Validation of a drift-corrected 3D MR temperature imaging sequence for breast MR-guided focused ultrasound treatments

Real-time temperature monitoring is critical to the success of thermally ablative therapies. This work validates a 3D thermometry sequence with k-space field drift correction designed for use in magnetic resonance-guided focused ultrasound treatments for breast cancer. Fiberoptic probes were embedded in tissue-mimicking phantoms, and temperature change measurements from the probes were compared with the magnetic resonance temperature imaging measurements following heating with focused ultrasound. Precision and accuracy of measurements were also evaluated in free-breathing healthy volunteers (N = 3) under a non-heating condition. MR temperature measurements agreed closely with those of fiberoptic probes, with a 95% confidence interval of measurement difference from -2.0 degrees C to 1.4 degrees C. Field drift-corrected measurements in vivo had a precision of 1.1 +/- 0.7 degrees C and were accurate within 1.3 +/- 0.9 degrees C across the three volunteers. The field drift correction method improved precision and accuracy by an average of 46 and 42%, respectively, when compared to the uncorrected data. This temperature imaging sequence can provide accurate measurements of temperature change in aqueous tissues in the breast and support the use of this sequence in clinical investigations of focused ultrasound treatments for breast cancer.

Automated summary

Real-time temperature monitoring is crucial for successful thermally ablative therapies, and this study validates a 3D thermometry sequence with k-space field drift correction for magnetic resonance-guided focused ultrasound treatments on breast cancer. The results show that the magnetic resonance temperature measurements closely match those of fiberoptic probes, with a confidence interval of -2.0 to 1.4 degrees C. The field drift correction method significantly improves precision and accuracy, making it a reliable tool for clinical investigations on focused ultrasound treatments for breast cancer.