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C Oppenheim

Publications and source records attributed to C Oppenheim.

At least 19 recordsLinked to original sources
PubMed2003

Early asymptomatic recurrence of cervical artery dissection: three cases.

Cervical artery dissection (CAD) recurrences are rare but the risk could be higher during the first month. Twenty-seven consecutive patients admitted for an acute CAD were investigated using a standardized imaging protocol. An early asymptomatic recurrence was observed in three patients 49 to 53 days after the initial diagnosis. Anticoagulation was maintained and the prognosis remained good. Early CAD recurrences may have been underestimated previously, because asymptomatic recurrences seem to be more frequent than symptomatic ones.

Adult↗
PubMed2003

[Lyrical and musical auditive mental imagery in functional MRI].

PURPOSE: to explore with functional MRI cerebral areas involved in musical and lyrical sounds signal processing with the mental imagery method. MATERIAL: and METHODS: nine volunteers (mean age: 27 years old) underwent functional MRI with BOLD contrast at 1.5 T. Box-car paradigms of partial recollections of musical or lyrical memories tasks were performed. Statistical correlations mappings were calculated and superimposed on previously realigned anatomical reference imaging to observe activated cerebral areas. RESULTS: all except one subjects had activation areas in primary and secondary auditive cortices in the temporal Heschl gyrus and the Planum Temporale, unilaterally (n=2) or bilaterally (n=6) during both mental tasks. Contralateral activation improvement was observed in 4 cases when the lyrical tasks were performed. Temporal and insular regions involved in language processing were observed in eight of nine subjects. CONCLUSION: auditive mental imagery can show in functional MRI cerebral areas involved in auditive functions and some of the areas involved in language processing.

Adult↗
PubMed2003

[Diffusion tensor MRI of Wallerian degeneration: a case report].

Diffusion tensor imaging allows a 3D analysis of water molecular motion and an exploration of white matter tracts integrity and orientation. We report a diffusion tensor study of wallerian degeneration of the corticospinal tract following a capsulo-lenticular hemorrhage in a 49-year old man. Reduced anisotropy (loss of fiber coherence) with preserved diffusivity of the damaged corticospinal tract was observed. This highlights the feasibility of diffusion tensor imaging on clinical MR units and its ability to quantify the degree of white matter tract destruction.

Anisotropy↗
PubMed2002

[Normal results].

THE TECHNIQUE: Today, magnetic resonance imaging (MRI) is the exploration of choice for a number of central nervous system disorders. This technique, which does not use ionising rays, examines the encephalus in all its dimensions. Various sequences are used to study the cerebral parenchyma: specific sequences in T1, with or without injection of a contrast product, specific sequence in T2, and FLAIR sequence. THE RESULTS OBTAINED: The diffusion and perfusion imaging respectively reveal the movement of the water molecules and the cerebral microcirculation. Visualisation of the arteries and veins is non-invasive with magnetic resonance angiographical techniques. Study of the chemical composition of tissues (magnetic resonance spectroscopy) and of cerebral activation (functional activation imaging) will not be addressed.

Arteries↗
PubMed2002

[Tumor pathology].

THE MRI DIAGNOSTIC SUPPORT: Magnetic resonance imaging is an efficient technique for revealing an intercranial tumor, and specifying its topography and loco-regional impact. A macroscopical approach is possible with MRI, since it distinguishes the components: tumoral tissue, cyst, necrosis and hemorrhage. DEPENDING ON THE TUMOR: Assessment of the tumoral limits is easy for extra-axial tumors. However, it is imprecise or even impossible for infiltrating intra-axial tumors. MRI specificity is low, however some lesions such as meningiomas, glioblastomas, arachnoid cysts and neurinomas are evocative.

Brain↗
PubMed2002

[Vascular pathology].

IN ARTERIAL ISCHEMIC PATHOLOGY: Magnetic resonance imaging is increasingly proposed for any suspicion of cerebral vascular accident. Because of its diffusion sequences, it permits the rapid diagnosis and screening of ischemic lesions and provides prognostic information. FOR OTHER CEREBRAL VASCULAR DISORDERS: Intra-parenchymatous and sub-arachnoid hemorrhages are easily revealed by MRI. Today, MRI is the most effective examination for the diagnosis of venous thrombosis and of its impact on the parenchyma.

Brain Ischemia↗
PubMed2002

[Traumatic, infectious or degenerative pathology].

CRANIO-ENCEPHALIC TRAUMAS: Scanography remains the examination of choice. However, MRI can be useful in diagnosis of diffuse axional lesions, not clearly visualized with scanography, and for screening the subsequent lesions. INFECTIOUS OR INFLAMMATORY LESIONS: Some are very evocative with MRI: cerebral abscesses, notably herpetic encephalitis and Creutzfeldt-Jacob's disease. If multiple sclerosis is suspected, MRI is considered as the principle para-clinical examination able to confirm the diagnosis with the first episode. It also supplies data for the diagnosis of metabolic, toxic and degenerative diseases.

Brain↗
PubMed2002

[Creation of an educational CD-ROM using a PACS].

Presentation of MIRIAM 2: We describe the materials used for the creation of and the content of a CD-ROM entitled '77 neuroradiological case reports'. We mention the gathering of clinical and imaging data, exclusively provided by a PACS. Our work demonstrates that a CD-ROM is an appropriate interactive medium for radiological teaching. Its creation can be simplified thanks to a PACS, but it nonetheless remains work intensive.

Brain Diseases↗
PubMed2002

DWI prediction of symptomatic hemorrhagic transformation in acute MCA infarct.

PURPOSE: Symptomatic hemorrhagic transformation is a severe complication of acute ischemic stroke which occurs at a higher frequency after thrombolysis. The present study was designed to analyze whether early DWI can be used for predicting the risk of hemorrhagic transformation with clinical worsening in MCA stroke patients. MATERIALS AND METHODS: Of 28 patients with a middle cerebral artery (MCA) infarct and proven MCA or carotid T occlusion on DWI and MR angiography performed within 14 hours after onset (mean 6.5 +/- 3.5 hours, median 5.2 hours), 4 developed hemorrhagic transformation with clinical worsening, while 24 did not. For the 2 groups, we compared admission NIHSS score, site of arterial occlusion, volume of DWI abnormalities, and several apparent diffusion coefficient (ADC) measurements: ADC(infarct) (mean ADC value of the whole infarct), ADC(core) (peak ADC decrease as calculated in a 57 mm(2) circular ROI, manually centered on the ischemic area with the lowest ADC value on the ADC maps), ADC(superficial) and ADC(deep). Discriminant function analysis was used to determine the most accurate predictors of symptomatic hemorrhagic transformation. RESULTS: The best predictor was the ADC(core) (F=5.34, p=2.9%, cut-off value=300 x 10(-6) mm(2)/s). This monovariate model allowed to correctly classify all 4 patients (ADC(core) 300 x 10(-6) mm(2)/s) with subsequent symptomatic hemorrhage, and 17 of the 24 patients without symptomatic hemmorrhage (ADC(core)>300 x 10(-6) mm(2)/s) (100% sensitivity, 71% specificity). CONCLUSION: Although preliminary, these results suggest that a simple measurement of minimum ADC values within an acute MCA stroke could be useful in targeting those patients with a high risk of severe hemorrhagic transformation.

Acute Disease↗
PubMed2001

Usefulness of magnetic resonance-derived quantitative measurements of cerebral blood flow and volume in prediction of infarct growth in hyperacute stroke.

BACKGROUND AND PURPOSE: The identification of the tissue at risk for infarction remains challenging in stroke patients. In this study, we evaluated the value of quantitative cerebral blood flow (CBF) and cerebral blood volume (CBV) measurements in the prediction of infarct growth in hyperacute stroke. METHODS: Fluid-attenuated inversion recovery (FLAIR), diffusion-weighted (DW), and gradient-echo echo-planar perfusion-weighted (PW) sequences were obtained in 66 patients within 6 hours of stroke onset; ischemia was confirmed on follow-up FLAIR images. We delineated the following: (1) the initial infarct on DW images, (2) the area of hemodynamic disturbance on mean transit time (MTT) maps, and (3) the final infarct on follow-up FLAIR images. MTT, CBF, and CBV were calculated in the following areas: area of initial infarct (INF), area of infarct growth (IGR, final minus initial infarct), the hemodynamically disturbed area that remained viable (OLI, hemodynamic disturbance minus final infarct), and all contralateral mirror regions. RESULTS: Compared with mirror regions, the MTT in abnormal areas was always prolonged. The respective mean+/-SD CBF and CBV values were as follows: for INF, 28+/-16 mL/min per 100 g and 6.9+/-2.7%; for IGR, 36+/-20 mL/min per 100 g and 8.9+/-3.1%; for OLI, 50+/-17 mL/min per 100 g and 11.2+/-3%; and for mirror regions, 64+/-23 mL/min per 100 g and 8.7+/-2.5%. The CBV and CBF values were significantly different between all abnormal areas (except for the CBF between INF and IGR). In the area of DW/PW mismatch, a combined CBF or CBV threshold of 35 or 8.2, respectively, predicted evolution to infarction with a sensitivity of 81% and a specificity of 76%. CONCLUSIONS: Quantitative measurements of CBF and CBV in hyperacute stroke may help to predict infarct growth and to select the subjects who will benefit from thrombolysis.

Acute Disease↗
PubMed2001

Is there an apparent diffusion coefficient threshold in predicting tissue viability in hyperacute stroke?

BACKGROUND AND PURPOSE: Rapid and precise identification of the penumbra is important for decision-making in acute stroke. We sought to determine whether an early and moderate decrease in the apparent diffusion coefficient (ADC) may help to identify, within the diffusion/perfusion (DWI/PWI) mismatch, those areas that will eventually evolve toward infarction. METHODS: We reviewed 48 patients not treated by thrombolytics who had a DWI/PWI within 6 hours after onset, with infarct evolution documented by follow-up magnetic resonance on days 2 to 4. We calculated absolute values for ADC and the ADC ratio (ADCr) in (1) the initial DWI hypersignal; (2) the final volume of the infarct, ie, the follow-up fluid-attenuated inversion recovery abnormalities; (3) the infarct growth (IGR) area; and (4) the oligemic area (OLI) that remained viable despite initial hemodynamic disturbance. We tested the value of the ADC to predict tissue outcome by using discriminant analysis. RESULTS: ADC values were marginally but significantly decreased in the IGR area (ADC 782+/-82x10(-6) mm(2)/s, ADCr 0.94+/-0.08) compared with mirror values (P=0.01) and with OLI (ADC 823+/-41x10(-6) mm(2)/s, ADCr 0.99+/-0.07; P=0.001). Of all quantitative DWI and PWI parameters, the ADCr best discriminated between IGR and OLI (F(1,50)=13.6, cutoff=0.97, 64% sensitivity, 92% specificity) and between the final volume of infarct and OLI (F(1,83)=219, cutoff=0.91, 91% sensitivity, 100% specificity). CONCLUSIONS: A simple approach based on ADC alone may allow the identification of tissue at risk of infarction in acute-stroke patients.

Acute Disease↗
PubMed2001

Diffusion-weighted imaging patterns of brain damage associated with cerebral venous thrombosis.

BACKGROUND AND PURPOSE: Apart from cases studies, little is known regarding diffusion-weighted imaging of brain lesions associated with human cerebral venous thrombosis (CVT). Our aim was to describe the initial diffusion-weighted imaging patterns observed in brain areas with MR signal changes associated with CVT and to compare them with those of follow-up imaging. METHODS: The cases of nine patients with brain lesions associated with CVT who underwent CT and diffusion-weighted imaging 3 hours to 4 days after sudden neurologic onset were retrospectively reviewed. The apparent diffusion coefficient (ADC) in abnormal brain was compared with that of contralateral normal regions using z score analysis. MR images obtained during 3 to 6 months of follow-up were available for seven patients. RESULTS: All patients had nonhemorrhagic T2-hyperintense brain regions. These were associated with partially hemorrhagic areas on the CT scans of four patients. In nonhemorrhagic edematous areas, ADC was heterogeneous (coexistence of increased, normal, or decreased ADC) in five patients and homogeneous in four. In the latter four patients, ADC values were within normal range in three, whereas a large homogeneous hyperintensity with decreased ADC values (0.3-0.4 10(-3)mm2/s, <-3 z scores) was observed in one. When available, follow-up images always showed hemorrhagic sequelae in initially hemorrhagic areas. Nonhemorrhagic edematous areas with initially increased ADC values returned to normal. Initially normal or decreased ADC values were predictive of reversibility, although imaging sequelae were rarely observed. CONCLUSION: The diffusion-weighted imaging/ADC pattern of venous stroke is more heterogeneous than previously thought. Large brain regions of reduced ADC values that are not predictive of ultimate infarction in cases of CVT can be observed.

Adult↗
PubMed2001

[Diagnostic imaging of brain arteriovenous malformations].

The goals of the imaging work-up of cerebral arteriovenous malformations are not only the diagnosis of malformations but also their radioanatomic characterization in order to define an appropriate treatment plan for a given lesion, to evaluate and to compare results of treatment modalities, to look for parameters correlated with a high risk of bleeding and to identify indications of radiosurgery. In this review, the diagnostic value of imaging techniques is discussed: CT scan, MR imaging, vascular explorations. Radioanatomic parameters most useful for therapeutic discussion are defined: feeding arteries, associated aneurysms, size and topography of nidus, draining veins.

Analog-Digital Conversion↗
PubMed2001

[Radiosurgery of choroidal and cisternal cerebral arteriovenous malformations].

PURPOSE: Cerebral arteriovenous malformations surrounded by cerebrospinal fluid seemed to exhibit worse response to radiosurgery than others. We searched to verify if this is was true and to find causes. MATERIAL: and methods. From our series of 705 patients with cerebral arteriovenous malformations treated by radiosurgery, 3,8% (27/705) had choroidal or cisternal arteriovenous malformations. Revelation mode was hemorrhage in 86% of cases but sometimes headaches occurred before hemorrhage; thus overall hemorrhage rate was 96%. Mean age of revelation was 24. Mean size was 20 mm, mean volume was 4 cc. Spetzler & Martin's grades were 35% in grade II, 43% in grade III and 22% in grade IV. Location was ventricular in 63% of cases and cisternal in 37%. Mean dose at reference isodose was 24 Gy with a higher rate of monoisocenters. We looked for differences between this population of arteriovenous malformations and the rest of the series for patients, treatments prior radiosurgery, cerebral arteriovenous malformations's characteristics, dosimetric parameters and complications. Statistical analysis was done with a Pearson chi2 test and Spearman non parametric correlation test. RESULTS: Obiteration rate was 47.6% with a mean delay of 26 months. Differential characteristics of choroidal or cisternal arteriovenous malformations were: younger age of revelation, higher frequency of hemorrhage, of intra or paranidal aneurysms, of deep unique drainage, a higher Spetzler grade and a smaller rate of complete recovering. Mortality and clinical morbidity due to radiosurgery were 0%. Actuarial rate of hemorrhage after radiosurgery was 4,34% per year and per patient or per hemorrhage. This rate was higher than in the global series. Parenchymal changes seen on MRI were less frequent (26,6%) and less serious (no grade 4 radionecrosis-like parenchymal changes). CONCLUSION: Choroidal or cisternal arteriovenous malformations seem to respond less to radiosurgery than others. One potential explanation is the higher frequency of multiafferences of these arteriovenous malformations with anastomoses of anterior and posterior choroidal arteries. However, radiosurgery still stay a treatment of choice for these arteriovenous malformations with little adaptations of the irradiation strategy.

Adolescent↗