Ethanol Ablation of the Thyroid Nodules: 2018 Consensus Statement by the Korean Society of Thyroid Radiology.

Minimally invasive treatment of symptomatic thyroid nodules is now commonplace. Ethanol ablation (EA) of thyroid cystic nodules has been performed since the 1990s, but there is no global consensus or guideline. Although various limitations of EA have been described, recommendations for practical application are necessary. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology initiated the present consensus statement and here we provide recommendations for the role of EA in the management of symptomatic thyroid nodules. These recommendations are based on evidence to date from the literature and expert opinion.

2017 Thyroid Radiofrequency Ablation Guideline: Korean Society of Thyroid Radiology.

Thermal ablation using radiofrequency is a new, minimally invasive modality employed as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed recommendations for the optimal use of radiofrequency ablation for thyroid tumors in 2012. As new meaningful evidences have accumulated, KSThR decided to revise the guidelines. The revised guideline is based on a comprehensive analysis of the current literature and expert consensus.

Core Needle Biopsy of the Thyroid: 2016 Consensus Statement and Recommendations from Korean Society of Thyroid Radiology.

Core needle biopsy (CNB) has been suggested as a complementary diagnostic method to fine-needle aspiration in patients with thyroid nodules. Many recent CNB studies have suggested a more advanced role for CNB, but there are still no guidelines on its use. Therefore, the Task Force Committee of the Korean Society of Thyroid Radiology has developed the present consensus statement and recommendations for the role of CNB in the diagnosis of thyroid nodules. These recommendations are based on evidence from the current literature and expert consensus.

Comparison of computed tomography features between follicular neoplasm and nodular hyperplasia.

BACKGROUND: To date, appropriate management for Bethesda IV thyroid nodules is controversial, and no specific features of follicular neoplasm and nodular hyperplasia on ultrasonography, computed tomography (CT), or other imaging modalities have been reported. This study aimed to compare CT features of follicular neoplasm and nodular hyperplasia and to determine the specific CT features that could be used to distinguish follicular neoplasm from nodular hyperplasia. METHODS: In 122 patients who underwent preoperative CT of the neck and thyroid surgery, 59 follicular neoplasms and 65 nodular hyperplasias were included. In each case, non-enhanced and contrast-enhanced CT images were obtained, and a single radiologist retrospectively analyzed CT images, including degree and pattern of attenuation, nodular configuration, margin, shape, pattern of calcification, degree and pattern of nodular enhancement, and CT halo sign. A univariate and multivariate logistic regression analyses were used to evaluate the predictive power of each variable and CT features with a high predictive power, respectively. RESULTS: According to the univariate analysis, iso-attenuation, intraglandular configuration, smooth margin, ovoid shape, decreased enhancement, and absence of CT halo sign were more frequently observed in nodular hyperplasia (p < 0.05), whereas low attenuation, expansile configuration, lobulated margin, taller-than-wide shape, increased enhancement, and presence of computed tomography halo sign were more frequently observed in follicular neoplasm (p < 0.05). Multivariate analysis revealed significant differences in configuration (OR: 2.73, 1.13-6.57), degree of enhancement (OR: 2.14, 1.21-3.78), and presence of CT halo sign (OR: 7.97, 2.74-23.37) between follicular neoplasm and nodular hyperplasia (p < 0.05). CONCLUSIONS: Neck CT may be helpful for distinguishing follicular neoplasm from nodular hyperplasia. TRIAL REGISTRATION: Rretrospectively registered.

Role of Real-Time Elastography in the Evaluation of Cervical Lymph Nodes in Patients with Kikuchi Disease.

The purpose of this study was to compare the use of conventional ultrasound (US) and real-time elastography (RTE) in Kikuchi disease (KD, n = 48) and malignant cervical lymphadenopathy (n = 100) and to evaluate the role of RTE in patients suspected of having KD. In univariate analysis, conventional US revealed each benign feature more frequently in KD than in malignant lymphadenopathy (p < 0.05). However, a considerable number of cases (29, 60.4%) of KD were assessed as malignant with US. KD was assessed as benign by RTE more frequently than malignant lymphadenopathy (37 [77.1%] vs. 37 [37.0%], p < 0.001). In multivariate analysis, perinodal hyper-echogenicity was predictive of KD (odds ratio: 67.25, confidence interval: 10.95-413.04, p < 0.001). There was a tendency for KD to be assessed as malignant with conventional US, but benign with RTE. RTE can help to avoid unnecessary biopsy in patients suspected of having KD on the basis of conventional US.

Cervical Lymph Node Imaging Reporting and Data System for Ultrasound of Cervical Lymphadenopathy: A Pilot Study.

OBJECTIVE: The objective of our study was to compare ultrasound (US) and real-time elastography (RTE) features of benign and malignant cervical lymphadenopathies and propose a structured reporting system for lymph nodes. MATERIALS AND METHODS: The study population for this retrospective study consisted of 291 consecutive patients who underwent US-guided biopsies for cervical lymphadenopathy between 2013 and 2014. The following imaging features were analyzed: shape, margin, echogenicity, echogenic hilum, gross necrosis, calcification, matting, intranodal vascular pattern, elasticity scores (four categories), and strain ratio. A score was assigned for each significant factor from a logistic regression analysis and was multiplied by the beta coefficient. The fitted probability of malignancy was calculated. The risk of malignancy was determined on the basis of the number of suspicious features. Interobserver agreement of the imaging features was retrospectively analyzed using a coefficient of interrater agreement. RESULTS: The imaging features that were significantly associated with malignant lymphadenopathy were round shape, noncircumscribed margin, hyperechogenicity, absence of hilum, gross necrosis, calcification, peripheral or mixed vascularity, high elasticity scores, and high level of strain ratio (p < 0.05). The fitted probability and risk of malignancy increased as the number of suspicious features increased. The risk of malignancy according to the Cervical Lymph Node Imaging Reporting and Data System categories was as follows: category 1, 3.3%; category 2, 10.9%; category 3, 26.7%; category 4, 51.8-74.4%; and category 5, 90.6-98.8%. An analysis of the overall interobserver agreement revealed that interobserver agreement was moderate to good. CONCLUSION: We propose the Cervical Lymph Node Imaging Reporting and Data System, which uses the number of suspicious US and RTE features to assess the risk of malignancy in cervical lymph nodes.

Diffusion-weighted imaging for evaluating lymph node eradication after neoadjuvant chemoradiation therapy in locally advanced rectal cancer.

BACKGROUND: As lymph node (LN) eradication is the prerequisite for clinical surveillance or local excision for patients who have achieved a complete response after preoperative chemoradiation therapy (CRT), the radiological evaluation of LN eradication is important. PURPOSE: To evaluate the added value of diffusion-weighted imaging (DWI) in the evaluation of LN eradication after CRT in patients with locally advanced rectal cancer (LARC). MATERIAL AND METHODS: Ninety-five consecutive patients (64 men, 31 women; mean age, 59 years; range, 32-82 years) who underwent pre- and post-CRT 1.5-T MRI with DWI (b = 0, 1000 s/mm(2)) were enrolled. To evaluate the added value of DWI in the evaluation of LN eradication after CRT, two radiologists first independently read the pre- and post-CRT T2-weighted (T2W) images and then read the combined T2W imaging set and the pre- and post-CRT DWIs with a 4-week interval. The radiologists recorded their confidence scores for LN eradication using a 5-point scale on a per-patient basis. The diagnostic performances were compared between the two reading sessions for each reader with pair-wise comparisons of receiver-operating characteristic curves. Histopathological reports served as the reference standards for LN eradication. RESULTS: The study population consisted of an LN-eradicated group (n = 66) and a non-eradicated group (n = 29). The diagnostic performances did not significantly differ between the two reading sessions for the two readers (AUCs for reader 1, 0.770 and 0.774, P = 0.8155; for reader 2, 0.794 and 0.798, P = 0.8588). CONCLUSION: Adding DWI to T2W imaging provided no additional diagnostic benefit for the evaluation of LN eradication following CRT in patients with LARC.

Clinical implications of ultrasound artifacts in the cervicofacial area following injection of permanent facial fillers.

PURPOSE: To evaluate ultrasound (US) findings in the cervicofacial area following injection of permanent facial fillers during a long-term follow-up period. METHODS: Fifty-seven consecutive patients with a history of previous facial filler injection were enrolled at a single institution between 2010 and 2014. All patients were female, and the mean age of the patients was 60.8 years. The mean follow-up period following injection of facial fillers was 16.6 years (range 2-30 years). We analyzed US findings in the face (injection site) and neck (noninjection site). RESULTS: In all patients, face US revealed a snowstorm appearance with strong posterior acoustic shadows and multifocal small anechoic lesions with posterior stepladder artifacts in the subcutaneous fat. Neck US demonstrated the same artifacts as those on the face through local spread of fillers in 14 patients (26.4 %) and abnormal cervical lymph nodes through lymphatic spread in 34 patients (59.6 %). In abnormal cervical lymph nodes, hyperechogenicity and multiple hyperechoic foci were observed in 26 (45.6 %) and 19 (33.3 %) patients, respectively. CONCLUSION: Various artifacts may be demonstrated on US in patients with injection of permanent facial fillers. When hyperechogenicity or multiple hyperehoic foci are seen in cervical lymph nodes, the possibility of migration of facial fillers to the cervical area should be considered.

Gray-scale and color Doppler sonographic features of complex fibroadenomas of the breast.

PURPOSE: To investigate gray-scale and color Doppler sonographic (US) features of complex fibroadenoma (FA), according to the Breast Imaging-Reporting and Data System (BI-RADS) lexicon. METHODS: From 2010 through 2013, 586 women with FAs were seen; 101 (17%) of those lesions were diagnosed as complex FAs on percutaneous needle biopsy or surgery. Among the patients with complex FAs, 67 who had US examination results available were included in this study. In addition, the results from 98 women who had simple FAs were included as controls. US features were retrospectively analyzed by two breast radiologists in consensus for shape, margin, echogenicity, posterior acoustic pattern, boundary, orientation, and associated findings. They also reassessed the BI-RADS category for FAs. Color Doppler US examination results were classified according to the amount of vascularity as absent, moderate, or marked. RESULTS: Complex FA were larger than simple FAs were (14.5 cm versus 12.1 cm, p > 0.05). On univariate analysis, a round to irregular shape, an uncircumscribed margin, the presence of associated findings, and BI-RADS categorization as 4a and 4b were more frequently revealed in complex than in simple FAs (p < 0.05). Multivariate analysis revealed that the tumor margin was a predictive factor for complex FA (odds ratio: 6.08; 95% confidence interval: 1.14-32.49, p < 0.05). On color Doppler US, the complex FAs had higher degrees of vascularity than simple FA (p < 0.05). CONCLUSIONS: Complex FAs, in comparison with simple FAs, tend to have more aggressive features and to be in higher BI-RADS categories on US examination.

Detection of an accidentally implanted wooden foreign body using CT: case report and literature review.

Regardless of advancement in imaging techniques, the recognition of vegetative foreign bodies in the abdomen remains a difficult task. Simple radiography and computed tomography will ignore radiolucent foreign bodies. Here, we report the case of a 34-year-old man with a penetrating injury to the abdomen caused by a radiolucent wooden foreign body that was not initially detected. However, imaging can be specific and reliably diagnostic when performed in the appropriate clinical setting. Multidetector computed tomography is frequently underused but has proven useful for the assessment of retained wooden foreign bodies in the abdomen.

Apparent diffusion coefficient for lymph node characterization after chemoradiation therapy for locally advanced rectal cancer.

BACKGROUND: Because further treatment plans depends on lymph node (LN) status after neoadjuvant chemoradiation therapy (CRT), the accurate characterization of LN is important. PURPOSE: To evaluate the diagnostic performance of apparent diffusion coefficient (ADC) for LN characterization after CRT and to compare the performance with that of LN size. MATERIAL AND METHODS: Fifty-three patients (36 men, 17 women; mean age, 58 years; age range, 34-79 years) who underwent CRT and subsequent surgery were included. All patients underwent 1.5-T magnetic resonance imaging (MRI). Each regional LN on post-CRT MRI was identified in consensus by two radiologists after reviewing the pre-CRT MRI. The ADC value and size in each LN was measured. To compare the mean ADC values and sizes of the metastatic and non-metastatic LNs after CRT, the t-test was used. To calculate the performance, a ROC curve analysis was performed. The histopathological examinations served as the reference standard. RESULTS: A total of 115 LNs (29 metastatic and 86 non-metastatic) were matched and analyzed. The mean ADC of the metastatic LNs was significantly higher than that of the non-metastatic LNs (1.36 ± 0.27 × 10(-3)mm(2)/s; 1.13 ± 0.23 × 10(-3)mm(2)/s, P < 0.0001). The mean size of the metastatic LNs was also significantly larger than that of the non-metastatic LNs (5.6 ± 3.1; 3.9 ± 1.2, P = 0.0078). There was no significant difference between the areas under the curve of the ADC and size (0.742 [95% CI, 0.652-0.819]; 0.680 [0.586-0.764], respectively, P = 0.4090). CONCLUSION: The performance of ADC for LN characterization after CRT was comparable to that of LN size.

Real-time elastography of cervical lymph nodes in Kikuchi disease.

We report, to our knowledge, the first cases of sonographic and real-time elastographic findings of cervical lymph nodes in patients with Kikuchi disease. Cervical lymph nodes had probably benign findings on grayscale sonography and real-time elastography.

Sonographic appearances of juvenile fibroadenoma of the breast.

OBJECTIVES: The purpose of this study was to evaluate characteristic features of juvenile fibroadenoma of the breast on sonography. METHODS: Our study included 34 juvenile fibroadenomas confirmed by surgical biopsy or sonographically guided 8-gauge vacuum-assisted biopsy in 23 patients (age range, 15-47 years; mean age, 25 years). Sonographic findings of the lesions were analyzed retrospectively by 2 radiologists in consensus according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) lexicon. The BI-RADS final assessment category was also established. RESULTS: On sonography, all fibroadenomas presented as masses. The mean size was 30 mm. Regarding shape, there were 29 oval, 2 round, and 3 irregular masses. The margins were circumscribed in 24, indistinct in 5, microlobulated in 4, and angular in 1. Regarding echogenicity, 16 masses were hypoechoic, 16 isoechoic, and 2 complex echoic. Posterior acoustic characteristics included posterior acoustic enhancement in 22 masses (65%), posterior shadowing in 1, and no posterior acoustic features in 9; this information was not available in 2. The lesion boundary presented as an abrupt interface in 32 and an echogenic halo in 2. The orientation was parallel in 32 and nonparallel in 2. Calcifications were present in 3 cases and absent in 31. On color Doppler sonography, the masses were usually hypervascular with vessel counts of 5 or more (87%). The BI-RADS final assessment categories were 3 in 24 and 4a in 10. CONCLUSIONS: The dominant sonographic presentation of juvenile fibroadenoma is a circumscribed oval hypoechoic or isoechoic mass, which resembles that of simple fibroadenoma. Juvenile fibroadenomas frequently show posterior acoustic enhancement and hypervascularity on color Doppler sonography.

Atypia of undetermined significance in thyroid fine-needle aspiration cytology: prediction of malignancy by US and comparison of methods for further management.

BACKGROUND: Further management for thyroid nodules with cytological atypia of undetermined significance (AUS) has made controversial conclusions. The aim of this study was to evaluate the most reliable ultrasonography (US) findings to predict malignancy in thyroid nodules with AUS, and to compare inconclusive rates of repeat fine-needle aspiration (rFNA) and core needle biopsy (CNB) in nodules with AUS. METHODS: We retrospectively reviewed cases of thyroid nodules with AUS from 8,421 US-guided fine-needle aspirations in our institution between 2010 and 2012. Nodules were confirmed either surgically or followed-up for at least 1 year and were compared based on nodule size, US findings, and US diagnosis to predict malignancy. Inconclusive rates of rFNA and CNB after initial AUS were compared. RESULTS: The incidence of AUS in all thyroid nodules was 3.2 % (273 of 8,421). Malignancies were identified in 42.1 % (64 of 152) nodules with surgery or sufficient follow-up. In univariate analysis, not-oval to round shape, irregular margin, taller-than-wide orientation, hypoechogenicity, marked hypoechogenicity, microcalcifications, and malignant US diagnosis were more frequent in actual malignancies (p < 0.05). In multivariate analysis, hypoechogenicity, marked hypoechogenicity, and malignant US diagnosis were significantly more frequent in malignancies (p < 0.05). With respect to further management of AUS, the inconclusive rate of CNB (17.6 %, 6/34) was significantly lower than that of rFNA (37.3 %; 44 of 118) (p = 0.032). CONCLUSIONS: Nodule echogenicity and US diagnosis can be predictive factors of malignancies for the thyroid nodules with cytological AUS. The CNB is more useful than rFNA for reducing the frequency of inconclusive results after initial AUS.

Incidence and predictive factors of inadequate fine-needle aspirates for BRAF(V600E) mutation analysis in thyroid nodules.

OBJECTIVE: BRAF(V600E) mutation (valine-to-glutamate substitution at residue 600 of the B-type Raf kinase gene) analysis from thyroid aspirates is increasingly used as a prognostic or diagnostic marker. However, it is limited under some conditions. The purpose of this study was to assess the incidence and predictive factors of thyroid nodules with specimens inadequate for BRAF(V600E) mutation analysis. MATERIALS AND METHODS: We performed a retrospective cohort study of consecutive patients who underwent ultrasound-guided fine-needle aspiration (FNA) and molecular testing of aspiration specimens. Patients who had inadequate specimens in both allele-specific polymerase chain reaction and direct DNA-sequencing methods were selected. Univariate and multivariate logistic regression analyses were performed to identify predictive factors of specimens inadequate for molecular tests. RESULTS: Specimens inadequate for BRAF(V600E) mutation analysis were seen in 168 of 7001 (2.4%) patients. Factors, including patient age and sex, nodule size, ultrasound diagnosis, the presence of calcification, and cystic changes within thyroid nodules, were not significant predictors of inadequate mutation analysis. Oval-to-round or irregular shapes (e.g., not taller-than-wide) and final benign results were significant factors in univariate analysis (p = 0.0002 and p = 0.0013, respectively). However, nodules aspirated by operators with less than 1 year of experience (odds ratio [OR], 3.005; p = 0.0070), and those that had spiculated margins (OR, 6.139; p = 0.0142), isoechogenicity (OR, 10.374; p = 0.0442), or nondiagnostic cytologic findings (OR, 73.637; p = 0.0055) remained significant risk factors after adjustment in multivariable analysis. CONCLUSION: Thyroid nodule specimens inadequate for BRAF(V600E) mutation analysis were frequently associated with FNA aspiration performed by inexperienced operators, nondiagnostic cytologic findings, benign nodules on final diagnosis, and probably benign ultrasound findings, such as isoechogenicity and not-taller-than-wide shape.

Predictive factors of malignancy in patients with cytologically suspicious for Hurthle cell neoplasm of thyroid nodules.

BACKGROUND: Our aim was to evaluate predictive factors of malignancy in patients with cytologically suspicious for Hurthle cell neoplasm (HCN) of thyroid nodules. MATERIALS AND METHODS: We searched cases with cytologically suspicious for HCN from 11,569 ultrasound-guided fine-needle aspirations (US-FNA) performed at our institution. Nodules that were confirmed surgically or followed-up for at least 2 years were compared with respect to age, gender, tumor size, US diagnosis, and US findings to predict malignancy. RESULTS: The incidence of cases with cytologically suspicious for HCN was 1.2% (143 of 11,569). Of 75 nodules that underwent sufficient follow-up or surgery, malignancies were found in 11 (14.7%). Malignant histological examination revealed oncocytic variants of papillary thyroid carcinoma (PTC) in 3 cases, classic PTC in 1, Hurthle cell carcinoma in 3, follicular carcinoma in 3 and an unclassified carcinoma in 1. In univariate analysis, tumor size was significantly larger in malignant nodules compared to benign nodules (p = 0.026). The best cut-off value of tumor size in predicting malignancy was 2.5 cm. (p = 0.006, sensitivity: 63.6%, specificity: 79.7%). The incidences of hypoechogenicity and malignant US diagnoses were higher in malignant nodules than in benign nodules (p < 0.001). In multivariate analysis, tumor size was an independent factor in predicting malignancies. (p = 0.037, odd ratio: 2.09, confidence interval: 1.046-4.161). CONCLUSION: Preoperative US provides predictive factors of malignancy in thyroid nodules with cytologically suspicious for HCN. Predictive factors include tumor size of 2.5 cm or greater, hypoechoic nodule and malignant US diagnosis.

Slot-scan digital radiography of the lower extremities: a comparison to computed radiography with respect to image quality and radiation dose.

OBJECTIVE: To compare the slot-scan digital radiography (SSDR) of the lower extremity region and the computed radiography (CR) method with respect to the image quality and radiation exposure. MATERIALS AND METHODS: We enrolled 54 patients who underwent both the SSDR and CR of the lower extremities. The study evaluated and statistically compared the image quality of four features (outer cortex, inner cortex, trabeculae and intermuscular fat) at six different levels (pelvis, hip, femur, knee, tibia and ankle) between each method. The image quality was evaluated using a visibility scale, and the entrance skin dose was measured using a dosimeter at three different levels of a phantom (hip, knee, and ankle). RESULTS: The mean image visibility scale values for the SSDR method were significantly higher than for the CR method. The entrance skin dose for the SSDR method was 278 microGy at each level, compared to the entrance skin doses of the CR method, which were 3,410 microGy for the hip, 1,152 microGy for the knee, and 580 microGy for the ankle. CONCLUSION: Both the image quality and patient entrance skin dose data suggest that the SSDR method is superior to the CR method for the lower extremity musculoskeletal examination.

Solid or partly solid solitary pulmonary nodules: their characterization using contrast wash-in and morphologic features at helical CT.

BACKGROUND: Solitary pulmonary nodule (SPN) evaluation based on analyses of combined wash-in (WI) and washout (WO) values obtained by helical dynamic CT (HDCT) scanning is useful for malignant SPN characterization, because this method has higher specificity and accuracy than that based on analyses of WI values only. However, increased specificity results in reduced sensitivity and the missing of malignant SPNs. Thus, the purpose of this study was to seek the most effective method for SPN characterization during HDCT scanning. METHODS: After obtaining unenhanced CT scans, dynamic CT scanning was performed using a helical technique (images were obtained at 30, 60, 90, and 120 s, and at 5 and 15 min after the initiation of IV contrast administration) in 486 patients with a solid or partly solid SPN. Diagnostic efficacies were compared for three approaches involving considerations of WI values (in Housfield units [HU]) only, both WI and WO HU values, and WI HU values and morphologic characteristics. RESULTS: Considering WI values only (> or = 25 HU), sensitivity, specificity, and accuracy for malignancy were 98% (233 of 237 nodules), 46% (114 of 249 nodules), and 71% (347 of 486 nodules), respectively. Using both a WI value of > or = 25 HU and a WO value of 5 to 36 HU, the corresponding values were 89% (212 of 237 nodules), 79% (197 of 249 nodules), and 84% (409 of 486 nodules), respectively; for a WI value of > or = 25 HU and a malignant morphology, the corresponding values were 92% (219 of 237 nodules), 79% (197 of 249 nodules), and 86% (416 of 486 nodules), respectively (these values were significantly different between the WI-only group and the other two groups; p = 0.001). CONCLUSIONS: The efficacy of SPN evaluation based on analyses of WI values plus morphologic features during HDCT scanning appears to be equivalent to that based on analyses of WI plus WO values, thus obviating the need for WO scans, which saves time and reduces radiation exposure of the patient.