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Biomedical subjects

D Ben Salem

Publications and source records attributed to D Ben Salem.

14 recordsLinked to original sources
PubMed2006

Is NAA reduction in normal contralateral cerebral tissue in stroke patients dependent on underlying risk factors?

BACKGROUND AND PURPOSE: This retrospective study investigated the dependence of N-acetyl aspartate (NAA) ratios on risk factors for cerebral vasculopathy such as sex, age, hypertension, diabetes mellitus, carotid stenosis, and dyslipidaemia, which may have affected brain vessels and induced metabolic brain abnormalities prior to stroke. We hypothesise that in stroke patients metabolic alterations in the apparently normal contralateral brain are dependent on the presence or not of such risk factors. METHODS: Fifty nine patients (31 male, 28 female: 58.8+/-16.1 years old) with cortical middle cerebral artery (MCA) territory infarction were included. Long echo time chemical shift imaging spectroscopy was carried out on a Siemens 1.5 T Magnetom Vision scanner using a multi-voxel PRESS technique. Metabolite ratios (NAA/choline, NAA/creatine, lactate/choline, etc) were studied using uni- and multivariate analyses with respect to common risk factors. The influence of age, stroke lesion size, and time since stroke was studied using a linear regression approach. RESULTS: Age, sex, and hypertension all appeared to individually influence metabolite ratios, although only hypertension was significant after multivariate analysis. In both basal ganglia and periventricular white matter regions in apparently normal contralateral brain, the NAA/choline ratio was significantly lower in hypertensive (1.37+/-0.16 and 1.50+/-0.19, respectively) than in normotensive patients (1.72+/-0.19 and 1.85+/-0.15, respectively). CONCLUSIONS: Regarding MCA infarction, contralateral tissue remote from the lesion behaves abnormally in the presence of hypertension, the NAA ratios in hypertensive patients being significantly lower. These data suggest that hypertension may compromise the use of contralateral tissue data as a reference for comparison with ischaemic tissue.

Adult↗
PubMed2005

[CT angiography of the neck: technical considerations].

Examination of acute stroke by CT angiography is an alternative to MRI. Technological improvement of multidetector CT scanners allows neuroimaging of stroke in a multimodal protocol including plain CT, cerebral CT perfusion and CT angiography of the cervical and intracranial arteries. CT angiography is a reliable non invasive technique for the evaluation both extracranial and intracranial vessels that may be used as an alternative to MR angiography.

Angiography↗
PubMed2004

[Neuroradiologic emergencies in infectious pathology].

The main goal of urgent imaging evaluation of patients with suspected CNS infection is to differentiate infectious from tumoral or vascular lesions in order to provide appropriate management. MR imaging, including diffusion weighted imaging and spectroscopy, is superior to CT imaging to characterize lesion location and etiology. The CT and MRI features of the more frequent bacterial, viral and parasitic CNS infections will be described.

Brain Abscess↗
PubMed2004

[Analysis of variation in delivered dose in diagnostic and therapeutic cerebral angiography].

OBJECTIVES: Analysis of dose-area product (DAP) in cerebral angiography, according to the type of pathology and technique used. MATERIALS AND METHODS: Use of dosimetric and clinical data resulting from 84 diagnostic cerebral angiograms and 32 cerebral embolizations. RESULTS: The diagnostic angiography data were divided into three categories: A/ When a secondarily embolized aneurysm was diagnosed: n=17. B/ When the final diagnosis was an arteriovenous malformation (AVM): n=10. C/ In the case where the diagnosis was neither AVM, nor aneurysm to embolize: n=57. The cerebral embolizations were classified in two sub-groups: K/ When the embolization immediately followed the diagnostic angiogram: n=15. L/ When the embolization of the aneurysm took place 24 to 48H after the angiography: n=17. The mean DAP of group B containing the AVM is higher than mean DAP values in groups A and C, because of the increased cinegraphic time. There is a strong correlation between the duration of the fluoroscopy and the DAP (n=116; r=0.931; p<0.0001). Addition of runs in the group L contributes to the augmentation of the exposure time (significant difference in time: p=0.0054) and thus with the fact that DAP L>DAPK. CONCLUSION: Radiation dose during diagnostic cerebral angiography is increased in the presence of AVM. DAP of embolizations are higher when diagnostic and therapeutic phases are separated in time.

Adult↗
PubMed2003

[Early study of myocardial perfusion with MRI in revascularized infarcts].

The aim of this work is to study the regional myocardial perfusion by MRI early after revascularised myocardial infarction and to compare it with regional function. This prospective work has included 15 patients with acute first myocardial infarction that was precociously revascularised. A myocardial MRI was performed between D2 and D10 after myocardial infarction. The regional myocardial thickening was evaluated from cine-MRI sequences. For the study of myocardial perfusion, the first pass of the contrast agent was analysed from curves of the signal evolution versus time. The signal enhancement on late images acquired 10 minutes after the perfusion of the contrast agent was also evaluated. Among 384 studied myocardial segments, those with a normal gadolinium first pass curve had a relative thickening of 46 +/- 38%. The segments with a severely reduced first pass kinetic have a markedly reduced relative thickening (14 +/- 20%) in relation with myocardial hypoperfusion. The myocardial enhancement is frequently seen in the infarct territory and appears related to a reduced regional contractility. The myocardium is enhanced on late images in 12% of the normally perfused segments. These segments have a mildly reduced wall thickening (3.36 +/- 2.84 mm vs 4.42 +/- 2.83 mm). The segmental contractility in a reperfused myocardial infarction appears to depend both on the myocardial perfusion which reflects the microvascularisation and on the myocardial enhancement which is linked to myocardial structural alterations. MRI appears to be an adequate method to evaluate these abnormalities and allows an easy assessment of the no-reflow phenomenon, if present.

Adult↗
PubMed2003

[Spontaneous hyperdense intracranial vessels seen on CT scan in polycythemia cases].

PURPOSE: A better understanding of the significance of diffuse hyperdensity affecting the circle of Willis and the dural sinuses on unenhanced CT. MATERIALS AND METHODS: We performed a retrospective study of 19 patients with a neurological manifestation and a CT scan without contrast injection. Among these 19 patients, six had been included because of primary or secondary polycythemia. The analysis of cerebral CT scans was made qualitatively by visual inspection and quantitatively. RESULTS: In patients with a hematocrit percentage exceeding 60%, both circle of Willis and dural sinuses were dense on unenhanced CT scans. A linear relation between the hemoglobin level and the contrast of the dural sinuses compared with the grey matter was observed with an excellent correlation (r = 0.934; n < 0.0001; p = 19). CONCLUSION: Increased density of cerebral vessels on unenhanced CT is a sign of a high hemoglobin level.

Adult↗
PubMed2002

Chondroblastoma of the temporal bone associated with a persistent hypoglossal artery.

A case of a chondroblastoma of the skull-base associated with a persistent hypoglossal artery (PHA) is presented. Neuroradiological findings of the PHA and the tumour are reported. The existence of a carotico-basilar communication such as a PHA should be recognized prior to skull base surgery because of the potential risk of cerebral ischemia.

Adult↗
PubMed2002

Meckel's diverticulum and mesenterium commune in a patient with gastrointestinal bleeding.

Lower gastrointestinal bleeding after aspirin intake was reported in a 64-year-old woman. Gastroscopy, colonoscopy and selective mesenteric angiography failed to reveal the source of hemorrhage; only a midgut malrotation was suggested by angiography. Small bowel enema finally demonstrated a blind sac on the antimesenteric border of the ileum, corresponding to a Meckel's diverticulum. This embryological remnant of the vitelline duct was associated with a mesenterium commune. Laparoscopy confirmed the small bowel study, and resection of the diverticulum was easily carried out. It is, to our knowledge, the first time that these developmental abnormalities have been preoperatively diagnosed together.

Aspirin↗
PubMed2001

[Comparison of MRA and angiography in the follow-up of intracranial aneurysms treated with GDC].

OBJECTIVE: Evaluation of TOF 3D MRA compared to angiography in the follow-up of intracranial aneurysms treated by Guglielmi detachable coils (GDC). MATERIAL: and method: Prospective analysis of follow-up MRA and angiographies for 20 patients with 22 aneurysms. There were 2 MRAs for 3 aneurysms giving a total of 25 cases. RESULTS: A poor correlation between MRA and angiography was observed in 21 cases of 25. For 9 cases, stable exclusion (95-100%) visible on MRA was confirmed by angiography. For 12 other cases, a residual flow within the aneurysmal neck or a residual flow between coils was detected by MRA and confirmed by angiography. A poor correlation was found in 4 cases out of 25: 3 residual flows within the aneurysmal neck and 1 residual flow within the coil mass not visible on MRA. MRA has a sensibility of 75% for the detection of an anomaly, a specificity of 100%, a positive predictive value of 100% and a negative predictive value of 69.2%. MRA is able to detect a large residual flow within aneurysmal neck and a re-growth, which would need a second embolization. Anomalies not visible on MRA as observed in our study, residual flow within the coil mass and the aneurysmal neck, do not require complementary treatment. CONCLUSION: A normal TOF 3D MRA can avoid an angiography in the follow-up of an intracranial aneurysm treated by GDC.

Adult↗
PubMed2001

[MRI screening of vestibular schwannomas without gadolinium: usefulness of the turbo gradient spin echo T2-weighted pulse sequence].

The purpose of this retrospective MRI work was to evaluate the use of turbo gradient spin echo (TGSE) high resolution imaging for the detection of eighth nerve schwannomas, without injection of gadolinium. The TGSE sequence (slice thickness: 3 mm with 1.5 mm interleaving; matrix: 512) was compared with a reference sequence: T1-weighted spin echo (SE) after gadolinium injection (slice thickness: 3 mm, matrix: 256). Among 380 internal auditory meatus (IAM) explored, 34 abnormalities were detected on T2-weighted TGSE images compared with 19 on contrast-enhanced T1-weighted SE images. This new sequence has a 100% sensitivity, a 96% specificity and a 100% negative predictive value. Using a rigorous protocol for IAM analysis with the TGSE sequence, gadolinium injection may no longer be needed systematically for vestibular schwannoma screening, but might only be necessary when an abnormality or a doubt persists after TGSE. This approach allows about 20% cost reduction for each patient, a savings of 11,433 euros considering only the true negatives observed in this study.

Adolescent↗
PubMed2000

[Lumbar intraspinal synovial cysts: imaging and treatment by percutaneous injection. Report of thirteen cases].

PURPOSE: The CT and MR imaging findings in 13patients with lumbar intra spinal synovial cysts were retrospectively analysed and the results of facet corticosteroid injection were evaluated. PATIENTS AND METHODS: Over a 7 year period, 13patients with radicular pain were identified as having lumbar intra spinal synovial cysts. They ranged from 42 to 87 years of age. All patients were evaluated by CT without contrast material and underwent facet arthrography associated with corticosteroid injection and CT arthrography. MR imaging was performed in all patients either before or after percutaneous treatment. CT scans and MR images were reviewed and patient outcome was evaluated at 1and 6month followup. RESULTS: CT scan revealed a cystic structure adjacent to a degenerated facet joint in 9 patients (69% sensitivity). MRI showed more accurately the cyst on T2 weighted and/or axial images. Complete or good relief of radicular pain and functional restrictions were achieved in 9 patients (69%) at 1 month follow up, still to be found in 6patients (46%) at 6months. CONCLUSION: In patients with radiculopathy and facet degenerative changes, intra spinal synovial cysts must be looked for. Facet corticosteroid injection is a useful alternative to surgical removal.

Adult↗