Optimal trigger threshold with the bolus-tracking technique for the renal CT angiography protocol

Area of Science:

• Radiology
• Medical Imaging
• Vascular Imaging

Background:

• Renal CT angiography (CTA) is crucial for diagnosing renal diseases and evaluating kidney transplant donors.
• Bolus-tracking techniques optimize contrast media delivery for enhanced image quality.
• Determining the optimal trigger threshold is essential for achieving diagnostic-quality renal CTA.

Purpose of the Study:

• To investigate the optimal trigger threshold for renal CTA using bolus-tracking.
• To compare image quality and timing between different trigger thresholds in renal CTA.

Main Methods:

• Retrospective study of 105 patients undergoing renal CTA.
• Comparison of two trigger thresholds: 50 HU and 100 HU.
• Radiologist assessment of CT attenuation and image timing (RA, late RA, CM).

Main Results:

• The 50 HU group showed significantly higher proportions of appropriate renal arterial (RA) timing (78.6%-64.3%) compared to the 100 HU group (50.8%-27.0%).
• The 50 HU group had a lower proportion of corticomedullary (CM) timing compared to the 100 HU group.
• Higher CT attenuation in the renal cortex and vein was observed in the 100 HU group.

Conclusions:

• A 50 HU trigger threshold is superior for achieving appropriate RA timing in renal CTA with bolus-tracking.
• The 50 HU threshold enhances diagnostic confidence by optimizing contrast opacification timing.
• This finding aids in refining renal CTA protocols for improved diagnostic yield.