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1.
A 16-year-old female was involved in a jet ski (water craft) accident resulting in bilateral lower extremity fractures but no loss of consciousness or any other evidence of head trauma. Thirty hours later she became comatose. Magnetic resonance imaging was consistent with diffuse axonal injury. She recovered after several weeks without any clinical sequelae. This patient demonstrates an unusual example of diffuse axonal injury without direct head trauma and with delayed onset of symptoms. The authors recommend that patients involved in high-velocity accidents, even without immediate evidence of head injury, be observed for signs of diffuse axonal injury.  相似文献   

2.
A case of classical type Pelizaeus-Merzbacher disease was reported. This patient exhibited marked motor and mental developmental delay, and nystagmus, with a positive familial history. Electrophysiological studies, such as on brainstem auditory evoked potentials, blink reflex and somatosensory evoked potentials, suggested marked disturbance of nerve conduction in CNS. T2-weighted magnetic resonance (MR) images revealed non-progressive diffuse T2 prolongation of cerebral white matter after a 2-year interval, indicating congenital hypomyelination in CNS. A newly developed magnetic resonance diffusion imaging method demonstrated the existence of diffusional anisotropy in the corpus callosum, internal capsule, and white matter of the frontal lobe. Although the diffusional anisotropy was considered to depend on the well-developed multiple layers of myelin around the axons, the imaging data of this patient demonstrated that the diffusional anisotropy did not necessarily depend on those multiple layers. These results may indicate the potential usefulness of MR diffusion imaging, combined with electrophysiological studies and conventional MR imaging, for analyzing the lesions of the cerebral white matter.  相似文献   

3.
BACKGROUND AND PURPOSE: Very few reports are available on serial changes in human brain after cardiac arrest. The primary objective of this study is to investigate sequential neuroradiological changes in patients remaining in a persistent vegetative state following resuscitation after cardiac arrest. METHODS: We repeatedly studied eight vegetative patients resuscitated from unexpected out-of-hospital cardiac arrest using computed tomographic (CT) scanning and high-field magnetic resonance (MR) imaging at 1.5 T. RESULTS: In seven of the eight patients, CT scans obtained between days 2 and 6 features symmetrical low-density lesions in the bilateral caudate, lenticular, and/or thalamic nuclei. These ischemic lesions were persistently of low density on serial CT scans. In these seven patients, MR images demonstrated what were thought to be hemoglobin degradation products derived from minor hemorrhages localized in the bilateral basal ganglia, thalami, and/or substantia nigra. Diffuse brain edema in the acute stage and diffuse brain atrophy in the chronic stage were consistent neuroradiological findings. No abnormal enhanced lesions were demonstrated by CT scans. CONCLUSIONS: The most characteristic findings on high-field MR images were symmetrical lesions in the bilateral basal ganglia, thalami, and/or substantia nigra with specific changes suggestive of minor hemorrhages that were not evident on CT scans. We speculate that these minor hemorrhages result from diapedesis of red blood cells in these regions during the reperfusion period through the endothelium disrupted by ischemia-reperfusion insult.  相似文献   

4.
MR imaging of the corpus callosum   总被引:1,自引:0,他引:1  
The corpus callosum is the major axonal commissure of the brain, connecting the two cerebral hemispheres and providing communication between the cortical and subcortical neurons. With MR imaging in the sagittal plane, the corpus callosum can be depicted in great detail. We review the normal anatomy, development, and process of myelination of the corpus callosum. The MR features of various pathologic conditions involving the corpus callosum are described. Finally, we discuss the evolving role of MR imaging in neuropsychiatric diseases with respect to the corpus callosum.  相似文献   

5.
The value of magnetic resonance (MR) to establish the diagnosis of multiple sclerosis (MS) is well known. This study was undertaken to compare MR imaging of the brain of MS patients at high (1.5T) and mid (0.5T) field strength. 25 patients with MS underwent two consecutive MR studies within one hour, each consisting of axial proton density and T2-weighted spin-echo images. Lesions in the supratentorial white matter and corpus callosum and those in the brain stem and cerebellum were separately counted. At 1.5T significantly more lesions were seen than at 0.5T (p < 0.05). Although T2-weighted images at 1.5T added significant information compared to images obtained at 0.5T, in none of our 25 patients the diagnosis was missed at 0.5T. However, at 1.5T dissemination in space was better demonstrated, suggesting MR scanning with high field-units to be favourable in patients with clinically suspected MS.  相似文献   

6.
PURPOSE: To evaluate MR imaging and lumbar cerebrospinal fluid enzymes as potential sensitive indicators of cerebral injury after open-heart valve replacement surgery. METHODS: Thirty-four patients with cardiac valvular disease were prospectively entered into this study and then underwent valve replacement or repair under cardiopulmonary bypass using a membrane oxygenator. In 26 patients, MR head images were obtained 12 to 24 hours before surgery; repeat MR images were obtained between 1 and 2 weeks after surgery. In 18 patients, lumbar puncture cerebrospinal fluid was analyzed 24 to 48 hours after surgery; the analyses included measurement of lactic dehydrogenase, creatine phosphokinase, adenylate kinase, and neuron-specific enolase. RESULTS: After surgery, MR imaging showed new ischemic lesions in 15 (58%) of 26 patients: 7 with deep white matter hyperintense lesions; 5 with brain stem, caudate, cerebellar, or thalamic/basal ganglia infarcts; 1 with intraparenchymal hemorrhage; 1 with a subdural hematoma and cortical infarct; and 1 with a corpus callosum lesion consistent with calcium or air. These new ischemic lesions seen on MR images were associated with a focal neurologic deficit in only 4 (27%) of the 15 patients. Neuron-specific enolase and lactic dehydrogenase were abnormally elevated after surgery in 5 (28%) of 18 patients. Adenylate kinase and creatine phosphokinase (brain isozymes) were elevated in one (67%) of the patients. Two (40%) of the five patients with abnormally high neuron-specific enolase or lactic dehydrogenase after surgery also showed a new focal neurologic deficit. CONCLUSIONS: MR imaging is a sensitive measure of subclinical cerebral ischemia after cardiac valve replacement under cardiopulmonary bypass. Cerebrospinal fluid neuron-specific enolase and lactic dehydrogenase are less sensitive than MR imaging for detecting subclinical cerebral ischemia, but these values were elevated after surgery more frequently than was adenylate kinase in our patients.  相似文献   

7.
BACKGROUND AND PURPOSE: Quantitative MR spectroscopy has a proved role in the investigation of hypoxia caused by near drowning. To date, no studies have addressed the MR imaging changes that may also accompany this condition. The purpose of this study was to describe the MR imaging findings in children with hypoxic encephalopathy caused by near drowning and to compare these findings with the results of qualitative and quantitative proton MR spectroscopy and clinical outcome. METHODS: Twenty-two children (6 months to 11 years old) admitted to the pediatric intensive care unit after near drowning incidents underwent cerebral MR imaging and quantitative proton MR spectroscopy. Clinical and imaging studies were reviewed retrospectively, and subjects were grouped according to outcome: good result, persistent vegetative state, and death. Images were scored for edema, basal ganglia changes, and cortical changes, and were compared with MR spectra and outcome at days 1 to 2, 3 to 4, and 5 or more. RESULTS: Six patients had a good outcome, four remained in a persistent vegetative state, and 12 died. Generalized/occipital edema correlated with poor outcome. Indistinct lentiform nuclei margins on T1-weighted images were a frequent finding (78%). Basal ganglia T2 hyperintensity correlated with poor outcome, progressing from a patchy/peripheral distribution to diffuse high intensity. Patchy high T2 signal in the cortex or subcortical lines were specific but insensitive for poor outcome, as were brain stem infarcts. CONCLUSION: MR images in children with hypoxic encephalopathy after near drowning show a spectrum of changes. The most sensitive prognostic result may be achieved by combining MR imaging with qualitative and quantitative MR spectroscopic data.  相似文献   

8.
OBJECTIVE: The purpose of this article is to describe the findings on MR imaging and MR arthrography in posterior capsular tear and teres minor muscle injury after posterior dislocation. We also correlate MR imaging with the arthroscopic findings and present treatment options for these patients. CONCLUSION: MR imaging is helpful in diagnosing abnormalities caused by posterior dislocation injuries and in directing therapy. Teres minor muscle and capsular injuries may occur without the typical reverse Bankart lesion. Isolated teres minor muscle tears seen on MR imaging after posterior dislocation injury may cause pain. However, no consensus exists as to whether the lesions seen on MR images in these patients should be treated surgically or conservatively.  相似文献   

9.
The authors report the postoperative magnetic resonance (MR) imaging findings in 36 patients with advanced Parkinson's disease who underwent unilateral microelectrode-guided posteroventral pallidotomy. The lesions were placed within 1 mm of the ventral border of the globus pallidus internus (GPi) to include pallidothalamic outflow pathways. Sequential MR studies were obtained within 1 to 3 days postoperatively and at 6-month follow-up examination. Thirty-four (94%) of the 36 patients enjoyed sustained moderate or marked improvement of their parkinsonian symptoms 6 months postoperatively. Transient side effects occurred in five patients (14%), but there were no persistent complications. The pallidal radiofrequency lesions were prolate spheroid shaped and were composed of three concentric zones in the early postoperative studies. The mean volume of the middle zone, corresponding to the area of hemorrhagic coagulation necrosis, was 44.4 +/- 17.6 mm3; the mean lesion volume as defined by the outer zone, corresponding to perilesional edema, was 262.2 +/- 111.6 mm3. Additional edema spreading to the internal capsule was noted in 32 of 34 cases and to the optic tract in 11 of 34 cases. In two patients small ischemic infarctions involving the corona radiata were found, and in one a venous infarction was detected. Ischemic infarction resulted in mild transient Broca's aphasia in one patient, but there was no detectable neurological deficit in the other two. The mean volume of late-phase (6 months) lesions was 22 +/- 28.8 mm3. In three patients no lesion was identified despite sustained clinical improvement. The lesion was located in the posteroventral GPi in all cases except in one patient in whom it was confined to the GP externus (GPe). This 49-year-old woman did not experience sustained benefit. The authors found no consistent correlations between lesion size and location and clinical outcome as measured by a global outcome score, the Unified Parkinson's Disease Rating Scale motor, activities of daily living, and bradykinesia "off" scores or rating of dyskinesias. Lesioning of pallidal and subpallidal pathways may contribute to the sustained clinical benefit in this series. Magnetic resonance imaging analysis showed that intraoperative microelectrode recording facilitated accurate placement of the lesion in this critical area.  相似文献   

10.
The relationships between protein extravasation, morphological changes in neurons, and reactive changes in axons were evaluated in rats subjected to right lateral fluid-percussion injury to the brain (4.8-5.6 atm, 20 ms). Serial sections of the brain were immunostained with antibodies to rat immunoglobulin G (IgG) and 68-kDa neurofilament at 1 h to 2 weeks after injury or sham injury. Ischemic changes in neurons were noted in the injured cortex at 6-48 h after injury, and macroscopic hemorrhages were noted in the right corpus callosum and external capsule at 1 h to 1 week after injury. Extracellular IgG immunostaining was observed in the right cortex and right hippocampus at 1 h to 1 week after injury, and in the cortices and hippocampi bilaterally at 2 weeks after injury, but was most prominent in those regions at 24 h after injury. Intracellular IgG staining was noted in the neurons of cortices, hippocampi, brainstem, and cerebellum at 1 h to 2 weeks after injury. The number of IgG immunoreactive neurons was greatest at 1 week after injury. Thickened IgG immunoreactive axons and reactive axonal changes seen with neurofilament immunostaining were both in the similar region of the brainstem at 1 h to 1 week after injury. It appears that prolonged and widespread breakdown of the blood-brain barrier to plasma protein occurs after severe concussive brain injury and that this breakdown is not always accompanied by morphological changes. Intra-axonal IgG immunostaining provides additional clues to the pathogenesis of axonal damage following diffuse brain injury.  相似文献   

11.
OBJECTIVE: This report describes subcutaneous sarcoidosis, focusing on the radiological and magnetic resonance (MR) features of the disease. DESIGN AND PATIENTS: The cases of four patients (one male and three female, age range 36-75 years) who had subcutaneous sarcoidosis with no other organs affected were reviewed. Lesions were nodular in two cases, and in the other two were diffuse. RESULTS: Computed tomography (CT) demonstrated a well-defined, homogeneous, and enhanced lesion in the nodular cases. However, in the diffuse cases, CT showed a heterogeneous, honeycomb-like appearance and little enhancement. Angiography showed a fine stain in the arterial phase. MR imaging of the nodular lesions was homogeneous with a signal intensity similar to muscle on T1-weighted images but heterogeneous with a higher signal than muscle on T2-weighted images. Diffuse lesions showed a striped or mesh pattern with intermediate signal intensity on both T1- and T2-weighted images. Contrast-enhanced MR images showed slight enhancement. CONCLUSIONS: Subcutaneous sarcoidosis should be considered in the differential diagnosis when a patient presents with the radiological and MR features described.  相似文献   

12.
BACKGROUND AND PURPOSE: Eosinophilia myalgia syndrome (EMS), a multisystemic disease induced by exposure to L-tryptophan, may result in serious CNS abnormalities. The purpose of this study was to determine the pattern of neurologic characteristics, MR imaging abnormalities, and brain neurometabolites in EMS. METHODS: Sixteen patients with EMS and CNS abnormalities (CNS-EMS) and 12 control subjects underwent evaluation, including medical and neurologic examination, proton MR spectroscopy, and MR imaging. RESULTS: Neurologic findings that were increased in CNS-EMS included minor depression (100%), amnesia (88%), and intermittent confusion (38%), although fatigue (31%), motor disorders (31%), recurrent headache (19%), major depression (13%), and dementia (6%) also occurred, but at a lesser significance. Self-reported disability was markedly increased in CNS-EMS. MR imaging findings included subcortical focal lesions, focal lesions in deep white matter, cortical atrophy, ventricular dilatation, and diffuse and periventricular white matter abnormalities. MR spectroscopic findings established two distinct spectral patterns: 1) increased choline-containing compounds, decreased N-acetylaspartate, and increased lipid-macromolecules, consistent with inflammatory cerebrovascular disease; and 2) increased glutamine, decreased myo-inositol, and decreased choline, consistent with acute CNS injury or metabolic encephalopathy. CONCLUSION: Neurologic abnormalities, self-reported disability, brain lesions, and MR spectroscopic abnormalities are common in CNS-EMS. The pattern of cerebral lesions and neurometabolites is consistent with widespread inflammatory cerebrovascular disease. However, a subgroup of patients with CNS-EMS have neurometabolic changes consistent with a metabolic encephalopathy identical or similar to hepatic encephalopathy. The neurologic abnormalities in EMS and related hypereosinophilic syndromes should be interpreted cautiously, with the recognition that both cerebrovascular injury and secondary metabolic encephalopathies may be involved.  相似文献   

13.
Germinomas occurring in the thalamus and basal ganglia sometimes cause atrophy of the cerebral hemisphere on the affected side. The authors present the case of a 12-year-old girl with a germinoma that developed in the basal frontal lobe and cerebral basal ganglia. Magnetic resonance imaging showed atrophy not only of the cerebrum but also of the brainstem. A T2-weighted image revealed an area of high intensity that proved to be wallerian degeneration extending from the corona radiata and internal capsule to the brainstem. The authors suggest that this pathological change may be involved in the development of the symptoms and hemiatrophy associated with germinomas in this region of the brain.  相似文献   

14.
PURPOSE: To evaluate the sites of injury in patients with posttraumatic olfactory deficits and to compare damage with findings on clinical olfactory tests. METHODS: Twenty-five patients with posttraumatic olfactory dysfunction were examined by means of olfactory testing, endoscopy, and MR imaging. MR surface-coil scans through the olfactory bulbs and tracts and head-coil scans of the temporal lobes were evaluated. Quantitative and qualitative gradings of damage to the olfactory bulbs, tracts, subfrontal region, hippocampus, and temporal lobes were compared with results on tests of odor identification, detection, memory, and discrimination. RESULTS: Twelve patients were anosmic, eight had severe impairment, and five were mildly impaired. Injuries to the olfactory bulbs and tracts (88% of patients), subfrontal region (60%), and temporal lobes (32%) were found, but these did not correlate well with individual olfactory test scores. Volumetric analysis showed that patients without smell function had greater volume loss in olfactory bulbs and tracts than did those posttraumatic patients who retained some sense of smell. Qualitative and quantitative assessments of damage showed few significant correlations with olfactory tests, probably because of multifocal injuries, primary olfactory nerve damage, and the constraints of a small sample size on the detection of clinically significant differences. CONCLUSION: MR imaging shows abnormalities in patients with posttraumatic olfactory dysfunction at a very high rate (88%), predominantly in the olfactory bulbs and tracts and the inferior frontal lobes.  相似文献   

15.
PURPOSE: To determine whether dynamic traditional spin-echo MR imaging, with the use of routine T1 parameters during contrast infusion, is superior to standard MR imaging after contrast administration for detecting microlesions of the pituitary gland. METHODS: Sixty-four patients with pituitary microlesions 3 to 10 mm in diameter were examined with a dynamic traditional spin-echo technique; that is, a typical T1 spin-echo sequence of 500-600/20-25/2 (repetition time/echo time/excitations), 3-mm-thick sections, 16-cm field of view, 256 x 128 matrix, and a scan time ranging from 2 minutes to 2 minutes 40 seconds during contrast infusion. In addition, standard imaging with unenhanced and contrast-enhanced spin-echo sequences were obtained. The three sequences were evaluated retrospectively and graded for gland-lesion contrast conspicuity, lesion homogeneity, and delineation of lesion margin. RESULTS: The dynamic sequence was judged to be better than the standard enhanced sequence for depicting microlesions in 42% to 47% of patients. Lesions were identified only on the dynamic study in an additional 1% to 14% of patients. Lesions were seen equally well on the standard and dynamic sequences only in 16% to 23% of cases. The standard postcontrast sequence was judged better in 12.5% to 17% of cases, with lesions identified only on the standard sequence in an additional 8% to 9%. CONCLUSION: Dynamic traditional spin-echo MR imaging improved lesion detection and provided increased clarity over standard sequences after contrast infusion. Both sequences are important, since lesions were detected only on the dynamic sequence in 11% to 14% of patients and only on the standard sequence in 8% to 9% of patients.  相似文献   

16.
OBJECTIVES: To describe the imaging features of nephroblastomatosis with US, CT and MR, to point out characteristics of differentiation between nephrogenic rests (NR) and Wilms' tumour (WT) and to determine the most appropriate imaging modality. MATERIALS AND METHODS: We reviewed the US, CT and MR images of 29 cases of histopathologically confirmed nephroblastomatosis sent to our department for reference evaluation (German nephroblastoma study). The series included 17 kidneys with NR, 6 kidneys with WT and 32 kidneys with both NR and WT. RESULTS: NR presented as multinodular, peripheral, cortical lesions, the diffuse form of distribution being less common. Foci were homogeneous and of low echogenicity, density or signal intensity. The lesions were most clearly depicted with contrast-enhanced CT and T1-weighted (T1-W) MR images. Lesions smaller than 1 cm were rarely identified by US. The most reliable criterion to differentiate NR from WT was their homogeneity. CONCLUSIONS: Contrast-enhanced CT and T1-W MR images are of similar potential and superior to US in the diagnosis of nephroblastomatosis. Due to the significant radiation dose of serial CT, MR imaging should be the method of choice wherever it is available. The cost-effectiveness and availability of US makes it ideal for serial follow-up of known lesions.  相似文献   

17.
A 9-year-old girl with rigidospastic quadriplegia as post-traumatic sequela was reported. The distribution of lesions observed on a MRI implied diffuse axonal injury; involvement of the substantia nigra was also detected. L-Dopa administration was remarkably effective for relief of the rigidity. As a result, she became able to walk on her knees and communicate by writing letters. L-Dopa administration should be considered for patients who show rigidity as sequela of diffuse axonal injury with involvement of the substantia nigra.  相似文献   

18.
The relationship between spastic hemiplegia in diffuse axonal injury (DAI) and neuroradiological findings was studied in 100 cases. These cases were prospectively collected from the files of Automobile Insurance Rating Organization in Japan between 1993 from to 1996. Requirements for entry to this study were as follows: presence of initial unconsciousness after head injury without any lucid interval. Existence of CT scan or MRI film obtained within 12 hours of injury showing no significant mass effects, as well as follow-up CT scan or MRI film obtained more than 3 months after the injury. Psychosocial outcome was described both by the medical professional and the caregiver. The hemiplegia was rated severe, mild, or none. The outcome and diffuse ventriculomegaly were classified as reported by the authors previously. Spastic hemiplegia or quadriplegia was documented in the chronic stage in 63 cases, including 53 severe cases with difficulty in walking and 10 mild cases with only pyramidal signs detected. Chi-square analysis showed significant correlation between hemiplegia and the DAI outcome level or ventriculomegaly rating. Focal brain contusion was noticed in 33 cases, but did not correlate with the hemiplegia at all. Radiological findings included 25 cases of parasagittal white matter injury (gliding contusion), 20 cases of callosal injury, 19 cases of basal ganglionic region injury, 5 cases of brain-stem injury, and 3 cases of cerebellar injury. Chi-square analyses of hemiplegia and contralateral presence of these injuries were significant in the former three types of injury. Presence of at least one of these 3 lesions was defined as GCB injury. There were altogether 46 GCB injury cases which were significantly correlated with contralateral hemiplegia by chi-square analysis and by Spearman rank analysis. Partial correlation analysis with hemiplegia as the target variable indicated highly significant correlation only with GCB injury and outcome level. In conclusion, spastic hemiplegia in DAI is a manifestation of primary shear injury. Neuroradiological findings of GCB injury were statistically able to be significantly correlated with the presence of hemiplegia, and suggested pyramidal tract injury either at the corona radiata or the internal capsule level.  相似文献   

19.
Clinical and evoked-potential studies in internal capsule and corona radiata infarction are lacking. We report the results of a clinical and central motor conduction time (CMCT) study in 16 patients with internal capsule and 17 with computed tomography (CT)-proven corona radiata infarction. Patients's outcome was defined at the end of 3 months on the basis of the Barthel Index score. Four patients with type A capsular infarction (middle third of posterior limb of internal capsule) all had severe weakness, while 2 also had persistently unrecordable CMCT and poor outcome. Twelve patients with type B internal capsular infarction (genu, anterior limb, anterior or posterior third of posterior limb) had a milder degree of weakness, and CMCT was recordable in 9. At 3 months' follow-up, however, CMCT was recordable in all 12 patients. All of these patients had a partial (n = 4) or complete (n = 5) recovery. Thirteen patients with type A corona radiata infarction (middle third of corona radiata) had more pronounced weakness, and CMCT was unrecordable in all of these patients except 1 on initial examination. Follow-up after 3 months was possible in 8 patients, and CMCT became recordable in 3. One of these patients had complete, 3 partial, and 4 poor recovery. In type B corona radiata infarction (anterior or posterior third of corona radiata), the clinical signs and CMCT did not follow a regular pattern. Clinical and CMCT abnormalities in internal capsular infarction followed a more predictable pattern compared with those in corona radiata infarction. A less predictable pattern of weakness and CMCT change in corona radiata infarction may be attributed to a less definite organisation of motor pathways compared with the internal capsule.  相似文献   

20.
Diffuse axonal injury (DAI) was diagnoses according to axonal reaction proved as balls by Palmgren's silver impregnation and axonal lesions by immunohistochemical investigation of ubiquitin and low molecular weight neurofilaments (68 kD). Diffuse axonal injury was found in 16 cases from a group of 36 persons deceased of craniocerebral trauma (44%). Diagnosis was based on the presence of axonal retraction balls in 15 cases; the balls showed also a striking positivity with antibodies against ubiquitin and low molecular neurofilaments as well. In the last patient who died 10 hours after a head injury, too early for axonal retraction balls to be formed, diagnosis of DAI could be settled because of the presence of axonal swellings immunohistochemically positive for ubiquitin and neurofilaments. A control groups of 6 persons after sudden death showed both axonal widenings and swellings but their immunohistochemistry was negative. Immunohistochemical methods of proving ubiquitin and low molecular weight neurofilaments represent substantial contribution to diagnosis of diffuse axonal injury. Earlier phase of axonal lesions than in simple histology can be observed and histological diagnosis of axonal injury independently confirmed.  相似文献   

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