Optimal temporal windows and dose-reducing strategy for coronary artery bypass graft imaging with 256-slice CT

Autor: Yu-Xiang Guan, Yi-Wei Lee, Chen-Tau Su, Kun-Mu Lu, Wei-Yip Law, Liang-Kuang Chen
Rok vydání: 2013
Předmět:
Zdroj: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 731:309-314
ISSN: 0168-9002
DOI: 10.1016/j.nima.2013.04.011
Popis: Objective To determine the optimal image reconstruction windows in the assessment of coronary artery bypass grafts (CABGs) with 256-slice computed tomography (CT), and to assess their associated optimal pulsing windows for electrocardiogram-triggered tube current modulation (ETCM). Methods We recruited 18 patients (three female; mean age 68.9 years) having mean heart rate (HR) of 66.3 beats per minute (bpm) and a heart rate variability of 1.3 bpm for this study. A total of 36 CABGs with 168 segments were evaluated, including 12 internal mammary artery (33.3%) and 24 saphenous vein grafts (66.7%). We reconstructed 20 data sets in 5%-step through 0–95% of the R–R interval. The image quality of CABGs was assessed by a 5-point scale (1=excellent to 5=non-diagnostic) for each segment (proximal anastomosis, proximal, middle, distal course of graft body, and distal anastomosis). Two reviewers discriminated optimal reconstruction intervals for each CABG segment in each temporal window. Optimal windows for ETCM were also evaluated. Results The determined optimal systolic and diastolic reconstruction intervals could be divided into 2 groups with threshold HR=68. The determined best reconstruction intervals for low heart rate (HR 68) were 76.0±2.5% and 45.0±0% respectively. Average image quality scores were 1.7±0.6 with good inter-observer agreement (Kappa=0.79). Image quality was significantly better for saphenous vein grafts versus arterial grafts (P Conclusions We determined optimal reconstruction intervals and ETCM windows representing a good compromise between radiation and image quality for following bypass surgery using a 256-slice CT.
Databáze: OpenAIRE
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