Brilliance 64

CT images were obtained by different multi-detector CT (MDCT) scanners. The following CT machines were used: Philips Brilliance 64 (Philips Healthcare, DA Best, the Netherlands), Discovery HD750 (GE Healthcare, Milwaukee, Wisconsin, USA), and optima 670 (GE healthcare, Tokyo, Japan). Dynamic CT images consisting of the unenhanced, arterial, portal venous and delayed phase images were obtained. All CE-CT were with the intravenous administration of Ultravist (Ultravist 300, Bayer Schering Pharma AG, 1.2 ml/kg body weight) at a rate of 3.0 ml/s followed by 40ml saline solution through the elbow vein via a power injector. The imaging parameters were as follows: tube voltage, 120 kVp; tube current, 200–400 mAs; a helical pitch of 1.375; slice thickness, 3.0 mm; slice interval, 3.0 mm, and a reconstruction interval of 1.25 mm. Fourteen cases of PNETs and 31 cases of PDAC patients underwent a 4-phase CT examination (unenhanced, arterial, portal venous, and delayed phase). The other 4 cases of PNETs and 8 cases of PDAC patients underwent a 3-phase CT examination (unenhanced, arterial and portal venous phase). The mean imaging time delay was 30 s for the arterial phase, 60s for the portal venous phase, and 120s for the delayed phase.

Coronary CTA was performed according to the Society of Cardiovascular Tomography (SCCT) guidelines^{7 (link)} using the following multi-detector CT scanners: Philips Brilliance 64, Philips Medical Systems, Best, the Netherlands; Somatom Definition AS, Siemens Healthineers, Germany. Lesions on coronary CTA were then categorized based on the severity of stenosis: 0% (no CAD) and 1–49% (non-obstructive CAD). Four classifications were defined according to coronary CTA: Traditional NOCAD classification: no CAD (0% stenosis) and NOCAD (1–49% stenosis). NOCAD-RADS classification was defined according to the highest degree of coronary stenosis: NOCAD-RADS 0 (0% stenosis), NOCAD-RADS 1 (1–24% stenosis) and NOCAD-RADS 2 (25–49% stenosis). Duke prognostic NOCAD index: Duke NOCAD 0 (0% stenosis in all vessels), Duke NOCAD 1 (1–24% stenosis, or at most 1 with 25–49% stenosis) and Duke NOCAD 2 (≥ 2 vessels of 25–49% stenosis). Stenosis proximal involvement (SPI) classification: SPI 0 (no CAD, 0% stenosis), SPI 1 (1–49% stenosis with no proximal lesion) and SPI 2 (1–49% stenosis with proximal lesion) (Fig. 2). We defined proximal involvement as any plaque was present (by visual estimation) in the main or proximal segments of coronary artery (left main, left anterior descending artery, left circumflex artery, or right coronary artery).
Figure 2

SPI classification assessed by coronary CTA.

To analyze the behavior of the ALL, three fresh-frozen human thoracolumbar spine segments (consisting of 6 FSUs from T12 to sacrum) were obtained through an ethically approved international donation program (Science Care Inc., Phoenix, AZ, USA) (Figure 1). The donors were all Caucasian, two males and one female (Table 1). Clinical computed tomography (CT) scans (Philips Brilliance 64, Philips Healthcare, Cleveland, OH, USA, with a resolution of 0.4 mm) were used to verify the state of degeneration and to determine the bone mineral density (BMD) [20 (link)]. No fractures, tumors were observed; however, all specimens showed some osteophytes, as can be expected with aged donors [21 (link)].
The spines were carefully cleaned on the anterior side, removing fat tissue and muscles in order to expose the ALL, while all the posterior osteo-ligamentous structures were left intact. The two extremities of the specimens were potted in poly methyl-methacrylate cement (PMMA, Technovit 3040, Heraeus Kulzer, Werheim, Germany). Specimen hydration was granted by spraying saline solution on their surface during the tests.

All radiographs (RX) were performed in a standard fashion, as already described in a previous paper [1 (link)]. Plain anteroposterior (AP) and lateral (LAT) view were acquired with a detector-to-tube distance of 1.15 m and using calibrators for the correction of magnification (Ysio, Siemens Healthcare, Erlangen, Germany).
All CT scans were performed on a 64-slice CT scanner (Philips Brilliance 64, Philips Healthcare, or Somatom Definition AS, Siemens Healthcare) using our standard protocol for knee joints. Technical specifications: tube voltage 120 kV, tube current 250 mAs, collimation 64 × 0.625 mm, and rotation time 0.5 s. Axial images were reconstructed with 1 mm slice thickness.
All MRI scans consisted of sagittal, coronal and axial sequences and were performed on a 3.0 T magnet (Skyra-fit, Siemens Healthcare, Erlangen, Germany) with a dedicated knee coil in supine position with stretched knee, as a part of the standard MRI procotol [2 (link)].