Bright Vessel Appearance on Arterial Spin Labeling MRI for Localizing Arterial Occlusion in Acute Ischemic Stroke

Yoo, Roh-Eul,Yun, Tae Jin,Rhim, Jung Hyo,Yoon, Byung-Woo,Kang, Koung Mi,Choi, Seung Hong,Kim, Ji-Hoon,Kim, Jeong Eun,Kang, Hyun-Seung,Sohn, Chul-Ho,Han, Moon Hee American Heart Association, Inc. 2015 Stroke Vol.46 No.2

<P><B>Background and Purpose—</B></P><P>The purpose of this study was to evaluate whether bright vessel appearance on arterial spin labeling (ASL) MRI can help localize arterial occlusion sites in patients with acute ischemic stroke.</P><P><B>Methods—</B></P><P>Patients who underwent MRI for suspected acute ischemic stroke, as identified by an area of restricted diffusion, were included. All images were visually analyzed for the presence or absence of (1) arterial occlusion on time-of-flight MR angiography, (2) bright vessel appearance on ASL images, and (3) susceptibility vessel sign. McNemar 2-tailed test was used to compare the sensitivities of ASL and susceptibility-weighted imaging for the detection of arterial occlusion, using MR angiography as the reference standard.</P><P><B>Results—</B></P><P>ASL bright vessel appearance was significantly more common in the group with occlusion than in the group without occlusion (94% [33 of 35] versus 21% [17 of 82], respectively; <I>P</I><0.001). The bright vessel appearance, when present, was seen proximal or distal to the occlusion site. The bright vessel appearance had a significantly higher sensitivity for the detection of occlusion than the susceptibility vessel sign (94% [33 of 35] versus 66% [23 of 35], respectively; <I>P</I>=0.002). In cases with negative MR angiography, the bright vessel appearance helped identify more additional arterial occlusions than the susceptibility vessel sign (21% [17 of 82] versus 10% [8 of 82], respectively; <I>P</I>=0.012).</P><P><B>Conclusions—</B></P><P>The bright vessel appearance on ASL imaging can provide an important diagnostic clue for the detection and localization of arterial occlusion sites in patients with acute ischemic stroke.</P>

Ultrasonographic Indeterminate Lymph Nodes in Preoperative Thyroid Cancer Patients: Malignancy Risk and Ultrasonographic Findings Predictive of Malignancy

Roh-Eul Yoo,김지훈,배정모,황인평,강경미,윤태진,최승홍,손철호,Jung Hyo Rhim,Sun-Won Park 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.5

Objective: Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancer patients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for US indeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation. Materials and Methods: A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or coreneedle biopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probably benign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilar vascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs using Mann-Whitney U test and Fisher’s exact test. Results: US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), and suspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the US probably benign (2.8% [2/72]) (p = 0.002) and US suspicious LNs (78.4% [152/194]) (p < 0.001). Among US indeterminate LNs, there were no significant differences in short, long, and long-to-short diameter (L/S) ratios between benign and metastatic LNs (3.9 vs. 3.8 mm, p = 0.619; 7.3 vs. 7.3 mm, p = 0.590; 1.9 vs. 1.9, p = 0.652). Conclusion: US indeterminate LNs were frequently encountered during preoperative evaluation and had intermediate malignancy risk. Given the lack of discriminative power of size criteria and L/S ratio, clinical factors such as surgical strategy and node size should be considered for proper triage of US indeterminate LNs in thyroid cancer.

The Emerging Role of Fast MR Techniques in Traumatic Brain Injury

Yoo, Roh-Eul,Choi, Seung Hong Korean Society of Magnetic Resonance in Medicine 2021 Investigative Magnetic Resonance Imaging Vol.25 No.2

Post-concussion syndrome (PCS) following mild traumatic brain injury (mTBI) is a major factor that contributes to the increased socioeconomic burden caused by TBI. Myelin loss has been implicated in the development of PCS following mTBI. Diffusion tensor imaging (DTI), a traditional imaging modality for the evaluation of axonal and myelin integrity in mTBI, has intrinsic limitations, including its lack of specificity and its time-consuming and labor-intensive post-processing analysis. More recently, various fast MR techniques based on multicomponent relaxometry (MCR), including QRAPMASTER, mcDESPOT, and MDME sequences, have been developed. These MCR-based sequences can provide myelin water fraction/myelin volume fraction, a quantitative parameter more specific to myelin, which might serve as a surrogate marker of myelin volume, in a clinically feasible time. In this review, we summarize the clinical application of the MCR-based fast MR techniques in mTBI patients.

Myelin Content in Mild Traumatic Brain Injury Patients with Post-Concussion Syndrome: Quantitative Assessment with a Multidynamic Multiecho Sequence

Yoo Roh-Eul,최승홍,Youn Sung-Won,Hwang Moonjung,Kim Eunkyung,Oh Byung-Mo,Lee Ji Ye,Hwang Inpyeong,Kang Koung Mi,Yun Tae Jin,Kim Ji-hoon,Sohn Chul-Ho 대한영상의학회 2022 Korean Journal of Radiology Vol.23 No.2

Objective: This study aimed to explore the myelin volume change in patients with mild traumatic brain injury (mTBI) with post-concussion syndrome (PCS) using a multidynamic multiecho (MDME) sequence and automatic whole-brain segmentation. Materials and Methods: Forty-one consecutive mTBI patients with PCS and 29 controls, who had undergone MRI including the MDME sequence between October 2016 and April 2018, were included. Myelin volume fraction (MVF) maps were derived from the MDME sequence. After three dimensional T1-based brain segmentation, the average MVF was analyzed at the bilateral cerebral white matter (WM), bilateral cerebral gray matter (GM), corpus callosum, and brainstem. The Mann–Whitney U-test was performed to compare MVF and myelin volume between patients with mTBI and controls. Myelin volume was correlated with neuropsychological test scores using the Spearman rank correlation test. Results: The average MVF at the bilateral cerebral WM was lower in mTBI patients with PCS (median [interquartile range], 25.2% [22.6%–26.4%]) than that in controls (26.8% [25.6%–27.8%]) (p = 0.004). The region-of-interest myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (1.87 cm3 [1.70–2.05 cm3] vs. 2.21 cm3 [1.86– 3.46 cm3]; p = 0.003) and brainstem (9.98 cm3 [9.45–11.00 cm3] vs. 11.05 cm3 [10.10–11.53 cm3]; p = 0.015). The total myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (0.45 cm3 [0.39–0.48 cm3] vs. 0.48 cm3 [0.45–0.54 cm3]; p = 0.004) and brainstem (1.45 cm3 [1.28–1.59 cm3] vs. 1.54 cm3 [1.42–1.67 cm3]; p = 0.042). No significant correlation was observed between myelin volume parameters and neuropsychological test scores, except for the total myelin volume at the bilateral cerebral WM and verbal learning test (delayed recall) (r = 0.425; p = 0.048). Conclusion: MVF quantified from the MDME sequence was decreased at the bilateral cerebral WM in mTBI patients with PCS. The total myelin volumes at the corpus callosum and brainstem were decreased in mTBI patients with PCS due to atrophic changes.

Quantitative dynamic contrast-enhanced MR imaging shows widespread blood-brain barrier disruption in mild traumatic brain injury patients with post-concussion syndrome

Yoo, Roh-Eul,Choi, Seung Hong,Oh, Byung-Mo,Do Shin, Sang,Lee, Eun Jung,Shin, Dong Jae,Jo, Sang Won,Kang, Koung Mi,Yun, Tae Jin,Kim, Ji-hoon,Sohn, Chul-Ho Springer-Verlag 2019 EUROPEAN RADIOLOGY Vol.29 No.3

Image quality of adaptive iterative dose reduction 3D of coronary CT angiography of 640-slice CT: comparison with filtered back-projection.

Yoo, Roh-Eul,Park, Eun-Ah,Lee, Whal,Shim, Hackjoon,Kim, Yeo Koon,Chung, Jin Wook,Park, Jae Hyung Kluwer Academic Publishers 2013 The international journal of cardiovascular imagin Vol.29 No.3

<P>To assess the image quality of coronary CT angiography (CCTA) of 640-slice CT reconstructed by Adaptive Iterative Dose Reduction (AIDR) three-dimensional (3D) in comparison with the conventional filtered back-projection (FBP). CCTA images of 51 patients were scanned at the lowest tube voltage possible on condition that the built-in automatic exposure control system could suggest the optimal tube current. They were, then, reconstructed with FBP and AIDR 3D (standard). Objective measurements including CT density, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were performed. Subjective assessment was done by two radiologists, using a 5-point scale (0:nondiagnostic-4:excellent) based on the 15-coronary segment model which was grouped into three parts as the proximal, mid, and distal segmental classes. Radiation dose was also measured. AIDR images showed lower noise than FBP images (45.0 +/- A 9.4 vs. 73.4 +/- A 14.6 HU, p < 0.001) without any significant difference in CT density (665.5 +/- A 131.7 vs. 668 +/- A 136.3 HU, p = 0.8). Both SNR (15.0 +/- A 2.1 vs. 9.2 +/- A 1.7) and CNR (16.8 +/- A 2.3 vs. 10.4 +/- A 1.8) were significantly higher for AIDR than FBP (p < 0.001). Total subjective image quality score was also significantly improved in AIDR compared with FBP (3.1 +/- A 0.6 vs. 1.6 +/- A 0.4, p < 0.001), with better interpretability of the mid and distal segmental classes (100 vs. 95 % for the mid, p < 0.001; 100 vs. 90 % for the distal, p < 0.001). Mean effective radiation dose was 2.0 +/- A 1.0 mSv. The AIDR 3D reconstruction algorithm reduced image noise by 39 % compared with the FBP without affecting CT density, thus improving SNR and CNR for CCTA. Its advantages in interpretability were also confirmed by subjective evaluation by experts.</P>

Recent Application of Advanced MR Imaging to Predict Pseudoprogression in High-grade Glioma Patients

YOO, Roh-EUL,CHOI, Seung Hong Japanese Society for Magnetic Resonance in Medicin 2016 Plant biotechnology Vol.15 No.2

<P>Pseudoprogression is regarded as a subacute form of treatment-related change with a reported incidence of 20–30%, occurring predominantly within the first three months after the completion of concurrent chemoradiotherapy (CCRT) in glioblastoma multiforme (GBM) patients. Occurrence of progressive lesions on conventional contrast-enhanced MR imaging may also accompany clinical deterioration, posing considerable diagnostic challenges to clinicians and radiologists. False interpretation of treatment-related change as true progression may lead to the cessation of effective first-line therapy (i.e., adjuvant temozolomide) and unnecessary surgery. Increasing awareness of the diagnostic challenge of the phenomenon has underscored the need for better imaging techniques that may aid in differentiating the treatment-related change from true progression. In this review, we discuss the recent applications of advanced MR imaging such as diffusion-weighted and perfusion-weighted imaging in the evaluation of treatment response in high-grade glioma patients and highlight their potential role in differentiating pseudoprogression from true progression.</P>

A literature review of quality, costs, process-associated with digital pathology

Yoo Jung Kim,Eul Hee Roh,Sangchan Park 한국운동재활학회 2021 JER Vol.17 No.1

진료 품질 향상을 위한 환자 데이터 맞춤형 분석 프로세스 개발: 외국인 환자를 중심으로

노을희 ( Eul Hee Roh ),김유정 ( Yoo Jung Kim ),박상찬 ( Sang Chan Park ) 한국품질경영학회 2018 품질경영학회지 Vol.46 No.3

Purpose: The purpose of this study was to find meaningful patient groups of disease using foreign patients data and analyze implemented test of the patient groups. Methods: The data was collected by foreign patients’ EMR data of K university hospital. The author proposed tree-form patients’ characteristic diagram through statistical methods that association rule, proportion test, clustering using prescription information and questionnaire information. Results: This study’s analysis process was applied high blood data and diabetes data. Analysis showed other characteristic of meaningful patient groups in high blood and diabetes. In high blood, test implementation rate of patient group showed the differences. And in diabetes, test implementation rate of patient group and implemented test list showed differences. Conclusion: The result of this study can play a role as basic data that can be clinical testing standard in preventive aspect. Eventually, 5 dimensions of SERVQUAL will be improved by this study’s process.

Blood-Brain Barrier Disruption in Mild Traumatic Brain Injury Patients with Post-Concussion Syndrome: Evaluation with Region-Based Quantification of Dynamic Contrast-Enhanced MR Imaging Parameters Using Automatic Whole-Brain Segmentation

Yoen Heera,Yoo Roh-Eul,Choi Seung Hong,Kim Eunkyung,오병모,Yang Dongjin,Hwang Inpyeong,Kang Koung Mi,Yun Tae Jin,Kim Ji-hoon,Sohn Chul-Ho 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.1

Objective: This study aimed to investigate the blood-brain barrier (BBB) disruption in mild traumatic brain injury (mTBI) patients with post-concussion syndrome (PCS) using dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and automatic whole brain segmentation. Materials and Methods: Forty-two consecutive mTBI patients with PCS who had undergone post-traumatic MR imaging, including DCE MR imaging, between October 2016 and April 2018, and 29 controls with DCE MR imaging were included in this retrospective study. After performing three-dimensional T1-based brain segmentation with FreeSurfer software (Laboratory for Computational Neuroimaging), the mean Ktrans and vp from DCE MR imaging (derived using the Patlak model and extended Tofts and Kermode model) were analyzed in the bilateral cerebral/cerebellar cortex, bilateral cerebral/cerebellar white matter (WM), and brainstem. Ktrans values of the mTBI patients and controls were calculated using both models to identify the model that better reflected the increased permeability owing to mTBI (tendency toward higher Ktrans values in mTBI patients than in controls). The Mann-Whitney U test and Spearman rank correlation test were performed to compare the mean Ktrans and vp between the two groups and correlate Ktrans and vp with neuropsychological tests for mTBI patients. Results: Increased permeability owing to mTBI was observed in the Patlak model but not in the extended Tofts and Kermode model. In the Patlak model, the mean Ktrans in the bilateral cerebral cortex was significantly higher in mTBI patients than in controls (p = 0.042). The mean vp values in the bilateral cerebellar WM and brainstem were significantly lower in mTBI patients than in controls (p = 0.009 and p = 0.011, respectively). The mean Ktrans of the bilateral cerebral cortex was significantly higher in patients with atypical performance in the auditory continuous performance test (commission errors) than in average or good performers (p = 0.041). Conclusion: BBB disruption, as reflected by the increased Ktrans and decreased vp values from the Patlak model, was observed throughout the bilateral cerebral cortex, bilateral cerebellar WM, and brainstem in mTBI patients with PCS.