A Triphasic Split-bolus Contrast Injection Protocol for Artery-vein Separation During Pulmonary Computed Tomographic...

Area of Science:

• Radiology
• Medical Imaging
• Cardiovascular Imaging

Background:

• Accurate preoperative 3D simulation of pulmonary vasculature is crucial.
• Minimizing contrast medium in CT angiography is a clinical goal.
• Distinguishing pulmonary arteries (PA) from pulmonary veins (PV) is essential for accurate simulation.

Purpose of the Study:

• To evaluate a split-bolus contrast protocol with test-bolus tracking for PA-PV differentiation.
• To assess the efficacy of this protocol in high-pitch single-pass CT angiography.
• To determine if adequate contrast enhancement can be achieved with reduced contrast volume.

Main Methods:

• A triphasic split-bolus injection protocol was used in 50 patients.
• Contrast medium was followed by a diluted contrast/saline mixture and a saline chaser.
• Scan timing was optimized using test-bolus tracking to target the pulmonary-venous dominant phase.

Main Results:

• Test bolus curves showed approximately 6-second peak enhancement intervals between PA and PV.
• Mean CT numbers were 246.4 HU for PA and 410.8 HU for the left atrium.
• A significant mean CT number difference of 164.4 HU was observed between PA and left atrium (P < 0.001).

Conclusions:

• The developed contrast enhancement protocol enables effective artery-vein separation in pulmonary CT angiography.
• This method supports preoperative 3D image simulation.
• Adequate pulmonary vasculature attenuation is maintained with this high-pitch, single-pass technique.