• Proceedings of the Korea Contents Association Conference
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• 2018.05a
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• pp.61-62
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• 2018

DTI (Diffusion Tensor Imaging)에서는 임상적으로 매우 중요하나 긴 획득시간으로 인하여 적용에 어려움이 있었다. 그러나 최근에 개발된 다중대역병렬기법 (Multiband SENSE)은 동시에 여러 개의 절편을 획득이 가능한 기법으로 기존에 사용되는 병렬기법(SENSE)과 비교하여도 매우 유용한 것을 알 수 있다.

• Investigative Magnetic Resonance Imaging
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• v.21 no.2
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• pp.106-108
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• 2017

The perfusion change in acute symptomatic hypoglycemic encephalopathy (ASHE) is not well known. We present the perfusion-weighted imaging of a patient with ASHE. The area of diffusion-weighted imaging abnormalities and adjacent normal-appearing white matter showed increased cerebral blood volume and flow, and shortening of time-to-peak.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.545-550
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• 2016

The purpose of this study is to improve the mapping between functional image and conventional image by using rectangular FOV technique. Diffusion weighted imaging which is widely used for stroke was acquired by reducing the FOV and compared each Apparent Diffusion Coefficient(ADC). As a result, there is no significant difference of each ADC value in one-way-anova analysis and post-hoc analysis. Thus, Mismatching problem may be improved by matching the FOV with rectangular FOV technique because there is no difference in ADC values.

• Journal of the Korean Society of Radiology
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• v.7 no.4
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• pp.265-269
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• 2013

This report aims at picturing out the clinical usefulness by analyzing the signal intensity in choroid plexuses which produce cerebrospinal fluids by diffusion weighted imaging. At first, subjects were chosen among the patients who showed high in signal intensity by diffusion weighted imaging. The subjects were taken another test by fluid attenuated inversion recovery diffusion weighted echo planer image(FLAIR-DW-EPI) the signals of fluid attenuation. And it was found that there are differences between the signal intensities of the two methods, which showed that the signal intensity in FLAIR-DW-EPI is equal to or low than, that in the Brain. By this, it is felt that it is helpful to diagnose the disease in choroid plexus by testing another more with FLAIR-DW-EPI methods the patients who showed high in signal intensity in choroid plexus by $T2^*$ diffusion weighted echo planer image($T2^*$-DW-EPI).

• Investigative Magnetic Resonance Imaging
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• v.21 no.1
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• pp.43-50
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• 2017

Chronic expanding organizing hematoma (CEH) occasionally mimics a soft tissue tumor on MRI, which becomes more problematic in patients with a history of surgical resection for musculoskeletal malignancy. Herein, we present a case of CEH which we were able to differentiate from recurrent tumor through MRI follow-up, including diffusion-weighted imaging (DWI) and dynamic contrast enhanced (DCE) imaging. A 66-year-old male visited our institution under suspicion of recurrent leiomyosarcoma of the thigh, 19 months after surgery and radiation therapy. Due to inconclusive results, three US-guided biopsies and 6 MRI examinations were performed over 2 years. In the end, we could diagnose a CEH using conventional and functional MRI techniques, and it was histopathologically confirmed after surgical resection. A CEH may occur remotely after an initiating event, and it may persist and expand over several years. Functional MR sequences, in addition to conventional sequences, are helpful in differentiating CEH from malignant neoplasms.

• Investigative Magnetic Resonance Imaging
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• v.25 no.4
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• pp.338-344
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• 2021

Solitary fibrous tumors (SFT) are rare mesenchymal tumors that most commonly develop in the pleura; they rarely involve the diaphragm. MRI has not been widely used to evaluate SFTs of the thoracic cavity, though it may be highly useful in assessing local invasion, predicting malignant potential, and helping in the differential diagnosis. However, MRI findings of malignant SFTs of the diaphragmatic pleura have been described in only two cases. We report a rare case of a malignant solitary fibrous tumor of the diaphragmatic pleura in an 82-year-old man. We describe the clinical and characteristic imaging features, including computed tomography, conventional MRI, and diffusion-weighted imaging. Contrast-enhanced MRI is more accurate than is CT in identifying the origin of SFTs, predicting whether they ae benign or malignant, and assessing local invasion. This imaging modality proved helpful in deciding on the treatment strategy for these rare tumors.

• Journal of Yeungnam Medical Science
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• v.18 no.1
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• pp.30-38
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• 2001

Background: The purpose of this study was to evaluate the usefulness of diffusion-weighted magnetic resonance imaging for monitoring the response to radiation therapy in metastatic bone marrow of the spines. Materials and Methods: Twenty-one patients with metastatic bone marrow of the spines were examined with MRI. Diffusion-weighted and spin-echo MRI were performed in 10 patients before and after radiation therapy with or without systemic chemotherapy, and performed in 11 patients after radiation therapy alone. Follow up spin-echo and diffusion-weighted MRI were obtained at 1 to 6 months after radiation therapy according to patients' condition. The diffusion-weighted imaging sequence was based on reversed fast imaging with steady-state precession (PSIF). Signal intensity changes of the metastatic bone marrows before and after radiation therapy on conventional spin-echo sequence MRI and diffusion-weighted MRI were evaluated. Bone marrow contrast ratios and signal-to-noise ratios before and after radiation therapy of diffusion- weighted MRI were analyzed. Results: All metastatic bone marrow of the spinal bodies were hyperintense to normal bone marrow of the spinal bodies on pretreatment diffusion-weighted MRI and positive bone marrow contrast ratios(p<0.001), and hypointense to normal spinal bodies on posttreatment diffusion-weighted MRI and negative bone marrow contrast ratios(p<0.001). The signal to noise ratios after treatment decreased comparing with those of pretreatment. Decreased signal intensity of the metastatic bone marrows on diffusion-weighted MRI began to be observed at average more than one month after the initiation of the radiation therapy. Conclusion: These results suggest that diffusion-weighted MRI would be an excellent method for monitoring the response to therapy of metastatic bone marrow of the spinal bodies, however, must be investigated in a larger series of patients with longer follow up period.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.13-18
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• 2010

Purpose : Diffusion tensor imaging(DTI) allows the visualization of fiber tract damage in patients with cerebral infarction. The purpose of this study is to evaluate the correlation between degree of NIH stoke scale and fractional anisotropy (FA) in patient with cerebral infarction. Material and Methods : 16 patients aged 36~77 years(male : 11, female : 5, mean age : 61y), diagnosed cerebral infarction by diffusion weighted imaging(DWI), underwent 24 directional diffusion tensor imaging(DTI). Patients had the DTI taken within 3days of stroke onset. Comparison of DWI, FA value on DTI were measured infarcted area and counter part of specific region of interest (ROI). And evaluation of differences between clinically improved patient group (n=9) and unimproved patient group (n=7) until 2 week follow up after development of cerebral infarction. Clinical status was scaled by NIH stroke scale. Results : Quantitative measurements of FA confirmed statistically the significant diffusion changes in the infarct compared with the matched-counter part region. In DWI, the infarcted area shows high signal intensity, however FA value on DTI was lower than normal brain parenchyma. The FA value of clinically improved patient by NIH stroke scale was 0.49, and the value of contralateral normal brain parenchyma was 0.41. On the contrary, FA value of infarcted area shows about 15% lower than normal brain parenchyma. But, the FA value of unimproved patient by NIH stroke scale represents a half those of contralateral normal brain parenchyma (0.28 on infarcted area vs. 0.56 on normal brain parenchyma). So, the FA value of unimproved patient group was considerably less than those of improved. Conclusion : It is concluded that the unimproved patient group after cerebral infarction showed much less FA value than that of normal brain parenchyma. The FA value of DTI may be one of the useful parameter to predict outcome of cerebral infarction patients.

• Korean Journal of Radiology
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• v.25 no.1
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• pp.43-54
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• 2024

Objective: To evaluate the added value of diffusion-weighted imaging (DWI)-based quantitative parameters to distinguish uterine sarcomas from atypical leiomyomas on preoperative magnetic resonance imaging (MRI). Materials and Methods: A total of 138 patients (age, 43.7 ± 10.3 years) with uterine sarcoma (n = 44) and atypical leiomyoma (n = 94) were retrospectively collected from four institutions. The cohort was randomly divided into training (84/138, 60.0%) and validation (54/138, 40.0%) sets. Two independent readers evaluated six qualitative MRI features and two DWI-based quantitative parameters for each index tumor. Multivariable logistic regression was used to identify the relevant qualitative MRI features. Diagnostic classifiers based on qualitative MRI features alone and in combination with DWI-based quantitative parameters were developed using a logistic regression algorithm. The diagnostic performance of the classifiers was evaluated using a cross-table analysis and calculation of the area under the receiver operating characteristic curve (AUC). Results: Mean apparent diffusion coefficient value of uterine sarcoma was lower than that of atypical leiomyoma (mean ± standard deviation, 0.94 ± 0.30 10^-3 mm²/s vs. 1.23 ± 0.25 10^-3 mm²/s; P < 0.001), and the relative contrast ratio was higher in the uterine sarcoma (8.16 ± 2.94 vs. 4.19 ± 2.66; P < 0.001). Selected qualitative MRI features included ill-defined margin (adjusted odds ratio [aOR], 17.9; 95% confidence interval [CI], 1.41-503, P = 0.040), intratumoral hemorrhage (aOR, 27.3; 95% CI, 3.74-596, P = 0.006), and absence of T2 dark area (aOR, 83.5; 95% CI, 12.4-1916, P < 0.001). The classifier that combined qualitative MRI features and DWI-based quantitative parameters showed significantly better performance than without DWI-based parameters in the validation set (AUC, 0.92 vs. 0.78; P < 0.001). Conclusion: The addition of DWI-based quantitative parameters to qualitative MRI features improved the diagnostic performance of the logistic regression classifier in differentiating uterine sarcomas from atypical leiomyomas on preoperative MRI.

• The Journal of Korean Physical Therapy
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• v.30 no.2
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• pp.73-77
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• 2018

Purpose: The prefrontal lobe, supplementary motor area, cerebellum, and basal ganglia are activated during gait. In addition, gait is controlled by nerves, such as the corticospinal tract (CST) and corticoreticular pathway (CRP). In this study, the presence of an injury to the CST and CRP was identified by diffusion tensor imaging and the characteristics of the gait pattern were investigated according to inferior cerebral artery infarction. Methods: One patient and six control subjects of a similar age participated. A 69-year-old female patient had an injury to the left basal ganglia, insular gyrus, corona radiata, dorsolateral prefrontal cortex, and postcentral gyrus due to an inferior cerebral artery infarction. Diffusion tensor imaging (DTI) data was acquired 4 weeks after the stroke. The kinematic and spatio-temporal parameters of gait were collected using a three-dimensional gait analysis system. Results: On 4 weeks DTI, the CST and CRP in the affected hemisphere did not show injury to the affected and unaffected hemisphere. Gait analysis showed that the cadence of spatio-temporal parameter was decreased significantly in the patient. The angle of the knee joint was decreased significantly in the affected and unaffected sides compared to the control group. Conclusion: The results of diffusion tensor imaging showed that although the patient was evaluated to be capable of an independent gait, the quality and quantity of gait might be reduced. This study could help better understand the gait ability analysis of stroke patients and the abnormal gait pattern of patients with a brain injury.