Imaging protocols for detection and interpretation of additional lesions and of background parenchymal enhancement
DCIS, EVENT, BREAST, INVASIVE CANCER
Conventional imaging (which may have included digital mammography, coned compression, magnification views, tomosynthesis, and breast ultrasound) was performed at outside practices or in our clinic. Following study enrolment, each participant underwent both MRI and CEM (with order determined by appointment availability) within 15 days of initial diagnosis. The protocols used for the acquisition of CEM and MRI images have been previously described in detail [MRI was performed using a 1.5-T Siemens Sonata Maestro Class machine (Siemens Healthcare, Erlangen, Germany), and a Siemens 4-channel breast coil. Unenhanced axial T2- and T1-weighted images were followed by multiple T1-weighted images commencing 90 s after intravenous injection of 0.1 mmol/kg of gadolinium-diethylenetriamine pentaacetic acid (Magnevist, Bayer Healthcare: Whippany, NJ, USA) at 3 mL/s.Each study was independently read on Agfa Picture Archiving and Communications System workstations (Agfa-Gevaert NV Mortsel, Belgium) by two sub-specialist breast radiologists, and a consensus report issued. In the event of disagreement, third-reader arbitration was used. The radiologists who read the MRIs had between 5 and 25 years of experience in breast imaging while the radiologists who read the CEM studies had reviewed a multimodality training set of nine cases (a mixture of six unifocal and multifocal invasive cancers, with and without associated DCIS component, and three with benign findings) prior to study commencement.Background parenchymal enhancement on both CEM and MRI was assessed according to the MRI Breast Imaging Reporting and Data System (BI-RADS) classification [