Adult-Onset Leukoencephalopathy with Axonal Spheroids and Pigmented Glia (ALSP) with Novel CSF1R Mutation

Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a subtype of dominantly inherited leukoencephalopathies caused by novel CSF1R gene mutation predominantly affecting the cerebral white matter. High signal lesions on diffusion weighted image (DWI) are characteristic. Herein, we describe a patent with ALSP with a novel mutation. The patient had persistent DWI lesions, worsening white matter changes associated with rapidly progressive clinical symptoms.

Adult-onset neuronal intranuclear inclusion disease: a case report and review of literature / 中华神经科杂志

The clinical, pathological features and diagnostic methods of one case of adult-onset neuronal intranuclear inclusion disease (NIID) were analyzed. The patient was 61-year-old female presented with progressive cognitive impairment, episodic unconsciousness, stroke-like attack and paroxysmal digestive tract symptoms. Diffusion-weighted images showed high signals at the cerebral cortico-medullary junction with lace-type distribution, which persisted. Skin biopsy revealed intranuclear inclusion bodies in adipocytes, fibroblasts, and sweat gland cells. This case suggests that adult neuronal nuclear inclusion disease is a chronically progressive neurodegenerative disease with a highly clinical heterogeneity. The subcortical lace sign and eosinophilic intranuclear inclusion bodies by skin biopsy contribute to the diagnosis.

Chlorfenapyr-Induced Toxic Leukoencephalopathy with Radiologic Reversibility: A Case Report and Literature Review

Chlorfenapyr is a widely used, moderately hazardous pesticide. Previous reports have indicated that chlorfenapyr intoxication can be fatal in humans. We reported the first non-fatal case of chlorfenapyr-induced toxic leukoencephalopathy in a 44-year-old female with resolution of extensive and abnormal signal intensities in white matter tracts throughout the brain, brain stem, and spinal cord on serial magnetic resonance imaging.

Microembolism after Endovascular Treatment of Unruptured Cerebral Aneurysms: Reduction of its Incidence by Microcatheter Lumen Aspiration / 신경중재치료의학

PURPOSE: Diffusion-weighted MR images (DWI) obtained after endovascular treatment of cerebral aneurysms frequently show multiple high-signal intensity (HSI) dots. The purpose of this study was to see whether we could reduce their incidence after embolization of unruptured cerebral aneurysms by modification of our coiling technique, which involves the deliberate aspiration of the microcatheter lumen right after delivery of each detachable coil into the aneurysm sac. MATERIALS AND METHODS: From January 2011 to June 2011, all 71 patients with unruptured cerebral aneurysms were treated using various endovascular methods. During the earlier period, 37 patients were treated using our conventional embolization technique (conventional period). Then 34 patients were treated with a modified coiling technique (modified period). DWI was obtained on the following day. We compared the occurrence of any DWI HSI lesions and the presence of the symptomatic lesions during the two time periods. RESULTS: The incidence of the DWI HSI lesions differed significantly at 89.2% (33/37) during the conventional period and 26.5% (9/34) during the modified period (p < 0.0001). The incidence of symptomatic lesions differed between the two periods (29.7% during the conventional period vs. 2.9% during the modified period, p < 0.003). CONCLUSION: Aspiration of the inner content of the microcatheter right after detachable coil delivery was helpful for the reduction of the incidence of microembolisms after endovascular coil embolization for the treatment of unruptured cerebral aneurysms.

Diffusion-Weighted Imaging for Pretreatment Evaluation and Prediction of Treatment Effect in Patients Undergoing CT-Guided Injection for Lumbar Disc Herniation

OBJECTIVE: To determine whether a change in apparent diffusion coefficient (ADC) value could predict early response to CT-guided Oxygen-Ozone (O2-O3) injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation. MATERIALS AND METHODS: A total of 52 patients with unilateral mono-radiculopathy received a single intradiscal (3 mL) and periganglionic (5 mL) injection of an O2-O3 mixture. An ADC index of the involved side to the intact side was calculated using the following formula: pre-treatment ADC index = ([ADC involved side - ADC intact side] / ADC intact side) x 100. We analyzed the relationship between the pre-treatment Oswestry Disability Index (ODI) and the ADC index. In addition, the correlation between ODI recovery ratio and ADC index was investigated. The sensitivity and specificity of the ADC index for predicting response in O2-O3 therapy was determined. RESULTS: Oswestry Disability Index and the ADC index was not significantly correlated (r = -0.125, p = 0.093). The ADC index and ODI recovery ratio was significantly correlated (r = 0.819, p < 0.001). When using 7.10 as the cut-off value, the ADC index obtained a sensitivity of 86.3% and a specificity of 82.9% for predicting successful response to therapy around the first month of follow-up. CONCLUSION: This preliminary study demonstrates that the patients with decreased ADC index tend to show poor improvement of clinical symptoms. The ADC index may be a useful indicator to predict early response to CT-guided O2-O3 injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation.

Rapid Regression of White Matter Changes in Hypoglycemic Encephalopathy

PURPOSE: In a previous report, it took several days for white matter lesions to regress in hypoglycemic encephalopathy. We present a case of rapid diffusion-weighted image (DWI) changes in hypoglycemic encephalopathy. CASE REPORT: A 58-year-old male patient was found semi-comatous with the only abnormality in his laboratory tests showing hypoglycemia (44 mg/dL). After rapid correction of glucose level, immediate brain DWI showed bilateral subcortical white matter lesions. After about 5 hours, follow-up DWI showed resolved subcortical white matter lesions, with newly-appeared bilateral fronto-temporo-parietal cortical lesions. CONCLUSION: Both white matter and cortex involvement in hypoglycemic encephalopathy has been shown in several reports, but rapid regression of white matter changes in hypoglycemic encephalopathy has been rarely reported. It is important to know that MR imaging changes in hypoglycemic encephalopathy can be made as quick as just a few-hour-long.

Role of Diffusion-Weighted Imaging as a Prognostic Indicator in Acute Hypoxic Encephalopathy / 대한임상신경생리학회지

BACKGROUND: Diffusion-weighted image (DWI) might be useful to predict the prognosis of acute hypoxic encephalopathy. The aim of our study was to test whether the early change and extent of DWI abnormalities can be an indicator of the clinical outcome of hypoxic encephalopathy. METHODS: Forty-four patients who were diagnosed as hypoxic encephalopathy due to the cardiorespiratory arrest were retrospectively identified. Clinical variables were determined, and the DWI abnormalities were counted by four areas: cortex, subcortical white matter, cerebellum and deep grey matter, and were divided into three groups by the extent of lesions. Prognosis was classified as 'poor' (Glasgow coma scale (GSC) at 30 days after arrest or =9). RESULTS: GCS at day 3 (p<0.001), presence of seizure (p=0.01), and presence of lesion (p<0.001) were significantly different in prognosis, but statistically there is no association with the extent of lesions and prognosis (p=0.26). CONCLUSIONS: Presence of early DWI changes could predict the clinical outcome of hypoxic encephalopathy after cardiorespiratory arrest.

Perfusion MR Imaging of Seizure-related Cerebral Cortical Lesion: A Case Report

When cerebral cortical hyperintensities on diffusion-weighted image are seen in patients with suspected acute stroke accompanying seizure, it is necessary to differentiate whether they are caused by infarction or seizure-related change. We report a case of seizure-related cortical hypertensities in a patient with suspected acute infarction. With perfusion MR imaging, we could differentiate from acute infarction.

Performance of PROPELLER technique in reducing susceptibility artifacts in diffusion-weighted MR images / 第二军医大学学报

Objective To evaluate the performance of PROPELLER diffusion-weighted magnetic resonance image (DWI) in reducing image distortion caused by susceptibility artifacts. Methods Forty volunteers with metal denture were enrolled in the present study; their PROPELLER and echo-planar DWI were taken for the skull base. The quality of each image was evaluated by using a four-point scoring system. Qualitative comparison of image distortion between PROPELLER DWI and echo-planar DWI was performed by ROC analysis. Results The area under the ROC curve was 0.979 (P<0.01), indicating a significant difference in the image distortion between PROPELLER DWI and echo-planar DWI. PROPELLER technique could greatly reduce the image distortion associated with magnetic susceptibility artifacts. Conclusion PROPELLER technique can greatly reduce metal denture-induced susceptibility-related image distortion, and ROC curve can be used for quantitative analysis of subjective assessment of image quality.

Pre-operative Evaluation of Consistency in Intra-axial Brain Tumor with Diffusion-weighted Images (DWI) and Conventional MR Images

PURPOSE: To retrospectively evaluate the usefulness of diffusion-weighted images, ADC maps and conventional MR images for determination of brain tumor consistency. MATERIALS AND METHODS: Twenty-three patients with brain tumor underwent MR examinations with T1, T2 and diffusion-weighted images. Regions of interest (ROIs) were drawn in the tumors, and the measured signal intensities (SI) were normalized with the contralateral side. We evaluated the correlation between SI ratios from various images and tumor consistency assessed at surgery. In three patients with both cystic and solid components, each component was evaluated independently. Qualitatively observed SIs were also correlated with tumor consistency. RESULTS: Statistical analysis revealed significant correlation between tumor consistency and ADC ratio (r = -0.586, p = 0.002), SI ratios on T2-weighted images (r = -0.497, p = 0.010), and observed SIs on T2-weighted images (r = -0.461, p = 0.018). The relative ratio of ADC value correlated with tumor consistency most strongly. CONCLUSION: The measured ratio of ADC, SI ratio and observed SI grade on T2-weighted images can provide valuable information about the consistency of brain tumor.

SNR and ADC Changes at Increasing b Values among Patients with Lumbar Vertebral Compression Fracture on 1.5T MR Diffusion Weighted Images / 의학물리

To examine among patients with vertebral compression fracture the extent to which signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values at the lumbar vertebral compression fracture site vary on diffusion-weighted MR images according to varying b values on the 1.5T MR device. Diffusion-weighted MR images of 30 patients with compression fracture due to chronic osteoporosis who underwent vertebral MRI from Jan. 2008 to Nov. 2009 were respectively obtained using a 1.5-T MR scanner with the b values increased from 400, 600, 800, 1,000 to 1,200 s/mm2. For diffusion-weighted MR images with different b values, the signal-to-noise ratio (SNR) was assessed at three sites: the site of compression fracture of the lumbar vertebral body at L1 to L5, and both the upper and lower discs of the said fracture site, while for ADC map images with different b values, the SNR and ADC were respectively assessed at those three sites. As a quantitative analysis, diffusion-weighted MR images and ADC map images with b value of 400 s/mm2 (the base b values) were respectively compared with the corresponding images with each different b value. As far as qualitative analysis is concerned, for both diffusion-weighted MR and ADC map images with b value of 400 s/mm2, the extent to which signal intensity values obtained at the site of compression fracture of the lumbar vertebral body at L1 to L5 vary according to the increasing b values were examined. The quantitative analysis found that for both diffusion-weighted MR and ADC map images, as the b values increased, the SNR were relatively lowered at all the three sites, compared to the base b value. Also, it was found that as the b values increased, ADC values were relatively lowered at all the three sites on ADC map images. On the other hand, the qualitative analysis found that as the b values increased to more than 400 s/mm2, the signal intensity gradually decreased at all the sites, while at the levels of more than 1,000 s/mm2, severe image noises appeared at all of the three sites. In addition, higher signal intensity was found at the site of compression fracture of the lumbar vertebral body than at the discs. Findings showed that with the b value being increased, both the signal-to-noise ratio (SNR) and Apparent Diffusion Coefficient (ADC) values gradually decreased at all the sites of the lumbar vertebral compression fracture and both the upper and lower discs of the fracture site, suggesting that there is a possibility of a wider range of applications to assessment of various vertebral pathologies by utilizing multi b values in the diffusion-weighted MRI examination.

Assessment of Osteoporosis Based on Changes in SNR and ADC Values on MR Diffusion Weighted Images / 의학물리

This study tested how S/N (Signal to Noise Ratio) ratios and ADC (apparent diffusion coefficient) values vary with different T-scores in a group of patients with osteoporosis. Based on DEXA (Dual Energy X-ray Absorptiometry) T-scores for L1?L4 for two groups of subjects consisting of 30 healthy people without osteoporosis and 30 patients who came for treatment of waist (lumbar or low back) pain and were suspected to have osteoporosis as judged from the simple X-ray findings, this study classified every spine into two groups of osteoporosis and osteopenia. Signal intensity measurements were made in the four regions of L1 to L4 on diffusion-weighted MR images obtained using 1.5T MR scanner, while ADC measurements were obtained from ADC map images. As an approach for quantitative analysis, the comparison of the variances in S/N ratios and ADC values for varying T-scores in the selected regions of interest was carried out based on averaged T-scores, S/N ratios, and ADC values. Also, the variances in S/N ratios and ADC values for each of the groups of osteoporosis and osteopenia, which were classified into by T-scores, were compared. For qualitative analysis, a careful naked eye examination of signal intensity differences in the area of L4 was made on T1-weighted sagittal images for each of the healthy (normal), osteopenia, and osteoporosis groups. In the qualitative analysis, it was found that for both the osteopenia group and the osteoporosis group, as T-scores deceased, the S/N ratios on diffusion-weighted MR images also decreased, with the greatest decrease in the S/N ratio found in the osteoporosis group. Additionally, among the three groups, the lowest S/N ratio was found in the osteoporosis group. With respect to ADC map, it was found that for both the osteopenia group and the osteoporosis group, as T-scores deceased, the ADC values on diffusion-weighted MR images also decreased, with the greatest decrease in the ADC values found in the osteoporosis group. Additionally, among the three groups, the lowest ADC value was found in the osteoporosis group. On the other hand, in the qualitative analysis, the osteoporosis group showed the highest signal intensity. Additionally, among the three groups, the lowest signal intensity was found in the healthy (normal) group. It was found that as osteoporosis progressed, S/N ratio and ADC decreased, whereas signal intensity increased on T1-weighted images. Also, in diagnosing osteoporosis, MRI tests turned out to be (more) effective.

Diffusion-weighted MRI Lesion Patterns in Large Artery Atherosclerotic Disease with Microembolic Signals

BACKGROUND: Microembolic signals (MES) are associated with the pathogenic mechanism of ischemic stroke with large-artery atherosclerotic disease. We examined the relationship between MES on a transcranial Doppler ultrasonography (TCD) and lesion patterns on diffusion-weighted MR imaging (DWI) in acute ischemic strokes associated with atherosclerotic diseases of the middle cerebral artery (MCA) and internal carotid artery (ICA). METHODS: A total of 405 consecutive patients were monitored for MES within 48 hours of symptom onset. Patients with MES and DWI lesions in the territory of the MCA or ICA and corresponding MCA/ICA stenosis or occlusion on MR angiography (MRA) were included. MCA velocities and lesion patterns on DWI were compared. RESULTS: MES were detected in 25 patients (MCA: 13, ICA: 12). The mean number of MES during 30 minutes of monitoring was 14.2+/-17.3 (range: 1-64, MCA: 13.9+/-13.6, ICA: 14.5+/-21.6, p-value=0.098). The mean flow velocity in the ipsilateral MCA in patients with MCA disease was higher than in patients with ICA disease (129.9+/-74.4 cm/s vs 61.1+/-28.2 cm/s, p=0.006). The frequency of multiple lesions on DWI was higher inpatients with ICA disease than in those with MCA disease (46.1% vs 100%, p=0.003). CONCLUSIONS: Multiple lesions on DWI were more frequent in ICA disease with MES than in MCA disease. Artery-to-artery embolism may be a more important stroke mechanism in acute ischemic stroke with ICA disease.

Three Cases of Transient Global Amnesia with Focal High Signal Intensity in Hippocampus in Diffusion Weighted Image

Transient global amnesia (TGA) is an amnesic disorder which is characterized by temporary loss of anterograde and recent retrograde memory with preserved consciousness. Though the pathogenesis of TGA is still unclear, current hypotheses include migraine, seizure, or cerebral ischemia. We present three patients with TGA who showed signal intensity change in diffusion weighted image in hippocampus. These findings might suggest that ischemia in hippocampus might be the cause of the TGA.

Relapsing Herpes Simplex Encephalitis

Herpes simplex encephalitis (HSE) is the most common type of viral encephalitis and a fourteen day administration of acyclovir is well-known as the treatment of choice for HSE. Occasionally HSE relapses, but rarely with acyclovir treatment. We report a case of relapsing HSE after treatment with acyclovir for 14 days. Our case suggests that patients with progressive high signal intensities in diffusion-weighted brain MRIs might need longer antiviral therapy over 14 days for preventing the relapse of herpes simplex encephalitis.

A Middle Cerebral Artery Occlusion Model in Rabbits: Development with Endovascular Interventional Techniques and Evaluation by Magnetic Resonance Imaging

PURPOSE: The aim of this study was to develop a new middle cerebral artery occlusion (MCAO) model in rabbits using a less invasive, endovascular interventional technique. The new animal model's technical feasibility and its success in producing lesions was evaluated using magnetic resonance imaging (MRI). MATERIALS AND METHODS: Ten rabbits were used to develop the MCAO models using a transfemoral catheter-based technique. After catheterization of the common carotid artery, a microcatheter was introduced coaxially through the catheter to cannulate the internal carotid artery and to embolize the MCA with polyvinyl alcohol particles. We evaluated how successful we were in selecting the vessels, catheterization, embolization, and also evaluated how many of the animals survived until the end of experiment. Diffusion-weighted imaging (DWI) and T2-weighted imaging (T2WI) were performed in one-hour intervals to monitor the ischemic lesion for a total of six hours following successful occlusion of the target artery. The relative volume of the lesion was calculated as a hemispheric lesion volume (HLV, %). The signals of the lesion and contralateral normal brain (control) were measured in each image at every time point. Lesion-to-control signal-intensity ratio (SIR) of DWI, and T2WI were obtained together with relative apparent diffusion coefficient (rADC). RESULTS: Catheterization and embolization of the internal carotid artery were successful in all 10 rabbits, which showed relevant lesions on MRI. All rabbits survived until the end of the experiment. The HLV (mean+/-standard deviation) was 35.7+/-14.6%. The relative ADC was 0.80+/-0.13. The lesion signals on DWI and T2WI showed a gradual increase as time passed, while the ADC value of the lesion gradually decreased (p<0.0001). CONCLUSION: The rabbit MCAO model using an endovascular interventional technique is technically feasible, and provides a reproducible lesion in the target arterial territory. MRI successfully revealed a typical finding of acute cerebral infarction. This model is also believed to be suitable for the MRI investigation of acute cerebral ischemia.

Two Cases of Hypertensive Brainstem Encephalopathy

Hypertensive encephalopathy is a medical disorder, which occurs with sudden increase of blood pressure (BP). The MRI findings of hypertensive encephalopathy are diffuse hyperintensity on T2-weighted images, predominantly within the cortex and subcortical white matter of the parieto-occipital lobe. The brainstem is rarely involved. Diffusion-weighted images do not show any abnormalities. We report two patients with hypertensive encephalopathy whose MRI showed exclusive brainstem involvement. They improved rapidly after BP control.

Two Cases of Hypertensive Brainstem Encephalopathy

Hypertensive encephalopathy is a medical disorder, which occurs with sudden increase of blood pressure (BP). The MRI findings of hypertensive encephalopathy are diffuse hyperintensity on T2-weighted images, predominantly within the cortex and subcortical white matter of the parieto-occipital lobe. The brainstem is rarely involved. Diffusion-weighted images do not show any abnormalities. We report two patients with hypertensive encephalopathy whose MRI showed exclusive brainstem involvement. They improved rapidly after BP control.

A Case of Post-Transfusion Posterior Leukoencephalopathy with Cytotoxic and Vasogenic Edema

We report a patient who developed posterior leukoencephalopatty (PLE) after a transfusion with vasospasm and both features of cytotoxic and vasogenic edema. The cytotoxic edema developed in the cerebral region hemodynamically more compromised. Different mechanisms may occur in PLE according to the degree of ischemic burden related to vasospasm.

A Serial Diffusion-weighted MR Imaging Study in Delayed Postanoxic Encephalopathy

BACKGROUND: Delayed postanoxic encephalopathy (DPE) is a demyelinating disorder in which cognitive, behavioral and movement deteriorations relapse in a few weeks after a complete recovery from initial hypoxic injury. To our knowledge, there have been no reports describing the temporal change of diffusion-weighted imaging (DWI) findings in DPE. METHODS: In a patient with DPE, serial brain MRI including DWI was performed at admission, 1, 3, 5 and 11 months after the onset of DPE. In order to obtain apparent diffusion coefficient (ADC) value of the lesion, we selected the same axial slices of the serial DWI and placed eight regions of interest (ROIs) in the periventricular white matter. Mean ADC values of ROIs and ADC map were serially compared. RESULTS: Compared to normal value, the ADC values of ROIs remained low at admission and one-month follow-up (0.68+/-0.08 and 0.67 +/- 0.08 X 10(-3)mm2/s) and then continued to increase on the 3, 5 and 11-month follow-up (0.78+/-0.05, 0.80+/-0.05 and 0.87 +/- 0.11 X 10(-3)mm2/s). Abnormal low signal density in both periventricular white matters on initial ADC map also disappeared slowly. Serial ADC maps revealed continuing diffuse cytotoxic edema over 1 month after the onset of DPE. CONCLUSIONS: Delayed cytotoxic edema associated with delayed clinical symptom of DPE might implicate that possible pathogenesis of DPE is apoptosis. DWI including ADC map might be useful to detect apoptotic brain lesion.