Infantile hypophosphatasia combined with vitamin B6-responsive seizures and reticular formation lesions on magnetic resonance imaging: A case report.

BACKGROUND: Hypophosphatasia (HPP) is a rare genetic disorder characterized by rachitic bone manifestations and a low serum alkaline phosphatase (ALP) level. It is caused by mutations in the tissue non-specific alkaline phosphatase (TNSALP) gene, which encodes the tissue non-specific isozyme of ALP. HPP patients exhibit various presentations depending on their age at onset, such as infantile HPP combined with vitamin B6-responsive seizures. CASE PRESENTATION: A newborn with infantile HPP presented with tonic convulsions from day 5 after birth and received intravenous vitamin B6 (10mg/kg/day pyridoxal phosphate). Eleven days later, frequent apneic episodes occurred, and head magnetic resonance imaging (MRI) showed bilateral reticular formation lesions in the brain stem, including the medulla oblongata. After the pyridoxal phosphate dose was increased (to 40mg/kg/day), the patient's seizures and apnea resolved, and her MRI findings also improved. Genetic testing revealed that she was homozygous for the 1559delT mutation of TNSALP. CONCLUSIONS: High-dose pyridoxal phosphate is a useful treatment for HPP-induced seizures and might improve reticular formation lesions.

CT and MRI findings of human herpesvirus 6-associated encephalopathy: comparison with findings of herpes simplex virus encephalitis.

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.

Automated method for identification of patients with Alzheimer's disease based on three-dimensional MR images.

RATIONALE AND OBJECTIVES: An automated method for identification of patients with cerebral atrophy due to Alzheimer's disease (AD) was developed based on three-dimensional (3D) T1-weighted magnetic resonance (MR) images. MATERIALS AND METHODS: Our proposed method consisted of determination of atrophic image features and identification of AD patients. The atrophic image features included white matter and gray matter volumes, cerebrospinal fluid (CSF) volume, and cerebral cortical thickness determined based on a level set method. The cortical thickness was measured with normal vectors on a voxel-by-voxel basis, which were determined by differentiating a level set function. The CSF spaces within cerebral sulci and lateral ventricles (LVs) were extracted by wrapping the brain tightly in a propagating surface determined with a level set method. Identification of AD cases was performed using a support vector machine (SVM) classifier, which was trained by the atrophic image features of AD and non-AD cases, and then an unknown case was classified into either AD or non-AD group based on an SVM model. We applied our proposed method to MR images of the whole brains obtained from 54 cases, including 29 clinically diagnosed AD cases (age range, 52-82 years; mean age, 70 years) and 25 non-AD cases (age range, 49-78 years; mean age, 62 years). RESULTS: As a result, the area under a receiver operating characteristic (ROC) curve (Az value) obtained by our computerized method was 0.909 based on a leave-one-out test in identification of AD cases among 54 cases. CONCLUSION: This preliminary result showed that our method may be promising for detecting AD patients.

Atopic myelitis with focal amyotrophy: a possible link to Hopkins syndrome.

Among 22 consecutive patients with myelitis, of unknown etiology, and atopic diathesis (atopic myelitis) who from April 2002 to March 2006 had been studied in our clinic, 5 (23%) showed focal amyotrophy in one or two limbs. These 5 patients were subjected to combined clinical, electrophysiological, neuroimaging and immunological studies. Ages were 18 to 58-years-old (average 39). Four showed amyotrophy of unilateral or bilateral upper limbs while one showed amyotrophy in both thighs. All patients showed on-going denervation potentials in the affected muscles, while motor conduction study including F wave was normal except for in one patient who showed prolonged F wave latency in one nerve. Two had localized high signal intensity lesions involving anterior horns on spinal cord MRI and three showed abnormalities suggesting pyramidal tract involvement on motor evoked potentials. All had a present and/or past history of atopic disorders and specific IgE against common environmental allergens, such as mite antigens and cedar pollens, and four showed mild eosinophilia, all of which were compatible with atopic myelitis. When clinical and laboratory findings were compared between atopic myelitis with (n=5) or without focal amyotrophy (n=17), the former showed a significantly higher frequency of present and past history of asthma (80% vs. 24%, p=0.0393) and tended to have higher EDSS scores (3.8+/-1.6 vs. 3.1+/-1.4). Two patients showed mild to moderate improvements after immunotherapies such as methylprednisolone pulse therapy or plasma exchange, while two recovered with low dose corticosteroids and one without treatment had a gradually progressive course. Although atopic myelitis preferentially involves the posterior column of the cervical spinal cord, it is possible that anterior horn cells are affected in some cases of atopic myelitis, especially in patients with asthma. This suggests a possible link between atopic myelitis and Hopkins syndrome (asthmatic amyotrophy).

Anterior periventricular linear lesions in optic-spinal multiple sclerosis: a combined neuroimaging and neuropathological study.

There are two distinct subtypes of multiple sclerosis (MS) in Asians, optic-spinal (OSMS) and conventional (CMS). In OSMS, severe spinal cord lesions are characteristic while brain lesions are scant. We sought to clarify atypical brain lesions in OSMS by neuroimaging and pathological studies. For brain MRI, 124 consecutive Japanese patients with clinically definite MS based on Poser criteria were enrolled, 57 with OSMS and 67 with CMS. Ten autopsied cases (seven OSMS and three CMS) were studied pathologically. Although the frequency of brain lesions fulfilling Barkhof criteria was significantly higher in CMS than in OSMS, periventricular linear lesions along with the anterior portion of the corpus callosum and the lateral ventricles were significantly more common in OSMS than in CMS. Pathologically, periventricular lesions in CMS extended deeply into the white matter, while those in OSMS were confined to periventricular areas. T cell infiltration in lesions was prominent in CMS but not in OSMS. Although severe axonal loss and cavity formation were commonly seen in periventricular and spinal cord lesions in OSMS, lymphocytic infiltrates and vessel wall thickening were observed only in the latter. Thus, we suggested that anterior periventricular linear lesions without ovoid ones are characteristic of OSMS.

MR tractography based on directional diffusion function validation in somatotopic organization of the pyramidal tract.

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.

Cortical damage in Alzheimer's disease estimation in medial and lateral aspects of the cerebrum using an improved mapping method based on diffusion-weighted magnetic resonance imaging.

RATIONALE AND OBJECTIVES: A method of estimating and mapping the cortical damage resulting from neurodegenerative diseases based on diffusion-weighted imaging was recently proposed. We improved on this method to visualize the cortical damage in Alzheimer's disease (AD) in the lateral and medial aspects of the cerebral hemispheres and to provide anatomic references. MATERIALS AND METHODS: Damage in the cerebral cortex was estimated based on diffusivity in the subcortical white matter according to a previously published method. A map of subcortical mean diffusivity (MD) was superimposed on the corresponding anatomic image so that the spatial extent of the abnormality could be anatomically localized. The right and left hemispheres were separated to evaluate the medial and lateral aspects of each hemisphere. This method was applied to 10 healthy subjects and 11 AD patients. MDs within 20 cortical regions were visually evaluated and statistically compared between AD and healthy subjects at a significance level of P < .01. RESULTS: In addition to the involvement of the lateral aspects of the bilateral parietal and temporal lobes and clear sparing of the bilateral pericentral regions that were previously reported, significant MD elevation was observed in the medial aspects of the right frontal, bilateral parietal, and right temporal lobes. The extent of MD abnormalities was easily identified by the background anatomic image. CONCLUSIONS: Results suggested that AD damage in the lateral and medial cerebral cortex can be visualized with an anatomic reference using our method.

Intraorbital lobular capillary hemangioma (pyogenic granuloma).

A 44-year-old man with a history of a foreign body in his right eye visited our hospital. On computed tomography a well-enhanced mass with low attenuation septal walls and a capsule was detected in the right orbit. On magnetic resonance imaging the mass showed inhomogenous high intensity on T2-weighted images and low intensity on diffusion-weighted images. The mass was histopathologically diagnosed as a lobular capillary hemangioma. This is the first report about image findings of lobular capillary hemangioma in the orbit.

Heterogeneity and continuum of multiple sclerosis in Japanese according to magnetic resonance imaging findings.

There are two distinct subtypes of multiple sclerosis (MS) in Asians: optic-spinal (OSMS) and conventional (CMS). Longitudinally extensive spinal cord lesions (LESCLs) extending over three or more vertebral segments are characteristic of patients with OSMS, yet in Asians, one-fourth of CMS patients also have LESCLs. To clarify the distinction between LESCLs in OSMS and CMS, and to characterize the relationship between the presence of LESCLs and brain magnetic resonance imaging (MRI) findings, we studied 142 patients with clinically definite MS of relapsing-remitting onset and 12 patients with primary progressive MS (PPMS) by MRI of the whole spinal cord and brain. The former was diagnosed by Poser criteria, including 57 with OSMS, 67 with CMS and 18 with brainstem-spinal form of MS, while the latter by McDonald criteria. The presence of LESCLs throughout the entire clinical course was significantly more common in OSMS patients than in CMS patients, while brain lesions fulfilling the Barkhof criteria (Barkhof brain lesions) were significantly more common in CMS patients than OSMS patients. LESCLs in OSMS patients most frequently affected the upper to middle thoracic cord, with either holocord or central gray matter involvement. By contrast, 70% of LESCLs in CMS patients predominantly affected the peripheral white matter of the mid-cervical cord. LESCLs in patients with PPMS also showed preferential involvement of the peripheral white matter of the mid-cervical cord. One-third of OSMS patients had neither LESCLs nor Barkhof brain lesions more than 10 years after disease onset, and showed significantly milder disability than OSMS patients with LESCLs. These findings suggest that LESCLs are heterogeneous between OSMS and CMS patients, and that there are distinct subtypes of MS in Japanese, according to clinical and MRI findings.

Cortical thickness difference across the central sulcus visualized in the presence of vasogenic edema.

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.

Surgical strategy for multiple huge spinal extradural meningeal cysts. Case report.

The authors describe the case of an 8-year-old boy who developed spastic paraparesis and hypalgesia below the middle thoracic level. Magnetic resonance (MR) imaging showed huge and multiple extradural cystic lesions posterior to the spinal cord from T-5 to S-1, which were associated with severe spinal cord compression, especially at the T5-8 level. Using constructive interference in steady state (CISS) MR imaging, many septa were visible that were dividing the cysts in a tandem arrangement, and the multiple cysts were distributed far laterally, extending to the root sleeves. Three transdural communications of cerebrospinal fluid into the cysts, including one that was located ventrally, were revealed by multiangled observation using CISS MR imaging and intraoperative inspection. The huge and multiple appearances of the extradural meningeal cysts on MR images suggested various stages of growth of these cysts. As this case demonstrates, cysts of this type (huge, multiple, extradural meningeal [arachnoid] cysts) need to be completely removed during one-stage surgery.

Intraarterial therapy for acute ischemic stroke: investigation of prognostic factors.

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.

Quantitative perfusion imaging with pulsed arterial spin labeling: a phantom study.

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.

Additional hippocampectomy in the surgical management of intractable temporal lobe epilepsy associated with glioneuronal tumor.

In surgery for epileptogenic glioneuronal tumor in the temporal lobe, whether additional hippocampectomy is needed remains in dispute. We retrospectively analysed clinical profile and seizure outcome in a consecutive series of six patients, paying special attention to pathophysiologic conditions in the ipsilateral hippocampus. Long-term video electroencephalography (EEG) monitoring showed attenuation of background activity, followed by ictal discharges in the ipsilateral temporal region in five cases. (18)Fluorodeoxyglucose-positron emission tomography (FDG-PET) in five cases showed hypometabolism in the ipsilateral medial temporal lobe. Intraoperative electrocorticography (ECoG) after removal of the tumor revealed frequent paroxysmal activity or electrographic seizure activity on the hippocampus in five cases. A high incidence of hippocampal pathology, such as hippocampal sclerosis in four cases and dysgenesis in one case, was demonstrated. Five patients who underwent additional hippocampectomy along with resection of the tumor became completely seizure-free. Our findings indicated a proclivity for the epileptogenic zone to encompass the medial structures and for hippocampal pathology to be present even when no direct medial tumor involvement was identified. Thus, it is conceivable that removal of the hippocampus with the guidance of pre- and intraoperative multimodal examinations, in addition to resection of the tumor, may be recommended to achieve 'complete' freedom from seizures.

Feasibility and limitation of constructive interference in steady-state (CISS) MR imaging in neonates with lumbosacral myeloschisis.

INTRODUCTION: The aim of this study was to evaluate three-dimensional Fourier transformation-constructive interference in steady-state (CISS) imaging as a preoperative anatomical evaluation of the relationship between the placode, spinal nerve roots, CSF space, and the myelomeningocele sac in neonates with lumbosacral myeloschisis. METHODS: Five consecutive patients with lumbosacral myeloschisis were included in this study. Magnetic resonance (MR) CISS, conventional T1-weighted (T1-W) and T2-weighted (T2-W) images were acquired on the day of birth to compare the anatomical findings with each sequence. We also performed curvilinear reconstruction of the CISS images, which can be reconstructed along the curved spinal cord and neural placode. RESULTS: Neural placodes were demonstrated in two patients on T1-W images and in three patients on T2-W images. T2-W images revealed a small number of nerve roots in two patients, while no nerve roots were demonstrated on T1-W images. In contrast, CISS images clearly demonstrated neural placodes and spinal nerve roots in four patients. These findings were in accordance with intraoperative findings. Curvilinear CISS images demonstrated the neuroanatomy around the myeloschisis in one slice. The resulting images were degraded by a band artifact that obstructed fine anatomical analysis of the nerve roots in the ventral CSF space. The placode and nerve roots could not be visualized in one patient in whom the CSF space was narrow due to the collapse of the myelomeningocele sac. CONCLUSION: MR CISS imaging is superior to T1-W and T2-W imaging for demonstrating the neural placode and nerve roots, although problems remain in terms of artifacts.

Heterogeneity of aquaporin-4 autoimmunity and spinal cord lesions in multiple sclerosis in Japanese.

Opticospinal multiple sclerosis (OSMS) in Asians has similar features to the relapsing-remitting form of neuromyelitis optica (NMO) seen in Westerners. OSMS is suggested to be NMO based on the frequent detection of specific IgG targeting aquaporin-4 (AQP4), designated NMO-IgG. The present study sought to clarify the significance of anti-AQP4 autoimmunity in the whole spectrum of MS. Sera from 113 consecutive Japanese patients with clinically definite MS, based on the Poser criteria, were assayed for anti-AQP4 antibodies by immunofluorescence using GFP-AQP4 fusion protein-transfected HEK-293T cells. Sensitivity and specificity of the anti-AQP4 antibody assay, 83.3 and 100%, respectively, were calculated using serum samples with NMO-IgG status predetermined at the Mayo Clinic. The anti-AQP4 antibody positivity rate was significantly higher in OSMS patients (13/48, 27.1%) than those with CMS (3/54, 5.6%), other neurological diseases (0/52) or healthy controls (0/35). None of the 11 patients tested with a brainstem-spinal form of MS were positive. Among OSMS patients, the antibody positivity rate was highest in OSMS patients with longitudinally extensive spinal cord lesions (LESCLs) extending over three vertebral segments and brain lesions that fulfilled the Barkhof criteria (5/9, 55.6%). Multiple logistic analyses revealed that emergence of the anti-AQP4 antibody was positively associated only with a higher relapse rate, but not with optic-spinal presentation or LESCLs. Compared with anti-AQP4 antibody-negative CMS patients, anti-AQP4 antibody-positive MS patients showed significantly higher frequencies of severe optic neuritis, acute transverse myelitis and LESCLs while most conditions were also common to anti-AQP4 antibody-negative OSMS patients. The LESCLs in anti-AQP4 antibody-positive patients were located at the upper-to-middle thoracic cord, while those in anti-AQP4 antibody-negative OSMS patients appeared throughout the cervical-to-thoracic cord. On axial planes, the former most frequently showed central grey matter involvement, while holocord involvement was predominant in the latter. In contrast, LESCLs in anti-AQP4 antibody-negative CMS patients preferentially involved the mid-cervical cord presenting a peripheral white matter-predominant pattern, as seen in the short lesions. Anti-AQP4 antibody-positive MS patients fulfilling definite NMO criteria showed female preponderance, higher relapse rate, greater frequency of brain lesions and less frequent responses to interferon beta-1b than anti-AQP4 antibody-negative OSMS patients with LESCLs. These findings suggested that LESCLs are distinct in anti-AQP4 antibody positivity and clinical phenotypes. There were cases of anti-AQP4 antibody-positive MS/NMO distinct from CMS, and anti-AQP4 antibody-negative OSMS with LESCLs in Japanese. This indicated that the mechanisms producing LESCLs are also heterogeneous in cases with optic-spinal presentation, namely AQP4 autoimmunity-related and -unrelated.

An intraorbital wooden foreign body: description of a case and a variety of CT appearances.

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.

Dynamic morphological changes in lumbosacral lipoma during the first months of life revealed by constructive interference in steady-state (CISS) MR imaging.

OBJECTS AND METHODS: In this study, we demonstrate the morphological change in two cases of lumbosacral lipoma during the first few months of life using a three-dimensional Fourier transformation-constructive interference in a steady-state (CISS) sequence that enables high-resolution images to be obtained with excellent contrast between cerebrospinal fluid (CSF), spinal roots, and lipoma. RESULTS: The CISS images clearly demonstrated the dynamic morphological changes such as lipoma growth observed in both cases and increased tethering effect in the case with lipomyelomeningocele. CONCLUSION: We have to keep in mind the potential for these morphological changes of the spinal lipoma during the first few months of life.

Mapping of subcortical white matter abnormality in Alzheimer's disease using diffusion-weighted magnetic resonance imaging.

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.

Cerebral white matter degeneration in frontotemporal dementia detected by diffusion-weighted magnetic resonance imaging.

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.