Biomedical subjects

Karim Benali

Publications and source records attributed to Karim Benali.

6 recordsLinked to original sources

PubMed2004

Quantitative coronary arteriography on digital flat-panel system.

On images acquired with a digital flat-panel (DFP) detector, known for its better image quality, the performance of a validated quantitative coronary arteriography (QCA) software, CAASII (Cardiovascular Angiography Analysis System or CAAS), and a DFP-dedicated QCA algorithm (flat-panel analysis software or FPAS) was compared in a phantom and a patient study. On phantom, FPAS performed with higher accuracy the quantification of the smallest tubes and the calibration of an empty catheter. The overall accuracy and precision for the quantification procedure was better for FPAS (0.07 +/- 0.04 mm) than for the CAAS (0.19 +/- 0.06 mm; P = 0.03 and P < 0.01, respectively). In the patient study, the main difference between the two algorithms was found in the small diameters: CAAS almost always gave higher values than FPAS for the minimal luminal diameter (P < 0.001) and could only give values up to 70% for diameter stenosis. In conclusion, the FPAS can be considered more appropriate for assessing severe stenoses on digital flat-panel images.

Algorithms↗

PubMed2002

Sinistrality in schizophrenia.

UNLABELLED: Sinistrality characterized by an excess of non-right handedness has been reported in schizophrenic patients. Two factors, sex and kind of evaluation of handedness have contributed to major discrepancies across studies. AIM: The hypothesis tested was that schizophrenic patients show a sinistral shift in handedness compared to controls taking into account the sex and using a continuum scoring system for evaluating handedness. METHODS: Seventy-three (73.1% males) schizophrenic patients (DSMIV) and 81 (64.2% males) controls were evaluated with the Edinburgh Handedness Inventory (EHI [Neuropsychologia, 9 (1971) 97]). RESULTS: The EHI score mean difference between patients with schizophrenia and control group was not significant when sex was taken into account. CONCLUSION: Schizophrenic patients taken as a whole did not show a sinistral shift in handedness even if the sex and the continuum score for handedness were considered.

Adult↗

PubMed2002

Sinistrality in subtypes of schizophrenia.

UNLABELLED: Sinistrality, characterized by an excess of non-right-handedness, has been reported in schizophrenic patients, but the findings are controversial. AIM: As sinistrality could be linked to a failure of hemisphere specialization in schizophrenia that would translate into language disorders, sinistrality was found out in disorganized and positive schizophrenic patients characterized by language disorders. METHODS: Seventy-three schizophrenic patients (DSM IV) and 81 controls were evaluated with the Edinburgh Handedness Inventory (EHI). Patients were evaluated and classified into five subtypes (deficit, positive, disorganized, mixed and residual) with the Positive and Negative Syndrome Scale and the Schedule for the Deficit Syndrome. RESULTS: Disorganized patients had a significantly more severe sinistrality in comparison to the deficit, residual and mixed subtypes and controls. A negative correlation was found between the disorganization and the EHI scores (r = - 0.34; P < 0.01). A significantly more severe sinistrality was also observed in the positive subtype in comparison to controls, but there was no correlation between hallucinatory and EHI scores (r = 0.06). CONCLUSION: The findings provided further evidence that the defects in the normal process of lateralization observed in schizophrenia affects primarily disorganized patients.

Adult↗

PubMed2002

Episodic and semantic remote autobiographical memory in ageing.

Many laboratory studies have demonstrated an age effect on episodic memory which is in contrast with the preservation of semantic memory. The aim of this study was the assessment of age effects on autobiographical memory according to the length of the retention interval, taking into account the episodic and semantic components. A total of 52 subjects, aged between 40 and 79, were divided into four age groups. They were tested with a sophisticated autobiographical questionnaire consisting of two tasks, one involving the recall of semantic information and another the recall of episodic events. Results revealed that episodic recall deteriorated more with age and retention interval than semantic recall. These data, gathered using an ecological test, confirm age differences demonstrated by laboratory tests on the episodic-semantic distinction. Furthermore, the profile of results obtained for the recall of specific detailed events, and analysed according to age of encoding, confirms the distribution of episodic memories across the lifespan, as modelled by Rubin, Wetzler, and Nebes (1986) with the cue-word technique.

Adult↗

PubMed2002

Proton magnetic resonance spectroscopy (1H MRS) in schizophrenia: investigation of the right and left hippocampus, thalamus, and prefrontal cortex.

Single voxel proton magnetic resonance spectroscopy (1H MRS) was used to study the metabolites N-acetylaspartate (NAA), choline (CHO), and myo-inositol (ml) in order to test a neurodegenerative hypothesis in schizophrenia (decrease of NAA, increase of CHO, and increase of ml) and a cerebral asymmetry of these metabolites. 1H MRS was performed in 17 schizophrenia patients and 14 healthy subjects in three cerebral areas highly involved in the pathophysiology of schizophrenia (the prefrontal cortex, the thalamus, and the hippocampus). The ratio amplitudes between metabolites and creatine plus phosphocreatine (Cr) were determined. No difference in the metabolites existed between patients and healthy subjects. However, relationships were noted between NAA/Cr and age in the thalami of the schizophrenia patients (r = -0.37; p = 0.14) and healthy subjects (r = -0.52; p = 0.05). A significant correlation was observed between NAA/Cr and age of onset of illness in the hippocampi of schizophrenia patients (r = -0.59; p < 0.05). Moreover, NAA/Cr was lower in the right than in the left prefrontal cortex in both schizophrenia patients and healthy subjects. There was no relationship between the metabolites and duration of illness or dose of antipsychotics. These findings might suggest a neurodegenerative process in the hippocampi of schizophrenia patients with late onset of illness, and the NAA/Cr ratio could be a marker of aging in the thalami.

Adult↗

PubMedDate not supplied

A novel image fusion visualizes the angioarchitecture of the perforating arteries in the brain.

We report a novel technique that fuses 3D digital subtraction angiograms and MR images. Image fusion was successfully performed within 20 minutes each in 11 consecutive cases. Our initial experience showed that this image fusion enabled clear and simultaneous visualization of perforating arteries and surrounding tissues. The relation between perforating arteries and normal brain or lesions was easily understood in a clinical setting by using this image fusion.

Adult↗