• Journal of the Korean Society of Radiology
• /
• v.83 no.3
• /
• pp.645-657
• /
• 2022

Purpose To evaluate and compare the diagnostic outcomes of ultrasonography (US)-guided fine needle aspiration (FNA) and core needle biopsy (CNB) performed on the same thyroid nodule using a surgical specimen for direct comparison. Materials and Methods We included 89 thyroid nodules from 88 patients from February 2015 to January 2016. The inclusion criterion was thyroid nodules measuring ≥ 20 mm (mean size: 40.0 ± 15.3 mm). Immediately after surgical resection, FNA and subsequent CNB were performed on the surgical specimen under US guidance. FNA and CNB cytopathologic results on the specimen were compared with the surgical diagnosis. Results Among the 89 nodules, 30 were malignant and 59 were benign. Significantly higher inconclusive rates were seen in FNA for malignant than benign nodules (80.0% vs. 39.0%, p < 0.001). For CNB, conclusive and inconclusive rates did not differ between benign and malignant nodules (p = 0.796). Higher inconclusive rates were seen for FNA among cancers regardless of US features, and in the subgroup of size ≥ 40 mm (62.5% vs. 22.9%, p = 0.028). Eleven cancers were diagnosed with CNB (36.7%, 11/30), while none was diagnosed using FNA. Conclusion In this experimental study using surgical specimens, CNB showed a potential to provide improved diagnostic sensitivity for thyroid cancer, especially when a conclusive diagnosis is limited with FNA.

• Korean Journal of Radiology
• /
• v.25 no.3
• /
• pp.289-300
• /
• 2024

Objective: To prospectively evaluate the outcomes of ultrasound (US)-guided radiofrequency ablation (RFA) in tertiary hyperparathyroidism (THPT). Materials and Methods: Patients with THPT underwent RFA between September 2017 and January 2022. Laboratory parameters, including serum intact parathyroid hormone (iPTH) levels, were monitored for 48 months after RFA and compared with the levels at baseline. Complications related to RFA and changes in hyperparathyroidism-related clinical symptoms were recorded before and after RFA. Results: A total of 42 patients with THPT were recruited for this study. Ultimately, 36 patients with renal failure and 2 patients who underwent successful renal transplantation (male:female, 17:21; median age, 54.5 years) were enrolled. The follow-up time was 21.5 ± 19.0 months in the 36 patients with renal failure. In these 36 patients, iPTH levels were significantly decreased to 261.1 pg/mL at 48 months compared with the baseline value of 1284.9 pg/mL (P = 0.012). Persistent hyperparathyroidism, defined as iPTH levels maintained at > 585.0 pg/mL for 6 months after treatment, occurred in 4.0% of patients (1/25). Recurrent hyperparathyroidism, defined as iPTH levels > 585.0 pg/mL after 6 months, were 4.0% (1/25) and 0.0% (0/9) at 6 months and 4 years after treatment, respectively. In two patients with THPT after successful renal transplantation, iPTH decreased from the baseline value of 242.5 and 115.9 pg/mL to 171.0 and 62.0 pg/mL at 6 months after treatment. All complications resolved within 6 months of ablation without medical intervention, except in 10.5% (4/38) patients with permanent hypocalcemia. The overall symptom recovery rate was 58.8% (10/17). The severity scores for bone pain, arthralgia, and itchy skin associated with hyperparathyroidism improved after treatment (P < 0.05). Conclusion: US-guided RFA is an effective and safe alternative to surgery in the treatment of patients with TPTH and improves hyperparathyroidism-related clinical symptoms.

• Korean Journal of Radiology
• /
• v.25 no.6
• /
• pp.565-574
• /
• 2024

Objective: To evaluate the safety and clinical outcomes of the Passeo-18 Lux drug-coated balloon (DCB) in endovascular revascularization procedures under real-world conditions in a Korean population with atherosclerotic disease of the infrainguinal arteries, including below-the-knee (BTK) arteries. Materials and Methods: Eight institutions in the Republic of Korea participated in this prospective, multicenter, single-arm, post-market surveillance study. Two hundred patients with Rutherford class 2-5 peripheral arterial disease and infrainguinal lesions suitable for endovascular treatment were competitively enrolled. Data were collected at baseline, the time of intervention, discharge, and 1-, 6-, 12-, and 24-month follow-up visits. The primary safety endpoint was freedom from major adverse events (MAE) within 6 months (except when limiting the time frame for procedure- or device-related mortality to within 30 days), and the primary effectiveness endpoint was freedom from clinically driven target lesion revascularization (CD-TLR) within 12 months after the procedure. Results: A total of 197 patients with 332 target lesions were analyzed. Two-thirds of the patients had diabetes mellitus, and 41.6% had chronic limb-threatening ischemia. The median target lesion length was 100 mm (interquartile range: 56-133 mm). Of the target lesions, 35.2% were occlusions, and 14.8% were located in the BTK arteries. Rate of freedom from MAE was 97.9% at 6 months, and the rate of freedom from CD-TLR was 95.0% and 92.2% at 12 and 24 months, respectively. Subgroup analysis of 43 patients and 49 target lesions involving the BTK arteries showed rate of freedom from MAE of 92.8% at 6 months and rates of freedom from CD-TLR of 88.8% and 84.4% at 12 and 24 months, respectively. Conclusion: The results of the present study, including the BTK subgroup analysis, showed outcomes comparable to those of other DCB studies, confirming the safety and effectiveness of Passeo-18 Lux DCB in the Korean population.

• Korean Journal of Radiology
• /
• v.25 no.4
• /
• pp.384-394
• /
• 2024

Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Dark-blood-HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.

• Korean Journal of Radiology
• /
• v.25 no.6
• /
• pp.511-517
• /
• 2024

Objective: To prospectively investigate the influence of the menstrual cycle on the background parenchymal signal (BPS) and apparent diffusion coefficient (ADC) of the breast on diffusion-weighted MRI (DW-MRI) in healthy premenopausal women. Materials and Methods: Seven healthy premenopausal women (median age, 37 years; range, 33-49 years) with regular menstrual cycles participated in this study. DW-MRI was performed during each of the four phases of the menstrual cycle (four examinations in total). Three radiologists independently assessed the BPS visual grade on images with b-values of 800 sec/mm² (b800), 1200 sec/mm² (b1200), and a synthetic 1500 sec/mm² (sb1500). Additionally, one radiologist conducted a quantitative analysis to measure the BPS volume (%) and ADC values of the BPS (ADC_BPS) and fibroglandular tissue (ADC_FGT). Changes in the visual grade, BPS volume (%), ADC_BPS, and ADC_FGT during the menstrual cycle were descriptively analyzed. Results: The visual grade of BPS in seven women varied from mild to marked on b800 and from minimal to moderate on b1200 and sb1500. As the b-value increased, the visual grade of BPS decreased. On b800 and sb1500, two of the seven volunteers showed the highest visual grade in the early follicular phase (EFP). On b1200, three of the seven volunteers showed the highest visual grades in EFP. The BPS volume (%) on b800 and b1200 showed the highest value in three of the six volunteers with dense breasts in EFP. Three of the seven volunteers showed the lowest ADC_BPS in the EFP. Four of the seven volunteers showed the highest ADC_BPS in the early luteal phase (ELP) and the lowest ADC_FGT in the late follicular phase (LFP). Conclusion: Most volunteers did not exhibit specific BPS patterns during their menstrual cycles. However, the highest BPS and lowest ADC_BPS were more frequently observed in EFP than in the other menstrual cycle phases, whereas the highest ADC_BPS was more common in ELP. The lowest ADC_FGT was more frequent in LFP.

• Korean Journal of Radiology
• /
• v.24 no.4
• /
• pp.338-348
• /
• 2023

Objective: Patients with a history of ischemic stroke are at risk for a second ischemic stroke. This study aimed to investigate the relationship between carotid plaque enhancement on perfluorobutane microbubble contrast-enhanced ultrasonography (CEUS) and future recurrent stroke, and to determine whether plaque enhancement can contribute to risk assessment for recurrent stroke compared with the Essen Stroke Risk Score (ESRS). Materials and Methods: This prospective study screened 151 patients with recent ischemic stroke and carotid atherosclerotic plaques at our hospital between August 2020 and December 2020. A total of 149 eligible patients underwent carotid CEUS, and 130 patients who were followed up for 15-27 months or until stroke recurrence were analyzed. Plaque enhancement on CEUS was investigated as a possible risk factor for stroke recurrence and as a possible adjunct to ESRS. Results: During follow-up, 25 patients (19.2%) experienced recurrent stroke. Patients with plaque enhancement on CEUS had an increased risk of stroke recurrence events (22/73, 30.1%) compared to those without plaque enhancement (3/57, 5.3%), with an adjusted hazard ratio (HR) of 38.264 (95% confidence interval [CI]:14.975-97.767; P < 0.001) according to a multivariable Cox proportional hazards model analysis, indicating that the presence of carotid plaque enhancement was a significant independent predictor of recurrent stroke. When plaque enhancement was added to the ESRS, the HR for stroke recurrence in the high-risk group compared to that in the low-risk group (2.188; 95% CI, 0.025-3.388) was greater than that of the ESRS alone (1.706; 95% CI, 0.810-9.014). A net of 32.0% of the recurrence group was reclassified upward appropriately by the addition of plaque enhancement to the ESRS. Conclusion: Carotid plaque enhancement was a significant and independent predictor of stroke recurrence in patients with ischemic stroke. Furthermore, the addition of plaque enhancement improved the risk stratification capability of the ESRS.

• Korean Journal of Radiology
• /
• v.24 no.6
• /
• pp.553-563
• /
• 2023

Objective: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) contribute to the localization of language areas, but their accuracy remains controversial. This study aimed to investigate the diagnostic performance of preoperative fMRI and DTI-t obtained with a simultaneous multi-slice technique using intraoperative direct cortical stimulation (DCS) or corticocortical evoked potential (CCEP) as reference standards. Materials and Methods: This prospective study included 26 patients (23-74 years; male:female, 13:13) with tumors in the vicinity of Broca's area who underwent preoperative fMRI and DTI-t. A site-by-site comparison between preoperative (fMRI and DTI-t) and intraoperative language mapping (DCS or CCEP) was performed for 226 cortical sites to calculate the sensitivity and specificity of fMRI and DTI-t for mapping Broca's areas. For sites with positive signals on fMRI or DTI-t, the true-positive rate (TPR) was calculated based on the concordance and discordance between fMRI and DTI-t. Results: Among 226 cortical sites, DCS was performed in 100 sites and CCEP was performed in 166 sites. The specificities of fMRI and DTI-t ranged from 72.4% (63/87) to 96.8% (122/126), respectively. The sensitivities of fMRI (except for verb generation) and DTI-t were 69.2% (9/13) to 92.3% (12/13) with DCS as the reference standard, and 40.0% (16/40) or lower with CCEP as the reference standard. For sites with preoperative fMRI or DTI-t positivity (n = 82), the TPR was high when fMRI and DTI-t were concordant (81.2% and 100% using DCS and CCEP, respectively, as the reference standards) and low when fMRI and DTI-t were discordant (≤ 24.2%). Conclusion: fMRI and DTI-t are sensitive and specific for mapping Broca's area compared with DCS and specific but insensitive compared with CCEP. A site with a positive signal on both fMRI and DTI-t represents a high probability of being an essential language area.

• Korean Journal of Radiology
• /
• v.25 no.5
• /
• pp.438-448
• /
• 2024

Objective: To evaluate the therapeutic outcomes of no-touch radiofrequency ablation (NT-RFA) using twin cooled wet (TCW) electrodes in patients experiencing recurrent hepatocellular carcinoma (HCC) after undergoing locoregional treatments. Materials and Methods: We conducted a prospective, single-arm study of NT-RFA involving 102 patients, with a total of 112 recurrent HCCs (each ≤ 3 cm). NT-RFA with TCW electrodes was implemented under the guidance of ultrasonography (US)-MR/CT fusion imaging. If NT-RFA application proved technically challenging, conversion to conventional tumor puncture RFA was permitted. The primary metric for evaluation was the mid-term cumulative incidence of local tumor progression (LTP) observed post-RFA. Cumulative LTP rates were estimated using the Kaplan-Meier method. Multivariable Cox proportional hazard regression was used to explore factors associated with LTP. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat (ITT; including all patients) and per-protocol (PP; including patients not requiring conversion to conventional RFA alone) analyses were performed. Results: Conversion from NT-RFA to conventional RFA was necessary for 24 (21.4%) out of 112 tumors. Successful treatment was noted in 111 (99.1%) out of them. No major complications were reported among the patients. According to ITT analysis, the estimated cumulative incidences of LTP were 1.9%, 6.0%, and 6.0% at 1, 2, and 3 years post-RFA, respectively. In PP analysis, the cumulative incidence of LTP was 0.0%, 1.3%, and 1.3% at 1, 2, and 3 years, respectively. The number of previous locoregional HCC treatments (adjusted hazard ratio [aHR], 1.265 per 1 treatment increase; P = 0.004), total bilirubin (aHR, 7.477 per 1 mg/dL increase; P = 0.012), and safety margin ≤ 5 mm (aHR, 9.029; P = 0.016) were independently associated with LTP in ITT analysis. Conclusion: NT-RFA using TCW electrodes is a safe and effective treatment for recurrent HCC, with 6.0% (ITT analysis) and 1.3% (PP analysis) cumulative incidence of LTP at 2 and 3-year follow-ups.

• Korean Journal of Radiology
• /
• v.24 no.5
• /
• pp.465-475
• /
• 2023

Objective: To evaluate the feasibility of ultrasound shear wave elastography (SWE) for predicting hepatic fibrosis and native liver outcomes in patients with biliary atresia. Materials and Methods: This prospective study included 33 consecutive patients with biliary atresia (median age, 8 weeks [interquartile range, 6-10 weeks]; male:female ratio, 15:18) from Severance Children's Hospital between May 2019 and February 2022. Preoperative (within 1 week from surgery) and immediate postoperative (on postoperative days [PODs] 3, 5, and 7) ultrasonographic findings were obtained and analyzed, including the SWE of the liver and spleen. Hepatic fibrosis, according to the METAVIR score at the time of Kasai portoenterostomy and native liver outcomes during postsurgical follow-up, were compared and correlated with imaging and laboratory findings. Poor outcomes were defined as intractable cholangitis or liver transplantation. The diagnostic performance of SWE in predicting METAVIR F3-F4 and poor hepatic outcomes was analyzed using receiver operating characteristic (ROC) analyses. Results: All patients were analyzed without exclusion. Perioperative advanced hepatic fibrosis (F3-F4) was associated with older age and higher preoperative direct bilirubin and SWE values in the liver and spleen. Preoperative liver SWE showed a ROC area of 0.806 and 63.6% (7/11) sensitivity and 86.4% (19/22) specificity at a cutoff of 17.5 kPa for diagnosing F3-F4. The poor outcome group included five patients with intractable cholangitis and three undergoing liver transplantation who showed high postoperative liver SWE values. Liver SWE on PODs 3-7 showed ROC areas of 0.783-0.891 for predicting poor outcomes, and a cutoff value of 10.3 kPa for SWE on POD 3 had 100% (8/8) sensitivity and 73.9% (17/23) specificity. Conclusion: Preoperative liver SWE can predict advanced hepatic fibrosis, and immediate postoperative liver SWE can predict poor native liver outcomes in patients with biliary atresia.

• Korean Journal of Radiology
• /
• v.23 no.7
• /
• pp.732-741
• /
• 2022

Objective: To determine the impact of dedicated subspecialized radiologists in multidisciplinary team (MDT) discussions on the management of lower gastrointestinal (GI) tract malignancies. Materials and Methods: We retrospectively analyzed the data of 244 patients (mean age ± standard deviation, 61.7 ± 11.9 years) referred to MDT discussions 249 times (i.e., 249 cases, as five patients were discussed twice for different issues) for lower GI tract malignancy including colorectal cancer, small bowel cancer, GI stromal tumor, and GI neuroendocrine tumor between April 2018 and June 2021 in a prospective database. Before the MDT discussions, dedicated GI radiologists reviewed all imaging studies again besides routine clinical reading. The referring clinician's initial diagnosis, initial treatment plan, change in radiologic interpretation compared with the initial radiology report, and the MDT's consensus recommendations for treatment were collected and compared. Factors associated with changes in treatment plans and the implementation of MDT decisions were analyzed. Results: Of the 249 cases, radiologic interpretation was changed in 73 cases (29.3%) after a review by dedicated GI radiologists, with 78.1% (57/73) resulting in changes in the treatment plan. The treatment plan was changed in 92 cases (36.9%), and the rate of change in the treatment plan was significantly higher in cases with changes in radiologic interpretation than in those without (78.1% [57/73] vs. 19.9% [35/176], p < 0.001). Follow-up records of patients showed that 91.2% (227/249) of MDT recommendations for treatment were implemented. Multiple logistic regression analysis revealed that the nonsurgical approach (vs. surgical approach) decided through MDT discussion was a significant factor for patients being managed differently than the MDT recommendations (odds ratio, 4.48; p = 0.017). Conclusion: MDT discussion involving additional review of radiology examinations by dedicated GI radiologists resulted in a change in the treatment plan in 36.9% of cases. Changes in treatment plans were significantly associated with changes in radiologic interpretation.