General electric lightspeed vct 64 slice platform

Standard protocol non-contrast cardiac-gated CT scans for CAC scoring were performed. Electron beam tomography was used in 93% of scans, while multi-detector CT (MDCT) was performed in 7% of scans. Previously no clinically significant difference in CAC scoring has been demonstrated between these scanning technologies (15 (link)). In this analysis, approximately 13% of patients were scanned with the Imatron C-100 scanner, 38% with the Imatron C-150, 38% with the C-300 and 3.5% with the e-speed scanner (GE-Imatron). The rest of the scans (7%) were performed on a 4-slice MDCT scanner (Somatom Volume Zoom, Siemens) and the General Electric LightSpeed VCT 64-slice platform (GE Healthcare). This has been previously described in the CAC consortium design and rationale (13 (link)). CAC was quantified in Agatston units in all participants and considered prevalent if CAC >0 and also categorized as CAC 0, CAC 1-99, 100-399, and CAC ≥ 400.

Non-contrast cardiac-gated CT scans for CAC scoring were performed at each individual site according to a common standard protocol for each scanner technology. CAC was quantified using the Agatston method in all patients. Most patients were scanned using electron beam tomography (EBT, approximately 93% of scans), while more recent CAC data at two sites was obtained using multi-detector CT (MDCT, approximately 7% of scans). Prior studies have demonstrated no clinically meaningful differences between CAC score derived from EBT versus MDCT scanners^{11 (link)}. In total, approximately 13% of patients were scanned with the Imatron C-100 scanner, 38% with the C-150, 38% with the C-300, and 3.5% with the e-Speed scanner (GE-Imatron). The remaining scans (7%) were performed on a 4-slice MDCT scanner (Somatom Volume Zoom, Siemens Medical Solutions) and the General Electric LightSpeed VCT 64-slice platform (GE Healthcare).
Vessel-specific Agatston scores were available in 54,678 patients (82%), total number of calcified lesions in 45,615 patients (68%), volume scores in 34,024 patients (51%), density (CT attenuation) of calcified lesions in 20,052 patients (30%), thoracic aortic calcium presence (41,066 [62%]) and scoring in 34,024 patients (51%), aortic valve calcification in 10,007 patients (15%), and mitral valve calcium and volume scores in 10,008 patients (15%).

CAC scans were performed in accordance with standard protocols (18 (link)). Because of the current study nature to investigate >10-year death for patients, electron beam tomography was obtained in approximately 93% of patients. In total, approximately 13%, 38%, 38% and 3.5% of patients were scanned with the Imatron C-100 scanner, the C-150, the C-300, and the e-Speed scanner (GE-Imatron), respectively. More recent data at two sites was collected using multidetector CT in 7% of patients on a 4-slice MDCT scanner (Somatom Volume Zoom, Siemens Medical Solutions) and the General Electric LightSpeed VCT 64-slice platform (GE Healthcare). Due to the long-term follow-up, most of the scans (>90%) were performed by electron beam tomography and the rest were scanned by multidetector CT. CAC and extracoronary calcification including thoracic aortic calcification (TAC), aortic valve calcification (AVC) and mitral valve calcification (MVC) were scored using Agatston method (19 (link)). Besides, CAC scores as well as volume score and mean CAC densities for left main and other main three vessels were also available. Additional information regarding CAC including total number of CAC plaques, CAC volume scores, CAC density, TAC scores, AVC scores and MVC scores were available in 68%, 51%, 30%, 51%, 15% and 15% of the cohort, respectively.