• Investigative Magnetic Resonance Imaging
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• 제26권1호
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• pp.32-42
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• 2022

Purpose: To evaluate the clinical benefit of 2D contrast-enhanced T2 fluid-attenuated inversion recovery (CE-T2 FLAIR) image for detecting leptomeningeal metastasis (LM) in the brain metastasis work-up for lung cancer. Materials and Methods: From June 2017 to July 2019, we collected all consecutive patients with lung cancer who underwent brain magnetic resonance image (MRI), including contrast-enhanced 3D fast spin echo T1 black-blood image (CE-T1WI) and CE-T2 FLAIR; we recruited clinico-radiologically suspected LM cases. Two independent readers analyzed the images for LM in three sessions: CE-T1WI, CE-T2 FLAIR, and their combination. Results: We recruited 526 patients with suspected lung cancer who underwent brain MRI; of these, we excluded 77 (insufficient image protocol, unclear pathology, different contrast media, poor image quality). Of the 449 patients, 34 were clinico-radiologically suspected to have LM; among them, 23 were diagnosed with true LM. The calculated detection performance of CE-T1WI, CE-T2 FLAIR, and combined analysis obtained from the 34 suspected LM were highest in the combined analysis (AUC: 0.80, 0.82, and 0.89, respectively). The inter-observer agreement was also the highest in the combined analysis (0.68, 0.72, and 0.86, respectively). In quantitative analyses, CNR of CE-T2 FLAIR was significantly higher than that of CE-T1WI (Wilcoxon signed rank test, P < 0.05). Conclusion: Adding CE-T2 FLAIR might provide better detection for LM in the brain-metastasis screening for lung cancer.

• Korean Journal of Radiology
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• 제22권4호
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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.

• Korean Journal of Radiology
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• 제24권12호
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• pp.1179-1189
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• 2023

Objective: We aimed to evaluate the reporting quality of research articles that applied deep learning to medical imaging. Using the Checklist for Artificial Intelligence in Medical Imaging (CLAIM) guidelines and a journal with prominence in Asia as a sample, we intended to provide an insight into reporting quality in the Asian region and establish a journal-specific audit. Materials and Methods: A total of 38 articles published in the Korean Journal of Radiology between June 2018 and January 2023 were analyzed. The analysis included calculating the percentage of studies that adhered to each CLAIM item and identifying items that were met by ≤ 50% of the studies. The article review was initially conducted independently by two reviewers, and the consensus results were used for the final analysis. We also compared adherence rates to CLAIM before and after December 2020. Results: Of the 42 items in the CLAIM guidelines, 12 items (29%) were satisfied by ≤ 50% of the included articles. None of the studies reported handling missing data (item #13). Only one study respectively presented the use of de-identification methods (#12), intended sample size (#19), robustness or sensitivity analysis (#30), and full study protocol (#41). Of the studies, 35% reported the selection of data subsets (#10), 40% reported registration information (#40), and 50% measured inter and intrarater variability (#18). No significant changes were observed in the rates of adherence to these 12 items before and after December 2020. Conclusion: The reporting quality of artificial intelligence studies according to CLAIM guidelines, in our study sample, showed room for improvement. We recommend that the authors and reviewers have a solid understanding of the relevant reporting guidelines and ensure that the essential elements are adequately reported when writing and reviewing the manuscripts for publication.

• Journal of Cerebrovascular and Endovascular Neurosurgery
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• 제26권2호
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• pp.152-162
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• 2024

Objective: Stroke is the second-leading cause of death globally. Intracranial atherosclerotic stenosis (ICAS) represents 10-15% of ischemic strokes in Western countries and up to 47% in Asian countries. Patients with ICAS have an especially high risk of stroke recurrence. The aim of this meta-analysis is to reassess recurrent stroke, transient ischemic attack (TIA), and other outcomes with stenting versus best medical management for symptomatic ICAS. Methods: The search protocol was developed a priori according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The OVID Medline, Embase, Web of Science, and Cochrane Library databases were searched from inception to August 14th, 2022. Results: This meta-analysis included four randomized controlled trials (RCTs), with a total number of 991 patients. The mean age of participants was 57 years. The total number of intracranial stenting patients was 495, and the number of medical treatment patients was 496. The included studies were published between 2011 and 2022. Two studies were conducted in the USA, and the other two in China. All included studies compared intracranial stenting to medical treatment for ICAS. Conclusions: In patients with ischemic stroke due to symptomatic severe intracranial atherosclerosis, the rate of 30-day ischemic stroke, 30-day intracerebral hemorrhage, one-year stroke in territory or mortality favored the medical treatment alone without intracranial stenting. The risk of same-territory stroke at last follow-up, disabling stroke at last follow-up, and mortality did not significantly favor either group. Intracranial stenting for atherosclerosis did not result in significant benefit over medical treatment.

• 한국멀티미디어학회:학술대회논문집
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• 한국멀티미디어학회 2012년도 춘계학술발표대회논문집
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• pp.102-105
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• 2012

ONVIF is becoming a de factor standard specification for supporting interoperability among network video products, which also supports a specification for video analytics service. A smart IP network camera is an IP network supporting video analytics. In this paper, we present our efforts in integrating ONVIF Video Analytics Service into our currently developing smart IP network camera(SS IPNC; Soongsil Smart IP Network Camera). SSIPNC supports object detection, tracking, classification, and event detection with proprietary configuration protocol and meta data formats. SSIPNC is based on TI' IPNC ONVIF implementation which supports ONVI Core specification, and several ONVIF services such as device service, imaging service and media service, but not video analytics service.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.104-104
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• 2001

Purpose： In this study, we investigated the possible motor pathways of hemiplegic stroke patients usin combined TMS and BOLD fMRI approach and evaluated the correlation between TMS a fMRI methods. Method： Four subjects, who demonstrated left hemiplegia after stroke, are included. TMS was performed using a Dantec Mag2 stimulator (Dantec Company, USA) in single puls mode with figure eight-shaped coil. Following TMS localization, The BOLD T2＊-weight images were acquired with echo planar imaging sequence (TR = 1.2 sec, TE = 60 msec, and flip angle = 90). Motor activation was studied by means of a repetitive fing flexion-extension task. The stimulation protocol comprised 10 cycles of alternating activati and rest (10 images per cycle). Total 60 cycles were performed and each cycle take abou 1.5 sec. The resulting images were then analyzed with STIMULATE (CMRR, U, o Minnesota) to generate functional maps using a student t-test (p < 0.0005) and cluste analysis.

• 대한핵의학회지
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• 제38권6호
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• pp.540-542
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• 2004

Although artifacts in tomographic imaging can arise from a number of sources, this case presents an artifact caused by using inadequate acquisition parameters which do not match the collimator with which a camera equipped in Tc-99m ECD brain SPECT. Whenever the collimator in tomographic studies is changed, we should take care to use suitable parameters of acquisition protocol according to the collimator with which a camera is fitted. Other ways to prevent an error of this type is to use a point source.

• Imaging Science in Dentistry
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• 제51권3호
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• pp.323-328
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• 2021

Tooth extraction after head and neck radiotherapy exposes patients to an increased risk for osteoradionecrosis of the jaw. This study reports the results of a radiographic analysis of bone neoformation after tooth extraction in a case series of patients who underwent radiation therapy. No patients developed osteoradionecrosis within a follow-up of 1 year. Complete mucosal repair was observed 30 days after surgery, while no sign of bone formation was observed 2 months after the dental extractions. Pixel intensity and fractal dimension image analyses only showed significant bone formation 12 months after the tooth extractions. These surgical procedures must follow a strict protocol that includes antibiotic prophylaxis and therapy and complete wound closure, since bone formation at the alveolar socket occurs at a slower pace in patients who have undergone head and neck radiotherapy.

• Nuclear Medicine and Molecular Imaging
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• 제43권1호
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• pp.55-59
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• 2009

목적: 전초림프절 스캔과 전초림프절 생검은 유방암 환자에서 액와림프절 전이를 인지하기 위해서 사용되지만, 표준화된 방법이 마련되어 있지 않다. 액와림프절 전이를 인지하기 위한 전초림프절 검사에 있어서 본 연구에서는 수술당일 주사하는 당일검사와 수술전날 주사하는 전날검사의 결과를 비교하여 보았다. 대상 및 방법: 본 연구에서는 2001년에서 2004년사이에 유방암으로 수술을 시행했던 349명의 환자를 대상으로 하였다. 171명의 환자는 Tc-99m Tin-Colloid (37 MBq) 0.8 ml를 유륜하로 수술당일(1시간 전)에 주사하였다. 178명의 환자는 Tc-99m Tin-Colloid (185 MBq) 0.8 ml를 유륜하로 수술전날(16시간 전)에 주사하였다. 앉은 자세에서 림프신티그라피가 시행되었고, 수술 중에 감마프로브로 전초림프절을 발견하였다. 결과: 당일검사를 시행한 전체 171명의 환자 중에서 153명(89.5%)이 림프신티그라피에 의해 전초림프절이 발견되었고, 150명(87.7%)이 감마프로브에 의해 전초림프절이 발견되었다. 전날검사를 시행한 전체 178명의 환자 중에서 159명(89.3%)이 림프신티그라피에 의해 전초림프절이 발견되었고, 154명(86.5%)이 감마프로브에 의해 전초림프절이 발견되었다. 당일검사와 전날검사에 있어서, 림프신티그라피와 감마프로브에 의한 전초림프절 발견율의 유의한 차이는 없었다(p>0.05, p>0.05). 결론 : 유방암 환자에서 전초림프절을 발견하는데 있어 당일검사와 전날검사에 의한 차이는 없었다. 전날검사는 전초림프절 스캔을 시행할 충분한 시간을 얻을 수가 있어서, 유방암 환자에서 전초림프절을 발견하는데 더 유용할 것이다.

• Investigative Magnetic Resonance Imaging
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• 제17권2호
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• pp.83-90
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• 2013

목적: 본 연구의 목적은 환자에서 임상적으로 사용되는 영상 프로토콜을 이용하여 시행된 3.0 T 심장자기공명영상을 1.5 T 와 비교하여 그 유용성을 알아보고자 하는데 있다. 대상과 방법: 10개월간 30명의 환자에서 얻은 1.5 T 자기공명영상과 20명의 3.0 T 영상을 후향적으로 비교하였다. 각각의 영상에 대하여 신호 대 잡음비 (signal-to-noise ratio: SNR), 대조도 대 잡음비 (contrast-to-noise ratio: CNR), 영상 화질 (artifact의 정도에 따라서 5단계로 분류)을 평가하고 비교하였다. 결과: T1심장 형태 영상 및 심근 생존능 평가 영상에서는 3.0 T 자기공명영상에서 영상화질 (T1: $3.8{\pm}0.9$ vs. $3.9{\pm}0.7$, p=0.438; T2-SPAIR: $3.8{\pm}0.9$ vs. $3.9{\pm}0.5$, p=0.744; 지연기 조영 증강 영상: $4.5{\pm}0.8$ vs. $4.7{\pm}0.6$, p=0.254)의 유의한 저하 없이 SNR과 CNR의 향상을 보였다 (T1: SNR 29%, p < 0.001, CNR 37%, p < 0.001; T2-SPAIR: SNR 13%, p=0.068, CNR 18%, p=0.059; 지연기 조영 증강 영상: SNR 45%, p=0.017, CNR 37%, p=0.135). 심장Cine 영상에서 3.0 T 심장영상이 1.5 T 영상과 비교하여 영상화질($3.6{\pm}0.7$ vs. $4.2{\pm}0.6$, p < 0.001)이 다소 떨어졌으나 SNR과 CNR의 유의한 상승을 보였다 (SNR 143% 상승, CNR 108% 상승, p < 0.001). 심근관류영상에서는 SNR (11% 감소, p=0.172)과 CNR (7% 감소, p=0.638) 이 통계적으로 유의하지 않은 정도로 감소되었으나 영상화질($4.6{\pm}0.5$ vs. $4.0{\pm}0.8$, p=0.006)은 유의한 향상을 보였다. 결론: 실제 임상영역에서 사용되는 영상 프로토콜로 시행된 3.0 T 심장자기공명영상은 1.5T 영상과 비교하여 충분한 영상의 질을 제공하였다.