A phase-contrast MRI study of acute and chronic hydrodynamic alterations after hydrocephalus induced by subarachnoid hemorrhage.

OBJECTIVE: To determine acute intracranial hydrodynamic changes after subarachnoid hemorrhage (SAH) via phase-contrast MRI (PC-MRI) analysis of the CSF stroke volume in the aqueduct (SVaq) and the foramen magnum (SVfm). METHODS: A prospective PC-MRI study was performed on 34 SAH patients in the acute and late phase. Data on CSF flow and hemorrhage site were analyzed according to acute or chronic hydrocephalus (HC). RESULTS: In the acute phase, CSF analysis was performed for 31 patients, 12 of whom presented HC. All 12 had an abnormal SVaq; those with communicating HC (n = 7) had an elevated SV and those with noncommunicating HC (n = 5) had a nil SV. None of the patients with a normal SVaq (n = 11) developed acute HC. Intraventricular bleeding led to more cases of acute HC (P = .005), which was communicating in 58% of cases. In the chronic phase, CSF analysis was performed for 27 patients, 7 of whom presented HC. None of these 7 patients displayed a depressed SVaq. CONCLUSION: SAH led to changes in cerebrospinal fluid hydrodynamics in the majority of patients. Acute HC was communicating in most cases, even when there was intraventricular bleeding. In the late phase, all chronic HC were communicating and did not display aqueductal stenosis.

Diffusion tensor imaging and white matter lesions at the subacute stage in mild traumatic brain injury with persistent neurobehavioral impairment.

Mild traumatic brain injury (mTBI) can induce long-term behavioral and cognitive disorders. Although the exact origin of these mTBI-related disorders is not known, they may be the consequence of diffuse axonal injury (DAI). Here, we investigated whether MRI at the subacute stage can detect lesions that are associated with poor functional outcome in mTBI by using anatomical images (T(1) ) and diffusion tensor imaging (DTI). Twenty-three patients with mTBI were investigated and compared with 23 healthy volunteers. All patients underwent an MRI investigation and clinical tests between 7 and 28 days (D15) and between 3 and 4 months (M3) after injury. Patients were divided in two groups of poor outcome (PO) and good outcome (GO), based on their complaints at M3. Groupwise differences in gray matter partial volume between PO patients, GO patients and controls were analyzed using Voxel-Based Morphometry (VBM) from T(1) data at D15. Differences in microstructural architecture were investigated using Tract-Based Spatial Statistics (TBSS) and the diffusion images obtained from DTI data at D15. Permutation-based non-parametric testing was used to assess cluster significance at p < 0.05, corrected for multiple comparisons. Twelve GO patients and 11 PO patients were identified on the basis of their complaints. In PO patients, gray matter partial volume was significantly lower in several cortical and subcortical regions compared with controls, but did not differ from that of GO patients. No difference in diffusion variables was found between GO and controls. PO patients showed significantly higher mean diffusivity values than both controls and GO patients in the corpus callosum, the right anterior thalamic radiations and the superior longitudinal fasciculus, the inferior longitudinal fasciculus and the fronto-occipital fasciculus bilaterally. In conclusion, PO patients differed from GO patients by the presence of diffusion changes in long association white matter fiber tracts but not by gray matter partial volume. These results suggest that DTI at the subacute stage may be a predictive marker of poor outcome in mTBI.

Percutaneous vertebroplasty for pain management in malignant fractures of the spine with epidural involvement.

PURPOSE: To evaluate the feasibility, efficacy, and safety of percutaneous vertebroplasty (PV) in the treatment of pathologic fractures owing to malignancy with epidural involvement, with or without neurologic symptoms of spinal cord or cauda equina compression. MATERIALS AND METHODS: This study was approved by the local ethics committee; informed consent was obtained from all patients. This retrospective review was performed for 51 consecutive patients with metastatic disease or multiple myeloma treated by means of vertebroplasty, who presented with at least one vertebral lesion with epidural involvement, with or without clinical symptoms of spinal cord or cauda equina compression. All patients with neurologic deficit were terminally ill. A neurologic examination was performed before and after treatment in all patients. All imaging examinations and treatments were reviewed, and chi(2), Mann Whitney, or Fisher exact testing was performed for univariate analysis of variables. RESULTS: A total of 74 vertebrae were treated in 51 patients, 22 women and 29 men with a mean age of 62.5 years (range, 28-85 years). Fifteen (29%) patients presented symptoms of complete or incomplete spinal cord or cauda equina compression before vertebroplasty and no further clinical deterioration was observed after treatment. The analgesic efficacy of vertebroplasty was satisfactory for 94% (48 of 51) of patients after 1 day, 86% (31 of 36) patients after 1 month, and 92% (11 of 12) patients after 1 year. One patient with no clinical neurologic deficit before treatment experienced symptoms of cauda equina compression 2 days after vertebroplasty. No other major complication was observed. CONCLUSION: The feasibility, efficacy, and safety of PV were confirmed in patients experiencing pain related to malignant spinal tumors with epidural extension, with a low complication rate. PV should become part of the palliative analgesic treatment for such patients. (c) RSNA, 2010.

[Contribution of phase-contrast MRI to the management of patients with normal pressure hydrocephalus: Can it predict response to shunting?]. / Apport de l'IRM de flux dans les hydrocéphalies à pression normale de l'adulte : intérêt prédictif dans les indications chirurgicales.

The diagnosis and management of patients with idiopathic normal-pressure hydrocephalus (NPH) remain somewhat controversial and there is no clear guideline for assessing the post-shunt outcome. The objective of this study was to investigate whether cerebrospinal fluid (CSF) flow dynamics is linked to post-shunt improvement. Fourteen NPH patients (nine males and five females; mean age, 68 years) investigated by magnetic resonance imaging (MRI) before surgical diversion of CSF were retrospectively reviewed. Phase-contrast sequences were added to the morphological clinical protocol for quantification of CSF oscillations, which were recorded at the level of the cerebral aqueduct and the C2 and C3 subarachnoid spaces (SAS). The phase-contrast images were analysed with custom-designed dedicated flow segmentation software. The oscillations measured in this hydrocephalus population were compared to a previously studied healthy population. A difference of at least two standard deviations was used to define a hyperdynamic or hypodynamic state of CSF flow. The cervical CSF flow of the hydrocephalus patients was not significantly different from those of the volunteer population. Of the 14 hydrocephalus patients, 12 had a good response to the shunt. Of these, 10 presented an increased ventricular CSF flow, one a low ventricular CSF flow, and the last one had a normal ventricular CSF flow. Phase-contrast MRI can help develop guidelines for surgical management of NPH. The shunt responders appear to be the patients with hyperdynamic ventricular CSF flow and normal cervical CSF flow.