• Korean Journal of Radiology
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• v.22 no.4
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• pp.535-546
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• 2021

Objective: To evaluate the feasibility of texture analysis on non-contrast-enhanced T1 maps of cardiac magnetic resonance (CMR) imaging for the diagnosis of myocardial injury in acute myocardial infarction (MI). Materials and Methods: This study included 68 patients (57 males and 11 females; mean age, 55.7 ± 10.5 years) with acute ST-segment-elevation MI who had undergone 3T CMR after a percutaneous coronary intervention. Forty patients of them also underwent a 6-month follow-up CMR. The CMR protocol included T2-weighted imaging, T1 mapping, rest first-pass perfusion, and late gadolinium enhancement. Radiomics features were extracted from the T1 maps using open-source software. Radiomics signatures were constructed with the selected strongest features to evaluate the myocardial injury severity and predict the recovery of left ventricular (LV) longitudinal systolic myocardial contractility. Results: A total of 1088 segments of the acute CMR images were analyzed; 103 (9.5%) segments showed microvascular obstruction (MVO), and 557 (51.2%) segments showed MI. A total of 640 segments were included in the 6-month follow-up analysis, of which 160 (25.0%) segments showed favorable recovery of LV longitudinal systolic myocardial contractility. Combined radiomics signature and T1 values resulted in a higher diagnostic performance for MVO compared to T1 values alone (area under the curve [AUC] in the training set; 0.88, 0.72, p = 0.031: AUC in the test set; 0.86, 0.71, p = 0.002). Combined radiomics signature and T1 values also provided a higher predictive value for LV longitudinal systolic myocardial contractility recovery compared to T1 values (AUC in the training set; 0.76, 0.55, p < 0.001: AUC in the test set; 0.77, 0.60, p < 0.001). Conclusion: The combination of radiomics of non-contrast-enhanced T1 mapping and T1 values could provide higher diagnostic accuracy for MVO. Radiomics also provides incremental value in the prediction of LV longitudinal systolic myocardial contractility at six months.

• Journal of the Korean Society of Radiology
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• v.83 no.3
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• pp.737-743
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• 2022

Aspergillus tracheobronchitis, an uncommon form of invasive pulmonary aspergillosis, is characterized by the development of a pseudomembrane, ulcers, or an obstruction that is predominantly confined to the tracheobronchial tree. Pseudomembranous Aspergillus tracheobronchitis is the most severe form of Aspergillus tracheobronchitis, and only a few cases have been reported in Korea. We report the characteristic chest CT findings in a patient diagnosed with pseudomembranous Aspergillus tracheobronchitis after bronchoscopy and successfully treated by proper antifungal treatment.

• Journal of the Korean Society of Radiology
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• v.82 no.1
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• pp.49-65
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• 2021

With the increase in the number of cases of silicone implant insertion either for cosmetic surgery or breast reconstruction after mastectomy, it is not unusual to encounter patients with silicone implants in clinical settings. Recently, the first case of breast implant-associated anaplastic large cell lymphoma was reported in Korea. In addition to previously known complications, such as implant rupture or contracture, the number of implant-associated imaging examinations has also increased. Considering this background, radiologists should have sufficient knowledge about the type of examination required in patients who have undergone implant insertion and imaging findings to correctly identify implant-associated complications. In this article, various complications of silicone implants are discussed, including various imaging findings, which radiologists should know.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.428-433
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• 2024

Dual left anterior descending artery (LAD) is a rare congenital coronary artery anomaly with a prevalence of approximately 1% in the general population. To date, 10 types of dual LAD artery anomalies have been reported. Among these, type 4 is one of the rarest. Knowledge and recognition of the dual LAD artery are important for correct diagnosis and planning of coronary bypass surgery and percutaneous coronary intervention. We report a case of a 59-year-old male with type 4 dual LAD artery who presented with dyspepsia and sweating for several months and had approximately 50%-70% stenosis in a major diagonal branch off the short LAD artery.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.258-269
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• 2024

Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.

• Journal of the Korean Society of Radiology
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• v.85 no.5
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• pp.902-915
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• 2024

Pancreatic cancer is usually detected through contrast-enhanced CT and MRI. However, pancreatic cancer is occasionally overlooked because of its small size or is misdiagnosed as other conditions due to atypical imaging features that present diagnostic challenges. Considering the rapid growth and poor prognosis associated with pancreatic cancer, the ability to accurately detect and differentiate pancreatic lesions is crucial for appropriate surgical intervention. Reviewing diverse challenging cases of pancreatic cancer at an early stage and other mimicking lesions may help us accurately interpret the imaging features of pancreatic cancer on CT and MRI scans. Therefore, we aimed to illustrate various imaging features of pancreatic cancer and its mimicking lesions and provide valuable insights for differential diagnosis.

• Clinical Endoscopy
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• v.56 no.2
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• pp.143-154
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• 2023

Advanced malignant hilar biliary obstruction (MHBO) with inaccessible papilla poses a significant challenge to endoscopists, as drainage of multiple liver segments may be warranted. Transpapillary drainage may not be feasible in patients with surgically altered anatomy, duodenal stenosis, prior duodenal self-expanding metal stent, and after initial transpapillary drainage, but require re-intervention for draining separated liver segments. Endoscopic ultrasound-guided biliary drainage (EUS-BD) and percutaneous trans-hepatic biliary drainage are the feasible options in this scenario. The major advantages of EUS-BD over percutaneous trans-hepatic biliary drainage include a reduction in patient discomfort and internal drainage away from the tumor, thus reducing the possibility of tissue or tumor ingrowth. With innovations, EUS-BD is helpful not only for bilateral communicating MHBO but also for non-communicating systems with bridging hilar stents or isolated right intra-hepatic duct drainage by hepatico-duodenostomy. EUS-guided multi-stent drainage with specially designed cannulas and guidewires has become a reality. A combined approach with endoscopic retrograde cholangiopancreatography for re-intervention, interventional radiology, and intraductal tumor ablative therapies has been reported. Stent migration and bile leakage can be minimized with proper stent selection and technique, and stent blocks can be managed with EUS-guided interventions in a majority of cases. Future comparative studies are required to establish the role of EUS-guided interventions in MHBO as rescue or primary therapy.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.102-111
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• 2022

Purpose To evaluate the correlation between Lee's grades and surgical intervention for central lumbar spinal stenosis (CLSS) and to assess whether this grading system can be used as a decision-making tool for the surgical treatment of this condition. Materials and Methods This retrospective study included 290 patients (M:F = 156:134; mean age, 46 ± 16 years). Radiologists assessed the presence and grade of CLSS at the stenosis point according to Lee's grading system, in which CLSS is classified into four grades according to the shape of the cauda equina. Correlation coefficients (r_s) between Lee's grades and the operation were calculated with Spearman rank correlation. Results Among the operated patients, grade 2 was the most commonly assigned grade (50%-58%), grade 3 was less common (35%), and grade 0 was the least common (2%-3%). Among the non-operated patients, grade 1 was the most common (63%-65%), grade 0 was less common (15%-16%), and grade 3 was the least common (8%). The distribution of grades differed between the operated and non-operated groups (p < 0.001). Less than 25% of patients who underwent surgery were assigned grades 0 and 1, and more than 88% were assigned grades 2 and 3. A moderate correlation was found between the grade and surgical intervention (r_s = 0.632 and r_s = 0.583). Conclusion Lee's grade was moderately correlated with surgical intervention. Lee's grading system can be a decision-making tool for the surgical treatment of CLSS.

• Journal of Trauma and Injury
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• v.24 no.2
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• pp.98-104
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• 2011

Purpose: The aim of this study was to evaluate the quality of the trauma care system of our hospital, in which emergency physicians care for major trauma patients in the emergency intensive care unit (ICU) in consultation with intervention radiologists and surgeons. Methods: This was a retrospective observational study conducted in an emergency ICU of a tertiary referral hospital. We enrolled consecutive patients who had been admitted to our emergency ICU with major trauma from March 2007 to September 2010. We collected data with respect to demographic findings, mechanisms of injury, the trauma and injury severity score (TRISS), emergency surgery, angiographic intervention, and 6-month mortality. Then, we compared the observed and predicted survivals of the patients. The Hosmer-Lemeshow test and calibration plots by using 10 groups, one for each decile, of predicted mortality were used to evaluate the fitness of TRISS. P-values of greater than 0.05 represent a fair calibration. Results: Among 116 patients, 12 (10.34%) were dead within 6 months after admission to the ICU, and 29 (25.00%) and 38 (32.80%) patients received emergency surgery and angiographic intervention, respectively. The mean injury severity score and revised trauma score were $36.97{\pm}17.73$ and $7.84{\pm}6.75$, respectively. The observed survival and the predicted survival of the TRISS were 89.66% (95% confidence interval [CI]: 84.03~95.28%) and 69.85% (95% CI: 63.80~75.91%), respectively. The calibration plots showed that the observed survival of our patients was consistently higher than the predicted survival of the TRISS ($p$ <0.001). Conclusion: The observed survival for the trauma care system of our hospital, in which emergency physicians care for major trauma patients in the emergency ICU in consultation with intervention radiologists and surgeons, was higher than the predicted survival of the TRISS.

• Korean Journal of Radiology
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• v.23 no.9
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• pp.866-877
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• 2022

Objective: The optimal imaging approach for evaluating pathological nipple discharge remains unclear. We investigated the value of adding ductography to ultrasound (US) for evaluating pathologic nipple discharge in patients with negative mammography findings. Materials and Methods: From July 2003 to December 2018, 101 women (mean age, 46.3 ± 12.2 years; range, 23-75 years) with pathologic nipple discharge were evaluated using pre-ductography (initial) US, ductography, and post-ductography US. The imaging findings were reviewed retrospectively. The standard reference was surgery (70 patients) or > 2 years of follow-up with US (31 patients). The diagnostic performances of initial US, ductography, and post-ductography US for detecting malignancy were compared using the McNemar's test or a generalized estimating equation. Results: In total, 47 papillomas, 30 other benign lesions, seven high-risk lesions, and 17 malignant lesions were identified as underlying causes of pathologic nipple discharge. Only eight of the 17 malignancies were detected on the initial US, while the remaining nine malignancies were detected by ductography. Among the nine malignancies detected by ductography, eight were detected on post-ductography US and could be localized for US-guided intervention. The sensitivities of ductography (94.1% [16/17]) and post-ductography US (94.1% [16/17]) were significantly higher than those of initial US (47.1% [8/17]; p = 0.027 and 0.013, respectively). The negative predictive value of post-ductography US (96.9% [31/32]) was significantly higher than that of the initial US (83.3% [45/54]; p = 0.006). Specificity was significantly higher for initial US than for ductography and post-ductography US (p = 0.001 for all). Conclusion: The combined use of ductography and US has a high sensitivity for detecting malignancy in patients with pathologic nipple discharge and negative mammography. Ductography findings enable lesion localization on second-look post-ductography US, thus facilitating the selection of optimal treatment plans.