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Background Adaptive control processing for mammography (ACM) is a novel program that automatically sets up appropriate image-processing parameters for individual mammograms (MMGs) by analyzing the focal and whole breast histogram. Purpose To investigate whether ACM improves the image contrast of digital MMGs and whether it improves radiologists' diagnostic performance in reading of MMGs. Material and Methods One hundred normal cases for image quality assessment and another 100 cases (50 normal and 50 cancers) for observer performance assessment were enrolled. All mammograms were examined with and without ACM. Five radiologists assessed the intra- and extra-mammary contrast of 100 normal MMGs, and the mean scores of the intra- and extra-mammary contrast were compared between MMGs with and without ACM in both the dense and non-dense group. They classified 100 MMGs into BI-RADS categories 1-5, and were asked to rate the images on a scale of 0 to 100 for the likelihood of the presence of category 3-5 lesions in each breast. Detectability of breast cancer, reading time, and frequency of window adjustment were compared between MMGs with and without ACM. Results ACM improved the intra-mammary contrast in both the dense and non-dense group but degraded extra-mammary contrast in the dense group. There was no significant difference in detectability of breast cancer between MMGs with and without ACM. Frequency of window adjustment without ACM was significantly higher than that with ACM. Reading time without ACM was significantly longer than that with ACM. Conclusion ACM improves the image contrast of MMGs and shortens reading time.

The detection of ground-glass opacities (GGOs) is an important issue in lung cancer screening with low-dose CT. The iterative reconstruction (IR) technique has the ability to improve the image quality relative to the filtered back projection (FBP) technique with low-dose CT. Our purpose was to investigate the ability to detect GGO in a chest phantom using a low-dose CT and hybrid IR, named iDose. Simulated GGOs in a chest phantom were scanned with 256-section CT at tube current second products of 20, 50, 100, and 200 mAs. Five radiologists visually assessed the detectability of GGOs in the phantom. The contrast-to-noise ratio (CNR) for GGOs was used as an estimate of image quality. Comparison of the detectability and CNR between standard images with 200 mAs-FBP and low-dose images with 20, 50, and 100-mAs FBP/iDose were performed by ANOVA with Dunnett's and Tukey's test. The detectability was significantly lower at 20-mAs FBP/iDose and 50-mAs FBP than that at 200-mAs FBP (p < 0.05). There was no significant difference between 50-mAs iDose and 200-mAs FBP and between 100-mAs iDose/FBP and 200-mAs FBP. The CNR was significantly higher on iDose images than that on FBP images at each mAs value. The CNR at 200-mAs FBP was the same as that at 50-mAs iDose (CNR:1.8). The hybrid IR technique and low-dose CT imaging with 50 mAs enabled noise and to maintain the detectability for GGOs in a chest phantom that is equivalent to the reference acquisitions of 200 mAs with FBP.

Purpose: We investigated possible correlations between apparent diffusion coefficient (ADC) values and prognostic factors of breast cancer., Methods: We retrospectively evaluated 81 patients who underwent magnetic resonance (MR) imaging of the breast and were diagnosed pathologically with invasive ductal carcinoma (IDC) not otherwise specified with invasive foci one cm or larger. We excluded ductal carcinoma in situ and IDC with invasive foci smaller than one cm because small lesions decrease the reliability of signal intensity of diffusion-weighted imaging (DWI). We also excluded special type cancers. We used t-test to compare the mean ADC values of cancers of Stage pT1 (≤2 cm) versus pT2 or 3 (>2 cm), cancers with versus without vascular invasion, axillary lymph node (N)-positive versus N-negative cancers, estrogen receptor (ER)-positive versus ER-negative cancers, and progesterone receptor (PgR)-positive versus PgR-negative cancers. We analyzed correlations between the ADC value with nuclear grade (NG) and human epidermal growth factor receptor 2 (HER2) score by rank test using Spearman's correlation coefficient., Results: The mean ADC value was significantly higher for N-positive (n=28; 0.97 ± 0.20 × 10(-3) mm(2)/s) than N-negative cancers (n=53; 0.87 ± 0.17 × 10(-3) mm(2)/s) (P=0.017); significantly lower for ER-positive (n=63; 0.88 ± 0.15 × 10(-3) mm(2)/s) than ER-negative cancers (n=18; 1.01 ± 0.21 × 10(-3) mm(2)/s) (P=0.005); and significantly lower for PgR-positive (n=47; 0.88 ± 0.16 × 10(-3) mm(2)/s) than PgR-negative cancers (n=34; 0.95 ± 0.18 × 10(-3) mm(2)/s) (P=0.048). Tumor size, vascular invasion, NG, and HER2 status showed no significant correlation with ADC values., Conclusion: ADC values were higher for N-positive and ER-negative breast cancers than N-negative and ER-positive cancers.