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COMPARISON OF DEDICATED DIGITAL SPECIMEN RADIOGRAPHY WITH DIRECT DIGITAL SPECIMEN MAMMOGRAPHY IMAGES J Morel, V Milnes, A Iqbal, R Wasan, C Peacock, D Evans, M Michell, Breast Radiology and NaBonal Breast Screening Training Centre, King's College Hospital, Denmark Hill, London, United Kingdom Introduction Specimen radiography is a long established procedure for confirming the presence of both calcified and noncalcified targeted lesions after needle localization and surgical excision(1,2) and to confirm the presence of targeted microcalcifcation following core biopsy(3). With the digitalization of breast radiology it is possible to perform rapid digital specimen radiography with a standard direct digital mammography unit. Prior to digital mammography specimen radiography has been performed on dedicated digital specimen equipment but with significant loss of sensitivity compared to screen/film mammography. Therefore these dedicated systems have been used for their rapidity but a film/ screen image has been required in addition due to poorer image quality. This study aims to compare the image quality obtained from a new generation digital specimen radiography system with the image quality from a standard direct digital mammography unit. Methods All surgical and core biopsy samples taken within our department during the study period were imaged with both a Direct Digital Radiography (DDR) unit and a Digital Specimen Radiography System(DSRS). The systems used in the study were Hologic Dimensions digital mammography and the Bioptics BioVision digital specimen radiography system. WLE specimens were imaged without magnification on both systems. Biopsy specimens were imaged with magnification. Two film readers assessed each set of images side by side. For all specimens containing microcalcifications the number of microcalcifications was recorded as 0, <5, <10, <15, <20, >20. In addition the visibility of each lesion was assessed on a 4 point scale where 1 signifies that the lesion is not visible and 4 signifies the lesion is well seen. Conclusions References 1)Gallager hs, Breast specimen radiography: obligatory, adjuvant, and investigative. Am J Clin Pathology 1975;64:749-755 2)Stomper PC, Davis SP, Sonnenfeld MR, Meyer JE, Greenes RA, Eberlein TJ, Efficacy of specimen radiography of clinically occult noncalcified breast lesions. AJR 1988;151:43-47 3)Meyer JE, Lester SC, Frenna TH, White FV. Occult breast calcifications sampled with large-core biopsy: confirmation with radiography of the specimen. Radiography 1993;188:581-582 Table – 1. Crosstabulation of number of microcalcifications demonstrated by direct digital radiography system and digital specimen x-ray Results Of the 67 specimans containing microcalcification, 44 of the specimens when imaged with the digital specimen x-ray system showed more than 20 microcalcifications as opposed to only 24 with the direct digital radiolgraphy system. This is shown to be significant with a p-value of 0.001. In two of the specimens where no calcification was demonstrated on the direct digital radiography system, the digital specimen x-ray system demonstrated <5 microcalcifications. Significant difference was also shown in the conspicuity of the lesions between the two systems with the lesions having greater conspicuity on the digital specimen x-ray system (p-value of 0.027) Results The total number of specimens was 97. Of these specimens 67 contained microcalcification, 23 masses, 4 distortions and 3 masses with calcification. Table – 3. Fisher exact test for number of microcalcifications seen DIGITAL SPECIMEN XRAY DIRECT DIGITAL RADIOGRAPHY SYSTEM No count <5 <10 <15 <20 >20 Total <5 2 2 0 0 0 0 4 <10 0 3 2 0 0 0 5 <15 0 5 4 1 0 0 10 <20 0 0 0 3 1 0 4 >20 0 0 1 11 8 24 44 Total 2 10 7 15 9 24 67 DIRECT DIGITAL MAMMOGRAPHY CONSPICUITY DIGITAL SPECIMEN XRAY CONSPICUITY 1 2 3 4 TOTAL 1 0 0 0 0 0 2 1 0 0 0 1 3 1 2 3 0 6 4 0 3 16 42 61 TOTAL 2 5 19 42 68 Microcalcifica>on Not well seen Clearly visible total Digital specimen xray 3 58 61 Direct Digital mammography 19 42 61 Fisher exact test Pvalue = 0.027 No. of Microcalcifica>on Total Less than 20 More than 20 Digital specimen xray 23 44 67 Direct Digital mammography 43 24 67 Fisher exact test Pvalue = 0.0001 Significantly more microcalcification is demonstrated by the digital specimen x-ray system when compared with direct digital mammography. Conspicuity of lesions is also shown to be significantly better with digital specimen x-ray. This provides increased confidence that a representative sample has been obtained at biopsy. This potentially avoids the need to take further samples and can lead to increased diagnostic confidence at biopsy. In addition, a digital specimen imaging modality avoids delay in the performance of specimen mammography in a busy breast imaging department. BioVision digital specimen radiography system from bioptics Table – 4. Fisher exact test for conspicuity of lesions containing microcalcifications Table – 2. Crosstabulation of conspicuity of lesions containing microcalcification Fig -1. Soft tissue mass shown on DSRS Fig – 2. Microcalcifi cation shown on DSRS
