• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.901-904
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• 2007

Purpose : Reversible posterior leukoencephalopathy syndrome is a complex disorder with characteristic clinical and radiologic findings that mainly involve the white/gray matter of the parieto-occipital lobes. The purpose of this study was to determine its clinical and radiological characteristics. Methods : A total of 15 pateints were involved in the study. Their medical records and radiological features of brain MRI were retrospectively reviewed and analyzed. Results : Fifteen pateints were involved. (9 males and 5 females). The patients' ages ranged from 2-20 years (mean age : 10 years). The brain MRI revealed fairly symmetric areas of increased T2 signal involving both white and gray matter of parieto-occipital regions. The condition seemed to be associated with cyclosporin A and steroid therapy or a variety of other conditions in which blood pressure rises acutely. Conclusion : Reversible posterior leukoencephalopathy syndrome is a complicated neurological condition, but a better understanding of this complex syndrome may obviate unnecessary investigations and lead to prompt and appropriate management of the associated problems.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.101-107
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• 2000

Objectives : The evaluation of peripheral nerve injuries has traditionally relied on a clinical history, physical examination, and electrodiagnostic studies. The purpose of the present study was to examine serial magnetic resonance image(MRI) changes following acute muscle denervation under experimental conditions and to identify potential advantages and disadvantages of this use of MRI. Methods : An experimental transection of right sciatic nerve on Spargue-Dawley rats was performed. MRI was performed with T1-weighted spin-echo and STIR sequences. The imaging findings were compared with EMG in order to determine its sensitivity relative to this standard procedure. A simultaneous histopathological study provided information about the morphological basis of the imaging findings. Signal intensities were expressed as a ratio of abnormal to normal. Results : The signal intensity ratio of muscles with the STIR sequence was increased significantly at 2 weeks after sciatic nerve transection(p<0.05), although definite signal change was seen as early as 4 days postdenervation in one. EMG revealed significant denervation potential from 3 days after nerve transection. Diffuse cell atrophy was revealed hostologically at 2 weeks after transection, which was at the same time of significant signal change in MRI. Conclusion : MRI signal changes in denervated muscles secondary to nerve injury correlate with the degree of muscle atrophy on histologic examination. In addition to EMG, MRI can document the course of muscle atrophy and mesenchymal abnormalities in denervation. These results indicate that MRI can play a complementary role in the evaluation of patients with denervation.

• Investigative Magnetic Resonance Imaging
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• v.24 no.3
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• pp.123-131
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• 2020

Purpose: Joint label fusion (JLF) is a popular multi-atlas-based segmentation algorithm, which compensates for dependent errors that may exist between atlases. However, in order to get good segmentation results, it is very important to set the several free parameters of the algorithm to optimal values. In this study, we first investigate the feasibility of a JLF algorithm for prostate segmentation in MR images, and then suggest the optimal set of parameters for the automatic prostate segmentation by validating the results of each parameter combination. Materials and Methods: We acquired T2-weighted prostate MR images from 20 normal heathy volunteers and did a series of cross validations for every set of parameters of JLF. In each case, the atlases were rigidly registered for the target image. Then, we calculated their voting weights for label fusion from each combination of JLF's parameters (r_pxy, r_pz, r_sxy, r_sz, β). We evaluated the segmentation performances by five validation metrics of the Prostate MR Image Segmentation challenge. Results: As the number of voxels participating in the voting weight calculation and the number of referenced atlases is increased, the overall segmentation performance is gradually improved. The JLF algorithm showed the best results for dice similarity coefficient, 0.8495 ± 0.0392; relative volume difference, 15.2353 ± 17.2350; absolute relative volume difference, 18.8710 ± 13.1546; 95% Hausdorff distance, 7.2366 ± 1.8502; and average boundary distance, 2.2107 ± 0.4972; in parameters of r_pxy = 10, r_pz = 1, r_sxy = 3, r_sz = 1, and β = 3. Conclusion: The evaluated results showed the feasibility of the JLF algorithm for automatic segmentation of prostate MRI. This empirical analysis of segmentation results by label fusion allows for the appropriate setting of parameters.

• The Korean Journal of Cytopathology
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• v.15 no.1
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• pp.52-55
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• 2004

Secretory meningioma is a distinct subtype of meningioma. We describe the cytologic features of a secretory meningioma on squash preparations, in comparision with other cytologic mimickers. A 54-year-old woman presented with hearing loss, vertigo, tinnitus, and headache for seven years. A brain MRI study revealed a 4.5cm sized mass in the cerebellopontine angle, which showed homogenous signal intensity in T2-weighted image. The intraoperative squash smear showed some well-defined, thin rimmed intracytoplasmic inclusions, containing a finely granular eosinophilic core among less cohesive meningiomatous cells. Histologic sections revealed a meningothelial meningioma with scattered inclusions, with periodic acid-Schiff, carcinoembryonic antigen, and cytokeratin positivity. Identification of characteristic intracytoplasmic inclusions is helpful for diagnosing secretory meningiomas. On squash preparations, differential diagnoses included tumors with inclusions or cytoplasmic vacuolizations, such as metastatic mammary infiltrating ductal carcinoma, gastric adenocarcinoma, hepatocellular carcinoma, and clear cell ependymoma, oligodendroglioma, hemangioblastoma, chordoma, and other variants of meningiomas (clear cell, xanthomatous, microcytic, and chordoid variants). In addition, the possibilities of glioma with eosinophilic granular body, and metastatic tumors from mammary infiltrating ductal carcinoma, gastric adenocarcinoma, and hepatocellular carcinoma in meningioma should be considered.

• Clinical and Experimental Pediatrics
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• v.57 no.12
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• pp.542-545
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• 2014

Bickerstaff's brainstem encephalitis is characterized by ophthalmoplegia, ataxia, and disturbance of consciousness. It is similar to Miller Fisher syndrome, a variant of Guillain-Barre syndrome, in that they share features such as ophthalmoplegia and ataxia. The difference is that patients with Bickerstaff's brainstem encephalitis have impaired consciousness, whereas patients with Miller Fisher syndrome have alert consciousness and areflexia. Here, we report the case of a 3-year-old child who was diagnosed with Bickerstaff's brainstem encephalitis presenting typical clinical features and interesting radiological findings. The patient showed ophthalmoplegia, ataxia, and subsequent stuporous mentality. Brain magnetic resonance imaging revealed high signal intensity in the pons and cerebellum around the 4th ventricle on a T2-weighted image. He was successfully treated with intravenous immunoglobulin. Differentiation of Bickerstaff's brainstem encephalitis and Miller Fisher syndrome is often difficult because they possess many overlapping features. Brain magnetic resonance imaging may be helpful in diagnosing Bickerstaff's brainstem encephalitis, especially when lesions are definitely found.

• Journal of the Korean Arthroscopy Society
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• v.12 no.1
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• pp.63-65
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• 2008

We treated a 37-year-old male with traumatic hematoma in the suprapatellar bursa that had developed in the form of persistent swelling on suprapatellar area of left knee after blunt trauma. Though there were no obvious abnormal findings on plain roentgenographs, an isolated suprapatellar cystic lesion with fluid-fluid level on T2-weighted sagittal image of MRI was noted. We found the suprapatellar plica with complete septum and no synovitis in the knee joint proper by arthroscopy. We incised the plica and found leakage of blood-stained fluid from the suprapatellar bursa. There were no findings of pigmented villonodular synovitis or other tumorous lesions. At 6 months after surgery, the patient felt symptom-free and there was no recurrence.

• Annals of Clinical Neurophysiology
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• v.4 no.1
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• pp.56-59
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• 2002

A 28-year-old man presented with headache, fever, and myalgia. Subsequently, rapidly progressive quadriplegia with areflexia developed. CSF examination revealed moderate pleocytosis and protein elevation. MRI of brain and spinal cord showed hyperintense lesions on T2-weighted image at midbrain and ventral horns along the whole spinal cord. Serial serologic examinations of CSF for Epstein-Barr virus and cytomegalovirus were negative. Culture and neutralization tests of stool and CSF for enterovirus were negative. Although the etiologic pathogen was not identified, we diagnosed him as poliomyelitis-like syndrome by clinical features and findings of MRI.

• Imaging Science in Dentistry
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• v.36 no.3
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• pp.163-168
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• 2006

A 60-year-old female, who complained of delayed healing and swelling after extraction of left lower second molar during chemotherapy, visited our department. She had a history of a resection surgery of breast cancer and postoperative radiotherapy. The conventional radiographs showed diffuse permeative bone destruction in posterior mandibular body, which gave the first radiologic impression of osteonecrosis associated with radiotherapy or chemotherapy. And bone metastasis from the breast cancer was also considered in the differential diagnosis. On the enhanced computed tomography (ECT) the posterior mandibular body was occupied by a large expansile lesion showing central low attenuation with peripheral rim enhancement. Magnetic resonance images revealed that the low attenuated area on ECT did not show as high signal intensity as water on T2 weighted image and indicated solid component of a tumor. The final diagnosis was central squamous cell carcinoma. We present the diagnostic imaging features of the patient with special emphasis on the differential diagnosis.

• Journal of Korean Neurosurgical Society
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• v.30 no.7
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• pp.947-950
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• 2001

Cavernous angiomas are being increasingly well recognized throughout the central nervous system due to the widespread use of magnetic resonance imaging(MRI). However, these malformations are uncommon in the spinal column and rarely occur in the spinal cord. Here, we report a case of a cervical cord intramedullary cavernous angioma in a 49-year-old man. The patient had complained of left upper extremity paresthesia and weakness in the left hand for 5 days prior to admission. A neurological examination showed a left C-6 dermatome paresthesia and a weakness in the left hand grasping power. A MRI demonstrated a mixed signal intensity core at the C-5 level and a surrounding edema on the T-2 weighted image. Conservatively, a laminectomy was performed and slightly hard and well demarcated intramedullary mass was removed. A histological examination confirmed the diagnosis of a cavernous angioma.

• Journal of Korean Neurosurgical Society
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• v.52 no.5
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• pp.491-494
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• 2012

We report a rare complication of iatrogenic spinal intradural following minimally invasive extradural endoscopic procedues in the lumbo-sacral spines. To our knowledge, intradural cyst following epiduroscopy has not been reported in the literature. A 65-year-old woman with back pain related with previous lumbar disc surgery underwent endoscopic epidural neuroplasty and nerve block, but her back pain much aggravated after this procedure. Postoperative magnetic resonance imaging revealed a large intradural cyst from S1-2 to L2-3 displacing the nerve roots anteriorly. On T1 and T2-weighted image, the signal within the cyst had the same intensity as cerebrospinal fluid. The patient underwent partial laminectomy of L5 and intradural exploration, and fenestration of the cystic wall was accomplished. During operation, the communication between the cyst and subarachnoid space was not identified, and the content of the cyst was the same as that of cerebrospinal fluid. Postoperatively, the pain attenuated immediately. Incidental durotomy which occurred during advancing the endoscope through epidural space may be the cause of formation of the intradural cyst. Intrdural cyst should be considered, if a patient complains of new symptoms such as aggravation of back pain after epiduroscopy. Surgical treatment, simple fenestration of the cyst may lead to improved outcome. All the procedures using epiduroscopy should be performed with caution.