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Dive into the research topics where Hyun-joo Kim is active.

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Featured researches published by Hyun-joo Kim.


The Spine Journal | 2012

Radiographic grading of facet degeneration, is it reliable?—a comparison of MR or CT grading with histologic grading in lumbar fusion candidates

Jae Chul Lee; Jang-Gyu Cha; Jae Ho Yoo; Hee Kyung Kim; Hyun-joo Kim; Byung-Joon Shin

BACKGROUND CONTEXT The current interest in motion-sparing surgery highlights the need for a more accurate radiologic evaluation of the degree of facet degeneration. In the presence of severe facet degeneration, a surgeon cannot ensure a positive outcome, even after successful surgery. To the best of our knowledge, no prospective study has compared the accuracy of grading facet degeneration by computed tomography (CT) or magnetic resonance (MR) scans with that attained from a real histologic evaluation. PURPOSE The purpose of this study was to determine the accuracy and reliability of CT or MR assessments of lumbar facet degeneration by comparing it with the histologic grading of the resected facets during surgery. STUDY DESIGN/SETTING A prospective study of consecutive patients undergoing posterior lumbar fusion surgery. METHODS Forty-four excised facets from 18 patients who received lumbar fusion were evaluated using radiographic and histologic techniques. All patients prospectively underwent CT scanning, routine axial T2-weighted MR scanning, and axial MR using a double echo steady state (DESS) sequence for cartilage imaging. The facets were graded radiologically using four-point scales. The inferior articular processes including the cartilage and subchondral bone of the corresponding facets were resected during surgery and evaluated histologically using a four-point grading system. RESULTS Radiologic grading revealed a tendency for underestimating facet degeneration than histologic grading. The number of facets undergraded by radiologic evaluations was 24 (55%) facets by CT, 16 (36%) by routine MR, and 22 (49%) by DESS. The weighted kappa coefficients between the histologic and radiologic grading also showed a poor correlation (0.120 for CT, 0.128 for routine MR, and 0.280 for MR using DESS sequence, respectively). The false-negative rates for detecting histologic degeneration by radiologic studies were 41% to 54%. The receiver operating characteristic curve revealed MR using DESS to have a better performance. CONCLUSIONS The degree of facet degeneration can be underestimated by current radiologic modalities, and their ability to detect facet degeneration is quite limited. Surgeons should be aware of these limitations during a preoperative evaluation of patients considered for motion-sparing techniques in lumbar spinal surgery.


European Radiology | 2018

Comparison between MRI with MR cholangiopancreatography and endoscopic ultrasonography for differentiating malignant from benign mucinous neoplasms of the pancreas

Ji-Young Hwang; Young Kon Kim; Ji Hye Min; Woo Kyung Jeong; Seong Sook Hong; Hyun-joo Kim

ObjectiveTo compare diagnostic performance of magnetic resonance imaging (MRI) and endoscopic ultrasonography (EUS) for differentiating malignant from benign intraductal papillary mucinous neoplasms (IPMN) and mucinous cystic neoplasms (MCN) of the pancreas.MethodsThis retrospective study included 55 patients with 47 surgically confirmed IPMNs (12 malignant, 35 benign) and eight MCNs (two malignant, six benign) who underwent contrast-enhanced pancreas MRI and EUS. Contrast enhancement was not routinely used at EUS examination. Two observers independently evaluated the MRIs, and another reviewed EUS images. They recorded their confidence for malignancy with each imaging modality. We calculated diagnostic performance using the area under the receiver operating characteristic curves (Az), and to determine the accuracy, sensitivity, specificity, and positive (PPV) and negative predictive (NPV) values.ResultsThe Az values of MRI were higher than those of EUS (0.712 and 0.688 for MRI vs. 0.543 for EUS; p = 0.007). The diagnostic accuracies (74.5%), specificity (78.0% and 80.5%) and PPV (50.0%) of MRI in two observers were higher than those (56.4%, 58.5% and 29.2%, respectively) of EUS (p = 0.013–0.049).ConclusionMRI showed better diagnostic performance than EUS for differentiating malignant from benign pancreatic IPMN and MCN.Key Points• The Azvalues of MRI were higher than those of EUS.• The diagnostic accuracies of MRI were higher than those of EUS.• The specificities of MRI were higher than those of EUS.


Journal of Magnetic Resonance Imaging | 2016

Topographical and sex variations in the T2 relaxation times of articular cartilage in the ankle joints of healthy young adults using 3.0T MRI

Youngsik Lim; Jang Gyu Cha; Jisook Yi; Sung Jin Kang; Young Koo Lee; Sun Joo Lee; Hyun-joo Kim; Bo Ra Lee

To prospectively evaluate topographical and sex variations in the T2 relaxation values of tibiotalar cartilage (TTC) of healthy young adults.


Journal of Medical Imaging and Radiation Oncology | 2015

Evaluation for fracture patterns around the wrist on three‐dimensional extremity computed tomography, especially focused on the triquetrum

Eunsun Oh; Hyun-joo Kim; Seongsook Hong; Jiyoung Hwang; Hyunkyung Lim; Sung-Tae Park; Junghwa Hwang

To describe fracture patterns of triquetrum and analyse them according to fracture classifications, anatomy of intrinsic carpal ligaments and comparison with other wrist fractures.


Ultrasonography | 2014

Acute diverticulitis of the terminal ileum: ultrasonography and CT findings

Jewon Jeong; Seong Sook Hong; Jiyoung Hwang; Hyun-joo Kim; Yun Woo Chang

We describe a rare case of terminal ileal diverticulitis in a 68-year-old female with a day of history Epub ahead of print of right lower quadrant pain and tenderness, mimicking acute appendicitis. Ultrasonography revealed small sac-like out-pouching lesions with increased echogenicity of surrounding fat in thickened terminal ileum, suggesting inflamed diverticula. We diagnosed terminal ileal diverticulitis primarily by ultrasonography. The diagnosis was confirmed by subsequent computed tomography.We describe a rare case of terminal ileal diverticulitis in a 68-year-old female with a day of history of right lower quadrant pain and tenderness, mimicking acute appendicitis. Ultrasonography revealed small sac-like out-pouching lesions with increased echogenicity of surrounding fat in thickened terminal ileum, suggesting inflamed diverticula. We diagnosed terminal ileal diverticulitis primarily by ultrasonography. The diagnosis was confirmed by subsequent computed tomography.


European Radiology | 2017

Capsule, septum, and T2 hyperintense foci for differentiation between large hepatocellular carcinoma (≥5 cm) and intrahepatic cholangiocarcinoma on gadoxetic acid MRI

Jiyoung Hwang; Young Kon Kim; Ji Hye Min; Seo-Youn Choi; Woo Kyung Jeong; Seong Sook Hong; Hyun-joo Kim; Soohyun Ahn; Hyeon Seon Ahn

ObjectiveTo determine the added value of capsule, septum, and T2 hyperintense foci for differentiating large hepatocellular carcinoma (HCC; ≥ 5 cm) from intrahepatic cholangiocarcinoma (ICC) using gadoxetic acid MRI.MethodsThe study included 116 patients (94 men, 22 women; mean age, 56.8 years) with surgically confirmed HCCs (n = 87, 5.0–18.0 cm) or ICCs (n = 29, 5.0–14.0 cm) who underwent gadoxetic acid MRI. Three observers independently reviewed MRIs in two sessions, examining enhancement patterns only and then adding capsule, septum, and T2 hyperintense foci. Reviewers used a five-point scale to score accuracy, sensitivity, and specificity.ResultsA significant increase was observed in accuracy when ancillary features (96.1–98.3%) were added compared to enhancement pattern only (83.6–88.4%; p ≤ 0.02). Sensitivity was significantly increased with combined reading (97.1–98.3%) compared to enhancement features only (81.6–88.5%; p ≤ 0.006) for two observers, with no difference in specificity (84.5–89.7% vs. 86.2–98.3%; p > 0.05). We found substantial to excellent interobserver agreement for ancillary features (0.598–0.976).ConclusionAdding capsule, septum, and T2 hyperintense foci to enhancement patterns for gadoxetic acid MRI increased diagnostic performance for characterizing large HCC by differentiating it from ICC.Key Points• Capsule, septum, and T2 hyperintense foci were useful for characterizing large HCC.• Adding ancillary features to enhancement pattern increased accuracy for diagnosing large HCC.• Interobserver agreement was substantial to excellent for ancillary features.


World Journal of Gastroenterology | 2016

Comparison of hepatic venous pressure gradient and endoscopic grading of esophageal varices.

EunJi Lee; Yong Jae Kim; Dong Erk Goo; Seung Boo Yang; Hyun-joo Kim; Jae Young Jang; Soung Won Jeong

AIM To determine the correlation between the hepatic venous pressure gradient and the endoscopic grade of esophageal varices. METHODS From September 2009 to March 2013, a total of 176 measurements of hepatic venous pressure gradient (HVPG) were done in 146 patients. Each transjugular HVPG was measured twice, first using an end whole catheter (EH-HVPG), and then using a balloon catheter (B-HVPG). The HVPG was compared with the endoscopic grade of esophageal varices (according to the general rules for recording endoscopic findings of esophagogastric varices), which was recorded within a month of the measurement of HVPG. RESULTS The study included 110 men and 36 women, with a mean age of 56.1 years (range, 43-76 years). The technical success rate of the pressure measurements was 100% and there were no complication related to the procedures. Mean HVPG was 15.3 mmHg as measured using the end hole catheter method and 16.5 mmHg as measured using the balloon catheter method. Mean HVPG (both EH-HVPG and B-HVPG) was not significantly different among patients with different characteristics, including sex and comorbid factors, except for cases with hepatocellular carcinoma (B-HVPG, P = 0.01; EH-HVPG, P = 0.02). Portal hypertension (> 12 mmHg HVPG) occurred in 66% of patients according to EH-HVPG and 83% of patients according to B-HVGP, and significantly correlated with Childs status (B-HVPG, P < 0.000; EH-HVGP, P < 0.000) and esophageal varies observed upon endoscopy (EH-HVGP, P = 0.003; B-HVGP, P = 0.006). One hundred and thirty-five endoscopies were performed, of which 15 showed normal findings, 27 showed grade 1 endoscopic esophageal varices, 49 showed grade 2 varices, and 44 showed grade 3 varices. When comparing endoscopic esophageal variceal grades and HVPG using univariate analysis, the P value was 0.004 for EH-HVPG and 0.002 for B-HVPG. CONCLUSION Both EH-HVPG and B-HVPG showed a positive correlation with the endoscopic grade of esophageal varices, with B-HVPG showing a stronger correlation than EH-HVPG.


Revista Da Associacao Medica Brasileira | 2018

Tuberculous peritonitis following intestinal perforation in malignancy

Ji-Young Hwang; Seong Sook Hong; Hyun-joo Kim; Yun-Woo Chang; Bo Da Nam; Eunsun Oh; EunJi Lee

Tuberculous peritonitis is one of the most common causes of exudative ascites, especially in the young, and is an important cause of extra-pulmonary disease. However, tuberculous peritonitis is challenging to diagnose because there are no pathognomonic clinical features or imaging findings. Therefore, it is commonly misdiagnosed as another type of peritoneal disease, especially so in elderly patients with malignant disease. In this report, we described two cases of tuberculous peritonitis that were observed after intestinal perforation in elderly patients with malignancies. These diagnoses were established by laparoscopic peritoneal biopsy or AFB cultures of the ascitic fluid. Both patients were treated with anti-TB medications.


Korean Journal of Radiology | 2018

Breast Lesions in Children and Adolescents: Diagnosis and Management

Eun Ji Lee; Yun-Woo Chang; Jung Hee Oh; Jiyoung Hwang; Seong Sook Hong; Hyun-joo Kim

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 of Medical Imaging and Radiation Oncology | 2018

Visibility of bony structures around hip prostheses in dual‐energy CT: With or without metal artefact reduction software

Jewon Jeong; Hyun-joo Kim; Eunsun Oh; Jang Gyu Cha; Jiyoung Hwang; Seong Sook Hong; Yun Woo Chang

The development of dual‐energy CT and metal artefact reduction software provides a further chance of reducing metal‐related artefacts. However, there have been only a few studies regarding whether MARs practically affect visibility of structures around a metallic hip prosthesis on post‐operative CT evaluation.

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Jiyoung Hwang

Soonchunhyang University

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Yun-Woo Chang

Soonchunhyang University

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EunJi Lee

Soonchunhyang University

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Eunsun Oh

Soonchunhyang University

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Bo Da Nam

Soonchunhyang University Hospital

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Deuk Lin Choi

Soonchunhyang University

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Dong Erk Goo

Soonchunhyang University

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Jang Gyu Cha

Soonchunhyang University

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Jewon Jeong

Soonchunhyang University

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