Novel T1 Analysis Method to Address Reduced Measurement Accuracy Due to Irregular Heart Rate Variability in...

Area of Science:

• Cardiovascular MRI
• Biomedical Engineering
• Medical Imaging Physics

Background:

• Polarity-corrected inversion time preparation (PCTIP) is a myocardial T1 mapping technique.
• PCTIP aims to reduce underestimation in modified Look-Locker inversion recovery methods.
• Conventional analysis of PCTIP shows reduced precision with heart rate variability.

Purpose of the Study:

• To evaluate a novel recurrence formula analysis for PCTIP T1 measurements.
• To determine the effect of recurrence formula analysis on accuracy and precision with irregular heart rate variability.
• To overcome precision limitations of conventional PCTIP analysis at high heart rates.

Main Methods:

• PCTIP scans performed on a 3T MRI scanner with simulated ECG-gated R-waves (30 combinations).
• T1 maps generated using nonlinear curve fitting with conventional and recurrence formulas.
• Accuracy against reference T1 and precision evaluated; relative fitting error calculated.

Main Results:

• Recurrence formula analysis demonstrated fitting errors <1% across all heart rate variability patterns.
• Conventional analysis showed larger fitting errors (10.1±2.0% for longer T1) and poor linearity.
• Recurrence formula analysis improved accuracy and linearity for longer T1, suppressing heart rate variability-dependent variations.

Conclusions:

• Recurrence formula analysis enables accurate and precise T1 measurements with PCTIP.
• This method is effective even with irregular heart rate variability.
• The recurrence formula analysis overcomes limitations of conventional PCTIP analysis.