Chang Suk Park

Observer variability in the sonographic evaluation of thyroid nodules

Inter‐ and intraobserver variabilities in the description and diagnostic categorization of sonographic (US) features of thyroid nodules were evaluated.

Observer Agreement Using the ACR Breast Imaging Reporting and Data System (BI-RADS)-Ultrasound, First Edition (2003)

Objective This study aims to evaluate the degree of inter- and intraobserver agreement when characterizing breast abnormalities using the Breast Imaging Reporting and Data System (BI-RADS)-ultrasound (US) lexicon, as defined by the American College of Radiology (ACR). Materials and Methods Two hundred ninety three female patients with 314 lesions underwent US-guided biopsies at one facility during a two-year period. Static sonographic images of each breast lesion were acquired and reviewed by four radiologists with expertise in breast imaging. Each radiologist independently evaluated all cases and described the mass according to BI-RADS-US. To assess intraobserver variability, one of the four radiologists reassessed all of the cases one month after the initial evaluation. Inter- and intraobserver variabilities were determined using Cohens kappa (k) statistics. Results The greatest degree of reliability for a descriptor was found for mass orientation (k = 0.61) and the least concordance of fair was found for the mass margin (k = 0.32) and echo pattern (k = 0.36). Others descriptive terms: shape, lesion boundary and posterior features (k = 0.42, k = 0.55 and k = 0.53, respectively) and the final assessment (k = 0.51) demonstrated only moderate levels of agreement. A substantial degree of intraobserver agreement was found when classifying all morphologic features: shape, orientation, margin, lesion boundary, echo pattern and posterior feature (k = 0.73, k = 0.68, k = 0.64, 0.68, k = 0.65 and k = 0.64, respectively) and rendering final assessments (k = 0.65). Conclusion Although BI-RADS-US was created to achieve a consensus among radiologists when describing breast abnormalities, our study shows substantial intraobserver agreement but only moderate interobserver agreement in the mass description and final assessment of breast abnormalities according to its use. A better agreement will ultimately require specialized education, as well as self-auditing practice tests.

Observer Variability and the Performance between Faculties and Residents: US Criteria for Benign and Malignant Thyroid Nodules

Objective To evaluate the interobserver variability and performance in the interpretation of ultrasonographic (US) findings of thyroid nodules. Materials and Methods 72 malignant nodules and 61 benign nodules were enrolled as part of this study. Five faculty radiologists and four residents independently performed a retrospective analysis of the US images. The observers received one training session after the first interpretation and then performed a secondary interpretation. Agreement was analyzed by Cohens kappa statistic. Degree of performance was analyzed using receiver operating characteristic (ROC) curves. Results Agreement between the faculties was fair-to-good for all criteria; however, between residents, agreement was poor-to-fair. The area under the ROC curves was 0.72, 0.62, and 0.60 for the faculties, senior residents, and junior residents, respectively. There was a significant difference in performance between the faculties and the residents (p < 0.05). There was a significant increase in the agreement for some criteria in the faculties and the senior residents after the training session, but no significant increase in the junior residents. Conclusion Independent reporting of thyroid US performed by residents is undesirable. A continuous and specialized resident training is essential to enhance the degree of agreement and performance.

Imaging features of invasive lobular carcinoma: comparison with invasive ductal carcinoma

PurposeThe aim of this study was to evaluate the imaging findings of invasive lobular carcinoma (ILC) compared to those of invasive ductal carcinoma (IDC).Materials and methodsThe study included ILCs (n = 27) and IDCs (n = 85). Imaging findings were retrospectively evaluated, according to the BI-RADS lexicon. We compared the imaging findings, multiplicity, and magnetic resonance imaging (MRI) detection accuracy of ILC with those of IDC.ResultsAt mammography, normal findings and mass lesions were more frequent with ILCs (14.8% and 59.2%, respectively) than with IDCs (1.2% and 44.7%, respectively) (P = 0.009). With ultrasonography (US), posterior acoustic shadowing was more frequently seen in ILCs (59.2%) than in IDCs (15.8%) (P < 0.001). With MRI, both ILCs and IDCs most commonly appeared as a heterogeneously enhancing, irregular mass with a spiculated border. Multifocality was more frequently associated with ILCs (40.7%) than with IDCs (14.1% 1% 0.002). However, multicentricity and bilaterality were not different between the two groups. The sensitivity and specificity of MRI for the detection of multiplicity were 91.6% and 73.3%, respectively, for ILCs and 83.3% and 80.3%, respectively, for IDCs.ConclusionNormal findings, mass lesions on mammography, and posterior acoustic shadowing on US were more frequently associated with ILCs than with IDCs. Multifocality was more prevalent with ILCs than with IDCs.

Readout-segmented echo-planar imaging in diffusion-weighted mr imaging in breast cancer: comparison with single-shot echo-planar imaging in image quality.

Objective The purpose of this study was to compare the image quality of standard single-shot echo-planar imaging (ss-EPI) and that of readout-segmented EPI (rs-EPI) in patients with breast cancer. Materials and Methods Seventy-one patients with 74 breast cancers underwent both ss-EPI and rs-EPI. For qualitative comparison of image quality, three readers independently assessed the two sets of diffusion-weighted (DW) images. To evaluate geometric distortion, a comparison was made between lesion lengths derived from contrast enhanced MR (CE-MR) images and those obtained from the corresponding DW images. For assessment of image parameters, signal-to-noise ratio (SNR), lesion contrast, and contrast-to-noise ratio (CNR) were calculated. Results The rs-EPI was superior to ss-EPI in most criteria regarding the qualitative image quality. Anatomical structure distinction, delineation of the lesion, ghosting artifact, and overall image quality were significantly better in rs-EPI. Regarding the geometric distortion, lesion length on ss-EPI was significantly different from that of CE-MR, whereas there were no significant differences between CE-MR and rs-EPI. The rs-EPI was superior to ss-EPI in SNR and CNR. Conclusion Readout-segmented EPI is superior to ss-EPI in the aspect of image quality in DW MR imaging of the breast.

The Value of Diffusion-Weighted Imaging in the Differential Diagnosis of Ovarian Lesions: A Meta-Analysis

Objectives The ability of contrast-enhanced MRI to distinguish between malignant and benign ovarian masses is limited. The aim of this meta-analysis is to evaluate the diagnostic performance of diffusion-weighted imaging (DWI) in differentiating malignant from benign ovarian masses. Methods A comprehensive literature search was performed in several authoritative databases to identify relevant articles. The weighted mean difference (WMD) and corresponding 95% confidence interval (95% CI) were calculated. We also used subgroup analysis to analyze study heterogeneity, and evaluated publication bias. Results The meta-analysis is based on 21 studies, which reported the findings for 731 malignant and 918 benign ovarian masses. There was no significant difference in apparent diffusion coefficient (ADC) values for DWI between benign and malignant lesions (WMD = 0.22, 95% CI = -0.02–0.47, p = 0.08). Subgroup analysis by benign tumor type revealed higher ADC values (or a trend toward higher values) for cysts, cystadenomas and other benign tumors compared to malignant masses (cyst: WMD = 0.54, 95% CI = -0.05–1.12, p = 0.07; cystadenoma: WMD = 0.73, 95% CI = 0.38–1.07, p < 0.0001; other benign tumor: WMD = 0.16, 95% CI = -0.13–0.46, p = 0.28). On the other hand, lower ADC values (or a trend toward lower values) were observed for endometrioma and teratoma compared to malignant masses (endometrioma: WMD = -0.09, 95% CI = -0.47–0.29, p = 0.64; teratoma: WMD = -0.49, 95% CI = -0.85–0.12, p = 0.009). Subgroup analysis by mass property revealed higher ADC values in cystic tumor types than in solid types for both benign and malignant tumors. Significant study heterogeneity was observed. There was no notable publication bias. Conclusions Quantitative DWI is not a reliable diagnostic method for differentiation between benign and malignant ovarian masses. This knowledge is essential in avoiding misdiagnosis of ovarian masses.

Breast cancer in very young women (<30 years): Correlation of imaging features with clinicopathological features and immunohistochemical subtypes

OBJECTIVE Early diagnosis of breast cancer in very young women (<30 years) is challenging and the characteristic imaging findings are not yet fully understood. We evaluated the imaging findings of breast cancer in very young women (<30 years) and to correlate them with clinicopathological features. MATERIAL AND METHODS A total of 50 surgically confirmed breast cancers were included in our retrospective study. The medical records were reviewed and the radiological features were analyzed according to the new 5th edition of the ACR BI-RADS lexicon. RESULTS The breast cancers in our study population most commonly presented as a self-detected mass (74%), T2-3 stage (58%), histological grade III (52.3%) and ER-positive (80%) subtype. The most common finding was an irregular (87.5%) hyperdense (66.7%) mass with indistinct margins (50%) on mammography and an irregular (75.6%) indistinct (57.8%) hypoechoic/heterogeneous (77.8%) mass without a posterior acoustic feature (60%) on ultrasonography. MRI revealed an irregular shape (63.3%), irregular margins (43.3%), and heterogeneous enhancement (60%) with washout kinetics (69.4%). Mammographically, microcalcifications were correlated with the HER2-enriched type, and mass-type lesions were correlated with triple-negative cancer (p=0.04). An oval/round mass on ultrasound (p=0.005), rim enhancement (p=0.004) and intralesional T2 high signal intensity (p=0.04) on MRI were associated with the triple-negative type. CONCLUSIONS On all imaging modalities, breast cancer in very young women usually presented as an irregular mass, and certain radiological features could be used for predicting the specific tumor type.

Radiologic findings of lobular carcinoma in situ: Mammography and ultrasonography

Purpose. The purpose was to evaluate the mammographic and sonographic (US) features of lobular carcinoma in situ (LCIS).

Correlation of Prognostic Factors of Invasive Lobular Carcinoma with ADC Value of DWI and SUVMax of FDG-PET

Invasive lobular carcinoma (ILC) is the second most common kind of breast cancer. Diffusion weighted imaging (DWI) and positron emission tomography/computed tomography (PET/CT) are functional modalities for presenting the biological characteristics of breast cancer. The purpose of this article is to study the relationship between DWI or PET/CT and ILCs prognostic factors. The relationship between the apparent diffusion coefficient (ADC) values, standard uptake value (SUV)max and prognostic factors of ILC were statistically evaluated. The ADC values were lower in mass types of ILC. SUVmax was statistically higher in grade 3 and 4 background parenchymal enhancement and positive lymph node metastasis. ADC values of DWI and SUVmax of PET/CT can be helpful in the prediction of the prognosis of ILC.

Sonography of Invasive Apocrine Carcinoma of the Breast in Five Cases

Objective To evaluate the sonographic features of invasive apocrine carcinoma (IAC) of the breast. Materials and Methods This study included five pathologically proven cases of IAC, and their sonographic features were retrospectively analyzed according to the Breast Imaging Reporting and Data System (BI-RADS) lexicon. Results All five lesions involved the left breast and were seen as irregularly shaped masses. All lesions, except one, had a parallel orientation to the chest wall. All five lesions showed noncircumscribed margins and heterogeneous echotexture; however, they showed various posterior features. One lesion had edema as an associated feature. Sonographic assessments were classified as BI-RADS category 4 in all five cases. Conclusion Invasive apocrine carcinoma sonographic findings are difficult to differentiate from those of invasive ductal carcinoma of no special type.