• Title/Summary/Keyword: 확산강조 자기공명영상

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Diffusion-weighted MR Imaging of Hypoxic-Ischemic Encephalopathy (저산소성-허혈성 뇌증의 확산강조영상 소견)

  • Choi, Hye-Young;Choi, Dae-Seob;Ryoo, Jae-Wook;Cho, Jae-Min;Ko, Eun-Sook;Shin, Tae-Beom;Na, Jae-Beom;Choi, Nak-Cheon
    • Investigative Magnetic Resonance Imaging
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    • v.12 no.1
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    • pp.49-54
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    • 2008
  • Purpose : The purpose of this study was to determine the characteristics of hypoxic-ischemic encephalopathy (HIE) on diffusion-weighted imaging (DWI) and the role of DWI for the diagnosis of HIE. Materials and Methods : Six patients with HIE underwent MRI including DWI. MR examinations were performed within 4 - 32 days (mean, 11.8 days) after hypoxic brain insult. We assessed the distribution of the lesions and compared the DWI and T2, FLAIR images for the subjective conspicuity of the lesions. Results : In all patients, symmetrical hyperintense lesions were demonstrated in the bilateral basal ganglia on T2, FLAIR, and DWI. On ADC map image, the lesions were hypointense in four of six patients and isointense in other two patients. Lesion conspicuity on DWI was higher than on T2 and FLAIR images in four of six patients and similar in other two patients. For the involvement of the cortex and subcortical white matter, in five of six patients, bilateral symmetric hyperintense lesions were seen on T2, FLAIR, and DWI. Lesion conspicuity on DWI was higher than on T2 and FLAIR images in three of them and similar in other two patients. On ADC map image, the lesions showed hypointensity in three of five patients and isointensity in other two patients. For the involvement of the deep cerebral white matter, T2, FLAIR, and DWI showed bilateral symmetric hyperintense lesions in four of six patients. Among them, Lesion conspicuity on DWI was higher than on T2 and FLAIR images in only one patient. Conclusion : HIE is characterized by symmetrical hyperintense lesions in the bilateral basal ganglia, cerebral cortex, and white matter on DWI and the lesions are more conspicuously demonstrated on DWI than on T2 and FLAIR images.

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High-Resolution Contrast-Enhanced 3D-Spoiled Gradient-Recalled Imaging for Evaluation of Intracranial Vertebral Artery and Posterior Inferior Cerebellar Artery in Lateral Medullary Infarction (고해상도 조영증강 삼차원 회손기울기 회상 영상을 이용한 측면연수경색 환자의 두개내 척추동맥 및 뒤아래소뇌동맥 평가)

  • Yoon, Youngno;Ahn, Sung Jun;Suh, Sang Hyun;Park, Ah Young;Chung, Tae-Sub
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.1
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    • pp.17-24
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    • 2014
  • Purpose : To determine whether high-resolution contrast-enhanced three dimensional imaging with spoiled gradient-recalled sequence (HR-CE 3D-SPGR) plays a meaningful role in the assessment of intracranial vertebral artery (ICVA) and posterior inferior cerebellar artery (PICA) in lateral medullary infarction (LMI). Materials and Methods: Twenty-five patients confirmed with LMI were retrospectively enrolled with approval by the IRB of our institute, and 3T MRI with HR-CE 3D-SPGR and contrast-enhanced magnetic resonance angiography (CE-MRA) were performed. Two radiologists who were blinded to clinical information and other brain MR images including diffusion weighted image independently evaluated arterial lesions in ICVA and PICA. The demographic characteristics, the area of LMI and cerebellar involvement were analyzed and compared between patients with arterial lesion in ICVA only and patients with arterial lesions in both ICVA and PICA on HR-CE 3D-SPGR. Results: Twenty-two of twenty-five LMI patients had arterial lesions in ICVA or PICA on HR-CE 3D SPGR. However twelve arterial lesions in PICA were not shown on CE-MRA. Concurrent cerebellar involvement appeared more in LMI patients with arterial lesion in ICVA and PICA than those with arterial lesion in ICVA alone (p = 0.069). Conclusion: HR-CE 3D-SPGR can help evaluate arterial lesions in ICVA and PICA for LMI patients.

The study of utility about magnetic resonance elastography for measurements of liver stiffness : the comparisons of ADC value & T2 weighted image (간 경화도 측정을 위한 3.0T 자기공명 탄성계수 영상의 유용성에 대한 고찰 : 확산계수 영상 및 T2 강조 영상과의 비교)

  • Kim, Sang-Woo;Kang, Chung-Hwan;Kim, Sung-Ho;Kim, Kyung-Soo;Kim, Soon-Bae
    • Korean Journal of Digital Imaging in Medicine
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    • v.14 no.1
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    • pp.21-29
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    • 2012
  • The purpose of this study is to evaluate the mutual relations by measuring SNR from T2 weighted image and ADC values on the basis of the stiffness values from liver tissues. This study was conducted that total 37 people(23 of males and 11 of females) were taken the liver MRI examination and average age was $54.5{\pm}12.7$ years old. The equipment was MAGNETOM Skyra 3.0T (SIEMENS, Erlangen, Germany) and 32 channel body-array coil. The examination were conducted with HASTE T2 weighted image by axial plane, Spin-echo EPI (echo planner image) DWI (b-value = 800) and Magnetic resonance elastography. The ROIs (region of interest: 200-300 $mm^2$) were established on the basis of the first axial stiffness image corresponded 95% confidence interval from axial stiffness image and then were measured values. After drawing the grid lines, signals were measured SNR from T2 weighted image and ADC values on the same locations that were analysed other 3 planes respectively. The results were showed correlation (0.057) that were increased to SNR from T2 weighted image by increasing stiffness value that no significant difference statistically p = 0.003. Other results were showed correlations (-0.301) that were decreased to ADC values by increasing stiffness values that no significant difference statistically p = 0.088. In the 3.0T equipment, the results may be error in much the same fashion as the 1.5T from ADC values by evaluation of fibrosis stage. However, Magnetic resonance elastography would be useful method that is used to diagnose exactly liver fibrosis stages in the 3.0T.

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The Usefulness of Deconvolution Perfusion CT in Patients with Acute Cerebral Infarction : Comparison with Diffusion MRI (급성 뇌경색 환자에서 Deconvolution perfusion CT의 유용성 : Diffusion MRI와 비교)

  • Eun, Sung-Jong;Kim, Young-Keun
    • Journal of radiological science and technology
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    • v.26 no.3
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    • pp.25-31
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    • 2003
  • This study was performed to evaluate the usefulness of Deconvolution perfusion CT in patients with acute cerebral infarction. Nine patients with acute cerebral infarction underwent conventional CT and cerebral perfusion CT within 23 hours of the onset of symptoms. The perfusion CT scan for each patient was obtained at the levels of basal ganglia and 1cm caudal to the basal ganglia. By special imaging software, perfusion images including cerebral blood volume(CBV), cerebral blood flow(CBF), and mean transit time(MTT) maps were created. The created lesions were evaluated on each perfusion maps by 3 radiolocical technician. MTT delay time was measured in the perfusion defect lesion and symmetric contralateral normal cerebral hemisphere. Lesion sire were measured on each perfusion map and compared with the value obtained by diffusion weighted MR imaging(DWMRI). All perfusion CT maps showed the perfusion defect lesion in all patients. There were remarkable CT delay in perfusion defect lesion. In comparison of lesion size between each perfusion map and DWMRI, the lesion on CBF map was the most closely correlated with the lesion on DWMRI(7/9). The size of perfusion defect lesion on MTT map was larger than that of lesion on DWMRI, suggesting that m map can evaluate the ischemic penumbra. Deconvolution Perfusion CT maps make it possible to evaluate not only ischemic core and ischemic penumbra but also hemodynamic status in 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.

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Atypical Presentation of Chronic Granulomatous Disease in a Neonate with a Pulmonary Granuloma Mimicking a Tumor: A Case Report (신생아에서 종양으로 오인되는 폐 육아종의 비전형적인 소견을 보인 만성 육아종성 질환: 증례 보고)

  • Young Jin Yoo;Joo Sung Sun;Jang Hoon Lee;Hyun Joo Jung;Yeong Hwa Koh;Joonho Jung;Hyun Gi Kim
    • Journal of the Korean Society of Radiology
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    • v.81 no.4
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    • pp.990-995
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    • 2020
  • Chronic granulomatous disease (CGD) is an uncommon primary immune deficiency caused by phagocytes defective in oxygen metabolite production. It results in recurrent bacterial or fungal infections. Herein, we present a case of CGD with a large pulmonary granuloma in a neonate and review the imaging findings. The patient was a 24-day-old neonate admitted to the hospital with fever. A round opacified lesion was identified on the chest radiograph. Subsequent CT and MRI revealed a round mass with heterogeneous enhancement in the right lower lobe. There were foci of diffusion restriction in the mass. Surgical biopsy of the mass revealed chronic granuloma. Finally, the neonate was diagnosed with CGD caused by mutation of the gp91phox gene. Herein, we present the clinical and imaging findings of this unusual case of CGD.

The Study on Reduction of Image Distortion by using Single-Shot Turbo Spin Echo in Brain Stem Diffusion MRI (자기공명 확산강조영상검사 시 영상왜곡 감소에 관한 연구)

  • Choi, Kwan-Woo;Lee, Ho-Beom;Na, Sa-Ra;Yoo, Beong-Gyu;Son, Soon-Yong
    • Journal of the Korean Society of Radiology
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    • v.10 no.4
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    • pp.279-284
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    • 2016
  • Single-shot echo planar imaging(SS-EPI) is well established as high sensitivity for ischemic stroke. However, it is prone to susceptibility artifact in brain stem that diminish the image quality. single-shot turbo spin echo(SS-TSE) is a new DWI technique that can reduce susceptibility artifact. Thus, this research was conducted so as to reduce geometric distortion in brain stem by using single-shot turbo spin echo technique. Thirty patients without brain disease underwent diffusion MR on a 3T scanner with SS-EPI and SS-TSE. Obtained images with both sequences were analyzed for geometric distortion and error percentage as well. Image quality in terms of geometric distortion of SS-TSE were found to be significantly better than those for SS-EPI. And error percentage was considerably reduced for 2.4% of b0 image(from 11.1% to 8.7%), 1.2% of b1000 image(from 11.4% to 10.1%), respectively. In summary, diffusion MR using SS-TSE significantly reduce geometric distortion compared to SS-EPI in brain stem and may provide improved diagnostic performance.

Correlation of the Speed of Enhancement of Hepatic Hemangiomas with Intravoxel Incoherent Motion MR Imaging (간혈관종의 조영증강속도와 복셀내비결집운동 MR영상과의 상관관계)

  • Yang, Dal Mo;Jahng, Geon-Ho;Kim, Hyun Cheol;Kim, Sang Won;Kim, Hyug-Gi
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.3
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    • pp.208-218
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    • 2014
  • Purpose : To evaluate the relationship between the speed of enhancement of hepatic hemangiomas on gadolinium-enhanced MRI and ADC values by using various parameters, including the D, f, $D^*$ and $ADC_{fit}$ on intravoxel incoherent motion (IVIM) MR Imaging. Materials and Methods: The institutional review board approved this retrospective study. A total of 47 hepatic hemangiomas from 39 patients were included (20 men and 19 women). The hemangiomas were classified into three types according to the enhancement speed of the hepatic hemangiomas on gadolinium-enhanced dynamic T1-weighted images: rapid (Type A), intermediate (Type B), and slow (Type C) enhancement. The D, f, $D^*$ and $ADC_{fit}$ values were calculated using IVIM MR imaging. The diffusion/perfusion parameters and ADC values were compared among the three types of hemangiomas. Results: Both the $ADC_{fit}$ and D values of type C were significantly lower than those of type A (P = 0.0022, P = 0.0085). However, for the f and $D^*$, there were no significant differences among the three types. On DWI with all b values (50, 200, 500 and $800sec/mm^2$), the ADC values of type C were significantly lower than those of the type A (P < 0.012). For b values with $800sec/mm^2$, the $ADC_{800}$ values of the type C hemangiomas were significantly lower than those of type B (P = 0.0021). We found a negative correlation between hepatic hemangioma enhancement type and $ADC_{50}$ (${\rho}=-0.357$, P = 0.014), $ADC_{200}$ (${\rho}=-0.537$, P = 0.0001), $ADC_{500}$ (${\rho}=-0.614$, P = 0.0001), and $ADC_{800}$ (${\rho}=-0.607$, P = 0.0001). Therefore, four ADC values of $ADC_{50}$, $ADC_{200}$, $ADC_{500}$, and $ADC_{800}$ were decreased with decreasing enhancement speed. Conclusion: Hepatic hemangiomas had variable ADCs according to the type of enhancement, and the reduced ADCs in slowly enhancing hemangiomas may be related to the reduced pure molecular diffusion (D).

Case of Treatment Using Adaptive Servo-Ventilation in a Patient with Central Sleep Apnea after a Lateral Medullary Infarction (외측 연수 경색에 의해 발생한 중추성 수면 무호흡 환자의 자동-적응형 양압기를 사용하여 치료한 경험)

  • Kim, Dae Jin;Cho, Jae Wook;Kim, Hyun Woo;Choi, Jeong Su;Mun, Sue Jean
    • Korean Journal of Clinical Laboratory Science
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    • v.52 no.3
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    • pp.278-283
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    • 2020
  • Central sleep apnea (CSA) is characterized by respiratory failure of at least 10 seconds without any effort of the chest and abdomen in the absence of upper airway resistance during sleep. In this case, the patient experiences respiratory failure that does not meet the CSA diagnostic criteria and CSA symptoms. Magnetic resonance imaging diffusion-weighted imaging (MRI DWI) scans revealed a lateral medullary infarction. Continuous positive airway pressure (CPAP) was applied as a primary treatment for CSA and respiratory failure. During the titration of CPAP, the apnea-hypopnea index (AHI) and arousal index (AI) were worse than the results before its use (AHI: 42.5/hr→82.8/hr, AI: 21.7/hr→40.8h). As a result, adaptive servo-ventilation (ASV) was chosen as the secondary treatment. Compared to the night-polysomnography results before the ASV treatment, the AHI improved (42.5/hr→8.6/hr). Therefore, ASV is a potential treatment for CSA and respiratory failure in these patients.