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The rate of detection of thyroid nodules and carcinomas has increased with the widespread use of ultrasonography (US), which is the primary imaging modality for the detection and risk stratification of thyroid nodules. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Although differentiated thyroid cancer has an excellent prognosis and low mortality, its recurrence rate has been reported to be very high. While surgery is recommended as the standard treatment for recurrent thyroid cancer, reoperation may increase the incidence of complications due to fibrosis and anatomical distortion. In patients with high surgical risk or those who refuse repeated surgery, ultrasonography-guided ablation techniques including radiofrequency ablation, ethanol ablation, and laser ablation are suggested as alternative treatments. In this manuscript, we introduce an anatomy-based management concept for radiofrequency ablation for recurrent thyroid cancer, and present a review of the relevant literature, including indications, basic techniques, clinical outcomes, and complications.

Background: We aim to validate the diagnostic performance of thyroid core needle biopsy (CNB) for diagnosing malignancy in clinical settings to align with the changes made in recently updated thyroid CNB guidelines.Methods: We retrospectively analyzed 1,381 thyroid CNB and 2,223 fine needle aspiration (FNA) samples. The FNA and CNB slides were interpreted according to the Bethesda System for Reporting Thyroid Cytopathology and updated practice guidelines for thyroid CNB, respectively.Results: Compared to FNA, CNB showed lower rates of inconclusive results: categories I (2.8% vs. 11.2%) and III (1.2% vs. 6.2%), and higher rates of categories II (60.9% vs. 50.4%) and IV (17.5% vs. 2.0%). The upper and lower bounds of the risk of malignancy (ROM) for category IV of CNB were 43.2% and 26.6%, respectively. The CNB subcategory IVb with nuclear atypia had a higher ROM than the subcategory without nuclear atypia (40%–62% vs. 23%–36%). In histologically confirmed cases, there was no significant difference in the diagnostic performance between CNB and FNA for malignancy. However, neoplastic diseases were more frequently detected by CNB than by FNA (88.8% vs. 77.6%, P=0.046). In category IV, there was no difference in unnecessary surgery rate between CNB and FNA (4.7% vs. 6.9%, P=0.6361).Conclusion: Thyroid CNB decreased the rate of inconclusive results and showed a higher category IV diagnostic rate than FNA. The revised guidelines for thyroid CNB proved to be an excellent reporting system for assessing thyroid nodules.

Purpose: This study compared the diagnostic performance of the modified Korean Thyroid Imaging Reporting and Data System (K-TIRADS) for thyroid malignancy with three international guidelines.Methods: From June to September 2015, 5,708 thyroid nodules (≥1.0 cm) in 5,081 consecutive patients who underwent thyroid ultrasound (US) at 26 institutions were evaluated. The US features of the thyroid nodules were retrospectively reviewed and classified according to all four guidelines. In the modified K-TIRADS, the biopsy size threshold was changed to 2.0 cm for K-TIRADS 3 and 1.0 or 1.5 cm for K-TIRADS 4 (K-TIRADS1.0cm and K-TIRADS1.5cm, respectively). We compared the diagnostic performance and unnecessary fine-needle aspiration biopsy (FNAB) rates for thyroid malignancy between the modified K-TIRADS and three international guidelines.Results: Of the 5,708 thyroid nodules, 4,597 (80.5%) were benign and 1,111 (19.5%) were malignant. The overall sensitivity was highest for the modified K-TIRADS1.0cm (91.0%), followed by the European (EU)-TIRADS (84.6%), American Association of Clinical Endocrinologists/American College of Endocrinology/Associazione Medici Endocrinologi (AACE/ACE/AME) (80.5%), American College of Radiology (ACR)-TIRADS (76.1%), and modified K-TIRADS1.5cm (76.1%). For large nodules (>2.0 cm), the sensitivity increased to 98.0% in both the modified K-TIRADS1.0cm and K-TIRADS1.5cm. For small nodules (≤2.0 cm), the unnecessary FNAB rate was lowest with the modified K-TIRADS1.5cm (17.6%), followed by the ACR-TIRADS (18.6%), AACE/ACE/AME (19.3%), EU-TIRADS (28.1%), and modified K-TIRADS1.0cm (31.2%).Conclusion: The modified K-TIRADS1.5cm can reduce the unnecessary FNAB rate for small nodules (1.0-2.0 cm), while maintaining high sensitivity for detecting malignancies >2.0 cm.

Early prediction of treatment response in nasopharyngeal carcinoma is clinically relevant for optimizing treatment strategies. This meta-analysis was performed to evaluate whether apparent diffusion coefficient (ADC) from diffusion-weighted imaging (DWI) can predict treatment response of patients with nasopharyngeal carcinoma. A systematic search of PubMed-MEDLINE and Embase was performed to identify relevant original articles until July 22, 2021. We included studies which performed DWI for predicting locoregional treatment response in nasopharyngeal carcinoma treated with neoadjuvant chemotherapy, definitive chemoradiation, or radiation therapy. Hazard ratios were meta-analytically pooled using a random-effects model for the pooled estimates of overall survival, local relapse-free survival, distant metastasis-free survival and their 95% CIs. ADC showed a pooled sensitivity of 87% (95% CI 72–94%) and specificity of 70% (95% CI 56–80%) for predicting treatment response. Significant between-study heterogeneity was observed for both pooled sensitivity (I2 = 68.5%) and specificity (I2 = 92.2%) (P

Purpose The aim of this study was to evaluate the efficacy of ethanol ablation (EA) in the treatment of cystic thyroid nodules using low-dose ethanol regardless of the initial volume of the nodule or properties of the aspirate. Methods Sixty-one nodules in 60 patients were treated with EA from October 2013 to January 2020. In each patient, EA was performed only once, using less than 5 mL of ethanol (99.5%) instilled and removed completely after a few minutes of retention. Nodule volume, the symptom score, the cosmetic score, and complications were evaluated before and after treatment. The therapeutic success rate (TSR) and volume reduction rate (VRR) according to nodule volume and properties of the aspirate were evaluated. Therapeutic success was defined as the absence of any residual fluid or sufficient volume reduction (≥50%) with improvement of nodule-related symptoms. Results The 61 nodules comprised 38 pure cysts and 23 predominantly cystic nodules. The initial nodule volume was 21.9±15.2 mL (range, 4.4 to 77.2 mL). The TSR was 88.5% (100% in pure cysts and 69.6% in predominantly cystic nodules, P

Background and Objectives: Fine needle aspiration cytology (FNAC) combined with washout thyroglobulin (Tg) measurement is the gold standard for the evaluation of metastatic lymph nodes (LNs) in thyroid cancer. However, few studies have assessed the clinical outcomes of discordant results between FNAC and washout Tg based on surgery status and follow-up imaging in real-world practice. Materials and Methods: A total of 707 LNs in 512 patients who underwent FNAC and washout Tg measurements from 2015 to 2017 were analyzed. The final LN outcomes were confirmed through postoperative histology, or through metastatic FNAC findings combined with high washout Tg level, follow-up imaging studies, or repeat FNA, if LNs were not dissected. Results: The cut-off values of washout Tg for indicating LN metastasis in preoperative and postoperative LNs were 9.6 ng/mL and 2.1 ng/mL. The diagnostic accuracy was improved by applying washout Tg according to surgery status and the results of discordant rate was reduced, Discordant between results of FNAC with washout Tg and final outcome were 9.2% (27/295) of preoperative LNs and 8.7% (36/412) of postoperative LNs. Due to inconclusive results, unnecessary neck dissection can occur in 13.9% (36/259 dissected cases). Conclusion: To improve diagnostic accuracy, cut-off values of washout Tg should be applied depending on surgery status. New biomarkers in washout fluid is necessary to resolve discordant findings.

In addition to the basic techniques used in radiofrequency ablation of thyroid nodules, a variety of more advanced techniques have been developed. To address hyper-vascular nodules, vascular ablative techniques have been described. Protective hydro-dissection can be used around the carotid artery and the trachea to improve safety. Rescue hydro dissection can be used to reverse nerve injury. Additionally, several new ablation devices show promise at increasing efficacy and safety. These techniques and devices will be reviewed to provide an understanding of these advanced techniques and novel devices.

Accurate preoperative localization of the intraparotid facial nerve (IFN) on MRI could reduce intraoperative injury. This study aimed to assess the detection rate of the IFN and its branches on MRI. PubMed-MEDLINE and Embase databases were searched for articles published up to October 2019. The inclusion criteria were (a) adults, (b) MRI-based identification of IFN by radiologists, (c) original articles, and (d) detailed results to assess the proportion of visible IFN. Two radiologists reviewed the original articles. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used to determine the quality of the selected studies. The DerSimonian-Laird random effects model was utilized to calculate the pooled estimates. Between-studies heterogeneity was evaluated using the chi-squared statistic test and Higgins’ inconsistency index (I2). A subgroup meta-regression was performed to explore the factors causing study heterogeneity. Nine original articles with 209 subjects were included. MRI reported a high pooled detection rate of 99.8% (95% CI, 98.4–100%) for the main trunk of the IFN. The pooled rates for the temporofacial and cervicofacial branches were 90.4% (95% CI, 84.1–96.7%) and 96.3% (95% CI, 96.1–99.5%), respectively. Heterogeneity was detected only in the temporofacial branch (I2 = 83%) as a result of both slice thickness and the use of steady-state sequences with diffusion-weighted imaging (DWI) implementation. MRI showed an overall high detection rate of the IFN and its branches. Furthermore, an increased identification was observed in studies that used a slice thickness of < 1 mm and steady-state sequences with DWI implementation. • MRI showed an overall high detection rate of the intraparotid facial nerve and its branches. • Higher detection rate was observed in studies that used a slice thickness of < 1 mm and steady-state sequences with diffusion-weighted imaging.

BACKGROUND This study aimed to evaluate whether computed tomography (CT)-based volumetric body composition analysis has prognostic value in head and neck cancer (HNC) patients. METHODS This single-center retrospective study included 79 patients with HNC treated with definitive radiotherapy from March 2009 to December 2018. The patients were assessed for (a) weight-based variables and (b) pretreatment and posttreatment CT-based body composition variables. Overall survival (OS) and recurrence-free survival (RFS) analyses were conducted using Cox proportional hazards analyses. RESULTS Depletion of cervical skeletal muscle volume on presentation was associated with poor OS (hazard ratio [HR] = 3.1; 95% CI = 1.2-7.8; P = .016). Low fat proportions before and after treatment were associated with poor OS (HR = 2.5-3.5; 95% CI = 1.3-9.3; P = .013-.026). In multivariate Cox analysis, increased posttreatment fat attenuation demonstrated the greatest prognostic value for both OS (HR = 4.7; 95% CI = 2.2-10.3; P

The role of radiosurgery has become further accentuated in the era of targeted agents (TA). Thus, the neurologic outcome of radiosurgery in brain metastasis (BM) of non-small cell lung cancer (NSCLC) was reviewed. We analyzed 135 patients with BM of NSCLC who were administered Cyberknife radiosurgery (CKRS) as either initial or salvage therapy. We evaluated local failure (LF), intracranial failure (IF), and neurological death (ND) due to BM. Primary outcome was neurological death-free survival (NDFS). Median follow-up was 16.2 months. Median CKRS dose of 22 Gy was administered to median 2 targets per patient. Among 99 deaths, 14 (14%) were ND. Upfront treatment for BM included CKRS alone in 85 patients (63%), CKRS + TA in 26 patients (19%), and WBRT in 24 patients (18%). No patients or tumor related factors were associated with ND. However, the type of upfront treatment for BM was significantly associated with ND [HR 0.07 (95% CI 0.01–0.57) for CKRS + TA, HR 0.56 (95% CI 0.19–1.68) for CKRS alone] compared with the WBRT group (P = 0.01). The 2-year NDFS rates for the CKRS + TA, CRKS alone, and WBRT groups were 94%, 87%, and 78%, respectively (P = 0.03). Upfront CKRS showed significantly higher 2-year LF-free survival rate (P

Background To evaluate the imaging features, clinical manifestations, and prognosis of patients with thyroid nodule rupture after radiofrequency ablation (RFA). Methods The records of 12 patients who experienced thyroid nodule rupture after RFA at four Korean thyroid centers between March 2010 and July 2017 were retrospectively reviewed. Clinical data evaluated included baseline patient characteristics, treatment methods, initial presenting symptoms, imaging features, treatment, and prognosis. Results The most common symptoms of post-RFA nodule rupture were sudden neck bulging and pain. Based on imaging features, the localization of nodule rupture was classified into three types: anterior, posterolateral, and medial types. The anterior type is the most often, followed by posterolateral and medial type. Eight patients recovered completely after conservative treatment. Four patients who did not improve with conservative management required invasive procedures, including incision and drainage or aspiration. Conclusion Thyroid nodule rupture after RFA can be classified into three types based on its localization: anterior, posterolateral, and medial types. Because majority of thyroid nodule ruptures after RFA can be managed conservatively, familiarity with these imaging features is essential in avoiding unnecessary imaging workup or invasive procedures.

This study aimed to train and validate deep learning (DL) models for differentiating malignant from benign thyroid nodules on US images and compare their performance with that of radiologists.Images of thyroid nodules in patients who underwent US-guided fine-needle aspiration biopsy at our institution between January 2010 and March 2020 were retrospectively reviewed. Four radiologists independently classified the images. Images of thyroid nodules were trained using three different image classification DL models (VGG16, VGG19, and ResNet). The diagnostic performances of the DL models were calculated for the internal and external datasets and compared with the diagnoses of the four radiologists. Pairwise comparisons of the AUCs between the radiologists and DL models were made using bootstrap-based tests.In total, 15,409 images from 7,321 patients (mean age, 60 ± 13 years; malignant nodules, 20.7%) were randomly grouped into training (n = 12,327) and validation (n = 3,082) sets. Independent internal (n = 432; 197 patients) and external (n = 168; 59 patients) test sets were also acquired. The DL models demonstrated a higher diagnostic performance than the radiologists in the internal test set (AUC, 0.83 - 0.86 vs. 0.71 - 0.76, P 0.05), but not in the external test set. The VGG16 model demonstrated the highest diagnostic performance in internal (AUC, 0.86; sensitivity, 91.8%; specificity, 73.2%) and external (AUC: 0.83; sensitivity: 78.6%; specificity: 76.8%) test sets. However, no statistical differences were found in the AUCs among the DL models.The DL models demonstrated comparable diagnostic performance to radiologists in distinguishing benign from malignant thyroid nodules on US images and may play a potential role in augmenting radiologists' diagnosis of thyroid nodules.

Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.

Purpose: To compare the efficacy and complication rates of radiofrequency ablation (RFA) and repeat surgery in the treatment of locally recurrent thyroid cancers. Materials and methods: A total of 221 patients with locally recurrent thyroid cancers who underwent either RFA (n = 96) or repeat surgery (n = 125) between March 2008 and March 2017 were retrospectively enrolled (range of follow-up, 1–10 years). Each cohort consisted of 70 patients after propensity score adjustment. Patients with more than three recurrent lesions were excluded. The primary and secondary end points were recurrence-free survival and complication rates, respectively. Recurrence-free survival curves were compared via the log-rank test. The complications—voice changes, hypocalcemia, and immediate procedural complications—were compared between the groups. In addition, pretreatment serum thyroglobulin (Tg) levels and those at the last follow-up were also compared between the two groups to examine therapeutic efficacy. Results: After propensity score matching, both groups showed no significant differences in baseline characteristics. The recurrence-free survival rates were comparable between the RFA and surgery groups (p = .2). There were no significant differences in mean serum Tg levels and their mean decrease after treatment between the groups (p = .891 and p = .963, respectively). Immediate procedural complications and voice changes also showed no significant between-group differences (p = .316, p = .084, respectively). Hypocalcemia occurred only in the repeat surgery group (n = 18). Overall complications were significantly more frequent in the repeat surgery group (RFA, n = 7; surgery, n = 27; p

Imaging plays a key role in the diagnosis and characterization of thyroid diseases, and the information provided by imaging studies is essential for management planning. A referral guideline for imaging studies may help physicians make reasonable decisions and minimize the number of unnecessary examinations. The Korean Society of Thyroid Radiology (KSThR) developed imaging guidelines for thyroid nodules and differentiated thyroid cancer using an adaptation process through a collaboration between the National Evidence-based Healthcare Collaborating Agency and the working group of KSThR, which is composed of radiologists specializing in thyroid imaging. When evidence is either insufficient or equivocal, expert opinion may supplement the available evidence for recommending imaging. Therefore, we suggest rating the appropriateness of imaging for specific clinical situations in this guideline.

Background: The increased incidence of primary papillary thyroid microcarcinoma (PTMC) has led to increased research in the field of nonsurgical therapeutic options for those who refuse surgery or ...

To explore the feasibility of using correlation-based time-delay (CTD) maps produced from time-resolved MR angiography (TRMRA) to diagnose perfusion abnormalities in patients suspected to have steno-occlusive lesions in the craniocervical arteries. Twenty-seven patients who were suspected to have steno-occlusive lesions in the craniocervical arteries underwent both TRMRA and brain single-photon emission computed tomography (SPECT). TRMRA was performed on the supra-aortic area after intravenous injection of a 0.03 mmol/kg gadolinium-based contrast agent. Time-to-peak (TTP) maps and CTD maps of the brain were automatically generated from TRMRA data, and their quality was assessed. Detection of perfusion abnormalities was compared between CTD maps and the time-series maximal intensity projection (MIP) images from TRMRA and TTP maps. Correlation coefficients between quantitative changes in SPECT and parametric maps for the abnormal perfusion areas were calculated. The CTD maps were of significantly superior quality than TTP maps (p < 0.01). For perfusion abnormality detection, CTD maps (kappa 0.84, 95% confidence interval [CI] 0.67-1.00) showed better agreement with SPECT than TTP maps (0.66, 0.46-0.85). For perfusion deficit detection, CTD maps showed higher accuracy (85.2%, 95% CI 66.3-95.8) than MIP images (66.7%, 46-83.5), with marginal significance (p = 0.07). In abnormal perfusion areas, correlation coefficients between SPECT and CTD (r = 0.74, 95% CI 0.34-0.91) were higher than those between SPECT and TTP (r = 0.66, 0.20-0.88). CTD maps generated from TRMRA were of high quality and offered good diagnostic performance for detecting perfusion abnormalities associated with steno-occlusive arterial lesions in the craniocervical area. • Generation of perfusion parametric maps from time-resolved MR angiography is clinically useful. • Correlation-based delay maps can be used to detect perfusion abnormalities associated with steno-occlusive craniocervical arteries. • Estimation of correlation-based delay is robust for low signal-to-noise 4D MR data.

Purpose: To assess the added prognostic value of the morphologic characteristics of intracranial arteries in the risk modeling of a future non-cardioembolic stroke. Materials and Methods: This retrospective study included 86 patients without acute ischemic stroke who first underwent magnetic resonance imaging (MRI) including the time-of-flight magnetic resonance angiography (TOF-MRA) at 3T. Diffusion- weighted imaging (DWI) was performed for the follow-up imaging of these patients > 120 days after the initial MRI. The TOF-MRA result was used to analyze three morphological characteristics: dilatation, stenosis, and tortuosity. The presence of acute ischemic stroke was assessed using the follow-up DWI data. We built two prognostic models: model 1 includes the conventional stroke-risk factors, while model 2 includes the conventional risk factors and the morphologic characteristics of the intracranial arteries. We used the likelihood-ratio test to compare these two models. The models’ performances were evaluated using Harrell’s concordance index. Results: Fourteen patients suffered non-cardioembolic strokes. The performances of the two models differed significantly regarding the future-risk modeling of the noncardioembolic stroke (p = 0.031). The Harrell’s concordance index of model 2 (0.78 ± 0.05) exceeded that of model 1 (0.72 ± 0.07). Conclusion: In addition to the conventional stroke-risk factors, the morphologic characteristics of the intracranial arteries were useful in the modeling of the future risk of the non-cardioembolic ischemic stroke.

Background/Aims Lymphocytic thyroiditis as cytology diagnosis from fine needle aspiration (FNA) is frequently detected in patients with thyroid nodules. However, the clinical outcome for upcoming hypothyroid events has been rarely clarified in euthyroid patients. Methods We retrospectively reviewed the data of patient who had lymphocytic thyroitidis on FNA cytology of thyroid nodule from January 2005 to December 2010 at a tertiary referral hospital. In total, 109 patients with follow-up thyroid function tests (TFT) were enrolled. Final outcomes included overt and subclinical hypothyroidism with thyroid stimulating hormone (TSH) levels ≥ 10 mIU/L. Potential parameters predicting clinical hypothyroidism were analyzed by multivariate analysis. Results Over the mean follow-up duration of 51.6 months, 14 out of 109 patients (12.8%) developed clinical hypothyroidism that required thyroid hormone replacement. The median onset time to hypothyroidism was 16 months (range, 3 to 88) and ≥ 60% of patients experienced clinical hypothyroidism within 1 year. By multivariate analysis, background thyroiditis (relative risk [RR], 9.78; p = 0.004), thyroid peroxidase antibody positivity (RR, 9.90; p = 0.003), nodule size (RR, 1.24; p < 0.001), and initial TSH (RR, 1.47; p = 0.009) were the independent risk factors for predicting hypothyroidism in euthyroid patients. Conclusions Hypothyroidism frequently occurs during the follow-up in euthyroid patients with thyroid nodules which show lymphocytic thyroiditis on FNA cytology. Close surveillance and regular TFT are needed in high-risk patients for upcoming clinical hypothyroidism.

BACKGROUND The liver is a central organ for the metabolism of iron and manganese and the places where those metals are commonly deposited overlap in the brain. PURPOSE/HYPOTHESIS To elucidate the relationship between pallidal T1 hyperintensity and iron deposition in the deep gray matter of liver cirrhosis patients using quantitative susceptibility mapping (QSM). STUDY TYPE Retrospective case–control study SUBJECTS: In all, 38 consecutive liver cirrhosis patients who received brain magnetic resonance imaging (MRI) as pretransplant evaluation. FIELD STRENGTH/SEQUENCE QSM was reconstructed from 3D multi- or single-echo phase images at 3T. T1-weighted images were used for the assessment of pallidal hyperintensity and pallidal index (PI). ASSESSMENT Patients were divided into two groups according to the presence of pallidal hyperintensity by consensus of two radiologists. Susceptibility values were acquired for five deep gray matter structures. STATISTICAL TEST QSM measures were compared between two groups using the t-test. We also calculated Pearson correlations between QSM measures and PI. RESULTS In all, 26 patients showed pallidal hyperintensity (T1h group) and 12 did not (T1n group). The susceptibility of the globus pallidus (GP) in the T1h group (120.6 ± 38.1 ppb) was significantly lower than that in the T1n group (150.0 ± 35.2, P = 0.030). The susceptibility of the dentate nucleus (DN) in the T1h group (88.1 ± 31.0) was significantly lower than that in the T1n group (125.6 ± 30.6, P = 0.001). Negative correlation between the susceptibility of GP (r = –0.37, P = 0.022) and the PI, and between DN (r = –0.43, P < 0.001) and the PI was found. DATA CONCLUSION Liver cirrhosis patients with pallidal T1 hyperintensity had lower susceptibility values in the GP and DN than those without it. This suggests a possible interaction between iron and manganese in the brains of liver cirrhosis patients. Level of Evidence: 3 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017.

The purposes of the present study are to assess whether different characteristics of oligodendrogliomas and astrocytic tumors are visible on MR imaging and to determine the added value of perfusion imaging in conventional MR imaging when differentiating oligodendrogliomas from astrocytic tumors. We retrospectively studied 22 oligodendroglioma and 54 astrocytic tumor patients, including glioblastoma multiforme (GBM). The morphological tumor characteristics were evaluated using MR imaging. The rCBV, K trans, and V e values were recorded. All imaging and clinical values were compared. The ability to discriminate between the two entities was evaluated using receiver operating characteristic curve analyses. Separate comparison analysis between oligodendroglioma and astrocytic tumors excluding GBM was also performed. The presence of calcification, higher cortex involvement ratio, and lower V e value were more representative of oligodendrogliomas than astrocytic tumors (P =

Shock thyroid is a part of the hypovolemic shock complex, which is a constellation of secondary computed tomographic (CT) findings that are observed in patients with hypovolemic shock. However, to the best of our knowledge, there has only been a single report on this condition, which described three cases associated with significant thoracoabdominal trauma. Here, we report four patients with profound hypotension who exhibited similar CT findings as those described in the initial report on shock thyroid, but with a more diverse clinical spectrum.

Background The embryological relationship between cerebellar arteries originating directly from the cavernous segment of the internal carotid artery and persistent trigeminal artery is not well understood. Purpose To evaluate the incidence and pattern of cerebellar arteries originating from the internal carotid artery and persistent trigeminal artery, and to discuss their probable embryological relationship. Material and Methods We reviewed 5113 angiographic studies from 5093 patients at our institution over the last eight years, searching for patients with persistent trigeminal artery and cerebellar arteries originating from a cavernous segment of internal carotid artery (persistent trigeminal artery variant). Results Of the 5093 patients, 27 patients had persistent trigeminal artery or persistent trigeminal artery variant (0.53%). Twenty patients (6 men, 14 women; median age = 54 years) had persistent trigeminal artery (0.39%). Seven patients (2 men, 5 women, age range = 37–72 years; median age = 57 years) had a persistent trigeminal artery variant with persistent trigeminal artery terminating in a cerebellar artery without direct connection to the basilar artery (persistent trigeminal artery variant; 0.14%). The terminal branch of the persistent trigeminal artery variant was an anterior inferior carotid artery in five patients and a superior cerebellar artery in two patients. Of the seven patients having persistent trigeminal artery variant, four patients had another artery from the basilar artery to the anterior inferior carotid artery territory. In 6/20 patients with persistent trigeminal artery, there was an anterior inferior carotid artery arising from the persistent trigeminal artery. One of these patients showed another arterial branch from the basilar artery to the anterior inferior carotid artery territory. Conclusion Persistent trigeminal artery variant and cerebellar arteries originating from the persistent trigeminal artery are both believed to be a spectrum of incomplete fusion of the longitudinal neural arteries. Understanding the precise anatomy is important in diagnostic and therapeutic settings for related vascular disease.

Although age-related changes of cerebral arteries were observed in in vivo magnetic resonance angiography (MRA), standard tools or methods measuring those changes were limited. In this study, we developed and evaluated a model to measure age-related changes in the cerebral arteries from 3D MRA using a 3D deep convolutional neural network. From participants without any medical abnormality, training (n = 800) and validation sets (n = 88) of 3D MRA were built. After preprocessing and data augmentation, a 3D convolutional neural network was trained to estimate each subject's chronological age from in vivo MRA data. There was good correlation between chronological age and predicted age (r = 0.83) in an independent test set (n = 354). The predicted age difference (PAD) of the test set was 2.41 ± 6.22. Interaction term between age and sex was significant for PAD (p = 0.008). After correcting for age and interaction term, men showed higher PAD (p0.001). Hypertension was associated with higher PAD with marginal significance (p = 0.073). We suggested that PAD might be a potential measurement of cerebral vascular aging.

Preoperative detection of cervical lymph node metastasis in papillary thyroid carcinoma (PTC) is crucial for determining the surgical strategy to prevent locoregional recurrence of the disease. We identified the cytological predictors of lymph node metastasis in 222 consecutive patients with PTC using fine-needle aspiration cytology (FNAC) of the thyroid. Cervical lymph node metastases occurred in 99 (44.6%) of 222 PTC patients. Lymph node metastasis was significantly associated with tumor multifocality (p = 0.003), and high cellularity (p = 0.021), atypical histiocytoid cells (p &lt, 0.001), and multinucleated giant cells (p &lt, 0.001) in thyroid FNAC. The BRAF V600E mutation was marginally associated with lymph node metastasis (p = 0.054). Multivariate analysis revealed that atypical histiocytoid cells (odds ratio = 2.717, p = 0.001) and multinucleated giant cells (odds ratio = 3.070, p = 0.031) were independent predictors of lymph node metastasis in patients with PTC. In a subgroup analysis of 164 patients with microcarcinomas, atypical histiocytoid cells (odds ratio = 2.761, p = 0.005) was an independent predictor of lymph node metastasis. Cytological detection of atypical histiocytoid cells and multinucleated giant cells on thyroid FNAC can be used to preoperatively predict cervical lymph node metastasis in patients with PTC.

Fine needle aspiration cytology (FNAC) and washout thyroglobulin (Tg) measurements are the standard for evaluating a metastatic lymph node (LN) in thyroid cancer. However, patients rarely benefit from these procedures due to false results. This study aims to identify a reliable biomarker that significantly improves the diagnosis of metastatic LNs, in addition to FNAC and washout Tg. This study analyzed 130 LNs that were suspected to have metastases on thyroid ultrasonography, from June 2016 to December 2017. All subjects underwent FNAC, washout Tg measurements and a new biomarker, washout Cytokeratin fragment 21-1 (CYFRA 21-1) measurement. The final LN outcomes were confirmed by surgical histology, repeat FNAC, or follow-up image. The diagnostic values of the presence of washout CYFRA 21-1 for diagnosing metastatic LNs were evaluated according to final LN outcomes. Among the 130 LNs, 42 were metastatic lesions and 88 were benign. The washout CYFRA 21-1 levels were significantly higher in metastatic LNs than in benign LNs. In contrast to the findings of washout Tg, washout CYFRA 21-1 showed little overlap between benign and malignant LNs, and its diagnostic cutoff values were not affected by surgery. The combinations of FNAC and washout CYFRA 21-1 showed higher sensitivity (91.9%), specificity (96.5%), negative predictive value (98.8%), and diagnostic accuracy (94.2%) than FNAC with washout Tg. The combination of FNAC, washout Tg, and washout CYFRA 21-1 showed the best sensitivity (98.8%). When washout CYFRA 21-1 was applied to the discordant results that were observed between FNAC and washout Tg, 20 of 22 LNs were correctly diagnosed. Washout CYFRA 21-1 measurements in thyroid LNs provide a diagnostic modality.

Background Predicting neurological outcomes after cardiac arrest is important to guide therapeutic decisions. We assessed the prognostic value of phase information of 2D T2*-weighted gradient echo imaging (T2*WI) of the brain in CA survivors. Methods This study included cardiac arrest survivors who had undergone MRI for prognostication. After application of homodyne filtering to T2*WI phase images, the contrast of three venous structures was assessed as normal (score 0) or abnormal (score 1): the superior sagittal sinus, the cortical veins, and the thalamostriate veins. The scores were summarized into a gradient-recalled echo (GRE) summary score. The prognostic performances of T2*WI, diffusion-weighted imaging (DWI), electroencephalography and serum biomarkers were evaluated using receiver operating characteristic (ROC) curves. Results Of the 39 enrolled patients, 12 (31%) had good outcomes and 27 (69%) had poor outcomes. ROC curve analysis showed that T2*WI had good prognostic performance; the area under the curve (AUC) of the GRE summary score (0.980, 95% confidence interval CI 0.950–1.000) was comparable to those of conventional outcome predictors, including DWI patterns (0.949, 95% CI 0.889–1.000). The AUC increased when the summary GRE score was added to DWI patterns (0.991, 95% CI 0.973–1.000), although the difference was not statistically significant (P = 0.117). Most subjects with isoelectric electroencephalography (5/6) showed abnormally high phase contrast in the cerebral veins. Conclusions Filtered phase images of T2*WI showed good prognostic value and can reveal various features of the cerebral metabolic consequences of cardiac arrest, such as decreased neuronal activity and brain death-like patterns.

ObjectivesThe extent of peritumoral tumor cell infiltrations in glioblastoma contributes to poor prognosis. We aimed to assess additive prognostic value of Minkowski functionals in analyzing heterogeneity of peritumoral hyperintensity on T2WI in glioblastoma patients.MethodsClinical data (age, sex, extent of surgical resection), O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and pre-operative T2WI of 113 pathologically confirmed glioblastoma patients (from our institution, n = 61; from the Cancer Imaging Archive, n = 52) were retrospectively reviewed. The patients were randomly grouped into a training set (n = 80) and a test set (n = 33). Peritumoral T2 hyperintensity was manually segmented and Minkowski functionals-a texture analysis method capturing heterogeneity of MR images-were computed as a function of 11 grayscale thresholds. The Cox proportional hazards models were fitted with clinical variables, Minkowski functionals features as well as both combined. The risk prediction performances of the Minkowski functionals and combined models were validated on a separate test dataset. The sex-specific survival difference of the entire cohort was analyzed according to MGMT methylation status via Kaplan-Meier survival curves.ResultsThirty-three Minkowski features (11 area, 11 perimeter and 11 genus) for each patient were acquired giving a total of 3729 features. Cox regression models fitted with clinical data, Minkowski features, and both combined had incremental concordance indices of 0.577 (P = 0.02), 0.706 (P = 0.02) and 0.714 (P = 0.01) respectively. The prediction error rate of the combined model-having clinical and Minkowski features-was lower than that of Minkowski functionals model (0.135 and 0.161, respectively) when validated on a test dataset. No sex-specific survival difference was found according to MGMT methylation status (male, P = 0.2; female, P = 0.22).ConclusionsMinkowski functionals features computed from peritumoral hyperintensity can capture heterogeneity of glioblastoma on T2WI and have additive prognostic value in predicting survival, demonstrating their potential in complementing currently available prognostic parameters.

SummaryBackground A recent concept was proposed that the noninvasive encapsulated follicular variant of papillary thyroid carcinoma reclassified as “noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)” is benign. Our aim was to identify the differences between NIFTP and non-NIFTP preoperatively. Methods This retrospective study included a total of 208 patients with 208 follicular variant of papillary thyroid carcinomas (FVPTC) that were surgically confirmed at three university hospitals from 2008 to 2014. Clinical factors, the biopsy techniques and ultrasonography (US) imaging characteristics were compared between the NIFTP and non-NIFTP groups. Results A total of 34 NIFTP (16·3%) and 174 non-NIFTP (83·7%) were observed. For NIFTPs, the need for surgery was indicated by ultrasonography-guided fine needle aspiration (US-FNA) in 54·3% and by ultrasonography-guided core needle biopsy (US-CNB) in 100% (P = 0·008). For non-NIFTP, no significant difference was noted in the rates of surgical indication between US-FNA and US-CNB (62·6% vs 78·9%, P = 0·054). The most common biopsy diagnosis of NIFTP was Bethesda category V (28·6%) in the US-FNA group and category IV (45·5%) in the US-CNB group. US diagnosis of NIFTP had a significantly lower rate of the high suspicion of malignancy than that of non-NIFTP (14·7% vs 37·9%, P = 0·024). Central nodal metastasis was found in only one case (2·9%) of NIFTP patients, but none had distance metastasis or recurrence. Conclusion Noninvasive follicular thyroid neoplasm with papillary-like nuclear features lacks malignant US features and is better triaged using US-CNB than using US-FNA to facilitate the surgical management. US evaluation is pivotal in determining the next step of FVPTC management.

Eight iatrogenic thyroid pseudoaneurysms (ITPAs) after thyroid biopsy are reported. The mean ITPA diameter was 7.2 mm (range 4 to 12 mm). Ultrasound (US)-guided compression was initially performed at the neck of the ITPA in all cases. Among them, 4 ITPAs persisted (50%) in which radiofrequency (RF) ablation was performed. Mean RF ablation time and power were 13.5 seconds (range 5 to 24 seconds) and 20 W (range 10 to 50 W), respectively. All 4 cases were treated with RF ablation without any complications.

We evaluated the value of diffusion-weighted readout-segmented EPI DW rs-EPI and diffusion-weighted fast spin echo images with BLADE PROPELLER k-space sampling DW BLADE in patients with ischemic stroke through intra-individual comparisons with diffusion-weighted single-shot EPI DW ss-EPI. Forty-four patients with acute ischemic stroke who had undergone three different types of diffusion weighted imaging DWI b=1000 s/mm2 were included. Two reviewers assessed the three types of DWI for diagnostic confidence based on a five-point confidence score CS. The inter- and intra-observer agreements for the CS were assessed. The DWI signal ratio to the contralateral normal area and the apparent diffusion coefficient ADC of DWI lesions were compared. The CSs of the three DWI methods were significantly different P

Purpose This study was performed to determine the malignancy risk of thyroid nodules with isolated macrocalcification and to evaluate the diagnostic efficacy of fine-needle aspiration (FNA) and core needle biopsy (CNB). Methods From May 2008 to December 2014, a total of 44 patients with isolated macrocalcifications were enrolled from 4,081 consecutive patients who underwent FNA or CNB at a single institution. We assessed the malignancy risk of nodules with isolated macrocalcification. We compared the diagnostic results between FNA and CNB, and the diagnostic efficacy of each procedure was evaluated by the rate of inconclusive results. We compared the diagnostic performance for malignancy between FNA and CNB with a criterion of malignant or atypia/follicular lesion of undetermined significance (indeterminate) diagnostic results. We investigated whether the ultrasonographic feature of isolated macrocalcification was predictive of malignancy. Results The malignancy risk of nodules with isolated macrocalcification was 16.1% in 31 nodules with final diagnoses and 11.4% in all nodules. CNB demonstrated a significantly lower rate of nondiagnostic and inconclusive results than FNA (7.7% vs. 53.8%, P=0.002 and 15.4% vs. 57.7%, P=0.003, respectively) in 26 nodules that underwent both FNA and CNB. CNB showed a marginally higher diagnostic performance for identifying malignancy than FNA (P=0.067). The ultrasonographic features of the anterior margin of isolated macrocalcification were not predictive of malignancy (P>0.999). Conclusion Thyroid nodules with isolated macrocalcification had a low to intermediate malignancy risk and should not be considered benign nodules. CNB showed a higher diagnostic efficacy than FNA in these nodules.

The role of ultrasound-guided core-needle biopsy (CNB) for the diagnosis of follicular neoplasm (FN) in the screening of thyroid nodules is controversial. We developed a diagnostic system for FN in CNB specimens and aimed to validate the clinical usefulness of the method compared with fine-needle aspiration cytology (FNAC). We reviewed 5993 FNACs and 1303 CNBs from the pathology database at Seoul St. Mary's Hospital between August 2012 and December 2014. The diagnostic rate of FN was significantly higher in CNB than in FNAC (15.7% vs. 2.4%, respectively; P 0.001). A total of 289 cases (117 FNACs and 172 CNBs) were confirmed histologically after surgical resection. NRAS mutation testing was performed with pyrosequencing. Comparing the FNAC and CNB groups, there were no differences in the positive predictive values for neoplasm (84.6% vs. 89.0%, respectively; P = 0.200) and malignancy (48.7% vs. 43.0%, respectively; P = 0.340). When we excluded the noninvasive encapsulated follicular variant of papillary carcinoma from the malignancy group, there was also no significant difference in the malignancy risk between the two groups (22.7% and 27.4% in the CNB and FNAC groups, respectively; P = 0.365). The NRAS mutation rate was 26.5% (57/215) in all FNs and occurred with similar frequency in both groups. The sensitivity, specificity, positive predictive value, and negative predictive value of a NRAS testing to predict malignancy were 40.6%, 84.9%, 68.4%, and 63.9%. In conclusion, FN was more frequently diagnosed in the CNB group than in the FNAC group, but the rates of malignancy, neoplasm, and NRAS mutation were equivalent in both groups. Therefore, CNB is a good method for the diagnosis of FN in thyroid nodule screening.