Definition flash ct

All methods were carried out in accordance with the Declaration of Helsinki.
The magnetic resonance data were obtained from a 35-year-old male (body weight 60 kg, height 172 cm) who had received partial medial meniscectomy (PMM) using an MRI scanner (SIEMENS 3.0 T Skyra, Germany). During the scan, the subject was in a lying position, and 3D proton density-weighted imaging sequence was selected. A dual-source 128-slice CT equipment (SIEMENS Definition Flash CT, Germany) was used for computed tomography scan of the same subject. The lower extremities were scanned in a neutral posture with a slice distance of 0.625 mm and a field of view of 500 mm.

The phantom scans were performed on a Definition Flash CT (Siemens Healthineers, Forchheim, Germany). The phantom was positioned on the couch, supine, with feet towards the gantry. Each study started with an anterior-posterior localiser radiograph (120 kV, 35 mA), followed by a sequential pre-monitoring slice and three sequential monitoring slices before the actual CTPA scans were performed. All monitoring slices were placed between lumbar spine vertebrae 4 and 5 (120 kV, 20 mAs, 1 × 10). Two identical spiral scans of a range of 32 cm without and with patient shielding were performed for standard CTPA. The short CTPA scans were the same except that the scan length was 22 cm. Scanning parameters were set according to the clinical protocol at the author’s site: 120 kV reference tube voltage, 85 mAs reference tube load, pitch 1.5, rotation time 0.28 s, and detector configuration 128 × 0.6. Tube current modulation (CARE Dose 4D) and automatic tube voltage selection (CARE kV) were used as in clinical practice at the site. Shielding was included in the inferior part of the localisers but not in the region of the spiral scans (Figure 1).