PURPOSE: To investigate the spontaneous cerebral microbleeding occurring at gradient-echo MRI, and its relationship with associated stroke lesions and risk factors. MATERIALS AND METHODS: Between September 2001 and December, 2002, 32 patients (21 men and 11 women; mean age 63 years) in whom cerebral microbleeding occurred at gradient-echo MRI were retrospectively investigated. Using a 1.5 T MR imager, spin-echo T1-weighted, fast spin-echo T2-weighted, diffusion-weighted, and gradient-echo images were obtained. The number and location of microbleeds seen on gradient echo images, patient data, and associated stroke lesions such as intracerebral hemorrhage and lacunar and territorial infarction were assessed. RESULTS: Among the 32 patients, 563 microbleeds and between 1 and 66 (mean, 17.6) were noted at gradientecho imaging. Microbleeding occurred in the cortical/subcortical area (n=216), the basal ganglia (n=173), thalamus (n=92), cerebellum (n=41), brainstem (n=36) and corpus callosum (n=1), and in 20 patients was bilateral. Patients had a history of hypertension (n=26), hypertriglycemia (n=12), heart disease (n=4), and diabetes mellitus (n=3). Stroke lesions were seen in 27 patients, intracerebral hemorrhage in ten, lacunar infarction in 24, and territorial infarction in four. CONCLUSION: The incidence and number of microbleeds was greater in older patients and in those with hypertension, hypertriglycemia, and stroke lesions such as intracerebral hemorrhage or lacunar infarction. The detection of microbleeding at gradient-echo imaging is helpful, since it predicts the possibility of cerebral hemorrhage in these patients.
Basal Ganglia ; Brain Stem ; Cerebellum ; Cerebral Hemorrhage ; Corpus Callosum ; Diabetes Mellitus ; Female ; Heart Diseases ; Humans ; Hypertension ; Incidence ; Infarction ; Magnetic Resonance Imaging* ; Male ; Retrospective Studies ; Risk Factors ; Stroke* ; Stroke, Lacunar ; Thalamus

In a jaundiced patient, it is important to ascertain as early as possible whether the bile duct is dilated. Ultrasonography, computed tomography & conventional cholangiography are widely accepted methods of determining the size of the extrahepatic bile ducts. But there is a considerable discrepancy among the size of the bile duct as measured from them. So the author analyzed and compared the respective diameters of the bile ducts in Korean normal adults as measured from cadaver, IV cholangiography, ultrasoud and computed tomography. The materials were 45 cases of cadaver, 38 cases of IV cholangiography, 100 cases of ultrasonography & 55 cases of computed tomography. The results were as follows ; 1. The diameters of the bile ducts were 7.58±2.26mm at CHD & 8.04±2.42mm at CBD from cadaver ; 5.38±1.90mm at CHD & 6.58±2.37mm at CBD from IV cholanglography ; 3.24±1.13mm at CHD & 4.71±1.48mm at CBD from ultrasonography ; and 4.56±1.51mm at CHD & 5.87±1.68mm at CBD from computed tomography. 2. The diameter of the bile duct was greatest in cadaver, and then reduced in IV cholangiography, computed tomography and ultrasonography in this orde.r 3. There were no size discrepancy between the diameter of the common hepatic duct and that of the common bile duct. 4. There were no discrepanry of the diameter of the bile duct by sex.
Adult* ; Bile Ducts* ; Bile Ducts, Extrahepatic ; Bile* ; Cadaver ; Cholangiography ; Common Bile Duct ; Hepatic Duct, Common ; Humans ; Ultrasonography

The mainly used polymeric material for the denture is PMMA because of its cost and easiness to handle. So it was widely used material among dentists for past decades. But the acrylic-based denture materials have several common weak points such as shrinkage after curing and lack of strength. In order to solve these problems, we adapted one of hybrid system using acrylic polymer and vinyloligosilsesquioxane(POSS). POSS, which is a well known expandable monomer during polymerization process, may eventually suppress volumetric shrinkage. And the hybrid system makes it possible for the polymer to be stable in various severe conditions. Eight different kinds of samples were designed and synthesized. Each samples were characterized with dynamic mechanical analyser(DMA) to confirm their thermodynamic properties, fractured to analyze the cross-sectional morphology of the samples. And elongation, flexural and impact tests were also executed to evaluate the mechanical properties of the samples. From the results, hybrid composites had well defined crosslinked network structure compared to the widely used denture materials, and the mechanical strength improved without changing any surface condition as increment with POSS ratio in hybrid system. Fractured morphology showed homogeneous surfaces in spite of mutli component system, therefore we can conclude that the adoption of the POSS brought the reinforcement of the denture resin.
Dentists ; Dentures* ; Humans ; Polymerization ; Polymers ; Polymethyl Methacrylate ; Thermodynamics

No abstract available.
Child* ; Humans ; Radioisotope Renography*

No abstract available.
Humans ; Sarcoma, Kaposi*

PURPOSE: This study aimed to evaluate the preliminary treatment results of fractionated stereotactic radiotherapy (FSRT) for metastatic brain tumors. MATERIALS AND METHODS: Between August 1997 and December 1998, frameless FSRT was performed in 11 patients with metastatic brain tumor (1S lesions). Primary sites were lung in 7 patients, breast in 2, stomach in 1, and malignant melanoma in 1, All patients received 30-36 Gy/10-20 fx external beam irradiation to whole brain. Eight patients received FSRT for 1 lesion, one for 2 lesions, and two for 4 lesions. Fractionation schedule was 25 Gy/5 fx in 11 lesions, 18 Gy(1 fx in 3, 30 Gy/5 fx in 2, 15 Gy/5 fx in 1. Mean tumor volume was 7.0 cc (0.39~55.23 cc). Multiple-arc FSRT was delivered to 16 lesions and conformal FSRT through irregular ports shaped to tumor profile to 2 lesions. RESULTS: No patient experienced any acute side reaction from FSRT. Follow-up radiologic evaluation was available in 9 patients. Six of nine patients achieved the complete response, but two showed the partial response and one showed no response on follow-up radiologic studies. Among six patients with complete response, 5 patients survived from 5 to 15 months and showed no evidence of metastatic brain d#isease clinically and/or radiologically at last follow-up. Among two patients who did not have radiologic evaluation, one showed clinically complete response until death and the other died just after FSRT caused by intercurrent disease. One patient with no response radiologically survived 7 months and showed nearly complete disappearance of clinical symptom with stable status radiologically, CONCLUSION: Initial experience in this study suggests that the external beam irradiation to whole brain with 30 Gy/10 fx followed by FSRT with 20~30 Gy/5~6 fx could be the good treatment option to the patients with metastatic brain tumor. This study suggests that the fractionation schedule for FSRT should be determined in consideration of performance status, number of metastasis, tumor volume, location, presence of extracranial disease, and age.
Appointments and Schedules ; Brain Neoplasms* ; Brain* ; Breast ; Follow-Up Studies ; Humans ; Lung ; Melanoma ; Neoplasm Metastasis ; Radiotherapy* ; Stomach ; Tumor Burden

OBJECTIVE: The authors evaluate the predictability of single voxel proton magnetic resonance spectroscopy(MRS) for hippocampal abnormalities in medial temporal lobe epilepsy(MTLE), lateral temporal lobe epilepsy(latTLE) and extratemporal lobe epilepsy(extraTLE). METHODS: Twenty healthy volunteers and 42 patients with MTLE, 17 with latTLE and 23 with extraTLE, were examined preoperatively with MRS. The NAA/(Cho+Cr) ratios were calculated from the MRS peaks obtained bilaterally from both hippocampi. RESULTS: The mean NAA/(Cr+Cho) ratios showed a stepwise increase from the ipsilateral hippocampus in the MTLE group to the normal control group. In the 42 MTLE patients, the mean NAA/(Cho+Cr) ratio value for the ipsilateral hippocampus was 0.39. This was 17.3% lower than the 0.489 measured for the contralateral hippocampus (p=0.005). This was also significantly lower when compared with the hippocampi of latTLE and extraTLE patients ipsilateral to the epileptogenic zone and also with the normal control group (p< 0.05). The mean ratio value of the contralateral hippocampi was also significantly lower when compared with the normal control group (p=0.000). The mean ratio value measured on postoperative MRS showed little metabolic recovery in the MTLE (from 0.455 to 0.481, p=0.48) compared to the latTLE (from 0.438 to 0.52, p=0.09). CONCLUSION: The MRS might be inconclusive in determining whether the non-epileptogenic hippocampus is affected by epileptiform discharge propagation from the epileptogenic hippocampus or from the remote epileptogenic zone other than the hippocampus. Therefore, physicians should be cautious when determining whether the contralateral hippocampus in MTLE or both hippocampi in neocortical epilepsy is abnormal and whether they should be resected together with the epileptogenic zone.
Epilepsy* ; Healthy Volunteers ; Hippocampus ; Humans ; Magnetic Resonance Spectroscopy* ; Protons ; Temporal Lobe

A 57-year-old woman experienced bilateral acute ischemic optic neuropathy after spine surgery. Routine MR imaging sequence, T2-weighted image, showed subtle high signal intensity on bilateral optic nerves. A contrast-enhanced T1 weighted image showed enhancement along the bilateral optic nerve sheath. Moreover, diffusion-weighted image (DWI) and an apparent diffusion coefficient map showed markedly restricted diffusion on bilateral optic nerves. Although MR findings of T2-weighted and contrast enhanced T1-weighted images may be nonspecific, the DWI finding of cytotoxic edema of bilateral optic nerves will be helpful for the diagnosis of acute ischemic optic neuropathy after spine surgery.
Contrast Media/diagnostic use ; Diffusion Magnetic Resonance Imaging/*methods ; Female ; Humans ; Intervertebral Disc Displacement/surgery ; Middle Aged ; Optic Neuropathy, Ischemic/*diagnosis ; Postoperative Complications/*diagnosis ; Spinal Stenosis/surgery

No abstract available.
Myocardial Infarction*

During the period from November 1982 to April 1986, a radioisotope cisternography was conducted on 29 patients with hydrocephalus at Seoul National University Hospital, and a ventriculoperitoneal shunting was performed on 15 patients. To correlate the preoperative radioisotope cisternography patterns with the results of ventriculoperitoneal shunting, we classified the radioisotope cisternography findings into five patterns and compared them with the surgical results. The cisternographic patterns are as follows: Type I: No ventricular activity, normal migration, Type II: No ventricular activity, delayed migration, Type III-A: Transient ventricular activity, clearance by usual migration, Type III-B: Transient ventricular activity, clearance without usual migration, Type IV: Persistent ventricular activity, inadequate clerance. All patients operated on were Type III(seven patients) or Type IV(eight patients). Of the eight Type IV patients, seven (88%) showed clinical improvements within two weeks after the shunting, while an improvement occurred in only one (14%) of seven Type III patients. We have concluded that when there is a prolonged ventricular retention of the isotope, the surgical shunting is successful suggesting that the radioisotope cisternography has a significant preoperative prognostic value.
Humans ; Hydrocephalus ; Seoul ; Ventriculoperitoneal Shunt