Sang Hyun Choi

Diagnosis of Metastasis to the Thyroid Gland Comparison of Core-Needle Biopsy and Fine-Needle Aspiration

Objectives Early detection and diagnosis of metastasis to the thyroid gland is important. This study aims to evaluate the clinical value of core-needle biopsy (CNB) by comparing the results of CNB and fine-needle aspiration (FNA) in patients with clinically suspected metastasis to the thyroid gland. Study Design Case series with chart review. Setting Tertiary referral practice. Subjects Fifty-two thyroid nodules from 52 patients with clinically suspected metastasis to the thyroid gland (mean age, 62.8 years). Methods Of these 52 patients, FNA was initially used in 41 patients and CNB in 20 patients (11 patients as the initial approach and 9 patients after inconclusive FNA results). Ultrasound features of metastasis to the thyroid gland were evaluated. The diagnostic performance, repeated diagnostic examination rate, and diagnostic surgery rate were evaluated for FNA and CNB. Results Among these 52 patients, 46 were diagnosed with thyroid metastases and 6 were diagnosed with primary thyroid cancer. Common ultrasound features were an ovoid to round shape (58.7%), ill-defined margin (56.5%), hypoechogenicity (65.2%), and no calcifications (87.0%). Core-needle biopsy achieved a significantly higher sensitivity than FNA (100.0% vs 58.6%, P = .008) without any false-negative results. Both the repeated diagnostic examination rate and the diagnostic surgery rate were significantly lower in CNB than in FNA (5.0% vs 46.3%, P = .001, and 5.0% vs 34.1%, P = .013, respectively). Conclusions In cases of known rare primary malignancy, nontypical ultrasound features of primary thyroid malignancy, and need for an additional immunohistochemical analysis, CNB may be primarily considered.

Evaluation of the Clinical Usefulness of BRAFV600E Mutation Analysis of Core-Needle Biopsy Specimens in Thyroid Nodules with Previous Atypia of Undetermined Significance or Follicular Lesions of Undetermined Significance Results

BACKGROUND The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study is to evaluate the clinical usefulness of BRAF(V600E) mutation analysis with core-needle biopsy (CNB+BRAF(V600E)) in thyroid nodules with previous atypia of undetermined significance (AUS) or follicular lesions of undetermined significance (FLUS) results. MATERIALS AND METHODS From January 2011 to December 2012, 590 CNB+BRAF(V600E) mutation analyses were performed. We analyzed 200 nodules from 200 patients with previous AUS/FLUS results (22 men, 178 women; mean age, 48.6 years). The clinical usefulness of CNB+BRAF(V600E) was assessed by comparing the rates of conclusive results, the additional value of BRAF(V600E) mutation analysis, diagnostic performances, and therapeutic/diagnostic surgery results with those of CNB alone. For the subgroup analysis, the study patients were divided into those with nodules with previous AUS results and those with previous FLUS results. RESULTS All CNB+BRAF(V600E) procedures were well-tolerated. CNB+BRAF(V600E) did not show significantly better diagnostic performance than CNB alone in thyroid nodules with previous AUS/FLUS results. However, the conclusive result rate of CNB+BRAF(V600E) was improved in thyroid nodules with previous AUS/FLUS results (76.5% vs. 73.0%, p=0.016), especially with previous AUS results (81.1% vs. 76.4%, p=0.031). Of the 56 previous AUS result thyroid nodules with surgical management, BRAF(V600E) mutation analysis led to therapeutic surgery in 5.4% by decreasing unnecessary diagnostic surgery. CONCLUSIONS In general, CNB+BRAF(V600E) did not show significantly higher diagnostic accuracy than CNB alone. Although CNB+BRAF(V600E) may add additional value in nodules with previous AUS results, routinely adding BRAF(V600E) mutation analysis to CNB is not recommended.

Initial clinical experience with BRAFV600E mutation analysis of core‐needle biopsy specimens from thyroid nodules

The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study was to evaluate the feasibility of core‐needle biopsy with BRAFV600E mutation analysis (CNB + BRAFV600E) and to compare the clinical usefulness of CNB + BRAFV600E and fine‐needle aspiration with BRAFV600E mutation analysis (FNA + BRAFV600E) in the diagnosis of thyroid malignancy.

Detection of Local Tumor Recurrence After Definitive Treatment of Head and Neck Squamous Cell Carcinoma: Histogram Analysis of Dynamic Contrast-Enhanced T1-Weighted Perfusion MRI

OBJECTIVE This study aimed to explore the added value of histogram analysis of the ratio of initial to final 90-second time-signal intensity AUC (AUCR) for differentiating local tumor recurrence from contrast-enhancing scar on follow-up dynamic contrast-enhanced T1-weighted perfusion MRI of patients treated for head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS AUCR histogram parameters were assessed among tumor recurrence (n = 19) and contrast-enhancing scar (n = 27) at primary sites and compared using the t test. ROC analysis was used to determine the best differentiating parameters. The added value of AUCR histogram parameters was assessed when they were added to inconclusive conventional MRI results. RESULTS Histogram analysis showed statistically significant differences in the 50th, 75th, and 90th percentiles of the AUCR values between the two groups (p < 0.05). The 90th percentile of the AUCR values (AUCR90) was the best predictor of local tumor recurrence (AUC, 0.77; 95% CI, 0.64-0.91) with an estimated cutoff of 1.02. AUCR90 increased sensitivity by 11.7% over that of conventional MRI alone when added to inconclusive results. CONCLUSION Histogram analysis of AUCR can improve the diagnostic yield for local tumor recurrence during surveillance after treatment for HNSCC.

Computed tomography findings in ABO-incompatible living donor liver transplantation recipients with biliary strictures

AbstractObjectivesTo evaluate CT findings of biliary strictures in ABO-incompatible living donor liver transplantation (LDLT) recipients, with emphasis on associated 1-month post-transplantation CT findings, and evaluate clinical outcomes.MethodsOf 351 ABO-incompatible recipients, we retrospectively evaluated CT scans in 65 recipients with biliary stricture. The biliary strictures on CT scans were classified as type A (perihilar) and type B (diffuse). Precedent CT abnormality patterns and the presence of a periportal halo sign at 1-month post-transplantation were evaluated. For each patient, clinical outcomes were evaluated.ResultsOf 65 ABO-incompatible recipients with biliary strictures, 36.9% had type B strictures. Compared with biliary strictures at diagnosis, similar CT abnormality patterns were observed for 84.4% in type A and 86.4% in type B strictures at 1-month post-transplantation. Complex periportal halo signs on the 1-month post-transplantation CT were more frequently noted for type B than type A strictures (86.4% vs. 3.1%, P < 0.001). Progressive clinical outcomes were more frequently observed for type B than type A strictures (79.2% vs. 26.8%, P < 0.001), with a significantly shorter graft survival time (46.4 months vs. 90.8 months, P < 0.001).ConclusionCT abnormality patterns and complex periportal halo signs on 1-month post-transplantation CT may be clinically useful for managing biliary strictures in ABO-incompatible LDLT recipients. Key Points• Of ABO-incompatible LDLT recipients, type B biliary stricture incidence was 6.8%.• Of type B strictures, 86.4% exhibited similar CT abnormality patterns at 1-month post-transplantation.• Complex periportal halo at 1 month was significantly associated with type B strictures.• Progressive clinical outcomes were more frequently observed in type B strictures.

Low Graft Attenuation at Unenhanced CT: Association with 1-Month Mortality or Graft Failure after Liver Transplantation

Purpose To investigate whether low graft attenuation at unenhanced computed tomography (CT) is associated with 1-month mortality or graft failure after liver transplant and determine its diagnostic performance. Materials and Methods Included were 663 recipients who underwent CT imaging within 7 days after liver transplant between December 2014 and August 2016. Initial poor function (IPF) was diagnosed by using a combination of laboratory values within 7 days after liver transplant and subdivided patients into primary and secondary IPF. At 1 month after the operation, mortality and graft failure or survival in recipients was categorized. Two radiologists who were blinded to clinical data retrospectively and independently evaluated graft attenuation on unenhanced CT images (high or isoattenuation, graft attenuation greater than or equal to that of spleen; low, graft attenuation less than that of spleen). The interobserver agreement was evaluated by using intraclass correlation coefficient and κ statics. Incidence of low graft attenuation between recipients with IPF and those with normal function was compared by using χ2 test. The relationship between graft attenuation and outcome in primary and secondary IPF was evaluated by using log-rank test. Results Of 663 recipients, 114 had IPF (80 primary; 34 secondary). After 1 month, 11 had graft failure or died, whereas 652 survived. Low graft attenuation was more common in patients with IPF than in normal-function patients (P < .001). In the primary group (those without identifiable cause), 15 patients had low graft attenuation, which led to mortality or graft failure within 1 month in seven of those patients. No recipient with high or isoattenuation had 1-month mortality or graft failure (P < .001). The secondary group (those with identifiable cause) showed no significant association between graft attenuation and 1-month mortality and graft failure (P = .181). Values of low graft attenuation for 1-month mortality and graft failure in primary IPF were positive predictive value, 46.7%; negative predictive value, 100%; sensitivity, 100%; specificity, 89.0%; and accuracy, 90.0%. There was excellent interobserver agreement in the assessment of graft attenuation (intraclass correlation coefficient, 0.957; κ = 1.00). Conclusion Low graft attenuation can be associated with 1-month mortality or graft failure in liver graft recipients with primary IPF.

Visibility of the graft hepatic artery using superb microvascular imaging in liver transplantation recipients: initial experience

Background Hepatic artery (HA) obstruction is one of the most threatening complications following liver transplantation (LT); however, conventional color Doppler imaging (CDI) suffers from technical limitations regarding the visualization of fine vessels and low-velocity blood flow. Purpose To test the visibility of HA in postoperative evaluation of LT using a superb microvascular imaging (SMI). Material and Methods This retrospective study was approved by our institutional review board. Fifty-five consecutive patients (58 grafts; mean age = 56 years) who underwent LT with Doppler ultrasonography (US) on postoperative day 1 were included. We compared the subjective visibility of HA and objective measurements of HA caliber, visible HA length on CDI, monochrome SMI (mSMI), contrast-enhanced mSMI (CE-mSMI), and contrast harmonic imaging (CHI). Reproducibility of HA caliber measurements on SMI techniques were also evaluated by using intraclass correlation coefficients (ICCs). Results The subjective image quality for visibility of HA tended to be graded higher with mSMI than CDI, and with CE-mSMI than mSMI (P < 0.001). The overall reproducibility of HA caliber measurements was good to excellent for both mSMI and CE-mSMI (ICC = 0.674–0.855). HA caliber measurements on mSMI and CE-mSMI strongly correlated with CHI (R = 0.785, 0.798, P < 0.001), while mean HA length on mSMI was significantly longer than on CDI (1.88 ± 0.83 vs. 1.42 ± 1.01cm, P = 0.004), and even longer on CE-mSMI (vs. 3.28 ± 1.11 cm, P < 0.001). Conclusion The mSMI technique shows good reproducibility and correlates well with currently used methods for postoperative evaluation of HA in LT recipients. It is further improved by administration of an US contrast agent.

MR cholangiography in potential liver donors: quantitative and qualitative improvement with administration of an oral effervescent agent: MRC With Oral Effervescent Agent

To determine whether an oral effervescent agent improves magnetic resonance cholangiography (MRC) images, both qualitatively and quantitatively, in potential live liver donors.