In dynamic contrast enhanced (DCE) breast MRI, delayed-phase kinetic enhancement curves provide useful supplementary evidence in the diagnosis of benign and malignant lesions.1 Washout kinetic curves suggest malignant pathology, whereas progressive curves are associated with benign lesions.2 For accurate and consistent curve differentiation, consecutive image acquisitions at standardized regular time points after contrast administration is key. If the post- contrast timing of scans is too short, resultant kinetic curves may fail to demonstrate contrast washout over time in malignant lesions and if too long this...

Breast MRI examinations with suspicious breast lesions performed at North Shore Hospital between November 2019 – September 2021 were retrospectively identified for review. All examinations were performed on 3.0T Philips scanners. Exclusion criteria included lesions that were < 5 mm in size, lesions with no available histopathology results and studies in which the first post-contrast scan was delayed >120 seconds after contrast injection. The ‘worst kinetic curve’ was manually identified for each lesion using DynaCAD software. This was defined as the most suspicious kinetic curve,...

A total of 52 suspicious breast lesions were identified in 48 patients. Of these, 35 returned histological diagnoses of invasive cancers (14 invasive lobular cancer, 21 invasive ductal cancer), 7 were DCIS and 10 were benign lesions. 1. Kinetic curves:Invasive cancers demonstrated the largest percentage of washout enhancement at 77% (90.5% of IDC and 57.1% of the ILC cancers). Of note, all grade 3 invasive cancers showed washout enhancement whereas grade 1 and 2 cancers showed a mix of plateau and progressive enhancement at 18%...

Reducing the number of post-contrast image acquisitions from 5 to 3, and thereby shortening post-contrast scan time by 2 minutes (to approximately 3.2 – 4 minutes) did not significantly impact our ability to differentiate washout curves. Therefore, this demonstrates that 3.2 to 4 minutes is sufficient for accurate identification of washout kinetics in suspicious breast lesions.

1. Kuhl et al. 1999. Radiology. doi: 10.1148/radiology.211.1.r99ap38101.2. Price, Jeremy. 2012. AJR . doi: 10.2214/AJR.12.91563. Partridge et al. 2014. Academic Radiology. doi: 10.1016/j.acra.2014.04.0134. Mann et al. 2008. Eur Radiol. doi:10.1007/s00330-008-0863-7