Somatom definition 64 slice ct scanner

As shown in Figure 2, 62 patients from Harbin (Heilongjiang Province) were scanned using a 256-slice CT scanner (Philips Healthcare, Cleveland, OH, US), 30 patients from Shuangyashan (Heilongjiang Province) were scanned with a Somatom Balance CT scanner (Siemens Healthcare, Forchheim, Germany), 27 patients from the Uygur autonomous region (Xinjiang Province) were examined with LightSpeed Plus (GE, Medical System, Milwaukee, USA), 21 patients from Chengdu (Sichuan Province) were examined with a 128-slice dual-source CT (Siemens Healthcare, Forchheim, Germany), and 10 patients from Xinxiang (Henan Province) were imaged with a Somatom definition 64 slice CT scanner (Siemens Healthcare, Forchheim, Germany). Twenty-five patients from Ankang (Shaanxi Province) were imaged with 16 slice, Optimal CT 520 (GE, Medical System, Milwaukee, USA), 34 patients from Langfang (Hebei Province) were imaged with BrightSpeed (GE, Medical System, Milwaukee, USA), and 12 patients from Tianjin (Hebei Province) were imaged with Aquilion 16 slice CT scanner (TOSHIBA, Medical Systems, Tokyo, Japan). All these CT images were reconstructed into a slice thickness of 1.0–5.0 mm. Scan were performed in the supine position during end-inspiration.

QCT images were acquired using Siemens Somatom Definition 64-slice CT scanner (Siemens AG, Erlangen, Germany) with a calibration Mindways QCT phantom (Mindways Software Inc., Austin, TX, USA). Scan parameters for CT scanning were as follows: 120 kV, 150 mAs, 1 mm slice thickness, 500 mm field of view(SFOV), and 512 × 512 matrix in spiral reconstruction and standard reconstruction. The Mindways calibration phantom was placed beneath the hip and scanned simultaneously. Both the hips were scanned by placing the patient in supine position from the top of the acetabulum to 3 cm below the lesser trochanter.

This retrospective observational study was conducted with consecutive patients older than 18 years with suspected AAS who underwent aorta CTA in the emergency department of an academic tertiary care center from January 2015 to September 2020. Patients were excluded if they were in a trauma-related condition, had prior AAS, or did not obtain a D-dimer plasma level from initial laboratory blood test.
During the study period, aortic surgery was available for 24 hours at our institution by thoracic surgeons. If the aortic dissection detection risk score (AAD-RS) was ≥1 or the clinician suspected an aortic emergency (acute aortic syndrome or traumatic aortic injury) among patients who visited the emergency department, D-dimer plasma levels were routinely measured at the time of initial blood sampling, and an aorta CTA scan was performed under the direction of the attending emergency physicians for differential diagnosis. D-dimer levels were measured by Sysmex CS-5100 (Sysmex, Kobe, Japan) with the quantitative automated immunoturbidimetric assay. The aorta CTA scan protocolized with a range of 1 cm superior to lung apices through aortic bifurcation (level of S1), was performed with a SOMATOM Definition 64-slice CT Scanner (Siemens, Erlangen, Germany), and the aorta CTA was read by a radiologist.