MRI | Acta Medica Marisiensis

Clinical Efficiency of Diffusion Weighted Imaging with Background Body Signal Suppression in Magnetic Resonance Mammography — Choosing a Qualitative or a Quantitative Approach

Nechifor-Boila IA¹, Buruian M¹, Frandeș-Podeanu Daniela¹, Charlot Matilde², Borda Angela³

1 Department of Radiology and Medical Imaging, County Emergency Clinical Hospital, Tîrgu Mureș, Romania
2 Department of Radiology and Medical Imaging, Lyon Sud Hospital Center, Pierre-Bénite, France
3 Department of Histology, University of Medicine and Pharmacy, Tîrgu Mureș, Romania

Objectives: Diffusion Weighted Imaging with Background Body Signal Suppression (DWIBS) is a new and promising imaging technique designed to improve diagnostic performance of Dynamic Contrast-Enhanced-Magnetic Resonance Mammography (DCE-MRM). The aim of our study was to assess the diagnostic efficiency of both qualitative and quantitative DWIBS in a retrospective cohort study.
Methods: We performed a registry-based study at the Department of Radiology, Lyon Sud Hospital. All consecutive MRM examinations from 02.2010 to 02.2011 were reviewed. DWIBS was interpreted blindly, both qualitatively (lesion characteristics and signal) and quantitatively (Apparent Diffusion Coefficient – ADC). The ADC cut-off value was determined using Receiver Operating Characteristics (ROC) curve analysis. Clinical efficiency indicators were calculated using either the pathological examination or the disease status after a minimum of 6 months follow-up as gold standard.
Results: The lot consisted of 78 women, with a mean age of 50.3±14 years and a total of 112 breast lesions. Qualitative DWIBS found 73 suspicious and 39 non-suspicious lesions, while the gold standard (pathological diagnosis/follow-up) reported 56 benign and 56 malignant ones. The sensitivity and specificity values for qualitative DWIBS were 84% and 53.37%, respectively. ROC curve analysis revealed the best performance for quantitative DWIBS at an ADC of 1.1×10-3 mm2/s, resulting in a sensitivity of 71.4% and a specificity of 76.8%.
Conclusion: DWIBS is a new and improved diffusion technique with a dual and efficient interpretation system applicable in clinical settings. Moreover, its use as a complement to DCE-MRM offers large potential for improving MRM efficiency in breast cancer diagnosis.

Introduction: Magnetic Resonance Mammography (MRM) is a new radiologic examination with wide perspectives in breast cancer diagnosis. We performed a systematic review of the literature, in order to obtain a clear view on the actual role of MRM, together with an accurate evaluation of its performance in clinical settings.
Material and methods: We conducted a thorough PubMed search, both directly and through MeSH (Medical Subject Headings), using specific keywords. We then applied the following filters: articles published only between 1999 and 2011 and written in English or French. Priority was given to reviews and clinic trials according to previously set criteria.
Results: We evaluated the clinical efficiency of MRM using sensitivity, specificity and predictive values (positive and negative). Sensitivity varied between 81 and 98%, while specificity had a much wider dispersion (65–93%), thus supporting the statement that MRM is a sensitive but not a specific examination. Diffusion MRM was comparable to standard MRM, while spectroscopy showed a low sensitivity and a high specificity.
Conclusions: MRM is a complex investigation, with well documented recommendations and good sensitivity. Diagnostic specificity remains an important issue, but with improvement perspectives from new techniques like diffusion and spectroscopy.