Biomedical subjects

In-Young Kim

Publications and source records attributed to In-Young Kim.

12 recordsLinked to original sources

PubMed2005

Interindividual reproducibility of glutamate quantification using 1.5-T proton magnetic resonance spectroscopy.

The goal of this study was to measure the interindividual reproducibility of glutamate quantification in 1.5-T (1)H MRS of human brains. To determine the effective echo time (TE) for glutamate quantification, spectra from a phantom and 12 participants were obtained with TE = 30, 35, 40, and 144 ms (repetition time (TR) = 2000 ms and volume of interest = 4 cm(3)). The average Cramer-Rao lower bounds for glutamate quantification using LCModel was lowest in two experiments when TE = 40 ms.Twenty-one subjects participated in experiments that measured interindividual reproducibility of glutamate quantification. Spectra were acquired with TR = 6000 ms and TE = 40 ms. Results showed that the coefficients of variance were 11.0 and 13.1% in the anterior cingulate cortex and insula, respectively. This suggests that glutamate can be reproducibly measured from 1.5-T (1)H MRS with long TR, effective TE, and the LCModel.

Adult↗

PubMed2005

Two cases of pineal germinoma with granulomatous inflammation.

We report two cases of pineal germinoma with remarkable chronic granulomatous inflammation. In the first case, the pineal mass was totally removed via an occipital transtentorial approach as symptoms were due to direct mass effect. In the second case, endoscopic third ventriculostomy and tissue biopsy was performed to alleviate worsening hydrocephalus. Pathological examination of specimens of both cases showed chronic granulomatous inflammation associated with a few germ cell tumor nests, which demonstrated positive staining for placental alkaline phosphatase. Both patients received post-operative craniospinal irradiation with no subsequent neurological deficits. Follow-up magnetic resonance imaging (MRI) of the second case showed an asymptomatic, shrunken residual tumor mass. MRI of the first case showed no residual or recurrent disease. Thus, a pineal mass with unusual features on MRI and chronic granulomatous inflammation on histopathology, should raise the suspicion of germinoma. In cases with symptomatic mass effect, open resection can be considered. In cases with lesser mass effect, conventional therapeutic modalities without resection can achieve a good outcome, as for other germinomas.

Adult↗

PubMed2005

Inflammatory aneurysm due to neurocysticercosis.

A 69-year old man presented with a subarachnoid hemorrhage associated with a large intracerebral hematoma in the right temporal lobe. The oblique views of cranio-orbital computerized tomographic angiography (CTA) were suspicious for an aneurysm on a middle cerebral artery branch. At surgery, a cystic mass was found in the Sylvian fissure, associated with an aneurysm on a distal branch of the anterior temporal artery. The aneurysm was not situated at a bifurcation of the artery and was located beneath the cyst. It was secured by trapping. Pathological examination revealed that the cystic lesion was neurocysticercosis and that the aneurysm was inflammatory. We report a ruptured inflammatory aneurysm of a distal branch of the anterior temporal artery associated with neurocysticercosis, and present the histological findings. We believe this is the first report of such an inflammatory aneurysm with histological confirmation.

Aged↗

PubMed2005

Preoperative evaluation of venous systems with 3-dimensional contrast-enhanced magnetic resonance venography in brain tumors: comparison with time-of-flight magnetic resonance venography and digital subtraction angiography.

BACKGROUND: Recent developments in magnetic resonance (MR) technology now enable the use of MR venography, providing 3-dimensional (3D) images of intracranial venous structures. The purpose of this study was to assess the usefulness of 3D contrast-enhanced MR venography (CE MRV) in the evaluation of intracranial venous system for surgical planning of brain tumors. METHODS: Forty patients underwent 3D CE MRV, as well as 25 patients, 2-dimensional (2D) time-of-flight (TOF) MR venography in axial and sagittal planes; and 10 patients, digital subtraction angiography. We determined the number of visualized sinuses and cortical veins. Degree of visualization of the intracranial venous system on 3D CE MRV was compared with that of 2D TOF MR venography and digital subtraction angiography as a standard. We also assessed the value of 3D CE MRV in the investigation of sinus occlusion or localization of cortical draining veins preoperatively. RESULTS: Superficial cortical veins and the dural sinus were better visualized on 3D CE MRV than on 2D TOF MR venography. Both MR venographic techniques visualized superior sagittal sinus, lateral sinus, sigmoid sinus, straight sinus, and internal cerebral vein and provided more detailed information by showing obstructed sinuses in brain tumors. Only 3D CE MRV showed superficial cortical draining veins. However, it was difficult to accurately evaluate the presence of cortical collateral venous drainage. CONCLUSION: Although we do not yet advocate MR venography to replace conventional angiography as the imaging standard for brain tumors, 3D CE MRV can be regarded as a valuable diagnostic method just in evaluating the status of major sinuses and localization of the cortical draining veins.

Adolescent↗

PubMed2004

Moyamoya disease with repeated intracranial haemorrhage in two consecutive pregnancies.

A 26-year-old woman presented with an intraventricular haemorrhage during the 27th week of gestation in July 1996, and recovered without general or neurological complications after external ventricular drainage. The fetus was delivered spontaneously through the vagina at the 30th week of gestation, but eventually died. Cerebral angiography demonstrated typical appearances of moyamoya disease with occlusion of the supraclinoid portion of both internal carotid arteries and presence of abnormal collateral vessels. Five years later the second haemorrhage, an intracerebral haematoma in the right temporoparietooccipital area, occurred during the 28th week of pregnancy. Emergency craniotomy was performed and the intracerebral haematoma was removed totally. It is still unknown whether repeated pregnancy increases the risk of cerebrovascular accident in moyamoya disease. A long-term follow up study of several patients with haemorrhagic moyamoya disease is needed to clarify risk factors for rebleeding.

Adult↗

PubMed2004

Nonlinear-analysis of human sleep EEG using detrended fluctuation analysis.

Quantification of the fractal scaling properties of human sleep EEG dynamics was sought and each normal sleep stage was compared with that of sleep apnea. The fractal scaling exponents that quantify power-law correlations were computed using detrended fluctuation analysis. Six healthy subjects, aged 30-35 years, participated and six recordings of the apnea were acquired from MIT/BIH polysomnography database. The data were 8-h baseline recordings (23:00-07:00 h). The EEG signals from the C4-A1 derivation were acquired with a resolution of 250 Hz. The sleep stages were visually scored for 30 s epochs, according to the criteria of Rechtschaffen and Kales. The mean scaling exponents increased from the awake stage to stages 1, 2 and 3-4, but decreased during rapid eye movement (REM) sleep. The scaling exponents of the apnea were lower than those of the healthy subject for all the stages. The scaling exponents could be attributed to the fractal nature of EEG, which would be more appropriate for describing the complexity of EEG due to its assumption of non-stationarity.

Adult↗

PubMed2004

Metastatic glioblastoma in cervical lymph node after repeated craniotomies: report of a case with diagnosis by fine needle aspiration.

Head and neck metastasis from glioblastoma is rare event usually seen in patients with previous and repeated surgery. We present the case of a 35 yr-old-female suffering from metastatic glioblastoma in cervical lymph node that was diagnosed by fine needle aspiration. During the last 4 yr, she had four separate craniotomies for the recurrent brain tumors. Cytological diagnosis was made by light microscopy with immunostaining with glial fibrillay acid protein. Chemotherapy with vincristine and procarbazine was performed. The cervical masses were decreased in size and some disappeared while the intracranial glioblastoma continued to grow during chemotherapy. We discuss possible explanations for these different courses after chemotherapy in extraneural metastatic glioblastoma and primary intracranial glioblastoma.

Adult↗

PubMed2003

Evaluation of automated and semi-automated skull-stripping algorithms using similarity index and segmentation error.

The skull-stripping in the MR brain image appears to be a key issue in neuroimage analysis. In this paper, we evaluated the accuracy and efficiency of both automated and semi-automated skull-stripping methods. The evaluation was performed on both simulated and real data with the ground truth in skull-stripping. Although automated method showed better efficient results, it should require additional intervention. In contrast to that, semi-automated method showed better accurate results, but it was time consuming and prone to operator bias. Therefore, it might be practical that the semi-automated method was used as the post-processing of the automated one.

Algorithms↗

PubMed2003

A PC-based high-quality and interactive virtual endoscopy navigating system using 3D texture based volume rendering.

As an alternative method to optical endoscopy, visual quality and interactivity are crucial for virtual endoscopy. One solution is to use the 3D texture map based volume rendering method that offers high rendering speed without reducing visual quality. However, it is difficult to apply the method to virtual endoscopy. First, 3D texture mapping requires a high-end graphic workstation. Second, texture memory limits reduce the frame-rate. Third, lack of shading reduces visual quality significantly. As 3D texture mapping has become available on personal computers recently, we developed an interactive navigation system using 3D texture mapping on a personal computer. We divided the volume data into small cubes and tested whether the cubes had meaningful data. Only the cubes that passed the test were loaded into the texture memory and rendered. With the amount of data to be rendered minimized, rendering speed increased remarkably. We also improved visual quality by implementing full Phong shading based on the iso-surface shading method without sacrificing interactivity. With the developed navigation system, 256 x 256 x 256 sized brain MRA data was interactively explored with good image quality.

Anatomy, Cross-Sectional↗

PubMed2002

Metastatic spinal cord compression of testicular yolk sac tumor.

INTRODUCTION: Pediatric testicular tumors are rare. Spinal metastasis of testicular yolk sac tumor (YST) is extremely rare, with only one reported case. CASE REPORT: We report a rare case of metastatic spinal cord compression of testicular YST in a 14-month-old boy who presented with progressive paraparesis and neurological bladder dysfunction. Two months prior to admission, he underwent a left radical orchiectomy for YST of the testis. Magnetic resonance imaging revealed severe spinal cord compression by the ventral epidural mass from T-9 to T-11 and at S-3. Emergency surgical resection was performed for tissue diagnosis and spinal decompression. Histopathological features of the epidural mass indicated metastasis of the testicular YST. CONCLUSION: Although spinal involvement with metastatic YST is rare, it must be considered in children with testicular YST exhibiting evidence of pain or weakness, and surgical decompression followed by adjuvant chemotherapy should not be delayed.

Decompression, Surgical↗

PubMed2002

Intensity based affine registration including feature similarity for spatial normalization.

This paper presents a new spatial normalization with affine transformation. The quantitative comparison of brain architecture across different subjects requires a common coordinate system. For the analysis of a specific brain area, it is required to normalize and compare a region of interest and global brain. Intensity based registration method matches the global brain well. But a region of interest may not be locally normalized compared to feature based method. The method of this paper uses feature similarities of local region as well as intensity similarities. The lateral ventricle and the central gray nuclei of brain including the corpus callosum, which is used for features in Schizophrenia detection, is appropriately normalized. In the results section, our method reduces the difference of feature area such as corpus callosum (7.7%, 2.4%) and lateral ventricle (8.2%, 13.5%) compared with mutual information and Talairach methods.

Algorithms↗

PubMedDate not supplied

Left anterior subregion of orbitofrontal cortex volume reduction and impaired organizational strategies in obsessive-compulsive disorder.

The orbitofrontal cortex (OFC) may be involved in the clinical and cognitive expressions of obsessive-compulsive disorder (OCD) and is a heterogenous region with respect to its cytoarchitecture, function and connectivity. This study was designed to examine the morphological abnormality of the anterior subregion of OFC and its relationship to clinical symptoms and cognitive performance in patients with OCD. We divided the OFC into anterior and posterior subregions using an external landmark and measured the gray matter volumes of each by three-dimensional magnetic resonance imaging in age- and sex-matched groups, which consisted of 34 OCD and 34 normal volunteers. Clinical and cognitive evaluations were completed using Yale-Brown Obsessive Compulsive Scale (YBOCS) and four sets of neuropsychological tests that assessed executive functions and visual memory. Volume reduction of the left anterior OFC was observed in patients with OCD versus normal controls. Also, a significant positive correlation was found between left anterior OFC gray matter volume and the copy score of the Rey-Osterrieth Complex Figure Test in patients with OCD. These results suggest that left anterior subregion volume reduction of the OFC may be related to impaired organizational strategies in patients with OCD.

Adult↗