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P Lecouffe

Publications and source records attributed to P Lecouffe.

At least 19 recordsLinked to original sources
PubMed2000

Alzheimer's disease and frontotemporal dementia are differentiated by discriminant analysis applied to (99m)Tc HmPAO SPECT data.

OBJECTIVE: Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most frequent neurodegenerative cognitive disorders. However, FTD remains poorly recognised clinically. The use of (99m)HmPAO-single photon emission computed tomography (SPECT) has been demonstrated in the differentiation of AD and FTD. Nethertheless, there are very few comparative studies designed to assess its precise value in this differential diagnosis. The aim was to determine a simple decision rule, deduced from statistical analysis, which, if applied to regions of interest (ROIs) and mini mental state examination (MMSE), could improve the predictive value of SPECT in differential diagnosis between AD and FTD. METHODS: Forty patients, 20 with probable AD and 20 with probable FTD were included. All patients underwent brain SPECT imaging, after an intravenous injection of (99m)Tc HmPAO-(555mBq). For each patient, 20 ROIs were determined on the Fleishig's slice and their activity was normalised to the mean cerebellar activity. Bivariate analysis (Wilcoxon rank tests) and multivariate analysis (stepwise discriminant analysis) were performed to determine the subgroup of variables able to give the highest predictive value for this differential diagnosis. A simple decision rule was built from a predictive score derived by factorial discriminant analysis. RESULTS: As previously described, the fixation defect was found in frontal regions of interest (ROIs) in FTD and in the left temporoparietal-occipital ROIs in AD. Among the 21 variables, five were finally selected: right median frontal, left lateral frontal, left tempoparietal, left temporoparietal-occipital areas, and MMSE. One hundred per cent of patients with FTD were correctly classified by the decision rule (20/20 patients) and 90% of patients with AD (18/20). CONCLUSION: AD and FTD are differentiated by SPECT. Automatic classification based on a decision rule deduced from factorial discriminant analysis could enhance its performance.

Alzheimer Disease↗
PubMed2000

Comparison between exercise whole body thallium imaging and ankle-brachial index in the detection of peripheral arterial disease.

BACKGROUND: Exercise whole body thallium imaging and rest/exercise ankle-brachial index can provide evidence of peripheral artery disease at the stage of intermittent claudication. The aim of this study was to compare both methods in the detection of asymptomatic peripheral artery disease. METHODS EXPERIMENTAL DESIGN: prospective non-randomised study. SETTING AND PATIENTS: general community, private practice, ambulatory patients referred in a Nuclear Medicine Department for exercise myocardial scintigraphy. Intermittent claudication was present in 8% of the whole study population. Coronary artery disease and diabetes were respectively present in 70% and 16% of the same population. MEASURES: rest/exercise ankle-brachial index and exercise whole body thallium imaging were measured in 105 patients (76 men and 29 women, mean age +/- 1 SD= 61 +/- 10 year) who performed a near-maximal or maximal treadmill test. Normal values of regional blood supply and indices of asymmetry at different levels of legs were determined in 14 patients with a very low probability of peripheral artery disease. RESULTS: The probability of peripheral artery disease was very high in 19 patients (group 1), because of abnormal rest and/or exercise ankle-brachial index, whereas in the 86 remaining patients, the index at rest and exercise was quite normal (group 2).With respect to rest and/or exercise ankle-brachial index, the sensitivity, specificity, positive and predictive negative value of exercise scintigraphy abnormalities were respectively 89%, 62%, 34% and 96%. The false positive scan group differed from the true positive group only by sex and redistribution of thallium 201. The proportion of diabetic patients was the same (15%) in both groups. CONCLUSIONS: Exercise whole body thallium imaging might contribute without additional cost to the detection, functional evaluation and/or risk stratification of peripheral artery disease in patients who perform exercise myocardial scintigraphy.

Adult↗
PubMed1999

[Importance of cerebral tomoscintigraphy using technetium-labeled sestamibi in the differential diagnosis of current tumor vs. radiation necrosis in subtentorial glial tumors in the adult].

CT scan and MR imaging are not always reliable in the differential diagnosis between radionecrosis and recurrence of brain tumor. We describe the results of a prospective study using 99mTc Sestamibi. 22 patients were included. The histology of the tumor was astrocytoma (grade 2-4) oligodendroglioma (grade 2-3) or mixed (grade 2-3). SPECT was performed using a Tomomatic 564, 1 h after the injection i.v. of 370 MBq of 99mTc Sestamibi. Ten slices parallel to the orbitomeatal plane were obtained. Two index were calculated i) CI: ratio of the mean counts in the lesion to the mean counts in the contralateral choroid plexus and ii) MI: ratio of the mean counts in the lesion to the contralateral mirror area. The results were compared to stereotactic biopsies or to clinical course at 6 months. Twelve patients out of 22 showed an increased uptake of the tracer and 11/12 presented with a recurrence. In 10 patients without fixation, 4 were false negative. The sensitivity for the detection of tumor recurrence was 73% and specificity was 85%. The positive predictive value was 91% and the negative predictive value was 60%. The use of a cut-off value superior to 2 for MI and superior to 0.5 for CI appears to be a good criterion for helping the diagnosis of relapse according to the analysis of Receiver Operating Characteristic curves (ROC). A positive SPECT was conclusive for the diagnosis of recurrence but a negative SPECT did not allow to assess the absence of recurrence. Limits of methods have to be stressed and searched for a better understanding of false negatives.

Aged↗
PubMed1999

Technetium HMPAO SPECT study in dementia with Lewy bodies, Alzheimer's disease and idiopathic Parkinson's disease.

UNLABELLED: The aim of this study was to compare the regional cerebral blood flow measurements studied by SPECT in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) to determine the contribution of SPECT to the differential diagnosis of these two diseases. METHODS: SPECT analysis with 99mTc-hexamethyl propyleneamine oxime (HMPAO) was performed in 20 patients with probable DLB, 20 patients with probable AD and 20 patients with idiopathic Parkinson's disease (IPD). Ten pairs of regions of interest were analyzed. Tracer uptake was expressed as a corticocerebellar activity ratio. RESULTS: Compared with IPD, in the DLB group there was a global decrease of HMPAO uptake in cortical regions of interest except in the posterior frontal and occipital regions; in the AD group there was limited left temporal and parietal hypoperfusion. In the DLB group, frontal HMPAO uptake was significantly lower than in the AD group. Two predictive scores were established by a factorial discriminant analysis from six left cortical indices (medial frontal, lateral frontal, posterior frontal, temporoparietal, parietal and parietooccipital) and the Mini-Mental State Examination, which correctly classified 53 of 60 patients (88%) (DLB, 18 of 20; AD, 16 of 20; IPD, 19 of 20). CONCLUSION: These findings indicate the presence of diffuse cortical abnormalities in DLB and suggest that SPECT may be useful in discriminating in vivo DLB from AD, revealing mainly frontal hypoperfusion in the former group. We estimate that SPECT study increases the possibility of separating DLB and AD because both disorders share different patterns of cerebral blood flow abnormality.

Aged↗
PubMed1998

Whole-body exercise thallium imaging in smokers.

Whole-body exercise thallium imaging (WBEI) can show abnormalities of leg muscle perfusion in patients with symptomatic peripheral artery disease (PAD). This study compared the exercise distribution of thallium-201 at different levels of the legs in asymptomatic smokers and non-smokers who performed a maximal graded treadmill test. A group of 74 smokers (more than 20 pack-years) with (n = 51) or without coronary artery disease (CAD) (n = 23) were included in group 1 and 64 non-smokers with a low probability of PAD and CAD in group 2. Patients in group 1 were older than the patients in group 2 (58 +/- 9 versus 48 +/- 12 years, p < 0.0001). Indexes of asymmetry were significantly higher in group 1, at each level of the legs, both in anterior and posterior views (0.001 < p < 0.05), except at thigh level in anterior view. Fractional uptake indexes of thallium-201 were significantly lower in group 1 than in group 2 at calf level (p = 0.0001 in anterior and posterior views) and buttocks (p = 0.006 and p = 0.009 in anterior view only). Interextremity asymmetry was four to six times more frequent at calf level in smokers than in non-smokers. These WBEI abnormalities in smokers are highly suggestive of silent PAD or at least decreased vascular reactivity in clinically uninvolved vessels.

Adult↗
PubMed1995

Tomographic measurements of regional cerebral blood flow in progressive supranuclear palsy and Parkinson's disease.

Intellectual changes observed in progressive supranuclear palsy (PSP) are sometimes seen with lesser intensity in Parkinson's disease (PD). Cognitive impairment of PSP has been attributed to a frontal lobe dysfunction explaining the frontal cortex hypometabolism detected by PET. To establish whether this frontal hypometabolism is more pronounced in PSP than in PD, we compared frontal and temporo-parietal cerebral blood flow (CBF) indexes studied by SPECT using Tc99m HmPAO in 18 PSP, 18 PD and 8 control subjects. For each patient neuropsychological performances were also assessed. A significant left frontal hypoperfusion was observed in PSP (mean index value: 0.78 +/- 0.03, p < 0.01) and PD (0.78 +/- 0.04, p < 0.05) as compared to controls (0.84 +/- 0.03), whereas there was no difference between PSP and PD. No correlation was discovered between neuropsychological performances and frontal cortical index changes. This frontal uptake reduction of Tc99m HmPAO in PSP and PD could result from a disconnection phenomenon secondary to subcortical lesions. In both groups mean frontal indexes showed only a left frontal hypoperfusion suggesting that subcortical structures might be asymmetrically involved in early stages of the diseases. The lack of difference for indexe values between PSP and PD might be explained by the difference between the mean disease duration: 4.3 years for the PSP and 7.8 years for the PD. It might also suggest that frontal CBF reduction exists in the same proportions in PD and PSP, but at a later stage in the former case.

Aged↗
PubMed1993

Early and delayed distribution of N-isopropyl-[123I]-p-iodoamphetamine in haemorrhagic and ischaemic brain.

Single photon emission computed tomography (SPECT) was used to study redistribution of N-isopropyl-[123I]-p-iodoamphetamine (IAMP) in 10 patients with intracerebral haemorrhage and 7 with ischaemic stroke. Delayed/early IAMP uptake ratios (D/E) were calculated for four different cerebral zones: haematoma or infarct, perilesional, normal and crossed cerebellar diaschisis areas. Delayed uptake was observed in all areas, but there were no significant differences between the haematoma and infarct results nor between the lesional and perilesional results. Delayed redistribution of IAMP therefore did not seem to be associated with neuronal metabolic activity.

Adult↗
PubMed1992

Use of pertechnetate 99mTc for abdominal scanning in localising an ileal duplication cyst: case report and review of the literature.

A 10-year-old boy presented with periumbilical postprandial pain and some melena. Physical examination was normal. All investigations were negative except a pertechnetate 99mTc abdominal scan which showed a very large and horn-shaped focus of high activity in the right flank. An ileal duplication was resected. It was lined by antral gastric mucosa with a large ulcer. The patient was treated successfully. The abdominal pertechnetate scan is discussed.

Child↗
PubMed1992

Increased pulmonary and intestinal permeability in Crohn's disease.

We tested the hypothesis that an increased epithelial permeability may affect sites other than the intestine in patients with Crohn's disease by simultaneously evaluating their pulmonary and intestinal permeability. Pulmonary and intestinal permeability were measured by clearance of inhaled technetium-99m diethylene triamine pentacetate (99mTc-DTPA) and by urinary recovery of chromium-51 ethylene diamine tetracetate respectively in 22 patients with Crohn's disease. The half time clearance of 99mTc-DTPA from lung to blood (t1/2LB) was decreased--that is pulmonary permeability increased--in the whole group of patients with Crohn's disease as compared with 13 controls (median 45.5 minutes (8-160) v 85 minutes (34-130) (p less than 0.003)). When analysed separately only patients with active Crohn's disease (n = 15) had a decreased t1/2 lung to blood v controls (42 minutes (8-160) v 85 minutes (34-130) (p less than 0.0025)). Among patients with active Crohn's disease, six were studied again when their disease was quiescent and their t1/2 lung to blood did not differ significantly. The intestinal permeability was increased in the whole group of Crohn's disease patients as compared with 15 controls (5.25% (1.2-24) v 1.7% (0.65-5.75) (p less than 0.0002)). When analysed separately both patients with active and inactive Crohn's disease had increased intestinal permeability v controls (8.1% (1.6-24) and 3.5% (1.2.9.2) v 1.7% (0.65-5.75)) (p less than 0.0001, p = 0.05 respectively). Six patients with active Crohn's disease were studied again when their disease was quiescent and their intestinal permeability decreased significantly p less than 0.04). Pulmonary permeability was increased in patients with Crohn's disease but was not greatly influenced by Crohn's disease activity as opposed to intestinal permeability. The mechanism of this increase is unknown, but may be related in some patients to the presence of an alveolitis.

Adolescent↗
PubMed1991

[Cerebral magnetic resonance imaging in the neonatal period. Initial results].

The place of neonatal cerebral MRI and its specific contribution compared with conventional imaging techniques were evaluated in 36 patients. The difficulties specific to the patient population studied met during this preliminary period are described, with their local solutions. A preliminary evaluation of the diagnostic and prognostic value of MRI according to the disease state and gestational age is presented. The specific contribution of MRI compared with transfontanellar ultrasonography and CT scan is discussed.

Anesthesia↗
PubMed1990

A new, fully versatile surface coil for MRI.

To enable surface coils to be adapted to a wide variety of examinations and anatomical features, the authors present a flexible detector coupled with an auto tuning device. The conductive loop, which is a flexible mercury filled tube, can be used to obtain various shapes, such as a single flat 22-cm diameter loop or an 11-cm diameter two-turn coil. Tuning is carried out at 21 MHz (0.5 T field) by a microprocessor controlled varactor. Studies conducted on a phantom are used to evaluate the signal/noise ratio and the spatial sensitivity of the coil according to different geometrical arrangements (saddle-shaped and two-turn). The results are compared with those obtained with the constructor's spine coil. The studies of patients described show good image resolution, even in the case of short sequences with thin slices and restricted fields of view. The clinical results and those obtained on the phantom demonstrate the feasibility and value of the device, particularly in examining anatomical regions of different forms.

Humans↗
PubMed1989

[Peroperative isotopic detection in the treatment of osteoid osteoma in children].

Peroperative isotopic detection, which was rendered possible by use of the cadmium telluride semi-conductor probe developed by C. Proye et al., has permitted nidus removal, as well as promoting cure in case of osteoid osteoma, by limiting bone resection to a strict minimum. Five cases are presented, all children. The method seems to present great value, particularly in case of localisations involving the spine or the neck of the femur.

Adolescent↗
PubMed1989

[Functional and motor study of retrosternal esophageal plasties].

The stomach may be used for esophageal reconstruction after resection of esophageal cancers. The aim of this study was to assess the motility of retrosternal esophagoplasty (RO) following the Akiyama procedure in 6 men (mean age: 56.7 years), at least two months after surgery by means of two techniques: a) manometry of the transplant with a multilumen perfused catheter in 50 and 40 cm from the incisor teeth including spontaneous (5 min) and poststimulation recordings, b) an isotopic method for assessing the gastric emptying of a meal labelled with 111In for the liquid phase and with 99mTc for the solid phase, compared to 12 volunteers as controls. Baseline pressure was 11.2 +/- 2.4 H2O cm without spontaneous activity. After dry and wet deglutition (5 ml of water), 6 patients showed synchronous rise in pressure, having mean amplitude of 12.7 +/- 2.3 cm H2O and lasting 4.3 +/- 1.2 s. Liquids T1/2 was 16.2 +/- 7.8 min in controls (p less than 0.01) and solids T1/2 was 17.7 +/- 6.4 min vs 61.7 +/- 16.5 min (p less than 0.001). The lack of propagated activity associated with rapid emptying of the meal through the plasty with no discrimination between solids and liquids suggests that RO does not participate actively in digestion.

Deglutition↗