Bilateral subdural hematomas exactly isodense to the subjacent gray matter.
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Emergency Service, Hospital↗
Biomedical subjects
A I Holodny
Publications and source records attributed to A I Holodny.
Quantitative assessment of cerebral ventricular volumes in chronic fatigue syndrome.
Previous qualitative volumetric assessment of lateral ventricular enlargement in chronic fatigue syndrome (CFS) has provided evidence for subtle structural changes in the brains of some individuals with CFS. The aim of this pilot study was to determine whether a more sensitive quantitative assessment of the lateral ventricular system would support the previous qualitative findings. In this study, we compared the total lateral ventricular volume, as well as the right and left hemisphere subcomponents in 28 participants with CFS and 15 controls. Ventricular volumes in the CFS group were larger than in control groups, a difference that approached statistical significance. Group differences in ventricular asymmetry were not observed. The results of this study provide further evidence of subtle pathophysiological changes in the brains of participants with CFS.
Adult↗
Tumor involvement of the corticospinal tract: diffusion magnetic resonance tractography with intraoperative correlation.
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Brain Neoplasms↗
Identification of the corticospinal tracts achieved using blood-oxygen-level-dependent and diffusion functional MR imaging in patients with brain tumors.
Diffusion-weighted MR imaging was used to delineate the corticospinal tract (CST) successfully and to depict its relationship to adjacent brain tumors. The CST was defined by a method by which it seems possible to delimit the distance from the CST to the main tumor mass and to show displacement and infiltration of the tract by the neoplasia. This information cannot be gathered from routine anatomic MR imaging.
Adolescent↗
Tumefactive fibroinflammatory lesion of the neck with progressive invasion of the meninges, skull base, orbit, and brain.
SUMMARY: Tumefactive fibroinflammatory lesions of the head and neck are rare. CNS involvement has not been reported. We present a histologically proven case of a tumefactive fibroinflammatory lesion that originated in the left side of the neck and progressed over 2 years to involve the meninges, the cavernous sinuses, the right temporal lobe, and the right orbit. The lesion caused destruction of the skull base and a subdural hematoma. The relationship of the present lesion to idiopathic hypertrophic pachymeningitis and Tolosa-Hunt syndrome is discussed.
Adult↗
Does a herniated nucleus pulposus contribute significantly to a decrease in height of the intervertebral disc? Quantitative volumetric MRI.
A lumbar intervertebral disc with a herniated nucleus pulposus (HNP) often exhibits a decrease in the height of the intervertebral space. Our purpose was to ascertain whether the loss of volume of an HNP is sufficient to cause a perceptible decrease in the height of the intervertebral space. MRI of 44 patients with 51 HNPs were reviewed. The volumes of the herniated material and of the intervertebral discs were calculated for every level from L1-2 to L5-S1. The average volume of the HNP was 503 +/- 301 mm3. The average volumes of all 220 intervertebral discs and of the 127 normal-appearing discs were 14,442 +/- 4200 mm3 and 17,476 +/- 2885 mm3 respectively. The average volume of the HNP represented 3.5% of the parent disc. An average HNP caused a decrease in intervertebral space height of 0.35 mm (0.56 pixels). Therefore, the loss of the volume of the HNP does not cause a significant decrease in the intervertebral space height. The average calculated decrease in the disc height is less than that reported in normal diurnal variation.
Adult↗
Double-shot magnetic resonance imaging of cerebral lesions: fast spin-echo versus echo planar sequences.
The authors compared two new rapid MRI techniques: double-shot echo-planar imaging (DS-EPI) versus double-shot fast spin-echo (DS-FSE) in the evaluation of cerebral lesions. The authors examined 35 patients with 37 lesions, which were hyperintense on long TR images. Patients were scanned with both DS-EPI and DS-FSE with a time of repetition (TR) of 10,000 milliseconds and an echo time (TE) of 80 milliseconds. Conspicuity was determined from region of interest measurements to calculate contrast to noise ratio (C/N). Visual comparisons between DS-EPI and DS-FSE, and between DS-EPI and T2-weighted conventional spin-echo (CSE) were also performed to evaluate the sequences' ability to depict hemorrhage. The mean C/N for both sequences was comparable: 36.7 for DS-FSE and 35.6 for DS-EPI, with no statistically significant difference (p = 0.77). With regards to depicting blood products, DS-EPI proved far more effective than DS-FSE and comparable to CSE. Also, DS-EPI proved to be more time-efficient, requiring 1.67 seconds per section, while DS-FSE required 3.33 seconds per section. Whereas DS-FSE and DS-EPI are comparable in their ability to depict hyperintense cerebral pathology, DS-EPI is more time-efficient, and therefore appears preferable. Because of the high magnetic susceptibility of DS-EPI, geometric distortion degrades visualization of lesions in the posterior fossa or near the sinuses. On the other hand, the high magnetic susceptibility results in high conspicuity of blood products.
Brain↗
Functional magnetic resonance imaging aided radiation treatment planning.
Functional MRI (magnetic resonance imaging) allows one to noninvasively identify various eloquent cortices in the brain. The integration of cortical activation information into radiosurgical treatment planning may provide an alternative to prevent or minimize radiation damage to eloquent cortex. A novel approach of directly integrating the fMRI (functional magnetic resonance imaging) brain map into treatment planning is proposed. Three brain tumor patients have been studied using this method with motor and/or visual paradigms. Brain activation was demonstrated in eloquent cortex at the precentral gyrus (motor area) and medial occipital lobe (visual area). The activation maps were transferred to a treatment planning workstation, (XKnife), and 3D (three-dimensional) activation maps were generated and co-registered to a 3D CT (computed tomography) anatomical data set, which provided the calibration localizer, for treatment planning. Radiosurgery was designed based on both functional and structural information by the medical team consisting of a radiation oncologist, a neurosurgeon and a physicist. The average maximum dose for the tumor was 2113 cGy. The average maximum dose for tissue surrounding the tumor was 1600 cGy. The average dose with fMRI information to the eloquent cortex was 163.4 cGy over three patients, while without fMRI information it was 240.5 cGy. The average percentage dose reduction over three patients is 32%. The results suggest that using this method can reduce the dose to the eloquent cortex. This approach provides the physician with additional information for treatment planning and may spare the patient unnecessary radiation exposure to adjacent eloquent cortices.
Adult↗
The effect of brain tumors on BOLD functional MR imaging activation in the adjacent motor cortex: implications for image-guided neurosurgery.
BACKGROUND AND PURPOSE: Functional MR (fMR) imaging data coregistered to a neurosurgical navigation system have been proposed as guides for the resection of brain tumor in or adjacent to eloquent cortices. The purpose of this study was to compare data obtained from the side of the brain affected by tumor with the contralateral side and to determine if there are physiological limitations of fMR imaging in accurately determining the location of the primary motor cortex. METHODS: Ten patients with tumors in or directly adjacent to the motor cortex were studied with fMR imaging (finger-tapping paradigm). fMR imaging data were analyzed using multiple R values. These data were coregistered to a real-time intraoperative neurosurgical navigation system. RESULTS: Significant variability of motor cortex activation patterns was noted among individual patients. The activation volumes on the side of the tumor were significantly smaller compared with the contralateral side for all tumors not previously resected (0.66+/-0.47). This was most pronounced in glioblastomas (0.27+/-0.21). We propose that these differences were caused by a loss of autoregulation in the tumor vasculature of glioblastomas and venous effects. CONCLUSION: Notwithstanding the differences noted, the motor cortex was identified successfully in all patients. This was confirmed by intraoperative physiological identification of the motor cortex and a lack of postoperative neurologic deficit.
Brain Neoplasms↗
Correlation between the degree of contrast enhancement and the volume of peritumoral edema in meningiomas and malignant gliomas.
Peritumoral edema and contrast enhancement of brain tumors are both thought to be due to breakdown of the blood-brain barrier (BBB); however, the exact mechanism by which these two phenomena occur and whether there is a quantitative or etiological relationship is not known. Our purpose was to determine whether the relationship between the breakdown of the BBB, defined radiologically as the degree of contrast enhancement, and the volume of surrounding edema is different for high-grade gliomas and meningiomas. We analyzed 13 meningiomas and 23 gliomas. A direct linear relationship between the degree of contrast enhancement (dC) and volume of peritumoral edema (V) with a high correlation coefficient (R = 0.66, P = 0.0006) was established for gliomas. A mathematical relationship between dC and V could not be established for meningioma. The findings for gliomas offer indirect radiological evidence that the defect in the BBB which causes edema is quantitatively and etiologically related to the defect in the BBB responsible for contrast enhancement. For meningiomas, the lack of a relationship between dC and V implies either that the mechanisms responsible for formation of edema and contrast enhancement are fundamentally different or that a physical barrier in certain meningiomas limits propagation of edema into the adjacent white matter.
Adolescent↗
Decreased BOLD functional MR activation of the motor and sensory cortices adjacent to a glioblastoma multiforme: implications for image-guided neurosurgery.
A patient with a glioblastoma multiforme and mild sensorimotor deficits had significantly less activation of the motor and sensory cortices on the side with the tumor than on the contralateral side on blood oxygen level-dependent (BOLD) functional MR images. This difference, which may be due to pressure effects or loss of vascular autoregulation, should be considered in preoperative planning in which BOLD functional MR imaging is used to identify eloquent cortices to be avoided during brain tumor surgery.
Adult↗
Optimization of gray/white matter contrast with fast inversion recovery for myelin suppression: a comparison of fast spin-echo and echo-planar MR imaging sequences.
We compared two MR imaging sequences, fast inversion recovery for myelin suppression (FIRMS) and echo-planar FIRMS (EP-FIRMS), for depicting gray/white matter contrast. In 18 patients, the frequency bandwidth (BW) was optimized for each sequence; in nine patients, the BW was held constant. In the BW-optimized group, the mean contrast-to-noise ratio (C/N) was three times higher with the FIRMS sequence. In the BW-constant group, the mean C/N was 27% higher with the EP-FIRMS sequence; however, geometric distortion degraded the EP-FIRMS images excessively. For optimal gray/white contrast, FIRMS appears to be the superior pulse sequence.
Brain Diseases↗
Hemorrhagic chondroid chordoma mimicking pituitary apoplexy.
We describe a hemorrhagic chondroid chordoma involving the sella turcica with suprasellar extension. The CT and MRI appearances mimiked a hemorrhagic pituitary adenoma. Chondroid chordoma is a variant composed of elements of both chordoma and cartilaginous tissue. An uncommon bone neoplasm, located almost exclusively in the spheno-occipital region, it is usually not considered in the differential diagnosis of a tumor with acute hemorrhage in the sellar region. We discuss the clinical and radiological characteristics which may allow one to differentiate chondroid chordoma from other tumors of this area.
Aged↗
Functional image-guided surgery of intracranial tumors located in or near the sensorimotor cortex.
OBJECT: The purpose of this study was to evaluate the efficacy of noninvasive preoperative functional imaging data used in an interactive fashion in the operating room. The authors describe a method of registering preoperative functional magnetic resonance (fMR) imaging localization of sensorimotor cortex with a frameless stereotactic surgical navigation device. METHODS: The day before surgery, patients underwent blood oxygen level-dependent fMR imaging while performing a finger-tapping motor paradigm. Immediately afterward an anatomical stereotactic MR image was acquired. Raw fMR imaging data were analyzed offline at a separate workstation, and the resulting functional maps were registered to a high-resolution anatomical scan. The fused functional-anatomical images were then downloaded onto a surgical navigation computer via an ethernet connection. At surgery, the brain was exposed in the standard fashion, and the sensorimotor cortex was identified by direct cortical stimulation, the use of somatosensory evoked potentials, or both. This localization was then compared with that predicted by the registered fMR study. Thirteen procedures were performed in 12 patients. The mean registration error was 2.2 mm. The predicted location of motor and/or sensory cortex matched that found on intraoperative mapping in all 12 patients tested. Maximal tumor resection was accomplished in each case and no new permanent neurological deficits resulted. CONCLUSIONS: Compared with conventional brain mapping techniques, fMR image-guided surgery may allow for smaller brain exposures, localization of the language cortex with the patient under general anesthesia, and the mapping of multiple functional sites. The scanning equipment used in this method may be more readily available than for other functional imaging techniques such as positron emission tomography or magnetoencephalography.
Adult↗
Focal dilation and paradoxical collapse of cortical fissures and sulci in patients with normal-pressure hydrocephalus.
OBJECT: The authors describe a subgroup of patients with shunt-proven normal-pressure hydrocephalus (NPH) who presented with focal fissural and sulcal dilation on imaging studies. The specific radiological features and methods of differentiating this condition from cortical atrophy are delineated. METHODS: Normal-pressure hydrocephalus has been described as dilation of the ventricles that is out of proportion to the sulci. Sulcal dilation has been taken as evidence of cortical atrophy and has even been used as a criterion to exclude patients from undergoing a shunting procedure. The authors describe five cases of patients with shunt-proven NPH who presented with focal dilation of cortical fissures and sulci. In three of the cases, there was a paradoxical decrease in the size of the dilated fissures and sulci that paralleled the decrease in the size of the lateral ventricles following successful shunting. CONCLUSIONS: This study demonstrates that focal fissural and sulcal dilation may represent reservoirs of cerebrospinal fluid analogous to the ventricular system. Patients should not be denied a shunting procedure solely on the basis of focally dilated fissures of sulci.
Aged↗
MR differential diagnosis of normal-pressure hydrocephalus and Alzheimer disease: significance of perihippocampal fissures.
PURPOSE: In the older patient with dilated ventricles, it is often difficult to differentiate normal pressure hydrocephalus (NPH) from cerebral atrophy caused by Alzheimer disease (AD). This study was undertaken to see if dilatation of the perihippocampal fissures (PHFs) could be used as a distinguishing characteristic of these two disorders. METHODS: MR images of 17 patients with AD were compared with those from an equal number of patients with NPH who improved after ventriculoperitoneal shunting. The PHFs, lateral ventricles, third ventricle, and temporal horns were graded subjectively. Objective, computer-aided volumetric measurements of the PHFs and lateral ventricles were obtained. The preshunt images of the NPH patients were evaluated. RESULTS: Significant differences between the two groups were found for the PHFs and lateral ventricles by both the subjective and objective methods, with a high degree of correlation between the two methods. CONCLUSION: The degree of dilatation of PHFs appears to be a sensitive and specific marker for differentiating AD from NPH by both subjective and objective means, with a very small overlap between the two groups. This observation may have relevance in day-to-day practice.
Aged↗
MRI of high-grade glial tumors: correlation between the degree of contrast enhancement and the volume of surrounding edema.
Contrast enhancement of malignant gliomas and the development of peritumoral edema are thought to be due to a breakdown of the blood-brain barrier (BBB). The degree to which these two factors are related to each other or to the degree of damage to the BBB is unknown. Our purpose was to quantitatively correlate the degree of enhancement with Gd-DTPA of anaplastic gliomas and glioblastoma multiforme with the volume of surrounding edema. In 14 patients, quantitative measurements of the volume of peritumoral edema and the degree of contrast enhancement were made. A high degree of correlation was found (r = 0.86, P < 0.01). These results can be viewed as indirect, radiological evidence that edema production is quantitatively related to the degree of breakdown of the BBB as determined by gadolinium enhancement. These results imply that the origin of the edema is in the area of breakdown of the BBB.
Adult↗
The use of hyperventilation in contrast-enhanced MR of brain tumors.
Angiographic studies have demonstrated improved visibility of glial tumors after hyperventilation. The present study was undertaken to determine whether hyperventilation would change the MR enhancement characteristics of various glial tumors. Eighteen patients were studied twice: once with standard contrast-enhanced MR imaging and again with standard imaging plus hyperventilation. After hyperventilation, six low-grade astrocytomas showed no change and three showed a small decrease in relative enhancement (<10%). The ependymomas showed a 10% to 13% increase in the degree of enhancement, but no change in the area of enhancement. All the anaplastic astrocytomas showed an increase in the degree of enhancement (mean, 38%). Three of the anaplastic astrocytomas showed new foci of enhancement that were not seen on the nonhyperventilation study. Hyperventilation appears to be an inexpensive and safe method for increasing the conspicuity of abnormal areas of the blood-brain barrier.
Adult↗