Ji Hyun Youk

Diagnostic Performance of Gray-Scale US and Elastography in Solid Thyroid Nodules

PURPOSE To evaluate the diagnostic performance of gray-scale ultrasonography (US) and elastography in differentiating benign and malignant thyroid nodules. MATERIALS AND METHODS This was an institutional review board-approved retrospective study with waiver of informed consent. A total of 703 solid thyroid nodules in 676 patients (mean age, 49.7 years; range, 18-79 years) were included; there were 556 women (mean age, 49.5 years; range, 20-74 years) and 120 men (mean age, 50.7 years; range, 18-79 years). Nodules with marked hypoechogenicity, poorly defined margins, microcalcifications, and a taller-than-wide shape were classified as suspicious at grayscale US. Findings at elastography were classified according to the Rago criteria and the Asteria criteria. The diagnostic performances of gray-scale US and elastography were compared. For comparison between the diagnostic performances of gray-scale US and the combination of gray-scale US and elastography, three sets of criteria were assigned: criteria set 1, nodules with any suspicious grayscale US feature were assessed as suspicious; criteria set 2, Rago criteria were added as suspicious features to criteria set 1; and criteria set 3, Asteria criteria were added as suspicious features to criteria set 1. The diagnostic performances of gray-scale US, elastography with Rago criteria, and elastography with Asteria criteria, and odds ratios (ORs) with 95% confidence intervals for predicting thyroid malignancy were compared using generalized estimating equation analysis. RESULTS Of 703 nodules, 217 were malignant and 486 were benign. Sensitivity, negative predictive value (NPV), and OR of gray-scale US for the 703 nodules were 91.7%, 94.7%, and 22.1, respectively, and these values were higher than the 15.7% and 65.4% sensitivity, 71.7% and 79.1% NPV, and 3.7 and 2.6 ORs found for elastography with Rago and Asteria criteria, respectively. Specificity, positive predictive value, and accuracy for criteria set 1 were significantly higher than those for criteria sets 2 and 3 for most of the nodule subgroups that were considered. CONCLUSION Elastography alone, as well as the combination of elastography and gray-scale US, showed inferior performance in the differentiation of malignant and benign thyroid nodules compared with gray-scale US features; elastography was not a useful tool in recommending fine-needle aspiration biopsy.

Value of US Correlation of a Thyroid Nodule with Initially Benign Cytologic Results

PURPOSE To investigate the value of ultrasonographic (US) features in thyroid nodules with initially benign cytologic results. MATERIALS AND METHODS The institutional review board approved this retrospective study and required neither patient approval nor informed consent for the review of images and records. From October 2003 to February 2006, 6118 focal thyroid nodules in 6025 consecutive patients underwent US-guided fine-needle aspiration biopsy (FNAB). This study included 1343 nodules 1 cm or larger in 1302 patients that were diagnosed as benign at initial cytologic evaluation and underwent pathologic or follow-up study. We compared the risk of malignancy according to US findings and calculated the likelihoods of different subgroups having benign nodules. RESULTS In total, 26 (1.9%) malignant and 1317 (98.1%) benign nodules were found according to reference standards. If initial cytologic results showed benign thyroid nodules, the likelihood of the nodule actually being benign was 98.1%. When a thyroid nodule had benign results at both initial and repeat FNAB, the likelihood increased to 100%. The likelihood of having a benign thyroid nodule with suspicious US features was lower (79.6%) than having a benign thyroid nodule with negative US features (99.4%, P<.001). In the nodule with benign features at initial US, the risk of malignancy for a thyroid nodule with an increase in size at follow-up US was slightly higher (1.4%) than that of a thyroid nodule with no interval change or decrease in size, but it was not significantly different (0.5%, P = .354). CONCLUSION Repeat FNAB should be performed for thyroid nodules that have suspicious US features, even if the initial cytologic results indicate that it is a benign lesion.

US-guided Fine-Needle Aspiration of Thyroid Nodules: Indications, Techniques, Results

Fine-needle aspiration (FNA) biopsy of thyroid nodules is minimally invasive and safe and is usually performed on an outpatient basis. However, the optimal application of FNA requires not only technical skill but also an awareness of the limitations of the procedure, the indications for its use, the factors that affect the adequacy of the biopsy specimen, and the postprocedural management strategy. Ultrasonographic (US) features that are considered indications for FNA include single and multiple thyroid nodules. The results of FNA biopsy are operator dependent. In addition, the results may be affected by the lesion characteristics, the accuracy of lesion and needle localization, the method of guidance, the number of aspirated samples, the needle gauge, the aspiration technique, and the presence or absence of on-site facilities for immediate cytologic examination. With regard to postprocedural management, nodules that are diagnosed as benign on the basis of an adequate FNA specimen should be monitored with follow-up US. Circumstances that necessitate repeat FNA include sample inadequacy, nodule enlargement, cyst recurrence, or clinical or imaging findings that arouse suspicion about the presence of a malignancy even when cytologic findings in the biopsy specimen indicate benignity. Supplemental material available at radiographics.rsnajnls.org/cgi/content/full/28/7/1869/DC1.

Sonographically Guided 14-Gauge Core Needle Biopsy of Breast Masses: A Review of 2,420 Cases with Long-Term Follow-Up

OBJECTIVE The objective of our study was to determine the diagnostic accuracy of sonographically guided core needle biopsy for breast masses by evaluating the outcomes of benign biopsies that had at least a 2-year follow-up. MATERIALS AND METHODS In this retrospective study, we included a total of 2,420 lesions from 2,198 women who had undergone sonographically guided 14-gauge core needle biopsy. For evaluating the diagnostic accuracy of this procedure, the pathologic results were reviewed and correlated with rebiopsy or long-term imaging follow-up. Agreement rate, high-risk underestimate rate, ductal carcinoma in situ (DCIS) underestimate rate, and false-negative rate were assessed. The false-negative diagnoses of core needle biopsy were reviewed in detail. RESULTS The pathologic results for the core needle biopsies were malignant in 52%, high-risk in 4%, and benign in 44%. The agreement rate was 96% (2,328 of 2,420). The underestimate rate was 29% (36 of 126) for DCIS and 27% (25 of 93) for high-risk (52% for 27 atypical ductal hyperplasia (ADH), 17% for 66 non-ADH). Of 1,071 benign lesions, malignancy was found at rebiopsy in 31 lesions (25 immediate and six delayed false-negative diagnoses), and the false-negative rate was 2.4% (31 of 1,312). The frequency of malignancy in lesions that had rebiopsy because of suspicious imaging findings (19.1%, 26 of 136) was significantly higher than that because of suspicious physical findings or request by patient or physician (0.9%, five of 584). CONCLUSION Sonographically guided 14-gauge core needle biopsy is an accurate method for evaluating breast masses. Imaging-pathologic correlation and follow-up of benign biopsy are essential for a successful breast biopsy program.

Extrathyroid Extension of Well-Differentiated Papillary Thyroid Microcarcinoma on US

BACKGROUND Extrathyroidal extension is an important factor to determine the extent of thyroid surgery. The aim of the present study was to evaluate the usefulness of high-resolution ultrasound (US) for predicting the extrathyroidal extension of papillary thyroid microcarcinoma (PTMC). METHODS This study included a total of 221 PTMCs in 181 patients. PTMC was defined as thyroid papillary carcinoma equal or less than 1 cm in size. The US findings, such as contact and disruption of thyroid capsule, were evaluated to predict the extrathyroidal extension of thyroid carcinoma. We calculated the diagnostic accuracy and odds ratio for each US finding. RESULTS Of the 221 PTMCs, extrathyroidal extension was present in 89 (40.3%) based on pathologic results. The mean size was not significantly different between PTMCs with and without extrathyroidal extension (p = 0.527). When the degree of contact was high, extrathyroidal extension of the thyroid cancer was high (p < 0.0001). Considering the odds ratio, Az value, and positive predictive value of each US finding, more than 25% contact with the adjacent capsule is the most accurate measurement for predicting extrathyroidal extension. CONCLUSIONS This study suggests that the presence and degree of contact between a PTMC and the adjacent capsule as found on preoperative US can provide an useful predictive information about an extrathyroidal extension.

Benign Papilloma without Atypia Diagnosed at US-guided 14-gauge Core-Needle Biopsy: Clinical and US Features Predictive of Upgrade to Malignancy

PURPOSE To evaluate the diagnostic accuracy of ultrasonographically (US)-guided 14-gauge core-needle biopsy (CNB) for benign papilloma without atypia and to determine whether clinical and radiologic features could be used to predict an upgrade to malignancy. MATERIALS AND METHODS This was an institutional review board-approved retrospective study, with a waiver of informed consent. The histologic results of US-guided CNB procedures performed from January 2006 through January 2009 were reviewed. A total of 160 benign papillomas without atypia that were diagnosed at CNB and excised surgically in 143 women (age range, 19-77 years) were assessed. Medical records and sonograms in the women were reviewed. Two radiologists working in consensus correlated imaging findings with the biopsy result to determine concordance. For the upgrade to malignancy after excision, malignant lesions were compared with nonmalignant lesions for the collected clinical and radiologic variables, which included patient age, lesion size, and lesion distance from the nipple, by using the χ(2) or Fisher exact test for categoric variables and the Mann-Whitney U test for continuous variables. RESULTS Eight (5.0%) of 160 papillomas were upgraded to malignancy. Lesions that were 1 cm or larger (seven [11%] of 63) showed a higher upgrade rate than lesions that were smaller than 1 cm (one [1%] of 97) (P = .006). The upgrade rate was higher in patients aged 50 years or older (six [16%] of 37) than in patients younger than 50 years (two [2%] of 123) (P = .002). Lesions that were 3 cm or farther from the nipple (four [13%] of 31) showed a higher upgrade rate than lesions that were less than 3 cm from the nipple (four [3.1%] of 129) (P = .046). Upgrade rates for Breast Imaging Reporting and Data System (BI-RADS) category 3, 4a, 4b, 4c, and 5 lesions were 0%, 2.5%, 6%, 27%, and 25%, respectively (P = .010). CONCLUSION At US-guided 14-gauge CNB, benign papilloma without atypia could be diagnosed accurately. Discordance between imaging and pathology results, as well as patient age of 50 years or older, lesion size of 1 cm or greater, lesion distance from the nipple of 3 cm or greater, and BI-RADS category may be helpful in predicting the possibility of upgrade to malignancy.

Factors affecting inadequate sampling of ultrasound-guided fine-needle aspiration biopsy of thyroid nodules

Purpose  The aim of this study was to evaluate the overall ultrasonographic features and clinical factors that contribute to inadequate sampling in ultrasound‐guided fine‐needle aspiration biopsy (US‐FNAB) of thyroid nodules.

Contrast-enhanced agent detection imaging: value in the characterization of focal hepatic lesions.

Objective. To assess the value of SH U 508A‐enhanced agent detection imaging in the characterization of focal hepatic lesions. Methods. Contrast‐enhanced agent detection imaging was performed on 78 focal hepatic lesions: 34 hepatocellular carcinomas, 22 metastases, 9 hemangiomas, 9 abscesses, 3 cysts, and 1 focal nodular hyperplasia. After administration of SH U 508A, interval delay scanning with agent detection imaging was performed with intervals of approximately 7 seconds (phase I), 30 seconds (phase II), and 90 seconds (phase III) after the first arrival of the contrast agent to the liver. Two observers blinded to the final diagnosis reviewed selected images and assessed the enhancement patterns of the lesions. For quantitative analysis, we calculated the enhancement ratio of the lesions and the difference of enhancement between the lesions and the liver parenchyma. Results. Agent detection imaging showed a distinctive enhancement pattern in focal liver lesions compared with that in the liver. Hepatocellular carcinomas were characterized by early enhancement (phase I) and wash‐out (phases II and III; sensitivity, 94.1%; specificity, 93.2%; positive predictive value, 91.4%). Metastases showed peripheral rim or targetlike enhancement (phase I, phase II, or both) and a defect (phase III) and had sensitivity of 77.3%, specificity of 100%, and a positive predictive value of 100%. Hemangiomas showed peripheral nodular or inhomogeneous (phase I, phase II, or both) and gradually centripetal (phase II, phase III, or both) enhancement (sensitivity, 88.9%; specificity, 100%; positive predictive value, 100%). Abscesses were partially enhanced from phase I to phase III (sensitivity, 66.7%; specificity, 95%; positive predictive value, 85.7%). The results of the quantitative analysis of lesion enhancement were compatible with those of the qualitative analysis. Conclusions. SH U 508A‐enhanced agent detection imaging may yield distinctive enhancement characteristics in focal liver lesions that would contribute positively to the characterization of these hepatic lesions.

Practice guideline for the performance of breast ultrasound elastography

Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented.

The diagnosis of non-malignant papillary lesions of the breast: comparison of ultrasound-guided automated gun biopsy and vacuum-assisted removal.

AIM To compare the histological upgrade rate of ultrasound (US)-guided vacuum-assisted removal (VAR) and US-14 G-automated core needle biopsy (ACNB) in the diagnosis of papillary breast lesions. MATERIALS AND METHODS Two hundred and seventy-one biopsies of 230 papillary lesions were examined, which underwent subsequent surgical excision or long-term follow-up after US-ACNB (n = 206) or US-VAR (n = 65). The false-negative and atypical papilloma underestimation rate were compared between the ACNB and VAR groups. Patient and lesion characteristics were collected. The histological upgrade rates of the diagnosis were estimated and compared. RESULTS Out of 271 papillary lesions, 195 (80.0%) were benign, 21 (7.7%) were atypical, and 55 (20.3%) were malignant. There were no false negatives or underestimated atypical papillomas in the VAR group. However, in the ACNB group, the false-negative rate was 7.6% (12 of 157 benign papillomas, 95% CI; 4.4-12.9%, p = 0.039) and the atypical papilloma underestimation rate was 33% (five of 15 atypical papillomas, 95% CI; 15.2-58.3%, p = 0.135). The histological upgrade rates of the diagnosis for papillary breast lesions were 0% for the VAR (0 of 66) group and 10.2% for the ACNB (21 of 206) group before adjusting for the population (p = 0.003). CONCLUSIONS ACNB was associated with significantly higher false-negative and histological upgrade rates of diagnosis for papillary breast lesions than VAR.