Diffusion tensor imaging: exploring the motor networks and clinical applications.

With the advances in diffusion magnetic resonance (MR) imaging techniques, diffusion tensor imaging (DTI) has been applied to a number of neurological conditions because DTI can demonstrate microstructures of the brain that are not assessable with conventional MR imaging. Tractography based on DTI offers gross visualization of the white matter fiber architecture in the human brain in vivo. Degradation of restrictive barriers and disruption of the cytoarchitecture result in changes in the diffusion of water molecules in various pathological conditions, and these conditions can also be assessed with DTI.

Expression of excision repair cross-complementation group 1 as predictive marker for nasopharyngeal cancer treated with concurrent chemoradiotherapy.

Purpose: Cisplatin-based concurrent chemoradiotherapy is the standard treatment of nasopharyngeal cancer. The expression of excision repair cross-complementation group 1 (ERCC1) has been reported to be associated with resistance to platinum-based chemotherapy. We evaluated whether ERCC1 expression could predict the treatment response and survival outcome of patients with locally advanced nasopharyngeal cancer who were treated with cisplatin-based concurrent chemoradiotherapy.

Focal time-to-peak changes on perfusion MRI in children with Moyamoya disease: correlation with conventional angiography.

Background: Moyamoya disease is a chronic progressive steno-occlusion of the distal internal carotid arteries with unknown etiology. As the classical presentation of childhood Moyamoya disease is ischemic stroke, cerebral hemodynamic evaluation is important for patient selection for surgery to prevent recurrent ischemic attacks. Perfusion MR imaging has been applied to evaluate cerebral hemodynamics.

Three-dimensional computed tomographic analysis of frontal sinus in Asians.

Although there are many reports on the measurement of the paranasal sinuses, few studies examined the development of frontal sinus with three-dimensional computed tomography (CT), especially in children. In this study, we evaluated the normal development of frontal sinus in Asian children, and we also analyzed the height, length, and width of the frontal sinus in Korean adults with three-dimensional CT imaging. We retrospectively reviewed three-dimensional facial bone CT of a total of 352 patients younger than 23 years.

Volumetric analysis of the substantia innominata in patients with Parkinson's disease according to cognitive status.

The cholinergic system arising from the substantia innominata (SI) of the basal forebrain has an important role in the cognitive functions of Parkinson's disease (PD). We performed magnetic resonance imaging based volumetric analysis to evaluate the SI volume in patients with PD-intact cognition (PD-IC), PD-mild cognitive impairment (PD-MCI), and PD dementia (PDD). The mean normalized SI volume was significantly decreased in patients with PD-IC (1.

Direct deposition of patterned nanocrystalline CVD diamond using an electrostatic self-assembly method with nanodiamond particles.

Micron-sized and precise patterns of nanocrystalline CVD diamond were fabricated successfully on substrates using dispersed nanodiamond particles, charge connection by electrostatic self-assembly, and photolithography processes. Nanodiamond particles which had been dispersed using an attritional milling system were attached electrostatically on substrates as nuclei for diamond growth. In this milling process, poly sodium 4-styrene sulfonate (PSS) was added as an anionic dispersion agent to produce the PSS/nanodiamond conjugates.

Initial experiences with proton MR spectroscopy in treatment monitoring of mitochondrial encephalopathy.

Purpose: Mitochondrial encephalopathy (ME) is a rare disorder of energy metabolism. The disease course can roughly be evaluated by clinical findings. The purpose of this study was to evaluate metabolic spectral changes using proton MR spectroscopy (MRS), and to establish a way to monitor ME by neuroimaging.

Diffusion tensor imaging of heterotopia: changes of fractional anisotropy during radial migration of neurons.

Purpose: Diffusion tensor imaging provides better understanding of pathophysiology of congenital anomalies, involving central nervous system. This study was aimed to specify the pathogenetic mechanism of heterotopia, proved by diffusion tensor imaging, and establish new findings of heterotopia on fractional anisotropy maps.

Materials And Methods: Diffusion-weighted imaging data from 11 patients (M : F = 7 : 4, aged from 1 to 22 years, mean = 12.

Atlas-based analysis of neurodevelopment from infancy to adulthood using diffusion tensor imaging and applications for automated abnormality detection.

Quantification of normal brain maturation is a crucial step in understanding developmental abnormalities in brain anatomy and function. The aim of this study was to develop atlas-based tools for time-dependent quantitative image analysis, and to characterize the anatomical changes that occur from 2years of age to adulthood. We used large deformation diffeomorphic metric mapping to register diffusion tensor images of normal participants into the common coordinates and used a pre-segmented atlas to segment the entire brain into 176 structures.

Blood-brain barrier impairment is functionally correlated with clinical severity in patients of multiple system atrophy.

Multiple system atrophy (MSA) has been regarded as a unique entity within the spectrum of oligodendrogliopathy. However, the pathomechanisms underlying the initial trigger and aggravating factors responsible for disease progression remain unknown. Even though the implication of blood-brain barrier (BBB) dysfunction has not been fully elucidated, this dysfunction may act as a modifier of disease progression in neurodegenerative disease.

Accuracy of 3 T MR angioraphy in vertebral artery stenosis and coincidence with other cerebrovascular stenoses.

Introduction: Ostium of vertebral artery (VA) is a common site of pseudostenosis on contrast-enhanced MR angiography (CE-MRA). The purpose of this study was to determine the diagnostic accuracy of CE-MRA at 3 T in the evaluation of ostial stenosis of VA and to find associated coincidental stenoses using logistic regression analysis.

Methods: One hundred and thirty-five VA ostial regions from 72 patients who received CE-MRA of neck vessels, intracranial time of flight (TOF) MRA, and digital subtraction angiography (DSA) were retrospectively reviewed.

Extranodal nasal-type NK/T-cell lymphoma: computed tomography findings of head and neck involvement.

Background: Extranodal nasal-type natural killer (NK)/T-cell lymphoma (NKTL) is a rare, but distinct clinical entity in Asian populations. However, it is not uncommon for NKTL to be belatedly or postoperatively diagnosed because radiologists are not familiar with its radiological features.

Purpose: To investigate the computed tomography (CT) findings in patients with extranodal nasal-type NKTL involving the head and neck.

Clear cell carcinoma of the pancreas--a case report and review of the literature.

Most of the malignant neoplasms of the pancreas demonstrate features that are consistent with adenocarcinoma. According to the WHO classification, primary clear cell carcinoma of the pancreas is rare and it is classified as a "miscellaneous" carcinoma. In addition, there is not an adequate systematic overview that can demonstrate its true existence as a definable entity.

Pseudoaneurysm of the inferior thyroid artery presenting as a thyroid nodule.

A 63-year-old woman complained of a growing neck mass. Sonography revealed a solid and cystic mass in the right thyroid lobe. Color Doppler study and computed tomography revealed anechoic cystic portions within the thyroid nodule to be a pseudoaneurysm arising from the right inferior thyroid artery.

Treatment of long tubular bone defect of rabbit using autologous cultured osteoblasts mixed with fibrin.

The osteogenic potential of autologous cultured osteoblasts mixed with fibrin when transplanted to bone defects was evaluated. Radial shaft defects over 15 mm were made in 30 New Zealand white rabbits. A total of 15 rabbits in the control group underwent an iliac bone graft and 15 rabbits in the experimental group underwent an autologous cultured osteoblast injection mixed with fibrin.

Molecular biomarkers for advanced renal cell carcinoma: implications for prognosis and therapy.

Objective: The aim of this study was to determine reliable predictive biomarkers for patients with metastatic renal cell carcinomas (RCCs) who had received cytokine therapy.

Methods: Tissue specimens were obtained from 62 patients with metastatic RCCs between 1995 and 2006. Paraffin wax embedded tissues were immunostained for carbonic anhydrase IX (CAIX), cyclooxygenase-2 (COX-2), and vascular endothelial growth factor (VEGF).

Vitamin C inhibits p53-induced replicative senescence through suppression of ROS production and p38 MAPK activity.

We previously reported that tumor cells expressing p53 increase intracellular levels of reactive oxygen species (ROS). In this study, we described an inhibitory effect of vitamin C on replicative senescence. Vitamin C was found to inhibit p53-induced senescence in human bladder cancer EJ cells.

Measuring fractional anisotropy of the corpus callosum using diffusion tensor imaging: mid-sagittal versus axial imaging planes.

Objective: Many diffusion tensor imaging (DTI) studies of the corpus callosum (CC) have been performed with a relatively thick slice thickness in the axial plane, which may result in underestimating the fractional anisotropy (FA) of the CC due to a partial volume effect. We hypothesized that the FA of the CC can be more accurately measured by using mid-sagittal DTI. We compared the FA values of the CC between the axial and mid-sagittal DTI.

Abnormal brain response during the auditory emotional processing in schizophrenic patients with chronic auditory hallucinations.

Objective: Few neuroimaging studies have been conducted regarding clinical associations between auditory hallucinations (AHs) and affective disturbances in patients with schizophrenia. This study aimed to elucidate the neurobiological basis of emotional disturbances in schizophrenic patients with persisting AHs.

Methods: Using functional magnetic resonance imaging (fMRI), the cortical responsiveness during the processing of laughing and crying sounds was measured and compared between 14 hallucinating schizophrenic patients, 14 nonhallucinating schizophrenic patients and 28 normal controls.

ORBIT: a multiresolution framework for deformable registration of brain tumor images.

A deformable registration method is proposed for registering a normal brain atlas with images of brain tumor patients. The registration is facilitated by first simulating the tumor mass effect in the normal atlas in order to create an atlas image that is as similar as possible to the patient's image. An optimization framework is used to optimize the location of tumor seed as well as other parameters of the tumor growth model, based on the pattern of deformation around the tumor region.

ERCC1 expression as a prognostic marker in N2(+) nonsmall-cell lung cancer patients treated with platinum-based neoadjuvant concurrent chemoradiotherapy.

Background: Excision repair cross-complementation Group 1 (ERCC1) overexpression is associated with resistance to cisplatin-based chemotherapy in patients with nonsmall-cell lung cancer (NSCLC). A preliminary study also suggested that ERCC1 expression is associated with radioresistance in lung cancer cells. The aim of this study was to evaluate the clinical implications of ERCC1 expression in stage IIIA N2-positive NSCLC patients treated with platinum-based neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery.

Multiparametric tissue characterization of brain neoplasms and their recurrence using pattern classification of MR images.

Rationale And Objectives: Treatment of brain neoplasms can greatly benefit from better delineation of bulk neoplasm boundary and the extent and degree of more subtle neoplastic infiltration. Magnetic resonance imaging (MRI) is the primary imaging modality for evaluation before and after therapy, typically combining conventional sequences with more advanced techniques such as perfusion-weighted imaging and diffusion tensor imaging (DTI). The purpose of this study is to quantify the multiparametric imaging profile of neoplasms by integrating structural MRI and DTI via statistical image analysis methods to potentially capture complex and subtle tissue characteristics that are not obvious from any individual image or parameter.

Neuroradiologic findings in children with mitochondrial disorder: correlation with mitochondrial respiratory chain defects.

Mitochondrial disorders are a heterogeneous group of disorders affecting energy metabolism that can present at any age with a wide variety of clinical symptoms. We investigated brain magnetic resonance (MR) findings in 40 children with defects of the mitochondrial respiratory chain (MRC) complex and correlated them with the type of MRC defects. Enrolled were 40 children with MRC defects in biochemical enzyme assay of the muscle specimen.