Observer variability in the sonographic evaluation of thyroid nodules.

OBJECTIVE: Inter- and intraobserver variabilities in the description and diagnostic categorization of sonographic (US) features of thyroid nodules were evaluated. METHODS: The current study was conducted on 72 malignant nodules and 61 benign nodules. The US findings for each thyroid nodule were analyzed twice at a 6-week interval by five radiologists. The analyses were in accordance with the guidelines proposed by the Thyroid Study Group of the Korean Society of Neuroradiology and Head and Neck Radiology (TSGKSNRHNR). Inter- and intraobserver variabilities were calculated using Cohen's kappa statistics. The sensitivity, specificity, positive-predictive value, and negative-predictive value in the assessment of the diagnostic accuracy using these guidelines were calculated. RESULT: The interobserver agreement was fair to substantial for US features and categorization. Of the US features of the thyroid nodules, internal content (solid versus cystic) showed substantial agreement (k = 0.64). There was moderate agreement with regard to shape, echogenicity, calcification, and diagnostic categories (k = 0.42, 0.57, 0.55, and 0.55, respectively). There was fair agreement for margin, echotexture, and capsule invasion (k = 0.34, 0.26, and 0.32, respectively). With regard to intraobserver agreement, there was moderate to substantial agreement for all US features except for echotexture and capsule invasion, which showed fair agreement. In particular, there was moderate to almost perfect agreement for the diagnostic category. The sensitivity, specificity, positive-predictive value, and negative-predictive value were 65.3%-81.9%, 60.7%-68.9%, 69.7%-73.8%, and 66.6%-75.5%, respectively. CONCLUSION: There were high degrees of inter- and intraobserver agreement using the "Guidelines for diagnostic thyroid ultrasonography," of the TSGKSNRHNR in the description and categorization of thyroid nodules.

Galactography acquired with digital mammography in patients with nipple discharge: a retrospective analysis.

PURPOSE: To evaluate the galactographic findings taken with digital mammography and to compare the findings between benign and malignant breast diseases. MATERIALS AND METHODS: Galactographic findings were retrospectively analyzed and compared with histopathological results for 42 patients who showed abnormal findings on galactography and had histologically proven diagnoses between January 2005 and March 2008. A galactography was acquired using full-field digital mammography (Hologic Lorad Selenia; Danbury, USA). The difference in galactographic findings between malignant and benign breast diseases was analyzed using chi(2) test. A value of P < 0.05 was considered statistically significant. RESULTS: Of the total 42 cases, 11 cases were malignant breast diseases and 31 were benign diseases. Common galactographic findings of benign diseases include ductal obstruction (48.3%) and single filling defect (51.6%), and common findings for malignant tumor include ductal dilatation (72.7%) and stenosis (63.6%). Ductal stenosis, microcalcifications or mass adjacent to abnormal duct, multiple filling defects, ductal wall irregularity, ductal distortion and irregular filling defects were more prevalently seen in malignant cases. A single filling defect and lobular filling defect was more prevalently seen in benign cases (P < 0.05). Ductal dilatation was a common finding in both malignant and benign cases with no significant difference. CONCLUSIONS: Ductal lesions were well visualized on galactography acquired with a digital mammography. A preoperative diagnostic galactography is useful in making a differential diagnosis between benign diseases and malignant tumors in patients with pathologic nipple discharge.

Interobserver variability of ultrasound elastography and the ultrasound BI-RADS lexicon of breast lesions.

BACKGROUND: Elastographpy is a newly developed noninvasive imaging technique that uses ultrasound (US) to evaluate tissue stiffness. The interpretation of the same elastographic images may be variable according to reviewers. Because breast lesions are usually reported according to American College of Radiology Breast Imaging and Data System (ACR BI-RADS) lexicons and final category, we tried to compare observer variability between lexicons and final categorization of US BI-RADS and the elasticity score of US elastography. METHODS: From April 2009 to February 2010, 1356 breast lesions in 1330 patients underwent ultrasound-guided core biopsy. Among them, 63 breast lesions in 55 patients (mean age, 45.7 years; range, 21-79 years) underwent both conventional ultrasound and elastography and were included in this study. Two radiologists independently performed conventional ultrasound and elastography, and another three observers reviewed conventional ultrasound images and elastography videos. Observers independently recorded the elasticity score for a 5-point scoring system proposed by Itoh et al., BI-RADS lexicons and final category using ultrasound BI-RADS. The histopathologic results were obtained and used as the reference standard. Interobserver variability was evaluated. RESULTS: Of the 63 lesions, 42 (66.7 %) were benign, and 21 (33.3 %) were malignant. The highest value of concordance among all variables was achieved for the elasticity score (k = 0.59), followed by shape (k = 0.54), final category (k = 0.48), posterior acoustic features (k = 0.44), echogenecity and orientation (k = 0.43). The least concordances were margin (k = 0.26), lesion boundary (k = 0.29) and calcification (k = 0.3). CONCLUSION: Elasticity score showed a higher level of interobserver agreement for the diagnosis of breast lesions than BI-RADS lexicons and final category.

Radiologists' performance for detecting lesions and the interobserver variability of automated whole breast ultrasound.

OBJECTIVE: To compare the detection performance of the automated whole breast ultrasound (AWUS) with that of the hand-held breast ultrasound (HHUS) and to evaluate the interobserver variability in the interpretation of the AWUS. MATERIALS AND METHODS: AWUS was performed in 38 breast cancer patients. A total of 66 lesions were included: 38 breast cancers, 12 additional malignancies and 16 benign lesions. Three breast radiologists independently reviewed the AWUS data and analyzed the breast lesions according to the BI-RADS classification. RESULTS: The detection rate of malignancies was 98.0% for HHUS and 90.0%, 88.0% and 96.0% for the three readers of the AWUS. The sensitivity and the specificity were 98.0% and 62.5% in HHUS, 90.0% and 87.5% for reader 1, 88.0% and 81.3% for reader 2, and 96.0% and 93.8% for reader 3, in AWUS. There was no significant difference in the radiologists' detection performance, sensitivity and specificity (p > 0.05) between the two modalities. The interobserver agreement was fair to good for the ultrasonographic features, categorization, size, and the location of breast masses. CONCLUSION: AWUS is thought to be useful for detecting breast lesions. In comparison with HHUS, AWUS shows no significant difference in the detection rate, sensitivity and the specificity, with high degrees of interobserver agreement.

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 Cohen's 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.