Shadi Aminololama-Shakeri MD, Presenter: Nothing to Disclose

Nicolas Demetrios Prionas BS, MS, Abstract Co-Author: Nothing to Disclose

Karen K. Lindfors MD, Abstract Co-Author: Research grant, Hologic, Inc

John M. Boone PhD, Abstract Co-Author: Consultant, Varian Medical Systems, Inc Consultant, Artemis, Inc Research funded, Varian Medical Systems, Inc Research funded, FUJIFILM Holdings Corporation Research funded, Hologic, Inc Research funded, Creatv MicroTech, Inc Research funded, Siemens AG

To compare the conspicuity of ductal carcinoma in situ (DCIS) on unenhanced dedicated breast CT (bCT), contrast enhanced dedicated breast CT (CEbCT) and digital mammography (DM).

A retrospective analysis of the image datasets of 26 patients (28 lesions total) who underwent dedicated breast CT imaging was performed (19 bCT, 9 bCT+CEbCT). All patients had BIRADS 4 or 5 lesions, histologically proven DCIS on core biopsy following the CT scan. Lesion conspicuity scores (CS) from 1-10 were independently assigned by two experienced radiologists for CEbCT vs. bCT and CEbCT vs. DM (1=excellent conspicuity at CEbCT and poor at comparison modality, 10=excellent conspicuity on the comparison modality and poor on CEbCT, and 5.5=equal conspicuitybetween modalities). CS for bCT vs. DM were assigned on a similar scale (1=excellent on bCT/ poor on DM, 10=excellent on DM/ poor on bCT). Mean voxel intensity of each lesion in hounsfield units (HU) was measured and normalized to that of adipose tissue. Enhancement was quantified as the difference of normalized pre and post contrast intensity. Data are shown as mean CS with 95% confidence intervals of the mean. Significant differences between modalities (p<0.05) were detected by a paired t-test and validated using a Wilcoxon signed rank as a complementary non-parametric approach.

Of the 28 lesions, 20 were calcifications only, 4 were masses only and 4 were masseswith calcifications. There were 13 high, 10 intermediate and 5 low grade DCIS lesions. DCIS was significantly more conspicuous on CEbCT than on bCT (3.7, 2.5-4.3, n=9, p<0.01) and was equally conspicuous on CEbCT and DM (5.8, 5-6.7, n=9, p=0.31). DCIS was significantly better seen on DM than unenhanced bCT (7.3, 6.8-7.9, n=28, p<0.0001). The mean enhancement of DCIS lesions was59.5 HU (SD+/-2.5, n=8, one patient who received split dose contrast was excluded). There was no difference in degree of enhancement or conspicuity based on DCIS grade.

DCIS was equally well seen on contrast enhanced breast CT and mammography, both of which were significantly superior to unenhanced bCT for DCIS conspicuity. Measurement of lesion enhancement may be important for detection of DCIS.

Contrast enhanced dedicated breast CT is an emerging imaging modality which shows potential for detecting DCIS. Future enhancements to bCT will likely improve microcalcification detection.

Aminololama-Shakeri, S, Prionas, N, Lindfors, K, Boone, J, Detection of DCIS with Dedicated Breast CT.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11007499.html