title: The feasibility of halfcycle reconstruction in high heart rates in coronary CT angiography using 320-row CT.
abstract: Our aim was to investigate when halfcycle reconstruction (HCR) was feasible in patients who were predicted to have a heart rate over 65 bpm in coronary CT angiography (CTA) using 320-row CT. Seventy-four patients who underwent multiple heart beat scanning were included. The time to reach 230 HU at the ascending aorta during the bolus tracking scan was recorded (T230). HCR image and multicycle reconstruction (MCR) image were reconstructed for each patient. Image quality for each coronary segment was rated on a 3-point scale (3: good, 1: poor). For each patient, we determined that a single beat acquisition was feasible for diagnosis (HCR group) when the number of segments graded score 1 in the HCR image was the same or less than that in the MCR image. Otherwise, we included the patients in the MCR group. HCR group and MCR group included 38 and 36 patients, respectively. Regression analysis showed that body height >1.66 m (odds ratio (OR), 5.74; CI 1.59-25.6; p < 0.007), T230 >16 s (OR 3.11; CI 1.07-9.58; p = 0.04), and heart rate ≤72 bpm (OR 3.18; CI 1.11-9.49; p = 0.03) were related with the HCR group. When all three criteria were fulfilled, the calculated probability that MCR would improve image quality was only 7 %. When the heart rate is ≤72 bpm, single heart beat acquisition is feasible for patients with body height >1.66 m and T230 > 16 s in coronary CTA using 320-row CT.
authors.affiliation: Department of Radiology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. tomizawa-tky@umin.ac.jp
authors.forename: Nobuo
authors.initials: N
authors.lastname: Tomizawa
authors.forename: Kodai
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Rumiko
authors.initials: R
authors.lastname: Torigoe
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kiryu
authors.forename: Kuni
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D000368:Aged; D001827:Body Height; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D013997:Time Factors