HIGH-RESOLUTION CT MAMMOGRAPHY OF SURGICAL BIOPSY SPECIMENS

Purpose: Our goal was to assess the performance of high resolution CT on breast biopsy specimens before considering the reevaluation of refi ned CT techniques in patients with breast abnormalities. Method: High resolution CT was done in 44 surgical biopsy specimens following conve ntional X-ray specimen mammography. The specimens comprised 38 palpabl e and nonpalpable soft tissue abnormalities with mean size of 19 mm an d 6 specimens with clustered microcalcifications only. There were 21 c arcinomas, 10 fibroadenomas, and 13 other benign conditions. Evaluatio n of CT and conventional images was done separately, and a feature-gra ding list was used to compare the two modalities. Results: In fatty sp ecimens, grading of morphologic features of masses and the confidence to detect a soft tissue abnormality were equal with both techniques. C T significantly improved the confidence to detect a mass in 17 specime ns with dense tissue: On a scale of 0-10, the mean score for detection was 3.8 with radiography and 5.8 with CT (p < 0.008). For clustered m icrocalcifications, X-ray was superior to CT. The mean CT attenuation of 18 malignant masses (82 HU) was significantly lower than the mean a ttenuation of 10 fibroadenomas (131 HU; p = 0.003). CT scans of the Am erican College of Radiology test phantom met the requirements for X-ra y accreditation. Conclusion: For soft tissue abnormalities, CT specime n mammography performed equally as or better than specimen radiography . These in vitro results suggest potential advantages for increased se nsitivity and specificity with CT and justify further investigations.