Monika Dhopeshwarkar MD, Presenter: Nothing to Disclose

Narinder S. Paul MD, Abstract Co-Author: Research grant, Toshiba Corporation

Andre Martins Pereira MD, Abstract Co-Author: Nothing to Disclose

Visal Pen, Abstract Co-Author: Nothing to Disclose

Yves Louis Provost MD, Abstract Co-Author: Nothing to Disclose

To evaluate the selection of the optimal cardiac R-R interval for motion free coronary artery image reconstruction comparing a commercially available fully automated software to fixed phase and manual phase selection.

A prospective study of 107 consecutive patients referred for CT Coronary Angiography (CTCA). All patients received PO metoprolol (50mg or 100mg)and SL nitroglycerine 300mcg prior to the procedure unless contraindicated. CTCA was performed on 64 row MDCT (Aquilion, Toshiba, Japan) using a standard technique (120kVp,300-450mA,GR 0.33-0.40s). Raw data was reconstructed to provide motion free images of the coronary arteries using 3 techniques on all patients: Method 1-automated optimal phase selection using ˜PhaseXact˜ (Toshiba, Japan), Method 2-reconstruction at 75% of the R-R interval, Method 3- best phase selection by the CT technologist with reconstruction of 2 additional phases ± 20ms. All CTCA were reconstructed and analysed by a cardiac radiologist. The phase chosen to reconstruct the CTCA was noted and correlated to the Method (1,2 or 3) for phase selection

107 patients have been analysed (68M), mean age 61 (24-88). The correct phase for image reconstruction was identified by Method 1 (PhaseXact) alone in 24 patients (22%), Method 2 alone (75% R-R) in 16 patients (15%) and by Method 3 alone (Techs) in 34 patients (32%). The remaining 33 (31%) patients had the correct phase chosen by both Methods 1 and 2. In total, the correct phase was chosen by Method 1: in 57 patients (53%), Method 2: in 49 patients (46%) and Method 3: in 34 patients (32%). A combination of PhaseXact and 75% R-R interval identified the correct phase in 73 (68%) patients

Fully automated optimal phase selection (AOPS)outperforms using a fixed phase at 75% of the R-R interval or a manual technique for correct phase selection in patients having CTCA with 64 row MDCT. A combination of AOPS and 75% of the R-R interval identifies the best cardiac phase for coronary artery image reconstruction in the majority of patients

Fully automated optimal phase selection is a promising technique for determining the correct cardiac R-R interval for CT Coronary Angiography

Dhopeshwarkar, M, Paul, N, Pereira, A, Pen, V, Provost, Y, Cardiac CT Coronary Angiography: Evaluating ˜Best Phase˜ Selection Techniques.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5015842.html