Acquisition Phase | Phase Included | Scan Delay | Respiration Phase | Anatomical Coverage |
Non Contrast | N/A | N/A | N/A | N/A |
Arterial Phase | Yes | Bolus triggered | Inspiration | Entire aortic vasculature |
Venous Phase | N/A | N/A | N/A | N/A |
Delayed Phase | N/A | N/A | N/A | N/A |
Scan Comments: The Flash Spiral Aorta Protocol is useful when aortic root pathology is a concern to eliminate cardiac motion. Additionally, the fast scan times are important when the patient is short of breath or a limited volume of contrast is needed. Non-contrast and delayed images may be necessary when following up stent placement or to r/o endovascular leak. Alternatively, dual energy can be used to provide virtual non-contrast images. All scans are performed using the ALARA principle. 3D post-processing is performed with this protocol. | ||||
Technical Parameters | Parameters |
kVp | 120 |
Effective mAs | Use dose reduction software |
Quality Reference mAs | 200 |
Time (Rotation) | 0.28 sec |
Average Acquisition Time | 2-3 sec |
Collimation | 128 x 0.6mm |
Pitch Value | 2.0 |
Scan Direction | Craniocaudal |
Comments: Dose reduction software is used to reduce patient dose. We prefer to keep the pitch lower (less than 2.5) when scanning through the abdomen. This will avoid increased image noise or spiral artifact while still minimizing both cardiac and breathing motion. | |
Reconstruction Parameters | Soft Tissue | Thin Data | Thin Data | Lung |
Slice Thickness | 3 mm | 0.75 mm | 0.75 mm | 3 mm |
Reconstruction Spacing | 3 mm | 0.5 mm | 0.5 mm | 3 mm |
Reconstruction Algorithm | I40f (2) | I26f (2) | B20f | I70f (2) |
Window Width and Level | 410/10 | 410/10 | 410/10 | 1600/-500 |
Reconstruction Comments: When using flash spiral mode, the DFOV is limited by the smaller of the two detector arrays to 33.2cm. This limitation can be overcome by reducing the pitch value to allow for a greater DFOV. | ||||
Reconstruction Parameters | Coronal | Sagittal |
Slice Thickness | 3 mm | 3 mm |
Reconstruction Spacing | 3 mm | 3 mm |
Reconstruction Algorithm | I40f (2) | I40f (2) |
Window Width and Level | 410/10 | 410/10 |
Reconstruction Comments: When using flash spiral mode, the DFOV is limited by the smaller of the two detector arrays to 33.2cm. This limitation can be overcome by reducing the pitch value to allow for a greater DFOV. | ||
Contrast Parameters | Parameters |
Contrast Type | Non-ionic |
Contrast Volume | 80-120 mL |
Saline Flush | N/A |
Injection Rate | 4-5 mL/sec |
Oral Contrast | H2O |
Contrast Volume | 1000 mL |
Comments: Bolus tracking is performed off the abdominal aorta using a 230 HU trigger setting. | |