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Objective: It is important to differentiate human herpesvirus 6 (HHV-6)-associated encephalopathy from herpes simplex encephalitis (HSE). Although these conditions are similar with regard to involvement of the mesial temporal lobe, HSE is sensitive to acyclovir but HHV-6 encephalopathy is not. We compared the imaging findings of the two conditions., Materials and Methods: We encountered eight cases of HHV-6 encephalopathy and nine cases of HSE. We divided an observation time into early, middle, and late periods defined as 0-2, 3-30, and more than 30 days from the onset of neurologic symptoms. Differences between HHV-6 encephalopathy and HSE on CT scans in the early period and in distribution and temporal changes in the affected regions on MR images in the three periods were analyzed., Results: At MRI in the early and middle periods, all eight patients with HHV-6 encephalopathy had exclusive involvement of the mesial temporal lobes, and all nine patients with HSE had involvement of both the mesial temporal lobes and the extratemporal regions (p < 0.01). Among patients who underwent head MRI, six of six with HHV-6 encephalopathy but none of six with HSE had resolution of high signal intensity on T2-weighted and FLAIR images (p < 0.01). Among patients who underwent head CT in the early period, none of the four with HHV-6 encephalopathy and six of the seven with HSE had abnormal findings, including parenchymal swelling, decreased attenuation of affected regions, and abnormal gyral enhancement (p < 0.05)., Conclusion: Serial MRI showed transient abnormal signal intensity in the mesial temporal lobes in patients with HHV-6 encephalopathy but persistent abnormal signal intensity in both the mesial temporal lobes and the extratemporal regions in patients with HSE. CT in the early period showed no abnormality in patients with HHV-6 encephalopathy but definite abnormal findings in patients with HSE. These differences may be useful in the differential diagnosis of the two conditions.

Continuous maturation of cerebral white matter (WM) in the postadolescent period is not fully understood. To elucidate the time course and location of possible postadolescent maturational changes in cerebral WM, we studied 60 healthy male subjects who were in their second to seventh decade using diffusion-weighted imaging. Mean diffusivity (MD) in subcortical WM was measured in 78 cortical regions in each subject's brain using an automated method. Regression analysis was used to model the age-related change in MD by either a linear or a quadratic function in each region. Age-related changes in subcortical MD were best modeled by either a linear function or a quadratic function in 27 regions including language-related regions, visual or multimodal areas in the bilateral occipital and temporal lobes, limbic areas including the bilateral parahippocampal gyri, and the bilateral postcentral and left precentral gyri. In these regions, the MD rapidly decreased until middle age and thereafter reached a plateau. Our results revealed microstructural changes in local subcortical WM and suggests a continuing maturational process in postoadolescent periods.

Modulation of water exchange in lanthanide(III)-DOTA type complexes has drawn considerable attention over the past two decades, particularly because of their application as contrast agents for magnetic resonance imaging. LnDOTA-tetraamide complexes display unusually slow water exchange kinetics and this chemical property offers an opportunity to use these complexes as a new type of contrast agent based upon the chemical exchange saturation transfer (CEST) mechanism. Six new DOTA-tetraamide ligands having side-chain amide arms with varying hydrophobicity and polarity were prepared and the water exchange characteristic of complexes formed with europium(III) complexes were investigated. The results show that introduction of steric bulk into the amide side-chain arms of the europium(III) complexes not only favors formation of the mono-capped twisted square antiprism coordination isomers, the isomer that is generally less favourable for CEST, but also accelerates water exchange in the mono-capped square antiprism isomers. However, converting single methyl groups on these bulky arms to carboxyl or carboxyl ethyl esters results in a rather dramatic decrease in water exchange rates, about 50-fold. Thus, steric bulk, polarity and hydrophobicity of the amide side-chains each contribute to organization of water molecules in the second hydration sphere of the europium(III) ion and this in turn controls water exchange in these complexes., (Copyright (c) 2009 John Wiley & Sons, Ltd.)

Previous neuropsychological studies indicate that OCD subtypes such as checking rituals might be associated with a working memory deficit. On the other hand, functional neuroimaging studies found functional abnormalities of the frontal cortex and subcortical structures in OCD. Combined with functional imaging method, we applied neuropsychological batteries to demonstrate a working memory deficit in OCD by comparison with normal controls. In addition, working memory and brain activation were further examined with symptom-based analysis. Forty patients with OCD and 25 normal controls were examined using neuropsychological tests including the WAIS-R, WCST, WMS-R, and R-OCFT and functional MRI (fMRI) during the N-back task including 0- and 2-back task. On fMRI, the brain regions activated during the performance and the differences in the activation between patients and controls were identified. Additional analyses of severity and subtypes were conducted by using Y-BOCS severity score, symptom-checklist and Leckman's four-factor model, respectively. On the neuropsychological tests, the OCD patients had significantly lower scores on the delayed recall section of the WMS-R and the immediate recall section of the R-OCFT compared to the controls. On fMRI, the patients showed greater activation in the right dorsolateral prefrontal cortex (DLPFC), left superior temporal gyrus (STG), left insula, and cuneus during two-back task compared to the controls. Right orbitofrontal cortex activity showed a significant positive correlation with Y-BOCS scores in OCD. Furthermore, patients with obsessions/checking rituals (n=10) showed severer memory deficits and decreased activity in the postcentral gyrus than patients with cleanliness/washing rituals (n=14). In conclusion, we found neuropsychological dysfunction and brain abnormalities in OCD. Furthermore, our results suggested that symptom severity and symptom subtype such as obsessions/checking might affect neuropsychological dysfunction and related brain activities.

Background and Purpose: There are few comparative studies regarding morphologic changes after kyphoplasty and vertebroplasty. The purpose of this study was to compare restoration of vertebral body height and wedge angle and cement leakage with kyphoplasty and vertebroplasty in osteoporotic compression fractures., Materials and Methods: Forty patients (57 vertebrae) were treated with kyphoplasty, and 66 patients (124 vertebrae) were treated with vertebroplasty. Cement leakage into the disk space and paravertebral soft tissues or veins was analyzed on immediate postoperative CT scans. The height and wedge angle were measured before and after treatment and analyzed with the Mann-Whitney U test and chi(2) test., Results: Kyphoplasty and vertebroplasty both improved vertebral body height and the wedge angles (P < .05). However, these differences were not statistically significant when the 2 techniques were compared (P > .05). There were 18% of the kyphoplasty group and 49% of the vertebroplasty group that showed cement leakage into the paravertebral soft tissues or veins (P < .01). Cement leakage into the disk space occurred in 12% of the kyphoplasty group and in 25% of the vertebroplasty group (P < .01). However, no complications related to cement leakage were noted., Conclusions: Both kyphoplasty and vertebroplasty achieved the same degree of height restoration and improvement of the wedge angle. Kyphoplasty resulted in less cement leakage into the disk space and paravertebral soft tissues or veins than vertebroplasty.

An off-resonance saturation (ORS) method was used for magnetic resonance imaging of superparamagnetic polymeric micelles (SPPM). SPPM was produced by encapsulating a cluster of magnetite nanoparticles (9.9+/-0.4 nm in diameter) in poly(ethylene glycol)-b-poly(D,L-lactide) (PEG-PLA) copolymer micelles (micelle diameter: 60+/-9 nm). In ORS MRI, a selective radiofrequency (RF) pulse was applied at an off-resonance position (0-50 ppm) from the bulk water signal, and the SPPM particles were visualized by the contrast on a division image constructed from two images acquired with and without pre-saturation. Here, the effects of saturation offset frequencies, saturation durations, and RF powers on ORS contrasts were investigated as these parameters are critical for optimization of ORS MRI for in vivo imaging applications. The ability to turn "ON" and "OFF" ORS contrast of SPPM solutions permits for an accurate image subtraction and a contrast enhancement to visualize SPPM probes for in vivo imaging of cancer.

Objective: The usefulness of cone-beam C-arm CT for percutaneous vertebroplasty has not been fully evaluated. The purpose of this study was to assess the feasibility of cone-beam CT for evaluation before and after vertebroplasty., Subjects and Methods: This prospective study included 22 consecutive patients (15 women and seven men) with osteoporotic compression fractures (51 vertebrae). Cone-beam CT and 64-MDCT were performed before and after percutaneous vertebroplasty. Multiplanar reformations of the axial, sagittal, and coronal planes were obtained. We evaluated the presence of cortical defects, vacuum phenomena in adjacent disks, and cement leakage, and we calculated the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of cone-beam CT compared with MDCT., Results: All 75 cortical defects in 51 vertebrae seen on MDCT were also observed on cone-beam CT (100% sensitivity and specificity). Vacuum phenomena were detected in 33 of 86 (38.4%) adjacent disk spaces on MDCT and in 29 on cone-beam CT (84.8% sensitivity, 98.1% specificity, and 93.0% accuracy). Cement leakage was noted at 17 disk spaces, 15 paravertebral soft tissues, and 12 veins on MDCT. All cement leakages were correctly identified on cone-beam CT., Conclusion: Cone-beam CT is able to correctly evaluate for vertebral fractures and vacuum phenomena in adjacent disks before vertebroplasty and for cement leakage after vertebroplasty.

Dysfunction of the frontal-subcortical circuits has been the most common finding in the pathophysiology of obsessive-compulsive disorder (OCD), and recent neuropsychological studies have shown cognitive impairments in OCD. To clarify the pathophysiology of OCD without the confounding effects of medication, we investigated the alterations of brain function in OCD patients and changes after clinical improvement due solely to behavior therapy. The participants were 11 outpatients with OCD and 19 normal controls. The patients received 12 weeks of behavior therapy. We investigated the differences in the behavioral performance and functional magnetic resonance imaging results during the Stroop test in the patients and normal controls, and their changes after treatment in the patients. The patients showed less activation in the anterior cingulate gyrus and cerebellum than control subjects. Following significant improvement in OC symptoms, the cerebellum and parietal lobe showed increased activation, and the orbitofrontal cortex, middle frontal gyrus, and temporal regions showed decreased activation during the Stroop task, and performance of the task itself improved. Our findings suggest that dysfunction of the posterior brain regions, especially the cerebellum, is involved in the pathogenesis of OCD, and that normalization in function can occur with improvement of OC symptoms.

Objective: Glossopharyngeal neuralgia is rare but causes severe pain. We retrospectively evaluated preoperative MR images of patients with glossopharyngeal neuralgia caused by neurovascular compression., Conclusion: MRI may be beneficial in patients with glossopharyngeal neuralgia and an offending compressing artery. If the offending vessel was the posterior inferior cerebellar artery (PICA), a loop formation at the supraolivary fossette was always seen, whereas if it was the anterior inferior cerebellar artery (AICA), glossopharyngeal neuralgia was difficult to diagnose before surgery.

Background and Purpose: Previous studies have suggested that use of an artificial neural network (ANN) system is beneficial for radiological diagnosis. Our purposes in this study were to construct an ANN for the differential diagnosis of intra-axial cerebral tumors on MR images and to evaluate the effect of ANN outputs on radiologists' diagnostic performance., Materials and Methods: We collected MR images of 126 patients with intra-axial cerebral tumors (58 high-grade gliomas, 37 low-grade gliomas, 19 metastatic tumors, and 12 malignant lymphomas). We constructed a single 3-layer feed-forward ANN with a Levenberg-Marquardt algorithm. The ANN was designed to differentiate among 4 categories of tumors (high-grade gliomas, low-grade gliomas, metastases, and malignant lymphomas) with use of 2 clinical parameters and 13 radiologic findings in MR images. Subjective ratings for the 13 radiologic findings were provided independently by 2 attending radiologists. All 126 cases were used for training and testing of the ANN based on a leave-one-out-by-case method. In the observer test, MR images were viewed by 9 radiologists, first without and then with ANN outputs. Each radiologist's performance was evaluated through a receiver operating characteristic (ROC) analysis on a continuous rating scale., Results: The averaged area under the ROC curve for ANN alone was 0.949. The diagnostic performance of the 9 radiologists increased from 0.899 to 0.946 (P < .001) when they used ANN outputs., Conclusions: The ANN can provide useful output as a second opinion to improve radiologists' diagnostic performance in the differential diagnosis of intra-axial cerebral tumors seen on MR imaging.

Purpose: To confirm the cortical thickness difference across the central sulcus (CS) visualized in the presence of vasogenic edema on MRI., Materials and Methods: T2-weighted images of 70 cerebral hemispheres showing vasogenic edema infiltrating into subcortical white matter around the CS were studied retrospectively. Two neuroradiologists measured the cortical thickness of the anterior and posterior banks of the CS, precentral sulci (PrCS), and postcentral sulci (PoCS). Additionally, we compared the cortical thickness of the anterior and posterior banks of each sulcus visually using a grading scale., Results: On T2-weighted images, the cerebral cortex was highlighted by a high signal-intensity vasogenic edema in the adjacent white matter, and its thickness was readily measurable. The unique cortical thickness difference between the anterior and posterior banks of the CS were confirmed with measurements of 2.67 and 1.48 mm (p<0.0001). The cortical measurements across other cerebral sulci were 2.04 and 1.95 mm (NS) for the PrCS, and 1.67 and 1.77 mm (NS) for the PoCS. The cortical thickness ratios were 1.86 for the CS, 1.05 for the PrCS, and 0.96 for the PoCS. On visual evaluation, the anterior bank of the CS was thicker than the posterior bank in 93% (65/70). For the PrCS and PoCS, the thickness of the anterior and posterior banks appeared to be equal in over 70% of the patients., Conclusion: A prominent cortical thickness difference across the CS in the presence of vasogenic edema was confirmed. This finding is considered to facilitate the identification of the CS in patients with brain tumors.

Background and Purpose: We investigated the relationship between tumor blood-flow measurement based on perfusion imaging by arterial spin-labeling (ASL-PI) and histopathologic findings in brain tumors., Materials and Methods: We used ASL-PI to examine 35 patients with brain tumors, including 11 gliomas, 9 meningiomas, 9 schwannomas, 1 diffuse large B-cell lymphoma, 4 hemangioblastomas, and 1 metastatic brain tumor. As an index of tumor perfusion, the relative signal intensity (SI) of each tumor (%Signal intensity) was determined as a percentage of the maximal SI within the tumor per averaged SI within normal cerebral gray matter on ASL-PI. Relative vascular attenuation (%Vessel) was determined as the total microvessel area per the entire tissue area on CD-34-immunostained histopathologic specimens. MIB1 indices of gliomas were also calculated. The differences in %Signal intensity among different histopathologic types and between high- and low-grade gliomas were compared. In addition, the correlations between %Signal intensity and %Vessel or MIB1 index were evaluated in gliomas., Results: Statistically significant differences in %Signal intensity were observed between hemangioblastomas versus gliomas (P < .005), meningiomas (P < .05), and schwannomas (P < .005). Among gliomas, %Signal intensity was significantly higher for high-grade than for low-grade tumors (P < .05). Correlation analyses revealed significant positive correlations between %Signal intensity and %Vessel in 35 patients, including all 6 histopathologic types (rs = 0.782, P < .00005) and in gliomas (rs = 0.773, P < .05). In addition, in gliomas, %Signal intensity and MIB1 index were significantly positively correlated (rs = 0.700, P < .05)., Conclusion: ASL-PI may predict histopathologic vascular densities of brain tumors and may be useful in distinguishing between high- and low-grade gliomas and in differentiating hemangioblastomas from other brain tumors.

Rationale and Objectives: Conventional tractography based on the "streamline" method only partially visualizes the pyramidal tract because of fiber crossing with other white matter tracts. Recently a new tractography method based on directional diffusion function (DDF) has been proposed. This method was reported to visualize the pyramidal tract to a larger extent than conventional techniques do. To validate the DDF-based tractography method, we studied the somatotopic organization of the pyramidal tract in the posterior limb of the internal capsule (PLIC)., Materials and Methods: Pyramidal tracts in the intact hemispheres of 14 brain tumor patients were drawn using the directional diffusion function-based tractography method. Each pyramidal tract was divided into four fiber bundles according to the cephalocaudal positions of their termination in the precentral gyrus. The cephalocaudal positions in the precentral gyrus of the four fiber bundles were correlated with their positional relationships in the PLIC along the mediolateral and anteroposterior axes., Results: Fiber bundles terminating more caudally in the precentral gyrus were located significantly more anteriorly in the PLIC (r = 0.59, Spearman's correlation coefficient, P < .0001). On the other hand, no significant correlation was shown between the cephalocaudal positions in the precentral gyrus of the four fiber bundles and their relative positions in the PLIC along the mediolateral axis., Conclusions: Estimated organization of the fiber bundles of the pyramidal tract in the PLIC was consistent with anatomically known somatotopic organization, which supported the validity of the DDF-based tractography method.

Background: Intraarterial therapy (IAT) for acute cerebral infarction has been proven to be profitable. However, the criteria for the indications, the choice of the thrombolytic agents, and the use of adjunctive agents are controversial. We retrospectively analyzed the prognostic factors of IAT., Materials and Methods: From 1994 to 2003, 28 patients underwent IAT due to middle cerebral artery occlusion (17 women and 11 men; median age, 69 years old). We evaluated the following prognostic parameters: institution of treatment, degree of paralysis at visit, size of high-intensity area on diffusion-weighted images, dose of intraarterial urokinase administration, elapsed time from symptom onset to completion of IAT, presence of penetration of embolus by microcatheter and microguidewire, recanalization after IAT, intracranial hemorrhage (ICH) within 24 hours after IAT, and intravenous heparin administration after IAT. The outcome was evaluated at discharge and was classified into the following categories according to the modified Rankin Scale: independence (0 to 2), dependence (3 to 5), and death (6)., Results: Seven patients were judged to be independent, 16 patients were judged to be dependent, and five patients died. Patients with recanalization after IAT had a better outcome than those without (p < 0.05); patients with intracranial hemorrhage had a worse outcome than those without (p < 0.05); and patients with intravenous heparin administration after IAT had a better outcome in activities of daily living than those without (p < 0.05)., Conclusion: In addition to ICH and recanalization, our results suggested that intravenous heparin administration after IAT had a favorable effect on patient outcome.

Aging may alter the motor functions of the basal ganglia and cerebellum; however, no previous neuroimaging study has investigated the effect of aging on the functional connectivity of the motor loops involving these structures. Recently, using fMRI with a parametric approach and structural equation modeling (SEM), we demonstrated a significant functional interaction within the basal ganglia-thalamo-motor (BGTM) loop during self-initiated (SI) finger movement in young normal subjects, whereas cerebro-cerebellar (CC) loop was mainly involved during externally triggered (ET) movement. We applied this method to 12 normal aged subjects (53-72 years old) in order to study the effect of age on BGTM and CC loops. Compared with the functional connectivity seen in young subjects, SEM showed decreased connectivity in BGTM loops during SI task, decreased interaction in the CC loop during ET task, and increased connectivity within motor cortices and between hemispheres during both types of tasks. These results suggest an age-related decline of cortico-subcortical connectivity with increased interactions between motor cortices. Aging effects on SI and ET movements are probably caused by functional alterations within BGTM and CC loops.

We present a case report in which a 4-year-old girl was involved in a fall that resulted in an injury of the right orbita. The girl kept a chopstick in her right hand that got into the right orbita due to this accident. Only a fraction remained in the orbita; the residual chopstick got lost. Hence, the substance of the chopstick was unknown. Computed tomography (CT) revealed a foreign body in the right orbita, but ophthalmologists had initially no indication of intervention. Further course according to the follow-up CT showed an increase of Hounsfield units (HU). These findings led to the assumption that the foreign body was made of wood. Through this, the ophthalmologists performed an evacuation. Motivated by these clinical results, we created an experimental setup that could demonstrate changes of HU in different coated chopsticks. It is concluded that wooden foreign bodies can display a variety of CT appearances depending on materials, types, coating, and time-course.

Purpose: Pulsed arterial spin labeling (PASL) is a magnetic resonance (MR) method for measuring cerebral blood flow. Although several validation studies for PASL in animals and humans have been reported, no reports have detailed the fundamental study of PASL using a flow phantom. We compared the true and theoretical flow rates in a flow phantom to confirm the analytical validity of quantitative perfusion imaging with Q2TIPS sequence., Methods: We built a flow phantom consisting of a 40-mm diameter plastic syringe filled with plastic beads and small plastic tubes 4 mm in diameter. Gd-DTPA-doped 8L water solution (0.1 mM) was circulated between the syringe and a tank through a plastic tube by a constant flow pump while the flow rate was adjusted between 0 and 2.61 cm/s. Q2TIPS sequence parameters were TI(1)=50 ms and TI(2)=1400 ms. Five imaging slices of 50 subtraction images were acquired sequentially in a distal-to-proximal direction using a single-shot echo planar imaging (EPI) technique. The theoretical flow rate calculated based upon the previously reported kinetic model for Q2TIPS was compared with the true flow rate., Results: A good linear relationship was observed between the theoretical, F', and true flow rates, F, in a flow rate range of 1.43 to 1.95 cm/s (F'=1.024*F-1.915, R(2)=0.902). The ratio of theoretical to true flow rate was 92 (+/-) 4%., Conclusion: Flow rate was quantified with reasonable accuracy when the entire amount of labeled bolus within the phantom could be recovered. Our experiment confirmed the analytical validity of Q2TIPS and suggested that blood flow measurement may be feasible using the Q2TIPS pulse sequence and kinetic model of the PASL equation.

Rationale and Objectives: White matter (WM) abnormality in Alzheimer's disease (AD) has been less well characterized than cortical damage. We studied the spatial distribution of the subcortical WM abnormality using diffusion-weighted magnetic resonance imaging (DWI)., Materials and Methods: Twenty-one AD patients and seven healthy, elderly subjects were included. DWIs were obtained using a cerebrospinal fluid (CSF)-nulled pulse sequence to reduce the partial volume contamination of CSF signal. Diffusivity in the subcortical WM voxels was mapped onto the cortical surface using original software so that the spatial distribution of subcortical WM damage, which was visualized as an area of increased diffusivity, could be viewed in a three-dimensional map. The damages in the lateral surface of the bilateral cerebral hemispheres were visually evaluated, and severities of the damages in five brain regions were compared with each other. In addition, the severity of the damage in each region was correlated with patient's mini-mental state examination (MMSE) score., Results: In both hemispheres, clear sparing of the pericentral regions and predominant involvement of the parietal and temporal regions were revealed with statistical significance (P < .05, respectively). Marginal correlation (P < .05 uncorrected for multiple comparisons) was observed between the damage severity in the bilateral frontal and right temporal regions and patient's MMSE score., Conclusion: We demonstrated a subcortical WM abnormality over the parietal and temporal regions with clear sparing of the pericentral region using our mapping method, which supported the hypothesis that the subcortical WM abnormality in AD originates in Wallerian degeneration.

Background and Purpose: Human herpesvirus-6 (HHV-6)-associated encephalopathy tends to develop in immunocompromised patients. Neurologic symptoms, such as disorientation, short-term memory loss, convulsion, coma, and hypopnea could occur, but they may be nonspecific. We retrospectively reviewed MR images of 6 adults with HHV-6-associated encephalopathy to study characteristic imaging findings that could be useful in making the diagnosis., Materials and Methods: Between 2003 and 2005, we encountered 6 cases of HHV-6-associated encephalopathy (3 men and 3 women; age range, 36-55 years) in 3 hospitals. The diagnosis was made clinically according to the neurologic symptoms accompanied by high-level copies of HHV-6 DNA in CSF or peripheral blood by quantitative polymerase chain reaction without the detection of any other infectious pathogen., Results: All 6 patients had abnormal hippocampus/amygdala findings on presentation, and no other regions were involved. In the early period (0-2 days from onset), abnormal high signal intensity on fluid-attenuated inversion recovery (FLAIR) imaging (2 of 3, 67%) and on diffusion-weighted images accompanied by apparent diffusion coefficient (ADC) reduction (2 of 2, 100%) were observed. In the middle period (3-30 days), abnormal low signal intensity on T1-weighted images (5 of 6, 83%) and abnormal high signal intensity on T2-weighted images (4 of 6, 67%) and FLAIR (5 of 6, 83%) were confirmed. In the late period (> 30 days), we saw the resolution of signal intensity abnormalities and the appearance of atrophic change (4 of 4, 100%) of the affected regions., Conclusion: HHV-6-associated encephalopathy in adults tends to affect the mesial temporal lobe. MR imaging is useful for detecting HHV-6 encephalopathy and distinguishing it from the other diseases of the central nervous system in immunocompromised patients.

Rationale and Objective: Brain tissue damage in frontotemporal dementia (FTD) has never been systematically studied using diffusion-weighted imaging (DWI). We studied FTD patients using DWI to determine whether microstructural changes in white matter can be detected in vivo., Materials and Methods: Thirteen FTD patients and 15 aged healthy subjects were studied. Mean diffusivity (MD) abnormalities in 28 white matter regions were visually evaluated. In addition, MD values in 10 white matter regions relative to that in the ipsilateral postcentral gyrus were measured. The results were compared between healthy subjects and FTD patients., Results: The visual rating resulted in a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, right orbitofrontal gyrus, bilateral anterior temporal lobes, and left middle temporal lobe (P < .01, respectively). Relative MD comparison revealed a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, bilateral orbitofrontal gyri, and bilateral anterior temporal lobes (P < .05 after Bonferroni correction, respectively)., Conclusion: Our results demonstrated white matter MD abnormalities in FTD patients. It was suggested that the observed white matter MD abnormalities are secondary to damage in the overlying cortex.

The basal ganglia and cerebellar loops are known to participate differently in self-initiated (SI) and externally triggered (ET) movements. However, no previous neuroimaging studies have illustrated functional organization of these loops in vivo. Here, we aimed to functionally visualize these loops during motor execution using functional magnetic resonance imaging (fMRI) with structural equation modeling (SEM). Twelve normal subjects (24-29 years old) were scanned while performing five different frequencies of sequential left finger movements using either SI or ET movements. Random effect analysis combined with a parametric approach revealed a significant positive linear dependence of cerebral activation upon movement rate in the right Put, GPi, VL, SMC and SMA during SI tasks. During ET tasks, significant positive linear relationships were found in the right SMC, VPL, left CB and DN, whereas tendency for linear relationships was seen in the right PMv. SEM further showed significant interactions within the right basal ganglia-thalamo-motor loop during SI tasks. In contrast, there were significant interactions within the entire right cerebral hemisphere-left cerebellar loop involving CB, DN, VPL, PMv and SMC during ET tasks. Therefore, our modeling approach enabled identification of different contributions of the motor loops of basal ganglia and cerebellum to SI and ET tasks during motor execution.

Background and Purpose: In Moyamoya disease, the relationship between cerebral hemodynamics and angiographic findings has not been fully evaluated. The purpose of this study is to evaluate hemodynamics in Moyamoya disease with perfusion-weighted MR imaging (PWI) and cerebral angiography., Methods: Twenty patients with Moyamoya disease were the subjects. Mean transit time (MTT) derived from PWI was calculated in the medial frontal lobes, the posterior frontal lobes, the occipital lobes, and the basal ganglia. From the angiographies, we classified the degrees of internal carotid artery (ICA) and posterior cerebral artery (PCA) stenoses as well as the degrees of Moyamoya vessels and leptomeningeal anastomosis (LMA). MTT in each region was compared with the angiographic findings., Results: MTT positively correlated with the degree of ICA stenosis in the medial frontal (P < .01), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001). MTT correlated with the degree of PCA stenosis in the medial frontal (P < .001), posterior frontal (P < .001), and occipital (P < .001) lobes, as well as in the basal ganglia (P < .001). MTT correlated with the degree of Moyamoya vessels in the medial frontal (P < .05) and posterior frontal (P < .01) lobes. A multivariate analysis revealed that ICA and PCA stenoses and Moyamoya vessels were independent factors that prolonged MTT., Conclusion: Both ICA and PCA stenoses may influence overall cerebral perfusion in Moyamoya disease. The development of Moyamoya vessels may indicate hemodynamic impairment.

Purpose: To reduce saline and heparin in continuous catheter perfusion in intraoperative cerebral angiography, a method using a syringe pump was tried., Materials and Methods: Ten patients with brain arteriovenous malformation (AVM) underwent intraoperative cerebral angiography. Seven internal carotid arteries (ICAs) and six vertebral arteries (VAs) were catheterized in these patients. Continuous catheter perfusion was performed at a low rate of 3 mL/hr with saline containing 8,000 units of heparin per liter using a syringepump., Results: Mean duration of catheter perfusion was 8.3 +/- 4.0 hrs (range, 3.0 to 15.7 hrs). Mean volume of saline was 25.0 +/- 11.9 mL (range, 9 to 47 mL) per catheter. Mean dosage of heparin was 200.0 +/- 94.9 units (range, 72 to 376 units) per catheter. No complications due to intraoperative angiography were observed in this trial., Conclusion: Reduction of the saline volume and heparin dosage was possible in intraoperative cerebral angiography by the continuous perfusion of a small amount of high-concentration heparinized saline using a syringe pump.

Previous studies have shown that diffusion-weighted imaging (DWI) is useful for detecting microstructural degradation of neuronal tissue in neurodegenerative diseases. Mapping of cortical degeneration by DWI is potentially useful, but is extremely difficult, mainly because of the partial volume effect resulting from the surrounding cerebrospinal fluid (CSF). In this study a novel method to map and display the cortical damage in neurodegenerative diseases using DWI is proposed. Instead of measuring the cortical diffusivity, the diffusivity of white matter directly beneath the cortex, where neuronal fibers enter or exit the overlying cortex, was measured and mapped onto the cortical surface. The map was viewed in a form of three-dimensional (3D) rendering. Patients with Alzheimer's disease (AD) showed cortical damage in the temporal and parietal cortices, and a patient with frontotemporal dementia showed damage in the frontal lobe, consistent with the typical topographical distribution of histopathological cortical damage in each of these diseases. The results suggest that subcortical diffusivity closely reflects cortical damage, and that the current mapping technique is a promising tool for evaluating neurodegenerative diseases., (2005 Wiley-Liss, Inc)

Background: Functional neuroimaging studies have implicated hyperactivity of the frontal cortex in obsessive-compulsive disorder (OCD); however, relationships between abnormal brain activity, clinical improvement, and neuropsychological function have not been clarified in OCD. To clarify the pathophysiology of this disorder, regional changes in brain function were examined during administration of cognitive and symptom provocation tasks in patients with OCD before and after treatment., Methods: Ten outpatients with OCD participated in the study. Functional magnetic resonance imaging (fMRI) was performed before and after treatment. Stroop and symptom provocation tasks were administered during fMRI. Each patient was randomly allocated to receive either pharmacotherapy with fluvoxamine 200 mg/day (n = 4) or behavior therapy (n = 6) for 12 weeks., Results: After 12-week treatment, mean (+/- SD) total score on the Yale-Brown Obsessive-Compulsive Scale decreased from 29.00 +/- 3.59 to 14.60 +/- 9.22, representing symptomatic improvement from moderate to mild. After symptom improvement, symptom provocation-related activation in the orbitofrontal, dorsolateral-prefrontal, and anterior cingulate cortices decreased. Conversely, Stroop task-related activation in the parietal cortex and cerebellum increased., Conclusions: After improvement of OCD with either fluvoxamine or behavioral therapy, hyperactivation of the frontal lobe related to a symptom-provocative state decreases, and posterior brain activity related to action-monitoring function increases.

Percutaneous vertebroplasty is a radiologically guided therapeutic procedure that consists of percutaneous injection of polymethylmetacrylate (PMMA) into pathologic vertebral bodies. It is a minimally invasive procedure that is effective in the treatment of pain resulting from bone metastasis. This procedure has the advantage of providing rapid pain relief and spinal stabilization. A patient with severe, aggressive pain from metastatic lumbar spinal tumor of thyroid follicular carcinoma is presented herein. Despite treatment with analgesic agents, external beam radiation therapy, radioiodine therapy, and posterior fusion surgery, the pain reemerged and progressed. After percutaneous vertebroplasty, definite pain relief was achieved. Vertebroplasty would be useful as an additional or alternative pain relief method in patients with metastatic vertebral tumors.

Rationale and Objective: Structure of the brain is generally thought to remain stationary over the course of young adulthood. However, there is some evidence that microstructural changes of the brain do occur during this period. Magnetic resonance diffusion tensor imaging (DTI) provides quantitative measures of structural changes in the brain. We used DTI to detect possible age-related structural changes in the brains of young adults., Materials and Methods: Twenty-five healthy adults in their 20s and 30s were studied using DTI. Maps of mean diffusivity and fractional anisotropy (FA) were created for subsequent histogram and region-of-interest analyses, and the results were correlated with the respective ages of the subjects., Results: The histogram analysis revealed a significant increase in the mean FA value (r = 0.407, P < .05) and a significant decrease in FA peak height (r = -0.578, P < .002) with increasing age. No age-related changes were observed in indices derived from mean diffusivity maps. Region-of-interest analysis showed no focal white matter regions with significant FA change., Conclusion: Quantitative DTI revealed age-related structural changes in the brains of young adults. Changes on FA histograms observed in this study were considered to be related to changes in the relative volumes of gray and white matter and may represent maturational changes.

Objective: The purpose of this study was to determine the capability of dynamic contrast MRI to differentiate hemangioma from schwannoma of the orbit., Materials and Methods: Sixteen patients (three males and 13 females; mean age, 39 +/- 17.3 [SD] years; age range, 10-71 years) with unilateral orbital tumors, including eight cavernous hemangiomas and eight schwannomas, were examined. In addition to conventional MRI, we performed a dynamic contrast study (fast spin-echo sequence, 20-sec interval) after bolus administration of the contrast material (gadopentetate dimeglumine, 0.1 mmol/kg). We evaluated the features of the contrast enhancement spread pattern and the tumors' time-intensity curves., Results: In the early phase, all the hemangiomas started the enhancement from one point or portion, although all the schwannomas started the enhancement from a wide area. The difference in the contrast-enhancement spread pattern features between the two types of tumors was statistically significant (p < 0.0001). The gradient of the time-intensity curve did not show a significant difference., Conclusion: Hemangioma and schwannoma of the orbit can be differentiated by the contrast-enhancement spread pattern on dynamic MRI.

Objective: The extracranial involvement of moyamoya disease has been reported in several studies. The main purpose of this study was to determine the prevalence of stenoocclusive lesions in the renal and major abdominal arteries in moyamoya disease., Materials and Methods: Abdominal angiography was performed in 73 patients with idiopathic moyamoya disease. The findings of abdominal angiography were retrospectively reviewed for the presence and appearance of stenosis in the renal and other major abdominal arteries., Results: Four (5%) of 73 patients presented with unilateral renal artery stenosis. Three patients had moderate stenosis, and one patient had mild stenosis. In the three patients with moderate stenosis, the renal artery stenosis was located in the proximal region of the main branch. Two patients (3%) with moderate stenosis of the unilateral renal artery had renovascular hypertension. No statistically significant differences were observed in age, sex, and the cerebral angiographic stage between patients with and without renal artery stenosis. No stenosis was found in the abdominal aorta or celiac, superior mesenteric, common hepatic, splenic, and proximal common iliac arteries. No occlusions were found in any abdominal arteries., Conclusion: The prevalence of renal artery stenosis in patients with moyamoya disease was 5% (4/73). Involvement of the proximal region of the renal artery was dominant. No stenosis was found in other abdominal arteries.