Wolfgang Bogner MSC, Presenter: Nothing to Disclose

Katja Pinker MD, Abstract Co-Author: Nothing to Disclose

Hubert Bickel MD, Abstract Co-Author: Nothing to Disclose

Thomas Hans Helbich MD, Abstract Co-Author: Research Consultant, Siemens AG Research Consultant, Hologic, Inc Research Grant, Siemens AG

Siegfried Trattnig MD, Abstract Co-Author: Nothing to Disclose

Stephan Gruber MD, Abstract Co-Author: Nothing to Disclose

To qualitatively and quantitatively compare the diagnostic value of diffusion weighted images (DWI) based on standard single-shot echo planar imaging (ss-EPI) and readout-segmented EPI (rs-EPI) in breast cancer patients at 3T.

34 patients (age: 49±14years) with histopathologic correlation were measured on a 3T MR scanner using a four channel breast coil. DWI by standard ss-EPI and rs-EPI with comparable imaging parameters (TR/TE/TI 7700/68 or 59/210 ms; TA 3min) was added to a standard breast imaging protocol. A T2-weighted sequence was acquired as a reference for geometric distortions on DWI. Qualitative and quantitative comparison between both DWI techniques was accomplished. Visual assessment of image quality was performed using scores from 1 (insufficient) to 4 (excellent). Image properties (i.e. signal-to-noise ratio, image contrast, geometric distortions) were determined. Regions of interest (ROIs) were drawn in all lesions (19 malignant, 17 benign) and healthy breast parenchyma to investigate possible differences in the apparent diffusion coefficient (ADC). The diagnostic accuracy was calculated based on an ADC threshold of 1.27 x10-3mm²/s.

There was no significant difference in the ADC obtained by ss-EPI and rs-EPI, neither in lesions (benign: 1559±287x10-3mm²/s and 1570±322x10-3mm²/s; malignant: 965±210x10-3mm²/s and 915±119x10-3mm²/s) nor in normal glandular breast tissue. A diagnostic sensitivity/specificity of 94%/95% (p<.001)(ss-EPI) and 94%/100% (p<.001)(rs-EPI) was reached. Geometric distortions were most pronounced on ss-EPI in prepectoral and perimamillar regions (3-14 mm). Rs-EPI reduced geometric distortions by a factor of three compared to ss-EPI. Also the image quality of rs-EPI was significantly improved (p<.001) with an average rating of 3.6 (rs-EPI) compared to 2.6 (ss-EPI).

DWI based on rs-EPI provided significantly higher image quality by three-fold reduction of geometric distortions and reduced image blurring compared to standard DWI based on ss-EPI. This enabled higher diagnostic accuracy for differentiation of benign and malignant breast lesions based on DWI at 3T and improved correlation with other image modalities.

DWI based on rs-EPI improves image quality and reduces geometric distortions compared to ss-EPI. This leads to a higher diagnostic accuracy for differentiation of benign and malignant breast lesions.

Bogner, W, Pinker, K, Bickel, H, Helbich, T, Trattnig, S, Gruber, S, Diffusion-weighted MRI of Breast Lesions at 3 Tesla: Readout-segmented EPI with Improved Image Quality.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034358.html