Defining the optimal systolic phase targets using absolute delay time for reconstructions in dual-source coronary CT angiography.
To define the optimal systolic phase for dual-source computed tomography angiography using an absolute reconstruction delay time after the R-R interval based on the coronary artery motion, we analyzed images reconstructed between 200 and 420 miliseconds (ms) after the R wave at 20 ms increments in 21 patients. Based on the American Heart Association coronary segmentation guidelines, the origin of six coronary artery landmarks (RCA, AM1, PDA, LM, OM1, and D2) were selected to calculate the coronary artery motion velocity. The velocity of the given landmark was defined as the quotient of the route and the length of the time interval. The x, y and z-coordinates of the selected landmark were recorded, and were used for the calculation of the 3D route of coronary artery motion by using a specific equation. Differences in velocities were assessed by analysis of variance for repeated measures; Bonferroni post hoc tests were used for multiple pair wise comparisons. 1488 landmarks were measured (6 locations at 12 systolic time points) in 21 patients and were analyzed. The mean values of the minimum velocities were calculated separately for each heart rate group (i.e. <65; 65-80; and >80 bpm). The mean lowest coronary artery velocities in each segment occurred in the middle period of each time interval of the acquired systolic phase i.e. 280-340 ms. No differences were found in the minimal coronary artery velocities between the three HR groups, with the exception of the AM1 branch (p = 0.00495) between <65 and >80 bpm (p = 0.03), and at HRs of 65-80 versus >80 bpm (p = 0.006). During an absolute delay of 200-420 ms after the R-wave, the ideal reconstruction interval varies significantly among coronary artery segments. Decreased velocities occur between 280 to 340 ms. Therefore a narrow range of systolic intervals, rather than a single phase, should be acquired.
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. celengcsilla@gmail.com.|MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68 Varosmajor Street, 1122, Budapest, Hungary. celengcsilla@gmail.com.
Csilla
C
Celeng
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. hvadvala@partners.org.
Harshna
H
Vadvala
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. Stefan.puchner@meduniwien.ac.at.
Stefan
S
Puchner
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. amit.pursnani@gmail.com.
Amit
A
Pursnani
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. umeshsharmaphd@yahoo.com.
Umesh
U
Sharma
MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68 Varosmajor Street, 1122, Budapest, Hungary. kovatti@gmail.com.
Attila
A
Kovacs
MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68 Varosmajor Street, 1122, Budapest, Hungary. maurovich.horvat@gmail.com.
Pâl
P
Maurovich-Horvat
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. uhoffmann@partners.org.
Udo
U
Hoffmann
Cardiovascular Imaging, Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA. bghoshhajra@mgh.harvard.edu.
Brian
B
Ghoshhajra
D000328:Adult; D000368:Aged; D000465:Algorithms; D059925:Anatomic Landmarks; D001783:Blood Flow Velocity; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012039:Regional Blood Flow; D012189:Retrospective Studies; D013599:Systole; D013997:Time Factors
Absolute delay time; Coronary CT angiography; Dual-source CT; Systolic phase targets