Patrik Rogalla MD, Presenter: Nothing to Disclose

Phillip Tran MD, Abstract Co-Author: Nothing to Disclose

Henning Meyer MD, Abstract Co-Author: Nothing to Disclose

Sonja Kandel MD, Abstract Co-Author: Nothing to Disclose

To evaluate whether low-dose tube settings influence perfusion values obtained from dynamic volume CT imaging.

12 pigs (weight 67-74 kg) underwent a dynamic volume CT during suspended breathing. A miniature cuff-shaped ultrasound flow probe was surgically implanted at the right kidney artery in each pig prior to the CT examination. Two series were obtained in randomized sequential order: Series I using standard dose settings (100 kV, 200 mAs) and Series II using low-dose settings (100 kV, 20 mAs). 80 volumes were obtained over a time span of 180 seconds. Contrast media bolus (volume: 0.5 ml/kg BW) was injected over 3 seconds in both series, injection flow was adapted accordingly. The volume with the highest cortical enhancement was used to determine cortical kidney volume. Maximum slope method was applied for calculating perfusion values in both series. Results were statistically compared and correlated to the normalized flow values (true perfusion) gained from the flow probe. 

Average measured perfusion values for Series I and II were 187.4 (SD: 12.2) and 195.5 (SD: 27.2) min-1 (n.s.), true perfusion values (flow probe) were 195.0 for Series I and 212.0 in Series II (n.s. as well). The mean kidney volume was 167.3 ml. Correlation between Series I, II and true perfusion was r=0.79, r=0.71, respectively.

Low-dose scanning technique has marginal influence on CT perfusion measurements and could be used in order to reduce radiation dose in patients.

Radiation dose in CT perfusion imaging might be relevantly reduced as low-dose scanning techniques do not compromise perfusion results.

Rogalla, P, Tran, P, Meyer, H, Kandel, S, Does Low-Dose Imaging Technique Compromise CT Perfusion Results?.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11015583.html