Table 2:
CT Scanning Parameters
| Siemens |
GE |
||||||
|---|---|---|---|---|---|---|---|
| Parameter | SOMATOM Definition | SOMATOM Force | Discovery CT750 HD | Light Speed | Revolution | Philips Brilliance | Total |
|
| |||||||
| CT parameter | |||||||
| Tube voltage (kVp) | |||||||
| 100 | 45 | 18 | NA | NA | NA | NA | 63 |
| 120 | 33 | 1 | 18 | 10 | 9 | 2 | 73 |
| 140 | NA | NA | 52 | NA | 6 | NA | 58 |
| Tube current (mA) | 106–650 | 106–650 | 146–701 | 146–701 | 273–325 | NA | |
| Gantry revolution time | 0.5 | 0.5 | 0.8 | 0.8 | 0.8 | 0.8 | NA |
| Helical pitch | 0.8 | 0.8 | 1.375 | 1.375 | 1.375 | 1 | NA |
| Acquisition mode | Helical | Helical | Helical | Helical | Helical | Helical | NA |
| Section thickness, section interval | |||||||
| 1 mm, 1 mm | 52 | 15 | 62 | 3 | 10 | NA | 142 |
| 2 mm, 2 mm | 22 | 15 | 7 | 1 | NA | 34 | |
| 3 mm, 3 mm | 4 | NA | 1 | 6 | 5 | 2 | 18 |
| Kernel | I30forI31f | Br40d | SOFT | SOFT | SOFT | B | NA |
| Reconstruction algorithm | SAFIRE S3 | SAFIRE S3 | ASiR 40%–60% | ASiR 40%–60% | ASiR 40%–60% | iDose4 level 4 | NA |
| Matrix | 512 × 512 | 512 × 512 | 512 × 512 | 512 × 512 | 512 × 512 | 512 × 512 | NA |
| CTDIvol median*† | 13.78 mGy (9.27–19.58) | 13.78 mGy (9.27–19.58) | 13.78 mGy (9.27–19.58) | 13.78 mGy (9.27–19.58) | 13.78 mGy (9.27–19.58) | 13.78 mGy (9.27–19.58) | NA |
| DLP median*† | 716.73 mGy × cm(467.61–1048.95) | 716.73 mGy × cm (467.61–1048.95) | 716.73 mGy × cm (467.61–1048.95) | 716.73 mGy × cm (467.61–1048.95) | 716.73 mGy × cm (467.61–1048.95) | 716.73 mGy × cm (467.61–1048.95) | NA |
| Contrast media injection parameters | |||||||
| Contrast media | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | Iopamidol 300 mg iodine/mL (Isovue 300; Bracco Diagnostics) | NA |
| Volume (mL) | 175 | 175 | 175 | 175 | 175 | 175 | NA |
| Injection rate (mL/sec) | 5 | 5 | 5 | 5 | 5 | 5 | NA |
| Time of scanning | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | Automatic bolus tracking with pancreatic parenchymal phase starting 15 sec after threshold (100 HU) was reached in aorta | NA |
| Saline flush after contrast media | 50 mL at 5 mL/sec | 50 mL at 5 mL/sec | 50 mL at 5 mL/sec | 50 mL at 5 mL/sec | 50 mL at 5 mL/sec | 50 mL at 5 mL/sec | NA |
Note.—ASiR = adaptive statistical iterative reconstruction, CTDIvol = volume computed tomography dose index, DLP = dose length product, iDose4 = fourth generation reconstruction technique, NA = not applicable, SAFIRE = sinogram-affirmed iterative reconstruction.
*
Data in parentheses are the interquartile range.
†
Source.—Reference 21.