Contrast timing optimization of a two-volume dynamic CT pulmonary perfusion technique

Area of Science:

• Medical Imaging
• Radiology
• Cardiovascular Imaging

Background:

• Pulmonary perfusion imaging is crucial for diagnosing lung conditions.
• Dynamic CT perfusion techniques offer detailed functional information.
• Reducing radiation dose in CT imaging is a significant clinical goal.

Purpose of the Study:

• To develop and validate an optimal timing protocol for a low-radiation-dose CT pulmonary perfusion technique.
• To enable accurate pulmonary perfusion assessment using only two volume scans.
• To establish a protocol for dynamic CT perfusion with reduced contrast and radiation exposure.

Main Methods:

• Developed an optimal contrast timing protocol for a two-volume dynamic CT perfusion technique based on pulmonary arterial input functions (AIFs) in swine.
• Validated the prospective two-volume technique by comparing its measurements with established retrospective methods.
• Quantitatively analyzed results using t-test, linear regression, and Bland-Altman analysis.

Main Results:

• An optimal contrast timing protocol was established, relating pulmonary artery time-to-peak to contrast injection duration (r=0.95).
• Prospective two-volume perfusion measurements closely correlated with retrospective measurements (PPRO = 0.87PRETRO + 0.56, r=0.88).
• The two-volume CT technique yielded low radiation doses (CTDI = 28.4 mGy, SSDE = 47.0 mGy).

Conclusions:

• The developed optimal timing protocol enables an accurate, low-radiation-dose, two-volume dynamic CT pulmonary perfusion technique.
• This technique offers a promising approach for efficient and safe assessment of lung perfusion.
• Further clinical validation is warranted to translate these findings to patient care.