Table 2 Parameters of CT imaging
Phase | Breathing position | Anatomical coverage | Tube voltage [kVp] | Reference tube current (eff.) [mAs] | Delay [s] | Rotation time [s] | Number of Acquisitions | Collimation [mm] | Slice thickness (recon.) [mm] | Pixel spacing [mm] | Reconstruction Kernel |
|---|---|---|---|---|---|---|---|---|---|---|---|
1) Standard 3-phasic CT scan (only performed if patient didn’t have an in-house CT scan of the abdomen within previous 4 weeks) Application of 80 ml of nonionic iodinated contrast agent; chaser bolus: 40 ml saline solution; bolus tracking in suprarenal aorta (threshold: 100 HU). | |||||||||||
Native | Inspiratory breath-hold | Upper abdomen | 120 | 210 | 4 | 0.5 | Helical | 2 × 64 × 0.6 | 3 | Variable | I30f |
Arterial | Inspiratory breath-hold | Upper abdomen | 120 | 210 | 10 | 0.5 | Helical | 2 × 64 × 0.6 | 3 | Variable | I30f |
Portal-venous | Inspiratory breath-hold | Whole abdomen | 120 | 210 | 50 | 0.5 | Helical | 2 × 64 × 0.6 | 3 | Variable | I30f |
15 min break for contrast medium clearance (as applied in previous studies [35, 42]). Patient remains on CT table. Patient is instructed to a shallow breathing technique for reducing motion artefacts in the perfusion acquisition. | |||||||||||
2) Native scan for verification of the correct position of the examination volume for CT perfusion imaging (performed in every patient) | |||||||||||
Native | Shallow breathing | Pancreas | 120 | 210 | n.a. | 0.5 | Helical | 2 × 64 × 0.6 | 3 | Variable | I30f |
3) CT perfusion imaging (performed in every patient) Application of 80 ml of nonionic iodinated contrast agent; chaser bolus: 40 ml saline solution; flow rate: 5 ml/s. | |||||||||||
CT perfusion imaging * | Shallow breathing | Tumor area | 80 | 270 | 13 | 0.5 (full rotation); 1.5 (cycle time) | 34 | 32 × 0.6 | 3 × 5.0 | 0.6 / 0.6 | B30f |