Tomas Jurencak, Presenter: Nothing to Disclose

Leen van Garsse, Abstract Co-Author: Nothing to Disclose

Bastiaan Kietselaer, Abstract Co-Author: Nothing to Disclose

Joachim Ernst Wildberger MD, PhD, Abstract Co-Author: Nothing to Disclose

Marco Das MD, Abstract Co-Author: Research Consultant, Bayer AG Research Grant, Siemens AG Speakers Bureau, Siemens AG

High pitch scanning of the aortic root up to femoral arteries as pre-TAVI (Transcatheter aortic valve implantation) assessment has recently evolved. The purpose of this study was to compare non-ECG-triggered high pitch scanning with comprehensive retrospective ECG-gated helical scanning of the aortic root.

46 consecutive TAVI candidates underwent ECG-gated low pitch (0.17) helical scanning of aortic valve region followed by a high pitch (3.0) non-ECG-gated whole aorta CTA (the second generation dual source scanner). Anatomical structures within aortic root and valve for pre TAVI planning were measured in both scans and compared: (1)short and (2)long axis of aortic annulus, annulus to (3)right and (4)left coronary ostia distance, (5)ascending aorta, aortic root at the level of (6)right and (7)left coronary artery ostia, (8)middle portion of aortic root and (9)left and (10)right aortic leaflet length. The measurements from 11 different time points (20 ms and 10% - 100%) from the ECG-gated scans were compared to the non-ECG-triggered high pitch scan using paired-sample t-test.

No statistically significant difference was found for annulus in long axis, left and right leaflet length and aortic root at left coronary ostium level. Significant differences were found for distance from annulus to right and left coronary ostia in four out of eleven timepoints (p<0.05). Annulus in short axis in high pitch scan was significantly different for time points less than 40% of the RR-interval. The aortic root at the right coronary ostium level (p<0.05), ascending aorta and aortic root in the middle portion (p<0.001) were significantly different in eight or more timepoints.

Measurements of annulus in short axis from high pitch scans were significantly different when compared to systolic images and measures of ascending aorta and aortic root in the middle portion were significantly different through the whole cardiac cycle. Functional information seems to be crucial for procedure planning. The high pitch non-gated data acquisition is well recommended for evaluation of vascular access.

Since aortic root acquires the biggest dimensions in systole, measuring e. g. aortic annulus in non-ECG-triggered high pitch scans could lead to underestimation of the prosthesis size.

Jurencak, T, van Garsse, L, Kietselaer, B, Wildberger, J, Das, M, Comparison of High Pitch Non-ECG-triggered MDCT of the Aortic Root with Retrospective ECG-gated Helical MDCT, Measurements of Aortic Root and Aortic Valve in Pre-TAVI Assessment.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12029964.html