Abstract P2-01-06: How much agreement can we expect on BI-RADS mammographic findings? Observer agreement among 10 expert mammographers

Purpose: To determine the agreement between expert readers on mammographic findings and calcification patterns.

Materials and Methods: Ten academic radiologists from 5 centers reviewed 250 de-identified mammographic cases without prior exams which were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. For benign cases diagnosed by percutaneous biopsy, 1 year of benign or negative imaging follow-up was required. Using standardized forms, each radiologist assessed the presence of any suspicious mammographic findings (microcalcifications, asymmetry (1-vew), focal asymmetry (2-view), architectural distortion), and the morphology (none, round/punctate, amorphous, coarse heterogeneous, fine pleomorphic, fine linear branching) and distribution (none, diffuse, regional, grouped, linear, segmental) of any identified microcalcifications. Agreement between radiologists for presence/absence of findings, morphology, and distribution of calcifications was determined by calculating the Kappa (k) coefficient with 95% confidence interval (95% CI). The kappa coefficient proposed strength of agreement is ≤0 = poor, .01-.20 = slight, .21-.40 = fair, .41-.60 = moderate, .61-.80 = substantial, and .81-1 = almost perfect, as established by Landis and Koch.1

Results: Of the 250 lesions, 156 (62%) were benign and 94 (38%) malignant. Agreement among the 10 expert readers was strongest for recognizing the presence/absence of calcifications (k = 0.82, 95% CI: 0.80-84), “almost perfect”). There was substantial agreement among the readers for the identification of a mass (k = 0.67, 95% CI: 0.66-69), whereas agreement was fair for the presence of a focal (2-view) asymmetry (k = 0.21, 95% CI: 0.1900.23) or architectural distortion (k = 0.28, 95%CI: 0.26-0.30). Agreement for asymmetries (1-view) was slight (k = 0.09, 95%CI: 0.08-0.11). Among the 6 categories of microcalcification distribution and morphology, reader agreement was moderate (distribution k = 0.60, 95%CI:0.59-0.61; morphology k = 0.51, 95%CI: 0.50-0.52).

Conclusion: When asked to characterize suspicious mammographic findings, this sampling of 10 expert academic breast imagers across 5 centers revealed varying strength of agreement for different findings, ranging from slight to almost perfect. Strongest agreement (“almost perfect”) was found for identifying the presence or absence of microcalcifications, although agreement drops to moderate when readers are asked to specify microcalcification morphology and distribution.

1 Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics.1977;33:159-174.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-01-06.

TU-E-217BCD-03: Characterization of Anatomical Noise in Mammography, Tomosynthesis and Breast CT

PURPOSE

The role of breast density in cancer detection has been well characterized, and newer modalities such as breast tomosynthesis and breast CT (bCT) were developed to improve cancer detection in the dense breast by reducing anatomical complexity. Anatomical noise was characterized on a small cohort of patient images and compared across digital mammography, tomosynthesis, and bCT images.

METHODS AND MATERIALS

An IRB-approved and HIPPA-compliant clinical study was performed on women undergoing breast biopsy, and mammography, tomosynthesis, and bCT were performed on both breasts immediately prior to biopsy. A total of 23 women participated in this study, and the unaffected breast (no lesion) was evaluated. A total of 1000 regions of interest were sampled on each image data set, and the 2D noise power spectrum (NPS) was evaluated. This was radially averaged to produce a 1D NPS, and the NPS was fit to a power law: ln{NPS(f)} = alpha+betaxln(f), over an anatomically-relevant range of spatial frequencies. The slope, beta, was averaged across patients and compared between modalities and projections.

RESULTS

The value of beta was determined for bCT data sets, and they were 1.75 (0.424), 1.83 (0.352), and 1.79 (0.397), for the coronal, sagittal and axial views, respectively. For tomosynthesis, beta was 3.06 (0.361) and 3.10 (0.315) for the CC and MLO views, respectively. For mammography, these values were 3.17 (0.226) and 3.30 (0.236), for the CC and MLO views, respectively. The values of beta for breast CT were significantly different than those for tomosynthesis and mammography (p<0.001, all 12 comparisons).

CONCLUSIONS

The results of this investigation demonstrate that the anatomical complexity of the breast, as characterized by the parameter beta, is statistically similar between mammography and tomosynthesis, a somewhat surprising finding. The breast CT image data, however, demonstrate a statistically-significant reduction in beta across all projections. Funded in part by Hologic Corporation and by a grant from the National Institute of Biomedical Imaging and Bioengineering, EB002138.

IL-1 beta increases abundance and activity of the negative transcriptional regulator yin yang-1 (YY1) in neonatal rat cardiac myocytes

Current research from both clinical and basic science perspectives indicates that cytokines play an important role in the genesis of cardiovascular pathology. Specifically, levels of cytokines such as interleukin-1 (IL-1), tumor necrosis factor- alpha (TNF- alpha), and interleukin-6 (IL-6) have been found to be elevated in both acute myocardial injury as well as situations of chronic dysfunction. Further, therapies directed primarily at interfering with cytokine action have suggested that such an immunomodulatory approach may be beneficial in some of these circumstances of myocardial injury. We recently reported that IL-1 beta induces a hypertrophic state in cultured neonatal rat cardiac myocytes that differs from other well described hypertrophic phenotypes in terms of myocardial gene expression (such as skeletal alpha -actin, sACT), an effect that appeared to co-localize with that of the negative regulator yin yang-1 (YY1).(1)In the present study, we further localize the area in the sACT promoter responsible for the IL-1 effect. These investigations indicate that sequences in and around the third upstream serum response element (SRE3) bind YY1 and are required for IL-1 beta mediated repression. This element is also capable of transferring both IL-1 beta and YY1-mediated transcriptional repression to a heterologous promoter. In support of an IL-1 beta induced post-translational modification of YY1 that results in an increase in DNA-binding activity,(32)P-labeling experiments reveal an increase in phosphorylated YY1 in IL-1 beta treated cells and phosphatase-treated myocyte nuclear proteins lose their ability to bind to the YY1 site. In summary, these results provide evidence that sequences within the SRE3 of the skeletal actin promoter represent an IL-1 beta response element and suggest that IL-1 beta activates the negative transcription factor YY1 by both transcriptional and post-transcriptional mechanisms.