Stephan Skornitzke, Presenter: Nothing to Disclose

Franziska Fritz, Abstract Co-Author: Nothing to Disclose

Miriam Klauss MD, Abstract Co-Author: Nothing to Disclose

Gregor Pahn DIPLPHYS, Abstract Co-Author: Nothing to Disclose

Jens Hansen DIPLPHYS, Abstract Co-Author: Nothing to Disclose

Jessica Hirsch, Abstract Co-Author: Nothing to Disclose

Lars Grenacher MD, Abstract Co-Author: Nothing to Disclose

Hans-Ulrich Kauczor MD, Abstract Co-Author: Research Grant, Boehringer Ingelheim GmbH Research Grant, Siemens AG Research Grant, Bayer AG Speakers Bureau, Boehringer Ingelheim GmbH Speakers Bureau, Siemens AG Speakers Bureau, Novartis AG

Wolfram Stiller PhD, DIPLPHYS, Abstract Co-Author: Nothing to Disclose

Breathing motion necessitates motion-correction for CT-perfusion measurements in abdominal organs. Six different scenarios were compared for assessing the impact of rigid and deformable motion-correction, as well as Dual-energy (DE) post-processing, on CT-perfusion measurements.

For 12 patients with suspected recurrent pancreatic carcinoma, DE CT-perfusion sequences were dynamically acquired over 51s (34 acq.). Three algorithms for motion-correction of image data were evaluated: rigid (RR) and non-rigid (NR) registration of commercially available CT-perfusion software (BodyPCT/syngo.via Body Perfusion, Siemens Healthcare, Forchheim, Germany), custom deformable registration (DR, demons algorithm), and a control group (CG) without motion-correction. All algorithms used 80kVp images, additionally DR was applied to DE-blended (DR-DE) and virtual non-contrast images (DR-VNC). After motion-correction, perfusion maps were calculated using a combined Maximum-Slope/Patlak-model. For quantitative evaluation relative changes in metric values of the motion-corrected images, R2, and residuals of the perfusion model fits were calculated. For qualitative evaluation three blinded, experienced radiologists rated motion-correction quality and resulting perfusion maps on a 4-point Likert-Scale (1=worst, 4=best). A significance level of p=0.05 was used.

For the motion-corrected images mean ratings differed significantly (DR and DR-DE 3.1, NR 2.9, DR-VNC 2.8, RR 2.7, CG 2.6), with the exception of comparing DR to DR-DE, and RR to the control group. DR and DR-DE achieved the highest reduction in metric values (DR 48.5%, DR-DE 45.6%, NR 29.2%, DR-VNC 22.8%, RR 0.6%, CG 0%, p<0.05 for all). Regarding perfusion maps, DR and DR-DE were rated highest (2.8/2.8, p<0.05 for all) and had significantly higher R2 and lower residuals. NR (2.5) was rated significantly higher than RR (2.1) or the CG (2.2; DR-VNC 2.4), with significantly higher R2 and lower residuals.

Deformable motion-correction improves the spatial alignment of the target region and the fit of CT-perfusion models. The use of DE-blended images and DE-VNC images for deformable registration offers no significant improvement.

CT-perfusion is a valuable tool for detecting isodense tumors, and the evaluated deformable algorithms for correction of breathing-induced abdominal organ motion allow for more accurate measurements.

Skornitzke, S, Fritz, F, Klauss, M, Pahn, G, Hansen, J, Hirsch, J, Grenacher, L, Kauczor, H, Stiller, W, Qualitative and Quantitative Evaluation of the Effectiveness of Rigid and Deformable Motion-correction Algorithms Using Dual-energy CT-images in View of Application to CT-perfusion Measurements in Abdominal Organs Affected by Breathing Motion.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14004834.html