Variations in breast doses for an automatic mammography unit.

PURPOSE: To assess variations of glandular doses for a group of patients when different dose modes are selected for a specific system. MATERIALS AND METHODS: All measurements were obtained with a Senographe DMR mammography unit (GE Medical Systems). Automatic exposure control with either contrast or standard mode was routinely used in patient examinations. Entrance surface air kerma (ESAK) values were estimated from the postexposure mAs and from the recorded data. Subsequently the mean glandular dose (MGD) for each view was calculated using the conversion factors assuming 50% glandular and 50% adipose tissue composition. RESULTS: The average MGD for the right craniocaudal view for all beam qualities was 1.65 mGy, and 46.7 mm was the average compressed breast thickness for this view. Average MGDs were 1.61, 1.76, and 1.35 mGy for Mo-Mo, Mo-Rh, and Rh-Rh anode filter selections, respectively. Conversely, 2.18 and 1.47 of breast doses were measured for contrast and standard dose modes at the most often used (Mo-Mo) anode filter selection. CONCLUSION: Breast dose measurement techniques with the standard phantom or on real patients are easy to implement for the mammography users. Obtaining ESAK versus breast thickness relationship is useful for retrospective dose evaluation; better correlation can be established (67% vs. 52%) if they are generated separately for each dose modes.

Investigation of mean glandular dose versus compressed breast thickness relationship for mammography.

The relationship between the mean glandular dose (MGD) and the compressed breast thickness (CBT) is commonly used for the presentation of mammographic dose survey results and could also be useful for the assessment of individual breast doses retrospectively in case of lack of necessary dosimetric instrumentation. The high data scattering from the best fit reduces the reliability of this technique. The aim of this study was to investigate the accuracy of this relationship using the data collected from a patient survey and phantom experiment. Patients were divided into three different groups according to their breast glandularities, which were predicted from the inspection of previous mammograms. X-ray beam qualities that will be used in patient examinations were determined according to breast thickness and predicted glandularities. The MGD versus CBT relationship for all the examined patients resulted in a poor correlation (R2 = 0.28). This relationship was separately obtained for each glandularity group and also for sub-groups of specific beam qualities. The best correlation (R(2) = 0.73) was obtained for the fatty breast group and Mo/Mo combination. A low correlation (R2 = 0.34) was observed in the mid-glandularity group due to inclusion of a wide range of glandularities in this group. In the case of the dense breast group, although the glandularity range was narrow, there were e still high data scattering (R2 = 0.25). This was probably due to the use of Mo/Rh and Mo/Mo combinations. This is validated by obtaining the MGD-CBT relationship specific to Mo/Mo combination (R2 = 0.61).

Hydatid cyst of the breast.

Hydatid disease (hydatid cyst or echinococcal disease) is contracted in humans through oral transmission by ingestion of eggs. Hydatid disease most frequently affects the liver and the lungs. Involvement of the breast is rare. A combination of radiological and cytological findings usually suggests the correct diagnosis. We present mammography and cytology findings of primary hydatid disease of the breast in a 56-year-old woman.

Perianal infections: reader agreement and diagnostic performance of fat-suppressed contrast-enhanced MRI.

We aimed to determine the diagnostic performance of the contrast-enhanced fat-suppression technique in the detectability of perianal infections and to compare this technique with different MR sequences used for this purpose. Thirty consecutive patients with clinically suspected anorectal infections were examined with fast spin-echo (FSE) T2-weighted, short-inversion-time inversion recovery (STIR), and fat-suppressed and non-fat-suppressed T1-weighted spoiled gradient-echo (SGE) (in-phase) dynamic contrast-enhanced sequences. The results of MRI were correlated with the findings of surgery, which was considered as the standard of reference. Receiver-operating-characteristic curves were reconstructed to describe and compare the diagnostic value of each MR technique. The values of kappa were used as a measure of observer reliability. Diagnostic performances of STIR, FSE T2-weighted and fat-suppressed and non-fat-suppressed, contrast-enhanced SGE T1-weighted techniques showed statistically insignificant differences in detection of perianal infections. There was almost perfect interobserver agreement regarding the presence of lesions on each MR technique. Fat-suppressed, contrast-enhanced SGE T1-weighted MRI showed adequate diagnostic performance in the detection of perianal infections. However, its significance is not different from the other MR sequences used for the present study.