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Showing papers in "Korean Journal of Radiology in 2018"


Journal ArticleDOI
TL;DR: The revised guideline for the optimal use of radiofrequency ablation for thyroid tumors is based on a comprehensive analysis of the current literature and expert consensus.
Abstract: 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.

340 citations


Journal ArticleDOI
TL;DR: Radiofrequency ablation performed by trained radiologists from multiple institutions using a unified protocol and similar devices was effective and safe for treating benign thyroid nodules.
Abstract: Objective To assess the efficacy and safety of thyroid radiofrequency (RF) ablation for benign thyroid nodules by trained radiologists according to a unified protocol in a multi-center study. Materials and Methods From 2010 to 2011, 345 nodules from 345 patients (M:F = 43:302; mean age ± SD = 46.0 ± 12.7 years, range = 15-79) who met eligibility criteria were enrolled from five institutions. At pre-ablation, the mean volume was 14.2 ± 13.2 mL (1.1-80.8 mL). For 12 months or longer after treatment, 276 lesions, consisting of 248 solid and 28 predominantly cystic nodules, were followed. All operators performed RF ablation with a cool-tip RF system and two standard techniques (a transisthmic approach and the moving-shot technique). Volume reduction at 12 months after RF ablation (the primary outcome), therapeutic success, improvement of symptoms as well as of cosmetic problems, and complications were evaluated. Multiple linear regression analysis was applied to identify factors that were independently predictive of volume reduction. Results The mean volume reduction at 12 months was 80.3% (n = 276) and at the 24-, 36-, 48-, and 60-month follow-ups 84.3% (n = 198), 89.2% (n = 128), 91.9% (n = 57), and 95.3% (n = 6), respectively. Our therapeutic success was 97.8%. Both mean symptom and cosmetic scores showed significant improvements (p < 0.001). The rate of major complications was 1.0% (3/276). Solidity and applied energy were independent factors that predicted volume reduction. Conclusion Radiofrequency ablation performed by trained radiologists from multiple institutions using a unified protocol and similar devices was effective and safe for treating benign thyroid nodules.

136 citations


Journal ArticleDOI
Young Jin Yoo1, Eun Ju Ha1, Yoon Joo Cho1, Hye Lin Kim1, Miran Han1, So Young Kang1 
TL;DR: The CAD system may be an adjunct to radiological intervention in the diagnosis of thyroid cancer and showed improved diagnostic sensitivity and NPV compared with the radiologist alone and the CAD-assisted radiologist.
Abstract: Objective To prospectively evaluate the diagnostic performance of computer-aided diagnosis (CAD) for detection of thyroid cancers via ultrasonography (US). Materials and methods This study included 50 consecutive patients with 117 thyroid nodules on US during the period between June 2016 and July 2016. A radiologist performed US examinations using real-time CAD integrated into a US scanner. We compared the diagnostic performance of radiologist, the CAD system, and the CAD-assisted radiologist for the detection of thyroid cancers. Results The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the CAD system were 80.0, 88.1, 83.3, 85.5, and 84.6%, respectively, and were not significantly different from those of the radiologist (p > 0.05). The CAD-assisted radiologist showed improved diagnostic sensitivity compared with the radiologist alone (92.0% vs. 84.0%, p = 0.037), while the specificity and PPV were reduced (85.1% vs. 95.5%, p = 0.005 and 82.1% vs. 93.3%, p = 0.008). The radiologist assisted by the CAD system exhibited better diagnostic sensitivity and NPV than the CAD system alone (92.0% vs. 80.0%, p = 0.009 and 93.4% vs. 88.9%, p = 0.013), while the specificities and PPVs were not significantly different (88.1% vs. 85.1%, p = 0.151 and 83.3% vs. 82.1%, p = 0.613, respectively). Conclusion The CAD system may be an adjunct to radiological intervention in the diagnosis of thyroid cancer.

59 citations


Journal ArticleDOI
TL;DR: Multiple electrode radiofrequency (RF) systems that use a multi-channel RF generator have been developed, and they demonstrate better efficiency in creating larger ablation zones than that using the conventional RFA with a single electrode.
Abstract: Radiofrequency ablation (RFA) has emerged as an effective loco-regional treatment modality for malignant hepatic tumors. Indeed, studies have demonstrated that RFA of early stage hepatocellular carcinomas can provide comparable overall survival to surgical resection. However, the incidence of local tumor progression (LTP) after RFA is significantly higher than that of surgical resection. Thus, to overcome this limitation, multiple electrode radiofrequency (RF) systems that use a multi-channel RF generator have been developed, and they demonstrate better efficiency in creating larger ablation zones than that using the conventional RFA with a single electrode. Furthermore, RFA with multiple electrodes can allow the "no-touch" ablation technique which may also help to reduce LTP. Another technique that would be helpful in this regard is multi-modality-ultrasound fusion imaging, which helps to not only more accurately determine the target lesion by enabling the RFA of small, poorly visible or invisible tumors, but also improve the monitoring of procedures and determine the appropriateness of the ablation margin. In addition, new energy sources, including microwave and cryoablation, have been introduced in imaging-guided tumor ablation. In this review, these recently introduced ablation techniques and the results of the most current animal and clinical studies are discussed.

48 citations


Journal ArticleDOI
TL;DR: The vascular anatomy relevant to PPH, the practical details of TAE emphasizing the timing of embolization, and various clinical conditions of PPH according to a recent literature review are reviewed.
Abstract: Postpartum hemorrhage (PPH) is a life-threatening condition and remains a leading cause of maternal mortality. Transcatheter arterial embolization (TAE) is an effective therapeutic strategy for PPH with the advantages of fast speed, repeatability, and the possibility of fertility preservation. We reviewed the vascular anatomy relevant to PPH, the practical details of TAE emphasizing the timing of embolization, and various clinical conditions of PPH according to a recent literature review.

42 citations


Journal ArticleDOI
TL;DR: A large nodule size (≥ 3 cm) showed a higher malignancy risk than smaller nodules in intermediate- and low-suspicion nodules, and the impact of nodule sizes differed according to the US pattern.
Abstract: Objective To test whether the impact of thyroid-nodule size on the malignancy risk differs according to the ultrasonography (US) patterns of nodules. Materials and Methods This study is a post hoc analysis using data from the Thyroid Imaging Reporting and Data System (TIRADS) multicenter retrospective study which included 2000 consecutive thyroid nodules (≥ 1 cm) with final diagnoses. A total of 2000 consecutive thyroid nodules from 1802 patients (1387 women and 613 men; mean age, 51.2 ± 12.2 years) were enrolled in this study. The malignancy risk of the nodules was assessed according to the nodule size and US patterns (Korean-TIRADS). Results Overall, the malignancy risk did not increase as nodules enlarged. In high-suspicion nodules, the malignancy rate had no association with nodule size (p = 0.467), whereas in intermediate- or low-suspicion nodules there was a trend toward an increasing malignancy risk as the nodule size increased (p = 0.004 and 0.002, respectively). The malignancy rate of large nodules (≥ 3 cm) was higher than that of small nodules (< 3 cm) in intermediate-suspicion nodules (40.3% vs. 22.6%, respectively; p = 0.001) and low-suspicion nodules (11.3% vs. 7.0%, respectively; p = 0.035). There was a trend toward a decreasing risk and proportion of papillary carcinoma and an increasing risk and proportion of follicular carcinoma or other malignant tumors as nodule size increased (p < 0.001, respectively). Conclusion The impact of nodule size on the malignancy risk differed according to the US pattern. A large nodule size (≥ 3 cm) showed a higher malignancy risk than smaller nodules in intermediate- and low-suspicion nodules.

40 citations


Journal ArticleDOI
TL;DR: MRI and PET-CT can be used as second-line imaging modalities and could help distinguish PAIS from PTE and to plan clinical management and make better survival outcomes of patients.
Abstract: Objective To describe CT and clinical findings of pulmonary artery intimal sarcoma (PAIS) compared with those of pulmonary thromboembolism (PTE), to investigate MRI and positron emission tomography (PET)-CT findings of PAIS, and to evaluate the effect of delayed diagnosis of PAIS on survival outcomes. Materials and Methods Twenty-six patients with PAIS were retrospectively identified and matched for sex, with patients with PTE at a ratio of 1:2. CT and clinical findings of the two groups were compared using Student's t test or chi-square test. The effect of delayed diagnosis on survival was investigated using Kaplan-Meier analysis. Results The most common tumor pattern in PAIS was tumoral impaction. Heterogeneous attenuation, wall eclipse signs, intratumoral vessels, acute interphase angles, single location, presence of lung ischemia, and central location were significantly more common in PAIS than in PTE (all p < 0.01). Levels of D-dimers and brain natriuretic peptide were lower in PAIS than in PTE (p < 0.05). In three patients of PAIS, long inversion time sequence MRI showed intermingled dark signal intensity foci suggestive of intermingled thrombi. All nine patients who had undergone PET-CT displayed hypermetabolism. Diagnosis was delayed in 42.3% of the PAIS patients and those patients had a significantly shorter overall survival than patients whose diagnosis was not delayed (p < 0.05). Conclusion The characteristic CT and clinical findings of PAIS may help achieve early diagnosis of PAIS and make better survival outcomes of patients. MRI and PET-CT can be used as second-line imaging modalities and could help distinguish PAIS from PTE and to plan clinical management.

40 citations


Journal ArticleDOI
TL;DR: Quantitative analysis of D CE-MRI and DCE-US was helpful for early prediction of response to NAC.
Abstract: Objective To determine the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and DCE ultrasound (DCE-US) for predicting response to neoadjuvant chemotherapy (NAC) in breast cancer patients. Materials and Methods This Institutional Review Board-approved prospective study was performed between 2014 and 2016. Thirty-nine women with breast cancer underwent DCE-US and DCE-MRI before the NAC, follow-up DCE-US after the first cycle of NAC, and follow-up DCE-MRI after the second cycle of NAC. DCE-MRI parameters (transfer constant [Ktrans], reverse constant [kep], and leakage space [Ve]) were assessed with histograms. From DCE-US, peak-enhancement, the area under the curve, wash-in rate, wash-out rate, time to peak, and rise time (RT) were obtained. After surgery, all the imaging parameters and their changes were compared with histopathologic response using the Miller-Payne Grading (MPG) system. Data from minor and good responders were compared using Wilcoxon rank sum test, chi-square test, or Fisher's exact test. Receiver operating characteristic curve analysis was used for assessing diagnostic performance to predict good response. Results Twelve patients (30.8%) showed a good response (MPG 4 or 5) and 27 (69.2%) showed a minor response (MPG 1-3). The mean, 25th, 50th, and 75th percentiles of Ktrans and Kep of post-NAC DCE-MRI differed between the two groups. These parameters showed fair to good diagnostic performance for the prediction of response to NAC (AUC 0.76-0.81, p ≤ 0.007). Among DCE-US parameters, the percentage change in RT showed fair prediction (AUC 0.71, p = 0.023). Conclusion Quantitative analysis of DCE-MRI and DCE-US was helpful for early prediction of response to NAC.

38 citations


Journal ArticleDOI
TL;DR: The Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency developed guidelines for primary imaging tests and appropriate biopsy methods for thyroid nodules, which recommend neck ultrasound (US) as a first-line imaging modality for the diagnosis of thyroid nodule in patients with suspected nodules.
Abstract: The Korean Society of Radiology and the National Evidence-based Healthcare Collaborating Agency developed guidelines for primary imaging tests and appropriate biopsy methods for thyroid nodules. These guidelines were developed using an adaptation process by collaboration between the development committee and the working group. The development committee, composed of research methodology experts, established the overall plan and provided support about methodological strategies. The working group, composed of radiologist experts in thyroid imaging, wrote the proposals. The guidelines recommend neck ultrasound (US) as a first-line imaging modality for the diagnosis of thyroid nodules in patients with suspected nodules, and US-guided fine-needle aspiration as a primary method for histologic examination of thyroid nodules.

35 citations


Journal ArticleDOI
TL;DR: The per-patient sensitivity and specificity of non-contrast MRIs were within a reasonable range for the initial diagnosis of HCC and may have a potential for surveillance of H CC.
Abstract: Objective To preliminarily evaluate the diagnostic performance of an unenhanced MRI for detecting hepatocellular carcinoma (HCC) with a case-control study design. Materials and Methods The case group consisted of 175 patients with initially-diagnosed HCC, who underwent a 3T liver MRI. A total of 237 HCCs were identified. The number of HCCs that were smaller than 1 cm, 1 cm ≤ and < 2 cm, and ≥ 2 cm were 19, 105, and 113, respectively. For the control group, 72 patients with chronic liver disease, who did not have HCC, were enrolled. Two radiologists independently reviewed the T2 half-Fourier acquisition single-shot turbo spin echo, T2 fast spin echos with fat saturation, T1 gradient in- and out-of-phase images, and diffusion-weighted images/apparent diffusion coefficient maps to detect HCC. Per-patient analyses were performed to evaluate the sensitivity and specificity of the non-contrast MRI for diagnosing HCC. Furthermore, the per-lesion sensitivity was also calculated according to tumor size. Results In the per-patient analyses, the sensitivity and specificity of reader 1 were 86.3% (151/175) and 87.5% (63/72), respectively; while those of reader 2 were 82.9% (145/175) and 76.4% (55/72), respectively. When excluding HCCs smaller than 1 cm, the sensitivity of reader 1 and 2 were 88.0% (147/167) and 86.2% (144/167), respectively. In the per-lesion analyses, the sensitivities of reader 1 and reader 2 were 75.9% (180/237) and 70.5% (167/237), respectively. Conclusion The per-patient sensitivity and specificity of non-contrast MRIs were within a reasonable range for the initial diagnosis of HCC. Non-contrast MRIs may have a potential for surveillance of HCC. Further confirmatory diagnostic test accuracy studies are needed.

34 citations


Journal ArticleDOI
TL;DR: TACE + MWA appears to have more advantages compared to TACE in prolonging OS, with a satisfactory TTP, for inpatients with solitary large or multinodular HCCs.
Abstract: Objective To evaluate the efficacy and prognostic factors associated with transcatheter arterial chemoembolization (TACE) combined with microwave ablation (MWA) versus TACE alone for a large solitary or multinodular hepatocellular carcinomas (HCCs). Materials and Methods This retrospective study involved 258 patients with a large solitary or multinodular HCCs (not more than 10 tumors) who underwent TACE + MWA (n = 92) or TACE alone (n = 166) between July 2011 and April 2015. Local tumor control, survival outcomes, and complications were compared between the two groups. Prognostic factors for time to progression (TTP) and overall survival (OS) were evaluated by univariate and multivariate analyses. Results The median duration of follow-up was 21.2 months (range, 4-45 months). The median TTP and OS were 12.5 months and 26.6 months, respectively, for the TACE + MWA group and 6.7 months and 17.1 months, respectively, for the TACE group (p < 0.001). The 1-, 2-, and 3-year OS rates were 85.9, 59.8, and 32.6%, respectively, for the TACE + MWA group and 59.0, 40.4, and 11.4%, respectively, for the TACE group (p < 0.001). The corresponding recurrence rates were 47.8, 78.3, and 94.6% for the TACE + MWA group, respectively, and 74.7, 96.4, and 97.6%, respectively, for the TACE group (p < 0.001). Logistic regression analyses showed that the treatment method, tumor size, and tumor number were significant prognostic factors for TTP and OS. Conclusion TACE + MWA appears to have more advantages compared to TACE in prolonging OS, with a satisfactory TTP, for inpatients with solitary large or multinodular HCCs. Treatment method, tumor size, and tumor number are significant prognostic factors for TTP and OS. Further randomized, multi-center, prospective trials are required to confirm the findings of this study.

Journal ArticleDOI
TL;DR: Percutaneous stent placement may be safe and effective for internal drainage in patients with MBHO and the stent type and configuration may not significantly affect clinical outcomes.
Abstract: Objective To investigate the outcomes of percutaneous metallic stent placements in patients with malignant biliary hilar obstruction (MBHO). Materials and methods From January 2007 to December 2014, 415 patients (mean age, 65 years; 261 men [62.8%]) with MBHO were retrospectively studied. All the patients underwent unilateral or bilateral stenting in a T, Y, or crisscross configuration utilizing covered or uncovered stents. The clinical outcomes evaluated were technical and clinical success, complications, overall survival rates, and stent occlusion-free survival. Results A total of 784 stents were successfully placed in 415 patients. Fifty-five patients had complications. These complications included hemobilia (n = 19), cholangitis (n = 13), cholecystitis (n = 11), bilomas (n = 10), peritonitis (n = 1), and hepatic vein-biliary fistula (n = 1). Clinical success was achieved in 370 patients (89.1%). Ninety-seven patients were lost to follow-up. Stent dysfunction due to tumor ingrowth (n = 107), sludge incrustation (n = 44), and other causes (n = 3) occurred in 154 of 318 patients. The median overall survival and the stent occlusion-free survival were 212 days (95% confidence interval [CI], 186-237 days) and 141 days (95% CI, 126-156 days), respectively. The stent type and its configuration did not affect technical success, complications, successful internal drainage, overall survival, or stent occlusion-free survival. Conclusion Percutaneous stent placement may be safe and effective for internal drainage in patients with MBHO. Furthermore, stent type and configuration may not significantly affect clinical outcomes.

Journal ArticleDOI
TL;DR: Histologic examination and biopsy should be considered in the event of abnormal imaging findings, such as non-circumscribed margins, complex solid and cystic components, posterior acoustic shadowing, size above 3 cm, or an increase in mass size.
Abstract: Pediatric breast disease is uncommon, and primary breast carcinoma in children is extremely rare. Therefore, the approach used to address breast lesions in pediatric patients differs from that in adults in many ways. Knowledge of the normal imaging features at various stages of development and the characteristics of breast disease in the pediatric population can help the radiologist to make confident diagnoses and manage patients appropriately. Most breast diseases in children are benign or associated with breast development, suggesting a need for conservative treatment. Interventional procedures might affect the developing breast and are only indicated in a limited number of cases. Histologic examination should be performed in pediatric patients, taking into account the size of the lesion and clinical history together with the imaging findings. A core needle biopsy is useful for accurate diagnosis and avoidance of irreparable damage in pediatric patients. Biopsy should be considered in the event of abnormal imaging findings, such as non-circumscribed margins, complex solid and cystic components, posterior acoustic shadowing, size above 3 cm, or an increase in mass size. A clinical history that includes a risk factor for malignancy, such as prior chest irradiation, known concurrent cancer not involving the breast, or family history of breast cancer, should prompt consideration of biopsy even if the lesion has a probably benign appearance on ultrasonography.

Journal ArticleDOI
TL;DR: Microwave ablation showed favorable technical and oncologic outcomes with a low incidence of major complications, Hence, image-guided percutaneous MWA can be considered as a safe and effective treatment for malignant renal tumors.
Abstract: Objective To systematically determine the treatment outcomes of percutaneous microwave ablation (MWA) in patients with malignant renal tumor. Materials and Methods Original studies that reported the clinical outcomes of MWA in patients with malignant renal tumors were identified in MEDLINE and EMBASE from 2012 to June 30, 2017. Inverse variance and random-effects models were used to evaluate and acquire meta-analytic summary estimates of various clinical outcomes, including technical outcomes (technical success rate [TSR] and technical efficacy rate [TER]), oncologic outcomes (local tumor recurrence rate [LRR], cancer-specific survival rate [CSSR], and overall survival rate [OSR]), and complications. Results Among the 145 articles screened, 13 articles including 567 patients carrying 616 malignant renal tumors were included in the meta-analysis. The meta-analytic pooled TSR and TER were 97.3% (95% confidence interval, 94.3-99.4%; I2 = 0.0%) and 97.6% (95.0-99.4%, I2 = 48.5%), respectively. The meta-analytic pooled LRR was 2.1% (0.3-4.7%, I2 = 54.1%). At 1-, 2-, 3-, and 5-year follow-up time points, the meta-analytic pooled CSSRs were 99.1% (97.2-100.0%; I2 = 0.0%), 98.4% (95.1-100.0%; I2 = 31.2%), 97.6% (93.4-99.9%; I2 = 52.3%), and 96.9% (93.3-99.2%; I2 = 0.0%) respectively, while the OSRs were 98.3% (96.1-99.8%; I2 = 0.0%), 94.9% (91.7-97.5%; I2 = 0.0%), 86.8% (81.9-91.1%; I2 = 22.1%), and 81.9% (75.4-87.6%; I2 = 0.0%). In terms of major complications, a 1.8% (0.6-3.3%; I2 = 0.0%) rate of meta-analytic pooled incidence was found. Conclusion Microwave ablation showed favorable technical and oncologic outcomes with a low incidence of major complications. Hence, image-guided percutaneous MWA can be considered as a safe and effective treatment for malignant renal tumors.

Journal ArticleDOI
TL;DR: Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD and internally validate quantitative CT parameters with Crohn's disease activity index.
Abstract: Objective To correlate CT parameters on detector-based dual-energy CT enterography (DECTE) with Crohn's disease activity index (CDAI) and externally validate quantitative CT parameters. Materials and Methods Thirty-nine patients with CD were retrospectively enrolled. Two radiologists reviewed DECTE images by consensus for qualitative and quantitative CT features. CT attenuation and iodine concentration for the diseased bowel were also measured. Univariate statistical tests were used to evaluate whether there was a significant difference in CTE features between remission and active groups, on the basis of the CDAI score. Pearson's correlation test and multiple linear regression analyses were used to assess the correlation between quantitative CT parameters and CDAI. For external validation, an additional 33 consecutive patients were recruited. The correlation and concordance rate were calculated between real and estimated CDAI. Results There were significant differences between remission and active groups in the bowel enhancement pattern, subjective degree of enhancement, mesenteric fat infiltration, comb sign, and obstruction (p < 0.05). Significant correlations were found between CDAI and quantitative CT parameters, including number of lesions (correlation coefficient, r = 0.573), bowel wall thickness (r = 0.477), iodine concentration (r = 0.744), and relative degree of enhancement (r = 0.541; p < 0.05). Iodine concentration remained the sole independent variable associated with CDAI in multivariate analysis (p = 0.001). The linear regression equation for CDAI (y) and iodine concentration (x) was y = 53.549x + 55.111. For validation patients, a significant correlation (r = 0.925; p < 0.001) and high concordance rate (87.9%, 29/33) were observed between real and estimated CDAIs. Conclusion Iodine concentration, measured on detector-based DECTE, represents a convenient and reproducible biomarker to monitor disease activity in CD.

Journal ArticleDOI
TL;DR: The current concepts for assessing tumor response, common post-treatment imaging features, and associated complications following radioembolization are discussed.
Abstract: Radioembolization using beta-emitting yttrium-90 microspheres is being increasingly used for the treatment of primary and metastatic liver cancers. It is a form of intra-arterial brachytherapy which delivers intense radiation to liver tumors with little embolic effect; this mode of action results in unique post-treatment imaging findings. It is important to understand these imaging findings to avoid misinterpretation of tumor response and to determine further management of the disease. Herein, we discuss the current concepts for assessing tumor response, common post-treatment imaging features, and associated complications following radioembolization.

Journal ArticleDOI
TL;DR: MRgH IFU and USgHIFU are safe and effective with the equivalent energy efficiency for complete ablation of fibroids.
Abstract: Objective The purpose of this study was to compare efficacy, sonication energy efficiency, treatment time and safety of magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) and those of ultrasound-guided high-intensity focused ultrasound (USgHIFU) for ablation of uterine fibroids. Materials and methods This study included 43 patients with 44 symptomatic uterine fibroids treated with MRgHIFU and 51 patients with 68 symptomatic uterine fibroids treated with USgHIFU. After therapy, contrast-enhanced MRI was conducted and complete ablation was defined as 100% non-perfused volume (NPV) of fibroids. Patients with completely ablated fibroids were selected for the comparison of the treatment data and sonication parameters between MRgHIFU and USgHIFU treated groups. Results Thirteen completely ablated fibroids in 10 patients (23.3%, 10/43) were achieved with MRgHIFU and 28 completely ablated fibroids in 22 patients (43.1%, 22/51) were achieved with USgHIFU. In completely ablated fibroids, the energy-efficiency factor (EEF) was 5.1 ± 3.0 J/mm3 and 4.7 ± 2.5 J/mm3 in the MRgHIFU and USgHIFU, respectively (p = 0.165). There was a negative linear correlation between EEF and the NPV of fibroids for MRgHIFU (p = 0.016) and USgHIFU (p = 0.001). The mean treatment time was 174.5 ± 42.2 minutes and 114.4 ± 39.2 minutes in the MRgHIFU and USgHIFU procedures, respectively (p = 0.021). There were no severe adverse events and major complications after treatment. Conclusion MRgHIFU and USgHIFU are safe and effective with the equivalent energy efficiency for complete ablation of fibroids. USgHIFU has shorter treatment time than MRgHIFU.

Journal ArticleDOI
TL;DR: This pictorial essay intends to demonstrate radiologic findings of a variety of inflammatory breast disorders, using selected cases with mammography, ultrasound and magnetic resonance images.
Abstract: Inflammatory breast disorders include a wide array of underlying causes, ranging from common benign infection, non-infectious inflammation and inflammation resulting from underlying breast malignancy. Because it is at times difficult to distinguish mastitis and breast cancer based on clinical features, awareness of detailed imaging features may be helpful for better management of inflammatory breast disorders. Therefore, this pictorial essay intends to demonstrate radiologic findings of a variety of inflammatory breast disorders, using selected cases with mammography, ultrasound and magnetic resonance images.

Journal ArticleDOI
TL;DR: MVA+ have different morphometric features in the left frontal and temporal lobe relative to MVA, which could be a source of distinct symptoms and serve as potential biomarkers of different MA subtypes.
Abstract: Objective Previous migraine studies have reported gray matter alterations in various cortical regions with conflicting results. This study aimed to explore a cortical morphometric difference in migraineurs with aura (MA) compared to healthy subjects (HS) and to delineate a possible difference between the cortical morphological features and different aura phenotypes. Materials and Methods Forty-eight MA and 30 HS that were balanced by sex, age, and educational level were selected for this study. T2-weighted and three-dimensional T1-weighted magnetic resonance imaging (MRI) of the brain were acquired using a 1.5T MRI scanner. Surface-based morphometry from the MRI data was used to identify differences between the MA and HS group, and then between MA subgroups. The MA group was subdivided into migraineurs who experienced only visual aura (MVA) and migraineurs who had visual, somatosensory and dysphasic symptoms (MVA+). Results The MVA+ group had significantly reduced cortical surface area of the left rostral middle frontal cortex compared with the MVA group (p < 0.001). Migraine patients had significantly reduced volume of the left fusiform gyrus relative to HS (p < 0.001). Also, the sulcal depth increased at the level of the left temporal pole in the MVA+ group relative to the MVA group (p < 0.001). The vertex-by-vertex analysis did not exhibit any significant difference in cortical thickness between MA and HS, and between MVA+ and MVA, when corrected for multiple comparisons. Conclusion Migraineurs with aura demonstrates different morphometric features from HS in multiple cortical regions. MVA+ have different morphometric features in the left frontal and temporal lobe relative to MVA, which could be a source of distinct symptoms and serve as potential biomarkers of different MA subtypes.

Journal ArticleDOI
TL;DR: Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-R FA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA.
Abstract: Objective To evaluate the clinical impact of using registration software for ablative margin assessment on pre-radiofrequency ablation (RFA) magnetic resonance imaging (MRI) and post-RFA computed tomography (CT) compared with the conventional side-by-side MR-CT visual comparison Materials and methods In this Institutional Review Board-approved prospective study, 68 patients with 88 hepatocellulcar carcinomas (HCCs) who had undergone pre-RFA MRI were enrolled Informed consent was obtained from all patients Pre-RFA MRI and post-RFA CT images were analyzed to evaluate the presence of a sufficient safety margin (≥ 3 mm) in two separate sessions using either side-by-side visual comparison or non-rigid registration software Patients with an insufficient ablative margin on either one or both methods underwent additional treatment depending on the technical feasibility and patient's condition Then, ablative margins were re-assessed using both methods Local tumor progression (LTP) rates were compared between the sufficient and insufficient margin groups in each method Results The two methods showed 148% (13/88) discordance in estimating sufficient ablative margins On registration software-assisted inspection, patients with insufficient ablative margins showed a significantly higher 5-year LTP rate than those with sufficient ablative margins (667% vs 270%, p = 0004) However, classification by visual inspection alone did not reveal a significant difference in 5-year LTP between the two groups (286% vs 305%, p = 079) Conclusion Registration software provided better ablative margin assessment than did visual inspection in patients with HCCs who had undergone pre-RFA MRI and post-RFA CT for prediction of LTP after RFA and may provide more precise risk stratification of those who are treated with RFA

Journal ArticleDOI
TL;DR: The main purpose of this article was to familiarize radiologists with imaging findings of metastasis to the urinary system on cross-sectional imaging, with an emphasis on abdominal and pelvic computed tomography and magnetic resonance imaging.
Abstract: Imaging features of metastases to the urinary system may closely mimic primary urinary tract tumors, and differential diagnosis by imaging alone may be problematic or even impossible in some cases. The main purpose of this article was to familiarize radiologists with imaging findings of metastasis to the urinary system on cross-sectional imaging, with an emphasis on abdominal and pelvic computed tomography and magnetic resonance imaging. In addition, we review the clinical importance and implications of metastases to the urinary tract and provide information on diagnostic work-ups.

Journal ArticleDOI
TL;DR: The IR algorithm may be used to save radiation doses without substantial image quality degradation in chest CT scanning of the adult anthropomorphic phantom, down to approximately 1.4 mGy in CTDIvol (60% reduced dose).
Abstract: Objective To describe the quantitative image quality and histogram-based evaluation of an iterative reconstruction (IR) algorithm in chest computed tomography (CT) scans at low-to-ultralow CT radiation dose levels. Materials and Methods In an adult anthropomorphic phantom, chest CT scans were performed with 128-section dual-source CT at 70, 80, 100, 120, and 140 kVp, and the reference (3.4 mGy in volume CT Dose Index [CTDIvol]), 30%-, 60%-, and 90%-reduced radiation dose levels (2.4, 1.4, and 0.3 mGy). The CT images were reconstructed by using filtered back projection (FBP) algorithms and IR algorithm with strengths 1, 3, and 5. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were statistically compared between different dose levels, tube voltages, and reconstruction algorithms. Moreover, histograms of subtraction images before and after standardization in x- and y-axes were visually compared. Results Compared with FBP images, IR images with strengths 1, 3, and 5 demonstrated image noise reduction up to 49.1%, SNR increase up to 100.7%, and CNR increase up to 67.3%. Noteworthy image quality degradations on IR images including a 184.9% increase in image noise, 63.0% decrease in SNR, and 51.3% decrease in CNR, and were shown between 60% and 90% reduced levels of radiation dose (p < 0.0001). Subtraction histograms between FBP and IR images showed progressively increased dispersion with increased IR strength and increased dose reduction. After standardization, the histograms appeared deviated and ragged between FBP images and IR images with strength 3 or 5, but almost normally-distributed between FBP images and IR images with strength 1. Conclusion The IR algorithm may be used to save radiation doses without substantial image quality degradation in chest CT scanning of the adult anthropomorphic phantom, down to approximately 1.4 mGy in CTDIvol (60% reduced dose).

Journal ArticleDOI
TL;DR: The size of the study population was small, the positive rate of 7.4% was like or lower than those in other lung cancer screening studies, and Lung-RADS may be applicable to participants in Korea, where pulmonary tuberculosis is endemic.
Abstract: Objective To report the radiological results of a pilot study for the Korean Lung Cancer Screening project conducted to evaluate the feasibility of lung cancer screening using low-dose chest computed tomography (LDCT) in Korea. Materials and Methods The National Cancer Center and three regional cancer centers participated in this study. Asymptomatic current or ex-smokers aged 55-74 years with a smoking history of at least 30 pack-years who had used tobacco within the last 15 years were considered eligible. In total, 256 participants underwent LDCT November 2016 through March 2017. The American College of Radiology Lung Imaging Reporting and Data System (Lung-RADS) was used to categorize the LDCT findings. Results In total, 57%, 35.5%, 3.9%, and 3.5% participants belonged to Lung-RADS categories 1, 2, 3, and 4, respectively. Accordingly, 7.4% participants exhibited positive findings (category 3 or 4). Lung cancer was diagnosed in one participant (stage IA, small cell lung cancer). Other LDCT findings included pulmonary emphysema (32.8%), coronary artery calcification (30.9%), old pulmonary tuberculosis (11.7%), bronchiectasis (12.9%), interstitial lung disease with a usual interstitial pneumonia pattern (1.2%), and pleural effusion (0.8%). Conclusion Even though the size of our study population was small, the positive rate of 7.4% was like or lower than those in other lung cancer screening studies. Early lung cancer was detected using LDCT screening in one participant. Lung-RADS may be applicable to participants in Korea, where pulmonary tuberculosis is endemic.

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TL;DR: In non-obese Chinese adults, the degree of hepatic fatty infiltration showed a strong correlation with abdominal fat on CT, and V FA at L2/3 level was more closely related to fatty liver compared with VFA at L4/5 level.
Abstract: Objective To investigate the correlation between non-alcoholic fatty liver disease and visceral adipose tissue in non-obese Chinese adults using computed tomography (CT). Materials and Methods The study included 454 subjects undergoing abdominal CT scan. Degree of CT attenuation in liver and spleen, and the degree of fat infiltration in liver were evaluated according to three indices: the attenuation value of liver parenchyma (CTLP), the attenuation ratio of liver and spleen (LSratio) and the attenuation difference between liver and spleen (LSdif). Visceral fat area (VFA) and total fat area (TFA) at L2/3 and L4/5 levels were measured, and the abdominal subcutaneous fat area (SFA) was calculated. Bivariate correlation analysis was carried out to determine the correlation among these factors. Results In men, VFA, SFA and TFA at L2/3 and L4/5 levels showed significant differences in terms of the three indices to distinguish fatty liver from non-fatty liver (all, p < 0.001). In men, all the three indices showed negative correlation with TFA, SFA and VFA (all, p < 0.001). The negative correlation between the three indices and VFA at the L2/3 level was higher than at L4/5 level (r = -0.476 vs. r = -0.340 for CTLP, r = -0.502 vs. r = -0.413 for LSratio, r = -0.543 vs. r = -0.422 for LSdif, p < 0.001, respectively). The negative correlation between LSratio, LSdif and VFA at L2/3 and L4/5 levels was higher than SFA at the corresponding level. In women, all the three indices showed negative correlation with VFA and TFA at L2/3 and L4/5 levels, and the negative correlation between CTLP and VFA was higher at L2/3 level than at L4/5 level (r = -0.294 vs. r = -0.254, p < 0.001). Conclusion In non-obese Chinese adults, the degree of hepatic fatty infiltration showed a strong correlation with abdominal fat on CT. VFA at L2/3 level was more closely related to fatty liver compared with VFA at L4/5 level.

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TL;DR: The characteristics of prostate-specific membrane antigen (PSMA)-targeting PET and their clinical applications in prostate cancer patients are described and the impact of improved diagnosis by PSMA on overall survival remains unanswered.
Abstract: The aim of this systematic review was to describe the characteristics of prostate-specific membrane antigen (PSMA)-targeting PET and their clinical applications in prostate cancer patients. There have been major strides in the design, synthesis of PSMA-targeting PET tracers over the past several years. PSMA-targeting PET tracers can be categorized, according to positron emitters and targeting strategies for the PSMA. The majority of PSMA PET studies has been focused on patients with biochemical recurrence, but additional values of PSMA PET have also been investigated for use in primary staging, treatment planning, response evaluation, and PSMA radioligand therapy. PSMA PET is expected to bring improvements in the management of patients, but the impact of improved diagnosis by PSMA on overall survival remains unanswered. Many challenges still await PSMA PET to expedite the use in the clinical practice. At this early stage, prospective multicenter trials are needed to validate the effectiveness and usefulness of PSMA PET.

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TL;DR: Pedal arch status has a positive impact on time to healing, limb salvage, and survival in diabetic patients with foot wounds undergoing infrainguinal endovascular revascularization.
Abstract: Objective To retrospectively evaluate the impact of pedal arch quality on tissue loss and time to healing in diabetic patients with foot wounds undergoing infrainguinal endovascular revascularization. Materials and Methods Between January 2014 and June 2015, 137 consecutive diabetic patients with foot wounds underwent infrainguinal endovascular revascularization (femoro-popliteal or below-the-knee, arteries). Postprocedural angiography of the foot was used to divide the patients into the following three groups according to the pedal arch status: complete pedal arch (CPA), incomplete pedal arch (IPA), and absent pedal arch (APA). Time to healing and estimated 1-year outcomes in terms of freedom from minor amputation, limb salvage, and survival were evaluated and compared among the three groups. Results Postprocedural angiography showed the presence of a CPA in 42 patients (30.7%), IPA in 60 patients (43.8%), and APA in 35 patients (25.5%). Healing within 3 months from the procedure was achieved in 21 patients with CPA (50%), 17 patients with IPA (28.3%), and in 7 patients with APA (20%) (p = 0.01). There was a significant difference in terms of 1-year freedom from minor amputation among the three groups (CPA 84.1% vs. IPA 82.4% vs. APA 48.9%, p = 0.001). Estimated 1-year limb salvage was significantly better in patients with CPA (CPA 100% vs. IPA 93.8% vs. APA 70.1%, p < 0.001). Estimated 1-year survival was significantly better in patients with CPA (CPA 90% vs. IPA 80.8% vs. APA 62.7%, p = 0.004). Conclusion Pedal arch status has a positive impact on time to healing, limb salvage, and survival in diabetic patients with foot wounds undergoing infrainguinal endovascular revascularization.

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TL;DR: Combined TACE plus RFA may be an alternative to SR for the treatment of patients with HCC within Milan the criteria and, compared with SR, TACEplus RFA had significantly higher 1-year OS and lower major complications after therapy.
Abstract: Objective To meta-analytically compare combined transarterial chemoembolization (TACE) plus radiofrequency ablation (RFA) and surgical resection (SR) for the treatment of hepatocellular carcinoma (HCC) within the Milan criteria. Materials and Methods PubMed, Medline, Embase, and Cochrane Library were searched for studies comparing these two therapies that were published between January 2006 and August 2017. Overall survival rate (OS), recurrence-free survival rate (RFS), major complications and the average length of hospital stay were compared between these two therapies. Meta-analytic pooled odds ratio (OR) was calculated using TACE plus RFA as the base category. Results Seven case-control studies and one randomized trial were identified. Meta-analytic results revealed that, compared with SR, TACE plus RFA had significantly higher 1-year OS (OR for survival = 0.50, p = 0.009) and lower major complications (OR = 1.88, p = 0.02) after therapy. Three studies reported on the length of hospital stay. The average length ± standard deviation reported in individual studies for SR and TACE plus RFA groups was 19.8 ± 8.4 days and 7.4 ± 2.2 days, respectively; 18.7 ± 4.9 days and 11.5 ± 6.9 days, respectively; and 16.6 ± 6.7 days and 8.5 ± 4.1 days, respectively (p < 0.0001 for all studies). Three or 5-year OS and 1-, 3-, or 5-year RFS did not significantly differ between the two therapies. Conclusion Combined TACE plus RFA may be an alternative to SR for the treatment of patients with HCC within Milan the criteria. Non-randomized design in most of the original studies was a limitation.

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TL;DR: Altered integrity of the frontoparietal WM contributes to cognitive dysfunction in HIV patients, and tract-based spatial statistics (TBSS) results suggest.
Abstract: Objective Human immunodeficiency virus (HIV) infection has been known to damage the microstructural integrity of white matter (WM). However, only a few studies have assessed the brain regions in HIV-associated neurocognitive disorders (HAND) with diffusion tensor imaging (DTI). Therefore, we sought to compare the DTI data between HIV patients with and without HAND using tract-based spatial statistics (TBSS). Materials and Methods Twenty-two HIV-infected patients (10 with HAND and 12 without HAND) and 11 healthy controls (HC) were enrolled in this study. A whole-brain analysis of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity was performed with TBSS and a subsequent 20 tract-specific region-of-interest (ROI)-based analysis to localize and compare altered WM integrity in all group contrasts. Results Compared with HC, patients with HAND showed decreased FA in the right frontoparietal WM including the upper corticospinal tract (CST) and increased MD and RD in the bilateral frontoparietal WM, corpus callosum, bilateral CSTs and bilateral cerebellar peduncles. The DTI values did not significantly differ between HIV patients with and without HAND or between HIV patients without HAND and HC. In the ROI-based analysis, decreased FA was observed in the right superior longitudinal fasciculus and was significantly correlated with decreased information processing speed, memory, executive function, and fine motor function in HIV patients. Conclusion These results suggest that altered integrity of the frontoparietal WM contributes to cognitive dysfunction in HIV patients.

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TL;DR: In this limited study, paclitaxel-coated balloons seem to improve the patency rate in cases of early restenosis of central veins, however, a further randomized control trial is necessary.
Abstract: Objective To report the results of angioplasty with paclitaxel-coated balloons for the treatment of early restenosis of central veins in hemodialysis patients. Materials and Methods Sixteen patients (9 men and 7 women; mean age 65.8 ± 14.4 years; range, 40-82 years) with 16 episodes of early restenoses of central veins within 3 months (median patency duration 2.5 months) were enrolled from January 2014 to June 2015. Ten native central veins and 6 intra-stent central veins were treated with double paclitaxel-coated balloons (diameter 6-7 mm) plus a high pressure balloon (diameter 12-14 mm). The study outcomes included procedural success (< 30% residual stenosis) and primary patency of the treated lesion (< 50% angiographic stenosis without re-intervention). Results Procedural success was achieved in all 16 cases of central vein stenoses. The mean diameter of the central vein was 3.7 ± 2.4 mm before the procedure vs. 11.4 ± 1.8 mm after the initial procedure. There were no procedure-related complications. The mean diameters of the central veins at 6 months and 12 months were 7.8 ± 1.3 mm and 6.9 ± 2.7 mm, respectively. The primary patency rates at 6 months and 12 months were 93.8% and 31.2%, respectively. One patient had significant restenosis of the central vein at 3 months. The median primary patency period was 9 months for paclitaxel-coated balloons and 2.5 months for the last previous procedure with conventional balloons (p < 0.001). Conclusion In our limited study, paclitaxel-coated balloons seem to improve the patency rate in cases of early restenosis of central veins. However, a further randomized control trial is necessary.

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TL;DR: “Clusters of micronodules”, seen on 7-mm thick post-mortem radiographs with tuberculosis proved to be clusters of tree-in-bud lesions within the three-dimensional space of secondary pulmonary lobule based on radiological/pathological correlation.
Abstract: The "tree-in-bud-pattern" of images on thin-section lung CT is defined by centrilobular branching structures that resemble a budding tree. We investigated the pathological basis of the tree-in-bud lesion by reviewing the pathological specimens of bronchograms of normal lungs and contract radiographs of the post-mortem lungs manifesting active pulmonary tuberculosis. The tree portion corresponds to the intralobular inflammatory bronchiole, while the bud portion represents filling of inflammatory substances within alveolar ducts, which are larger than the corresponding bronchioles. Inflammatory bronchiole per se represents the "tree" (stem) and inflammatory alveolar ducts constitute the "buds" or clubbing. "Clusters of micronodules", seen on 7-mm thick post-mortem radiographs with tuberculosis proved to be clusters of tree-in-bud lesions within the three-dimensional space of secondary pulmonary lobule based on radiological/pathological correlation. None of the post-mortem lung specimens showed findings of lung parenchymal lymphatics involvement.