• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.467-487
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• 2020

Anatomical imaging is the basis of the diagnosis and treatment response assessment of brain tumors. Among the existing imaging techniques currently available in clinical practice, diffusion-weighted imaging and perfusion imaging provide additional information. Recently, with the increasing importance of evaluation of the genomic variation and heterogeneity of tumors, clinical application of imaging techniques using radiomics and deep learning is expected. In this review, we will describe recommendations for magnetic resonance imaging protocols focusing on anatomical images that are still important in the clinical application of brain tumor imaging, and the basic principles of diffusion-weighted imaging and perfusion imaging among the advanced imaging techniques, as well as their pathophysiological background and clinical application. Finally, we will review the future perspectives of radiomics and deep learning applications in brain tumor imaging, which have been studied to a great extent due to the development of computer technology.

• Progress in Medical Physics
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• v.24 no.2
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• pp.108-118
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• 2013

Currently, an arterial spin labeling (ASL) magnetic resonance imaging (MRI) technique does not routinely used in clinical studies to measure perfusion in brain because optimization of imaging protocol is required to obtain optimal perfusion signals. Therefore, the objective of this study was to investigate changes of perfusion-weighed signal intensities with varying several parameters on a pulsed arterial spin labeling MRI technique obtained from a 3T MRI system. We especially evaluated alternations of ASL-MRI signal intensities on special brain areas, including in brain tissues and lobes. The signal targeting with alternating radiofrequency (STAR) pulsed ASL method was scanned on five normal subjects (mean age: 36 years, range: 29~41 years) on a 3T MRI system. Four parameters were evaluated with varying: 1) the labeling gap, 2) the labeling delay time, 3) the labeling thickness, and 4) the slice scan order. Signal intensities were obtained from the perfusion-weighted imaging on the gray and white matters and brain lobes of the frontal, parietal, temporal, and occipital areas. The results of this study were summarized: 1) Perfusion-weighted signal intensities were decreased with increasing the labeling gap in the bilateral gray matter areas and were least affected on the parietal lobe, but most affected on the occipital lobe. 2) Perfusion-weighted signal intensities were decreased with increasing the labeling delay time until 400 ms, but increased up to 1,000 ms in the bilateral gray matter areas. 3) Perfusion-weighted signal intensities were increased with increasing the labeling thickness until 120 mm in both the gray and white matter. 4) Perfusion-weighted signal intensities were higher descending scans than asending scans in both the gray and white matter. We investigated changes of perfusion-weighted signal intensities with varying several parameters in the STAR ASL method. It should require having protocol optimization processing before applying in patients. It has limitations to apply the ASL method in the white matter on a 3T MRI system.

• Investigative Magnetic Resonance Imaging
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• v.17 no.4
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• pp.312-315
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• 2013

When cerebral cortical hyperintensities on diffusion-weighted image are seen in patients with suspected acute stroke accompanying seizure, it is necessary to differentiate whether they are caused by infarction or seizure-related change. We report a case of seizure-related cortical hypertensities in a patient with suspected acute infarction. With perfusion MR imaging, we could differentiate from acute infarction.

• Journal of the Korean Society of Radiology
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• v.6 no.1
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• pp.19-26
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• 2012

It is very important for early diagnosis and therapy with ischamic cerebral infarction patients. This study was to know the ischemic penumbra lesion which compared CT-perfusion and diffusion weighted MRI(DWMRI) with acute cerebral infarction patients. 12 acute cerebral infarction patients had performed perfusion CT and performed DWMRI. Perfusion images including cerebral blood volume(CBV), cerebral blood flow(CBF), time to peak(TTP) and mean transit time(MTT) maps obtained the values with defect lesion and contralateral normal cerebral hemisphere and DWMRI was measured by signal intensity and compared of lesion size between each perfusion map. All perfusion CT maps showed the perfusion defect lesions in all patients. There were remarkable TTP and MTT delay in perfusion defect lesions. The lesions on CBF map was the most closely correlated with the lesions on DWMRI. The size of perfusion defect lesions on TTP and MTT map was larger than that of lesions on DWMRI, suggesting that MTT map can evaluate the ischemic penumbra. Perfusion CT maps make it possible to evaluate not only ischemic core and ischemic penumbra, but also hemodynamic status in the perfusion defect area. These results demonstrate that perfusion CT can be useful to the diagnosis and treatment in the patients with acute cerebral ischemic infarction.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.388-391
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• 2011

A lesion that is hyperintense on diffusion-weighted imaging (DWI) and hypointense on the apparent diffusion coefficient (ADC) map is a characteristic magnetic resonance imaging (MRI) finding in acute ischemic infarction. In some cases, however, these findings can persist for a few months after infarct onset. It is thought that these finding reflect the different evolution speeds of the infarcted tissue. We report a patient with a right middle cerebral artery territory infarction with persistent hyperintensity on DWI and hypointensity on the ADC map for over 8 months. To our knowledge, this is the most persistent case of hyperintensity lesion on DWI and the serial MRI images of this patient provide important information on the evolution of infarcted tissue.

• Journal of Yeungnam Medical Science
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• v.37 no.2
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• pp.147-147
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• 2020

• Proceedings of the KSMRM Conference
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• 2001.11a
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• pp.169-169
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• 2001

Purpose： To assess the clinical usefulness of Transfer Insensitive Labeling Technique (TILT) in t evaluation of ischemic cerebrovascular disease. Method： Arterial spin labeling (ASL) is a method of perfusion weighted imaging usin endogenous water as a tracer. To avoid MT-related artifacts, which is common in usual A technique, a transfer insensitive labeling technique (TILT) was used, which globall manipulate macromolecular spins in the same way by both labeling and reference preparatio while free water is labeled in one case and left unchanged in the other. Philips Interal 1.5 T system was used. 40cm FOV and 32 repeated measurements were done because of the wea perfusion signal. 5 slices of supratentorial brain were obtained in 5 patients ｛MCA infar (n=3), moyamoya disease (n=2)｝. We simultaneously obtained contrast enhanced T2＊-weighted perfusion MRI and correlate to TILT images.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1066-1082
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• 2021

Incidental adnexal masses considered indeterminate for malignancy are commonly observed on ultrasonography. Multiparametric MRI is the imaging modality of choice for the evaluation of sonographically indeterminate adnexal masses. Conventional MRI enables a confident pathologic diagnosis of various benign lesions due to accurate tissue characterization of fat, blood, fibrous tissue, and solid components. Additionally, functional imaging sequences, including perfusion- and diffusion-weighted imaging, improve the diagnostic efficacy of conventional MRI in differentiating benign from malignant adnexal masses. The ovarian-adnexal reporting and data system (O-RADS) MRI was recently designed to provide consistent interpretations in assigning risk of malignancy to ovarian and other adnexal masses, and to provide a management recommendation for each risk category. In this review, we describe the clinical application of multiparametric MRI for the evaluation of adnexal masses and introduce the O-RADS MRI risk stratification system.

• Proceedings of the KSMRM Conference
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• 2000.11a
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• pp.55-56
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• 2000

• Proceedings of the KSMRM Conference
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• 2000.11a
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• pp.24-25
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• 2000