A simple method to estimate cardiac function during routine multi-row detector CT exams

Area of Science:

• Radiology
• Cardiology
• Medical Imaging

Background:

• Morphological abnormalities on CT scans, like cardiac enlargement, can suggest cardiac dysfunction but lack specificity.
• Existing methods for assessing cardiac function often require specialized imaging or invasive procedures.

Purpose of the Study:

• To evaluate the predictive capability of right-to-left cardiac transit time of contrast during CT for cardiac output and ejection fraction.
• To establish and validate a CT-based method for estimating cardiac function parameters.

Main Methods:

• A single-level CT scan was performed on 100 patients to measure right-to-left ventricular transit time of contrast.
• Cardiac index (CI) and ejection fraction (EF) were independently measured using cardiac magnetic resonance imaging (CMR) for comparison.
• A predictive model was developed using data from 50 patients and validated in another 50 patients.

Main Results:

• A strong correlation was observed between CT-derived CI and CMR-measured CI (R²=0.70) and EF (R²=0.49) in the validation group.
• CT-based estimates of CI and EF showed good correlation with CMR results (R²=0.66 for CI, R²=0.49 for EF).
• A right-to-left transit time exceeding 10.5 seconds demonstrated 100% specificity and positive predictive value for detecting cardiac dysfunction.

Conclusions:

• Right-to-left ventricular transit time measured during routine body CT can provide valuable physiological information on global cardiac function.
• This CT-based method offers a non-specific yet effective way to predict cardiac output and ejection fraction.
• The study highlights the potential of CT to non-invasively assess cardiac function, particularly in identifying cardiac dysfunction.