations of previous studies including only normal sized patients or with missing data on BMI 43 have been overcome by Boos' study, with findings offering additional value to the current literature.…”