1.Cerebral Fat Embolism as a Rare Complication of Postgastrectomy: Case Report.
Journal of the Korean Radiological Society 2004;51(6):591-594
Cerebral fat embolism syndrome is a rare complication of trauma, and it particularly involves fractures of the long bones. This syndrome may occur in a diverse series of conditions such as diabetes mellitus, acute hemorrhagic pancreatitis, acute fatty cirrhosis, prolonged corticosteroid therapy, lymphography and liposuction. The author reports the CT and MRI findings in a patient with cerebral fat embolism that occurred as a rare complication of postgastrectomy.
Diabetes Mellitus
;
Embolism, Fat*
;
Fibrosis
;
Humans
;
Lipectomy
;
Lymphography
;
Magnetic Resonance Imaging
;
Pancreatitis
2.Antegrade Recanalization of Parent Artery after Internal Trapping of Ruptured Vertebral Artery Dissecting Aneurysm.
Yon Kwon IHN ; Jae Hoon SUNG ; Je Hoon BYUN
Journal of Korean Neurosurgical Society 2012;51(5):301-304
We report a patient with a ruptured vertebral artery (VA) dissecting aneurysm that was treated by internal trapping of the aneurysm and parent artery using detachable coils with subsequent antegrade recanalization of occluded vertebral artery during the follow-up period. A 38-year-old man was admitted with a ruptured right VA dissecting aneurysm just distal to origin of right posterior inferior cerebellar artery. The dissected segment of the VA was occluded by coil embolization. The 14 months follow-up angiography showed that dissected aneurysm was completely occluded, but the parent artery was recanalized in an antegrade fashion. Based on this unique case, the authors suggest that careful angiographic follow-up of dissecting aneurysm is required, even in patients successfully treated with endovascular occlusion of the affected artery and aneurysm.
Adult
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Aneurysm
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Aneurysm, Dissecting
;
Angiography
;
Arteries
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Follow-Up Studies
;
Humans
;
Parents
;
Vertebral Artery
3.The Significance of Diffusion Weighted Imaging for the Diagnosis of Pyogenic Ventriculitis.
Yon Kwon IHN ; Seong Su HWANG ; Tae You KIM
Journal of the Korean Radiological Society 2007;57(2):129-135
PURPOSE: To evaluate the significance of diffusion weighted imaging (DWI) for the diagnosis of pyogenic ventriculitis. MATERIALS AND METHODS: In this retrospective study, 9 patients with pyogenic ventricultis underwent a set of imaging sequences that included DWI, T1-and T2-weighted imaging, FLAIR and enhanced T1 weighted imaging. DWI consisted of an axial single shot spin echo EPI pulse sequence with b values of 0 and 1000 sec/mm2. We evaluated the presence and signal intensity of ventricular debris, hydrocephalus, periventricular signal abnormality, and ependymal enhancement. The apparent diffusion coffiecient values of ventricular debris and cortical gray matter were calculated from the ADC map. RESULTS: In all patients, ventricular debris was hyperintense on the DWIs. A periventricular hyperintense signal was present in all cases on FLAIR and T2WI. Ependymal enhancement was detected in eight (89%) of 9 cases. A hydrocephalus was observed in 6 (67%) of 9 cases. The mean ADC value of ventricular debris was 0.735 +/- 0.117 (10(-3) mm2/sec). These ADC values were significantly lower than those for cortical gray matter (1.052 +/- 0.149 (10(-3) mm2/sec)). CONCLUSION: Ventricular debris was most conspicuous finding of ventriculitis on DWI. Areas of intraventricular hyperintensity on DWI corresponded to the decreased ADC values.
Cerebral Ventricles
;
Diagnosis*
;
Diffusion Magnetic Resonance Imaging
;
Diffusion*
;
Encephalitis
;
Humans
;
Hydrocephalus
;
Retrospective Studies
4.Endovascular Treatment for Spontaneous Vertebral Arteriovenous Fistula in Neurofibromatosis Type 1: A Case Report.
Yon Kwon IHN ; Won Sang JUNG ; Bum Soo KIM
Neurointervention 2010;5(2):110-114
We report the case of a 42- year-old woman with spontaneous, right vertebral arteriovenous fistula associated with neurofibromatosis type 1. The patient presented with neck pain, retroauricular bruit, quadriparesis, and cervical spinal cord compression caused by an enlarged epidural vein. Endovascular treatment using coils and a balloon resulted in successful occlusion of the fistula. At six months post-embolization, the patient had improved significantly and was ambulant with support.
Arteriovenous Fistula
;
Female
;
Fistula
;
Humans
;
Neck Pain
;
Neurofibromatoses
;
Neurofibromatosis 1
;
Quadriplegia
;
Spinal Cord Compression
;
Veins
5.Acute Marchiafava-Bignami Disease: Diffusion-Weighted MRI in Cortical and Callosal Involvement.
Yon Kwon IHN ; Seong Su HWANG ; Young Ha PARK
Yonsei Medical Journal 2007;48(2):321-324
Marchiafava-Bignami disease (MBD) is a fatal disorder characterized by demyelination of the corpus callosum. MRI, suggestive of corpus callosum demyelination with associated white matter involvement in both cerebral hemispheres, indicates a diagnosis of MBD. In this case, MR diffusion-weighted findings taken at an acute stage of MBD revealed lesions not only in the corpus callosum but also in the cerebral cortex. Lower apparent diffusion coefficient values of the corpus callosum and cortical lesions were associated with poor clinical outcome.
Middle Aged
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Male
;
Humans
;
Demyelinating Diseases/*pathology
;
Corpus Callosum/*pathology
;
Brain/*pathology
;
Alcoholism/complications
6.The Usefulness of Diffusion Weighted Imaging in the Differential Diagnosis of Various Intracranial Cystic Lesions.
Yon Kwon IHN ; Jeong Su JUN ; Seong Su HWANG ; Jun Hyun BAIK ; Young Ha PARK
Journal of the Korean Radiological Society 2004;50(6):415-421
PURPOSE: The purpose of this study was to evaluate the usefulness of diffusion-weighted imaging (DWI) for the differential diagnosis of various intracranial cystic lesions. MATERIALS AND METHODS: This study included 19 patients (13 males, 6 females) with a mean age of 42.5 years. The final histopathological diagnoses for 14 patients were pyogenic brain abscess (n=3), glioblastoma (n=3), ependymoma (n=1), anaplastic astrocytoma (n=1), pilocytic astrocytoma (n=1), hemangioblastoma (n=2), arachnoid cyst (n=1), epidermoid (n=1) and schwannoma (n=1). The other cases of metastasis (n=4) and arachnoid cyst (n=2) were diagnosed on the basis of clinical, laboratory and imaging data. DWI imaging studies were performed with a 1.5 T MR system. A single shot spin echo EPI pulse sequence was applied. B values were set at 0 and 1000 sec/mm2. The apparent diffusion coefficient (ADC) were calculated from the ADC map of 10 different cystic brain lesions. Conventional MR imaging included T2WI, T1WI, FLAIR and contrast enhanced T1WI. We analyzed the location, nature, signal intensity on DWI, and the enhancement pattern of the lesions. RESULTS: All of the 3 cases of brain abscess, 1 of 4 cases of metastasis and 1 case of epidermoid showed hyperintensity on DWI. The mean ADC value of brain abscess (2 cases) was less than 1.15 (0.13x10-3 mm2/s). The mean ADC values of the other cystic lesions (8 cases) were variable, ranging from 2.840.66 to 3.100.16 (10-3 mm2/sec). CONCLUSION: DWI and ADC values were useful in the differential diagnosis of various intracranial cystic lesions, but some metastatic tumors may mimic a brain abscess on DWI. Therefore, a clinical correlation is mandatory.
Arachnoid
;
Astrocytoma
;
Brain
;
Brain Abscess
;
Diagnosis
;
Diagnosis, Differential*
;
Diffusion*
;
Ependymoma
;
Glioblastoma
;
Hemangioblastoma
;
Humans
;
Magnetic Resonance Imaging
;
Male
;
Neoplasm Metastasis
;
Neurilemmoma
7.Diffuse Hepatic Hemangiomatosis without Extrahepatic Involvement in an Adult Patient.
Eun Hui KIM ; Soo Youn PARK ; Yon Kwon IHN ; Seong Su HWANG
Korean Journal of Radiology 2008;9(6):559-562
We report an extremely rare case of a diffuse hepatic hemangiomatosis without extrahepatic involvement in an adult. The imaging findings of this tumor were similar to those of a hepatic hemangioma and included contrast enhancement with a centripetal filling pattern of the entire hepatic tumor on the delayed phase of a dynamic CT and inhomogeneous diffuse uptake of the entire tumor on blood-pool images obtained five hours later on a 99mTc-labeled red blood cell scan. Despite its rarity, diffuse hepatic hemangiomatosis can be suggested in adult patients with diffusely involved hepatic tumors showing the radiological findings of a hepatic hemangioma.
Adult
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Female
;
Gated Blood-Pool Imaging
;
Hemangioma/*diagnosis/pathology/ultrasonography
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Humans
;
Liver Neoplasms/*diagnosis/pathology/ultrasonography
;
Tomography, X-Ray Computed
8.Natural Evolution of Grafted Anterior Cruciate Ligament of the Knee: Prospective Follow-up MR Studies.
Dong Won PARK ; Jae Hyun CHO ; Yon Kwon IHN ; Yong Woon SHIM ; Jin Seok SUH ; Byung Heum MIN ; Jung Ho SUH
Journal of the Korean Radiological Society 1998;38(1):151-157
PURPOSE: To described the MR findings in the periodic changes of the size and signal intensity ofreconstructed anterior cruciate ligament (ACL) of the knee and the efficacy of oblique axial imaging in patientswho underwent arthroscopic ACL reconstruction using autogenous patellar tendon. MATERIALS AND METHODS: Twenty-onepatients who had undergone ACL reconstruction were evaluated by follow-up MRI at postoperative 1 week, 1, 2, 3 and6 months, and 1 year, Conventional Fast-Spin-Echo (FSE) sagittal and coronal images and oblique axial images(proton density and T2-WI; VEMP TR/TE, 2000/20/70) were obtained perpendicular to the ligament, and using an ROIcurve in the intra-articular area, periodic changes in the cross-sectional area were evaluated by proton densityimaging and signal intensity by T2WI imaging. Cross-sectional morphology was categorized as either smooth, andround or notch-shaped and periodic changes in configuration were observed. In three cases, we evaluated the retearof reconstructed ACL by comparing the oblique axizl image obtained by conventional sagittal and coronal imaging. RESULTS: The cross-sectional area and signal intensity of grafted ACL increased significantly (p<0.05) after 3months and at 1 year, respectively. Cross-sectional morphology was smooth and round in 86% of cases, and notchedin 14%, and during follow-up MR studies, no periodic changes were seen. Notch-shaped ACL and decreased perigraftsignal intensity, as seen on sagittal images, could lead to a misdiagnosis of partial tear ; on oblique axialimages, ACL and perigraft signal intensity were found to be normal. CONCLUSION: During the natural evolution ofgrafted ACL, cross-sectional area and signal intensity increased significantly after 3 months and at 1 year,respectively ; on follow-up MR studies, cross-sectional morphology did not change, however. Oblique axial imagingprovides important information for evaluating whether the reconstructed ACL is torn or not.
Anterior Cruciate Ligament*
;
Cross-Sectional Studies
;
Diagnostic Errors
;
Follow-Up Studies*
;
Knee*
;
Ligaments
;
Magnetic Resonance Imaging
;
Patellar Ligament
;
Prospective Studies*
;
Protons
;
Transplants*
9.Dural Arteriovenous Fistula Involving an Isolated Sinus Treated Using Transarterial Onyx Embolization.
Yon Kwon IHN ; Myeong Jin KIM ; Yong Sam SHIN ; Bum Soo KIM
Journal of Korean Neurosurgical Society 2012;52(5):480-483
The authors present a case of isolated dural arteriovenous fistula (DAVF) in the transverse sinus, which developed six years after microvascular decompression caused by hemifacial spasm via suboccipital craniectomy. The lesion was successfully treated by transarterial embolization using Onyx. We reviewed the related radiologic and therapeutic features of DAVF involving an isolated sinus and described the feasibility of the use of Onyx.
Central Nervous System Vascular Malformations
;
Hemifacial Spasm
;
Microvascular Decompression Surgery
10.Measurement of Fractional Anisotropy in Normal Cerebral White Matter and Brain Tumors with Diffusion Tensor Imaging.
Seung Koo LEE ; Dong Ik KIM ; Si Yeon KIM ; Yon Kwon IHN ; Sang Heum KIM
Journal of the Korean Radiological Society 2002;47(2):147-153
PURPOSE: The purpose of this study was to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of normal adult brain tissue and tumors, and to compare the differences. MATERIALS AND METHODS: Eight normal adults and ten patients in whom intracranial tumors had been diagnosed were included. Imaging was performed using a 1.5 T MR unit and a single-shot spin-echo EPI pulse sequence (TR/TE=4024/94 msec, 128 acquisition/256 reconstruction, 23 cm FOV, 5 mm thickness, 2 mm interslice gap, 4 NSA), six different direction gradients (x, y, z, xy, yz, xz), and 2 b-values (0, 1000). Isotropic ADC (D) was obtained from seven images per slice, and fractional anisotropy (FA) was calculated from the isotropic ADC and eigenvalues of three directions. A region of interest was drawn at frontal gray and white matter, periventricular white matter, the corpus callosum, internal capsule, caudate nucleus and center of the tumor mass, and for each region, fractional anisotropy readings were obtained. RESULTS: In normal adults, the findings were as follows: frontal gray matter: D=0.81+/-0.06, FA=0.32+/-0.03; frontal white matter: D=0.79+/-0.04, FA=0.56+/-0.09, periventricular white matter: D=0.77+/-0.02, FA=0.51 +/-0.04; corpus callosum: D=0.79+/-0.07, FA=0.82+/-0.07; internal capsule: D=0.73+/-0.04, FA=0.77+/-0.05; caudate nucleus: D=0.76+/-0.05, FA=0.35+/-0.05. High anisotropy was demonstrated in white matter, especially in the corpus callosum and internal capsule, and the degree of anisotropy was similar in gray and deep gray matter. For most brain tumors, isotropic ADC was similar to that of white matter, but fractional anisotropy was lower. A low-grade astrocytoma showed higher isotropic ADC and lower fractional anisotropy than normal white matter, and at the center of a meningioma, fractional anisotropy was high. CONCLUSION: For the classification of brain tumors and determination of the extent of disease, comparison between the apparent diffusion coefficient and fractional anisotropy is useful.
Adult
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Anisotropy*
;
Astrocytoma
;
Brain Neoplasms*
;
Brain*
;
Caudate Nucleus
;
Classification
;
Corpus Callosum
;
Diffusion Tensor Imaging*
;
Diffusion*
;
Humans
;
Internal Capsule
;
Meningioma
;
Reading