Claudio Losio MD, Presenter: Nothing to Disclose

Pietro Panizza MD, Abstract Co-Author: Nothing to Disclose

Francesco Aldo De Cobelli MD, Abstract Co-Author: Nothing to Disclose

Elena Belloni MD, Abstract Co-Author: Nothing to Disclose

Isabella Fedele, Abstract Co-Author: Nothing to Disclose

Alessandro Del Maschio MD, Abstract Co-Author: Nothing to Disclose

Due to its sensitivity to random water motion, which is restricted in tumors, DWI can be helpful for characterization of breast lesions, with the challenge to overcome the main limitation of breast MRI, that is the low specificity. Our aim was to evaluate the feasibility and diagnostic contribution of DWI sequences to standard MRI examination in a heterogeneous population.  

108 women with different clinical conditions (newly diagnosed lesions, operated breasts, familial hystory, CUP syndrome) underwent bilateral contrast-enhanced breast MRI, followed by Single-shot DW EPI sequences (b value of 900). Standard post-processing (subtractions, time-enhancement curves) was completed with qualitative evaluation of DW images and quantitative assessement of Apparent Diffusion Coefficient, by tracing perilesional ROIs on ADC maps. We evaluated the diagnostic accuracy of DWI, also comparing ADC values of benign vs malignant lesions, and evaluated the concordance of ADC with time-enhancement curves. Gold standard was based on citology, histology or follow-up.  

DWI identified 68 of 71 lesions (ranging from 5 to 43 mm) depicted with standard MRI (sensitivity 95 %, specificity 100%). ADC was significantly lower in malignant lesions than in benign (0.92±0.32 vs 1.89±0.27, P<0.00001), with a diagnostic accuracy of 92% (using a threshold value of 1.5 mm²/s). ADC was diagnostic even in case of indeterminate or falsely benign time-enhancement curves. ADC incorrectly diagnosed as malignant 4 benign lesions (3 sclerosing adenosis, 1 fibroadenoma). Diagnostic value of DWI for axillary nodes was poor.  

Our study demonstrated that DWI is a fast and reliable technique for further characterization of breast lesions identified with conventional MRI; in addition, diagnostic accuracy of ADC is superior to time-enhancement curves.

DWI is an easy and cost-effective completion to standard breast MRI, increasing its specificity.

Losio, C, Panizza, P, De Cobelli, F, Belloni, E, Fedele, I, Del Maschio, A, Diffusion-weighted Magnetic Resonance Imaging (DWI) of the Breast: Diagnostic Contribution to Standard Examination in 108 Patients.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6021093.html