Kinetic Analysis of Lesions Identified on a Rapid Abridged Multiphase (RAMP) Breast MRI Protocol

Abstract

Rationale and objectives: We implemented a rapid abridged multiphase (RAMP) breast magnetic resonance imaging (MRI) protocol to reduce scan time and increase workflow efficiency. In this study, we compared delayed-phase kinetic analyses of benign and malignant lesions on the RAMP protocol versus a full dynamic contrast-enhanced (DCE) MRI protocol.

Materials and methods: Consecutive breast MRI examinations obtained from October 2015 to August 2016 with tissue diagnoses of suspicious MRI lesions were identified. RAMP MRI included one precontrast and two postcontrast phases. Full DCE MRI included one precontrast and at least three postcontrast phases. Lesion kinetic analyses including mean delayed-phase volume percentage of washout, predominant curve type, and worst curve type were assessed. Kinetic analyses assessed on RAMP and DCE MRI protocols were compared using Wilcoxon rank-sum test and Chi-Square test. Receiver operating characteristic analysis was performed to discriminate benign and malignant lesions based on delayed-phase parameters.

Results: The study included 177 consecutive breast lesions (50 benign, 127 malignant) in 162 women. RAMP MRI (23 benign, 61 malignant) and DCE MRI examinations (27 benign, 66 malignant) demonstrated 8.4% vs 9.3% washout (p = 0.36) for benign lesions and 18.5% vs 17% washout (p = 0.66) for malignancies, respectively. There was no difference in the predominant and worst curve types for malignant and benign lesions or in area under the receiver operating characteristic curves for delayed-phased parameters between the two protocols (p > 0.05).

Conclusion: Lesion kinetic analyses from the RAMP MRI protocol can achieve the same discriminatory ability as the full DCE protocol. By reducing scan time, the RAMP MRI protocol improves patient comfort and enhances workflow efficiency and can be easily implemented in any clinical setting.

Keywords: Breast MRI; abbreviated breast MRI protocol; breast cancer; kinetic analysis.