Yonggao Zhang, Presenter: Nothing to Disclose

Jianbo Gao MD, Abstract Co-Author: Nothing to Disclose

Shaohua Hua, Abstract Co-Author: Nothing to Disclose

Jie Liu, Abstract Co-Author: Nothing to Disclose

Shuting Liu, Abstract Co-Author: Nothing to Disclose

To find the best cardiac phase for measuring the antral septal defect (ASD) and ventricular septal defect (VSD) area in Coronary CT angiography (CCTA) using the echocardiography and surgical results as references of standard.

20 cases of ASD and 16 cases of VSD underwent retrospective ECG-gated CCTA. The original data were reconstructed at 10 cardiac phases (5% - 95%). Multiple planar reformation, maximum intensity projection, curve planar reformation and volume rendering images were obtained for measuring ASD and VSD areas.

The areas for the 20 ASD cases were 402.83±356.12mm2 and 385.52±340.69mm2 from surgical and ECHO results, respectively. There was no difference between them. The CCTA measurements in mm2 were: 82.86±71.91, 93.58±81.01, 135.44±125.64, 203.09±194.79, 375.79±335.63, 402.69±354.25, 374.74±332.44, 212.99±216.59, 180.96±179.33 and 102.77±111.81, for cardiac phases at 5% to 95% (5% increment), respectively. The differences between surgical results and measurements at 45%, 55% and 65% phases in CCTA were not statistically significant (P>0.70), with the smallest and biggest differences at 55% and 5% phases, respectively. The areas for the 16 VSD were 180.77±202.24 mm2 and 174.91±198.48 mm2 from surgical and ECHO results, respectively. There was no difference between them. The CCTA measurements in mm2 were 183.58±205.93, 169.76±194.65, 108.27±122.09, 73.96±83.31, 59.87±66.84, 47.61±48.05, 66.23±75.98, 81.32±93.59, 107.72±124.04, and 170.54±196.51 for cardiac phases at 5% to 95% (5% increment), respectively. The differences between surgical results and CCTA results at 5%, 15%, 25%, 35%, 75%, 85% and 95% phases were not significant (P>0.05), with the smallest and biggest difference at 5% and 55% phases, respectively.

With appropriate phase selection, CCTA can provide accurate area measurements for ASD and VSD. In CCTA, the maximum and minimum areas of ASD appeared in 55% phase (slowing ejection period) and 5% phase (atrial systolic period), respectively. The maximum areas of VSD appeared in 5% phase and 55% phase, respectively.

This research has good guiding value in MDCT scanning no matter adopt retrospective or prospective ECG-gated technology.

Zhang, Y, Gao, J, Hua, S, Liu, J, Liu, S, Finding the Best Cardiac Phases for Measuring the Areas of Antral and Ventricular Septal Defects Using 64 Detector Spiral CT—In Comparison with Echocardiographic and Surgical Results.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12035517.html