Findings in this study indicate that radiologist's interpretation accuracy in interpreting digital mammograms depends on lesion type. Interpretation accuracy was not influenced by the image-processing method.

The data show that PEM is safe, feasible, and has an encouraging accuracy rate in this initial experience. Lesion-to-background ratios >2.5 were found to be a useful threshold value for identifying positive (malignant) results. This study supports the further development of PEM.

Operation of a high resolution compact clinical PET Scanner (PEM Flex TM ) device as a breast scanner is described. The device features high spatial resolution (1.5 mm FWHM intrinsic resolution) as a result of small crystals and compact position-sensitive photomultipliers. The compactness of the system allows it to reside within a stereotactic x-ray mammography unit, or as a separate standalone system capable of breast compression. The gamma rays are detected for a volumetric reconstruction by two heads, each of which contains 2,028 2 mm by 2 mm by 10 mm lutetium-containing crystals. The heads travel within x-ray transparent compression paddles. A window is provided in one of the paddles for direct correlation with ultrasound transducers and for interventional access. To enable real-time interventions, images are reconstructed and displayed while the detectors are still acquiring data. The maximum-likelihood reconstruction provides quantitative images with threefold improved contrast as compared to simple backprojections.

The purpose of the study was to demonstrate the feasibility of a hybrid functional/anatomic breast imaging platform with biopsy capability for facilitating lesion detection and diagnosis. This platform consists of an investigative dedicated positron emission mammography (PEM) device mounted on a stereotactic X-ray mammography system, permitting sequential acquisition of mammographic and emission images during a single breast compression. There is automatic coregistration of images from both modalities, and these results can be successfully correlated with histopathologic findings. The potential utility of functional images correlated to anatomic images would include noninvasively detecting clinically and radiographically occult cancers, assessing response to therapy, discriminating between benign and malignant breast masses, and ultimately reducing the number of invasive and costly surgical interventions. A spot-digital mammogram and subsequent PEM image, collected over a 4-minute period, were obtained in a single patient with the breast in compression after intravenous injection of (F-18)-2-deoxy-2-fluoro-D-glucose (FDG) at the time of stereotactic biopsy. The authors conclude that FDG-based lesion localization information may be combined with the lesion X-ray attenuation characteristics using this common imaging platform.

The evaluation of mammographic abnormalities has become a substantial effort for surgeons and radiologists. The vacuum-assisted core biopsy (VACB) has been touted as a more accurate tool for the evaluation of mammographic lesions. Diagnosis of atypical ductal hyperplasia (ADH) from a percutaneous needle biopsy of the breast is associated with a significant risk of missing a significant breast lesion. We compared 2 methods of sampling with stereotactic-guided breast biopsy, 14-gauge automated gun core biopsy (AGCB) and VACB, on the accuracy of diagnosis of ADH at a single institution. All cases of ADH, without associated malignancy, found via image-guided breast biopsy of nonpalpable lesions between March 1996 and April 2002 were evaluated. VACB biopsy needles were utilized between July 1998 to April 2002 (686 patients) and 14-gauge AGCB from March 1996 to June 1998 (350 patients). The results of these biopsies were reviewed and compared to surgical biopsy and pathological records. ADH alone was found in 53 cases (5.1% of biopsies; mean age 57.9 years). Of these, 39 patients with ADH subsequently underwent wire-localized excisional biopsy. The other 14 patients were observed. VACB biopsy understaged 7 of 29 (24%) patients with ADH (all of which were DCIS), AGCB understaged 4 of 10 cases (40%) with one being invasive. Of the patients in the core biopsy group who were initially followed, 2 developed significant lesions within 3 years of follow-up in the same quadrant of the breast. If these cases are added to the AGCB group, then 50 per cent were understaged and significantly more invasive lesions were understaged than with VACB (17% vs. 0%; P = 0.018). The VACB resulted in less understaging of ADH than AGCB. However, there remains a significant risk of missing DCIS in this setting even with the VACB. Furthermore, the risk of understaging an invasive lesion is significantly lower in this setting with a VACB than an AGCB. Although the risk of understaging ADH is lower with the VACB, we continue to recommend excisional biopsy in a good-risk patient when a diagnosis of ADH is rendered via VACB biopsy.