Diffusion Weighted Imaging (DWI) is currently used in addition to the standard DCE-T1 and T2 series in breast MRI. DWI acquires the diffusion or motion of hydrogen protons in a voxel due to Brownian motion and is most often quantified in the apparent diffusion coefficient (ADC). Diffusion is affected by the tissue properties and obstacles (for example lipophilic cell membranes) and restricted in tissues with a high cellular density. In malignant lesions, the cells are more densely packed and the extracellular space is reduced, in...

Patient population: In this retrospective study 41 consecutive women (ages 22-75, mean age 47) with 50 mass enhanced breast lesions (44 malignant and 6 benign), with an area of ≥ 0.8 cm2 were included between November 2008 and February 2011. Mean lesions size was 2.0 cm2 (0.8-8.9 cm2). Lesions smaller than 0.8 cm2 and non-mass enhancement lesions were excluded to reduce partial volume effect. Exclusion criteria were: Cystic lesions, previous breast malignancy, breast surgery or breast radiation. Final diagnosis was acquired by mastectomy (24), lumpectomy...

Breast lesions: Forty-four (88%) out of the 50 breast lesions were malignant. Malignant breast lesions were invasive ductal carcinoma (41) or invasive lobular carcinoma (3). The size of ROI1 for malignant lesions varied between 0.8 cm2 and 8.4 cm2. For the 6 benign lesions (12%) the size varied between 0.8 cm2 and 6.3 cm2. The benign lesions consisted of five fibroadenomas (1 histologically proven, 4 with follow-up MRI) and one chronic mastitis. Size of ROI1: ROI 1 is a manually positioned oval of freehand size,...

The purpose of this study was to compare the reproducibility and diagnostic use of the currently most widely applied ROI method featuring coverage of the entire lesion, to three alternative methods comparing the ADC values in ROIs standardized by fixing both size and shape. Any of the alternative ROI methods, featuring either fixed-size ROIs in the middle of the lesion (ROI2, 0.3 cm2) or ones at lowest ADC (ROI3, 0.3 cm2; ROI4 (0.6 cm2), yielded strong inter- and intra-observer agreements, similar to those of ROI1....

M. Wielema, MD University Medical Center Groningen,University of Groningen,Department of Radiology,Center for Medical Imaging - North East Netherlands. Hanzeplein 1 PO Box 30.001 9700 RB Groningen, the Netherlands Phone: + 31503610443 Fax: + 31503617008 e-mail : [email protected]

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