Optimization of scan delay for multi-phase computed tomography by using bolus tracking in normal canine kidney

Area of Science:

• Veterinary Radiology
• Medical Imaging
• Comparative Anatomy

Background:

• Accurate timing of contrast enhancement is critical for multi-phase renal computed tomography (CT).
• Individual variations in transit times can affect image quality and diagnostic interpretation.
• Bolus-tracking techniques offer a potential solution for optimizing scan timing in animal studies.

Purpose of the Study:

• To determine optimal scan delay times for canine kidney imaging using a bolus-tracking technique.
• To establish precise timing for renal arterial, corticomedullary, and nephrographic phases in canine CT studies.
• To evaluate the efficacy of bolus-tracking for multi-phase renal CT in beagle dogs.

Main Methods:

• Six beagle dogs underwent multi-phase renal CT with varying scan delays after a bolus-tracking trigger.
• Aortic enhancement of 100 Hounsfield units (HU) served as the trigger point.
• Scan delays were systematically varied to capture different contrast enhancement phases.

Main Results:

• Peak renal artery-to-vein contrast difference was observed at 5 seconds.
• Peak renal cortex-to-medulla contrast difference occurred at 10 seconds.
• Cortex-to-medulla contrast approached zero by 30 seconds post-trigger.

Conclusions:

• Optimal scan delays for canine kidney CT are 5 sec (arterial), 10 sec (corticomedullary), and 30 sec (nephrographic) after 100 HU aortic enhancement trigger.
• The bolus-tracking technique is effective for multi-phase renal CT in dogs, compensating for transit time variations.
• This method reduces contrast media dosage and avoids additional radiation exposure, making it efficient and safe.