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1.
Comput Biol Med ; 40(5): 469-77, 2010 May.
Article in English | MEDLINE | ID: mdl-20346449

ABSTRACT

Single photon emission computed tomography (SPECT) is an accurate imaging method for the diagnosis of refractory partial epilepsy. Two scans are carried out: interictal and ictal. The interest of this method is to provide an image in the ictal period, which allows hyperperfused areas linked to the seizure to be localized. The epileptic foci localization is improved by subtracting the two acquisitions (subtracted ictal SPECT: SIS). In some cases, the SIS method is not effective and does not isolate the seizure foci. In this article, we investigate a new method based on texture analysis using fractal geometry features. Fractal geometry features were extracted from each scan in order to quantify the heterogeneity change resulting from the hyperperfusion. A support vector machine (SVM) classification algorithm was used to classify the voxels into two classes: focal and healthy. Quantitative evaluation was performed on simulated images and clinical images from 22 patients with temporal lobe epilepsy. Results on both experiments showed that the proposed method is more specific and more sensitive than the SIS method.


Subject(s)
Algorithms , Epilepsy, Temporal Lobe/diagnostic imaging , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Pattern Recognition, Automated/methods , Tomography, Emission-Computed, Single-Photon/methods , Artificial Intelligence , Fractals , Humans , Image Enhancement/methods , Phantoms, Imaging , Reproducibility of Results , Sensitivity and Specificity
2.
Rev Neurol (Paris) ; 165(5): 440-8, 2009 May.
Article in French | MEDLINE | ID: mdl-19150099

ABSTRACT

INTRODUCTION: The objective was to assess the value of single photon emission computerized tomography (SPECT) and factorial discriminant analysis (FDA) in the differential diagnosis of Parkinson's disease (PD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD). PATIENTS AND METHODS: Sixty-two patients with clinical diagnoses of either CBD, PSP or PD were studied using brain HmPaO-SPECT. Thirteen pairs of regions of interest (ROIs) were drawn on the slices located 50mm and 90mm above the canthomeatal plane. Twenty-six uptake indices and 13 asymmetry indices were determined. FDA was performed in order to determine whether or not the patients could be classified into the correct clinical group on the basis of SPECT data alone. The most discriminant parameters were used to generate two predictive scores, which were tested in a second group of 15 patients. RESULTS: FDA of all 39 variables correctly classified all the patients. A subset of 10 variables was used to build predictive scores, which correctly classified 90% of PD patients, 100% of PSP patients and 86% of CBD patients. When tested in the validation group of 15 patients, these predictive scores correctly classified 87% of the individuals. The frontal medial, temporoparietal and parietal regions were the most discriminant. CONCLUSION: Using SPECT data alone, this study enabled us to distinguish between PD, PSP and CBD in patients with clear clinical presentations of the diseases in question. This novel, statistical approach provides reliable information. However, a prospective study dealing with de novo parkinsonian syndromes will be necessary.


Subject(s)
Brain/diagnostic imaging , Parkinsonian Disorders/classification , Parkinsonian Disorders/diagnostic imaging , Aged , Diagnosis, Differential , Discriminant Analysis , Female , Humans , Male , Middle Aged , Nerve Degeneration/diagnostic imaging , Parkinsonian Disorders/chemically induced , Prospective Studies , Supranuclear Palsy, Progressive/diagnostic imaging , Tomography, Emission-Computed, Single-Photon/methods
3.
Article in English | MEDLINE | ID: mdl-19163568

ABSTRACT

One of the imaging modalities used for the diagnosis of epilepsy is SPECT (Single-Photon Emission Computed Tomography). Ictal and interictal images are registered to MR images (SISCOM (Substracted Ictal Spect COregistred to MR) to delineate the sources. However, in some cases and for many reasons, the used method does not lead to precise delimitation of epileptic fit sources. In this case, works have been investigated on group's studies or in combining others modalities like EEG (Electroencephalography). This study investigates the possibility of using a mathematic model for the image texture to detect the changes on SPECT images. Beyond encouraging preliminary results concerning the multifractal analysis to distinguish volunteers and epileptic patients, our aim was to detect sources by the singularity spectrum compute. The experiment is divided into two phases. First, we developed a 3D method for the singularity spectrum compute. In the test phase, we applied this multifractal spectrum to the sources detection on SPECT images. The results obtained on a base of seven patients show that the proposed method is encouraging. Indeed, the detections of epileptic fit sources obtained were in agree with the expert diagnostic.


Subject(s)
Brain/pathology , Epilepsy/diagnosis , Epilepsy/pathology , Imaging, Three-Dimensional/methods , Tomography, Emission-Computed, Single-Photon/methods , Algorithms , Computer Graphics , Fractals , Humans , Image Processing, Computer-Assisted/methods , Models, Theoretical , Nervous System Diseases/diagnosis , Nervous System Diseases/pathology , Reference Values , Reproducibility of Results
4.
Article in English | MEDLINE | ID: mdl-18002727

ABSTRACT

A new improving method to compute Spearman rank correlation test has been developed. This method is based on the use of a response to stimulation delay referred by many authors. Visual results tend to prove the method efficiency which is confirmed by obtained overlap rates; moreover this method can easily be adapted in a clinical context.


Subject(s)
Brain Mapping/methods , Data Interpretation, Statistical , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Statistics, Nonparametric , Subtraction Technique , Adult , Algorithms , Computer Simulation , Female , Humans , Male , Models, Neurological , Models, Statistical , Reproducibility of Results , Sensitivity and Specificity
5.
Rev Med Interne ; 27(12): 932-45, 2006 Dec.
Article in French | MEDLINE | ID: mdl-16870308

ABSTRACT

PURPOSE: Fluorodeoxyglucose positron emission tomography (FDG-PET) is a promising imaging technique that has already proven effective in modifying patient care in oncology. Fluorodeoxyglucose still remains the main radiopharmaceutical agent routinely used for PET imaging. A growing interest has recently lead to broaden PET research on benign disorders. The field of inflammatory or immune diseases and globally the field of internal medicine could also be impacted by FDG-PET. MAIN POINTS: Great vessels vasculitides and fever of unknown origin have both been studied by several teams and could become indications for PET. In addition, current indications now extend to paraneoplastic syndromes. It is thus possible to foresee that the clinical applications for PET will continue to expand in these patients. PERSPECTIVES AND PROJECTS: In the future, inflammatory arthritis, chronic inflammatory bowel diseases, systemic erythematous lupus, histiocytosis, or pulmonary and retroperitoneal fibrosis might benefit from PET even if, available data remains scarce to this day. Although PET will probably alter the landscape of patient management in internal medicine in the near future, additional clinical research is still needed to ascertain the exact role of PET.


Subject(s)
Internal Medicine , Positron-Emission Tomography/methods , Fever of Unknown Origin/diagnostic imaging , Fluorodeoxyglucose F18 , Forecasting , Humans , Internal Medicine/trends , Positron-Emission Tomography/trends , Radiopharmaceuticals , Vasculitis/diagnostic imaging
6.
Rev Med Interne ; 27(6): 478-81, 2006 Jun.
Article in French | MEDLINE | ID: mdl-16563574

ABSTRACT

INTRODUCTION: Takayasu arteritis (TA) is an inflammatory arteritis affecting large vessels, predominantly the aorta, its main branches, and the pulmonary arteries. Up to now, arteriography was considered as the "gold standard". But others exams are emerging in the management of TA: vascular ultrasound, angio-scanner, magnetic resonance imaging and 18FDG positron emission tomography (18FDG PET). Such investigations allow a study of the lumen but also of the arterial walls. However, at the time, no biological or radiological test is able to determine the activity of TA. 18FDG PET could be effective to estimate the disease activity. EXEGESIS: We report the case of a young woman for who 18FDG PET permit to assert a relapse of TA. CONCLUSION: 18FDG PET could be effective to estimate the disease activity.


Subject(s)
Fluorodeoxyglucose F18 , Positron-Emission Tomography , Takayasu Arteritis/diagnostic imaging , Adult , Anti-Inflammatory Agents/therapeutic use , Diagnosis, Differential , Female , Humans , Positron-Emission Tomography/methods , Prednisone/therapeutic use , Radiopharmaceuticals , Takayasu Arteritis/diagnosis , Takayasu Arteritis/drug therapy , Treatment Outcome
7.
Conf Proc IEEE Eng Med Biol Soc ; 2006: 1010-3, 2006.
Article in English | MEDLINE | ID: mdl-17945616

ABSTRACT

A new approach to compute z-score and Student's test in functional MRI has been developed. This approach tends to involve standard z-score and Student's test computation. This approach is based on the delay of the response compared to the stimulation introduced by many authors. The results obtained prove the methods efficiency; moreover these methods can be easily adapted in a clinical context. This paper presents the new computation and the validation.


Subject(s)
Brain Mapping/methods , Brain/physiology , Data Interpretation, Statistical , Evoked Potentials/physiology , Image Interpretation, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Reaction Time/physiology , Algorithms , Image Enhancement/methods , Reproducibility of Results , Sensitivity and Specificity
8.
Diabetes Metab ; 31(2): 125-33, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15959418

ABSTRACT

OBJECTIVES: The diagnosis of osteomyelitis in patients with diabetic foot is difficult both clinically and radiologically. An early diagnosis is crucial to optimize therapeutic strategy. Among the diagnostic methods currently used, scintigraphy with ex-vivo labelled white blood cells is the gold standard, but cannot be performed in all centers; therefore 67Gallium citrate (67Ga) imaging in combination with a bone scintigraphy is still widely used. METHOD: The results of imaging 24 diabetic patients with 31 suspected osteomyelitic lesions using the antigranulocyte Fab' fragment (Sulesomab or LeukoScan or immunoscintigraphy) were prospectively compared with results from the bone scan coupled with 67Ga. The diagnosis of osteomyelitis was confirmed by either biopsy or follow-up, radiological imaging and clinical outcome. RESULTS AND CONCLUSION: Sulesomab correctly identified 12 of 18 osteomyelitic lesions while 67Ga was able to detect only 8 of 18. Therefore the sensitivity is 67% for Sulesomab and 44% for 67Ga. Among the 13 non-osteomyelitic lesions imaging with Sulesomab was able to rule out infection in 11 cases and 67Ga in 10 cases. The specificity is therefore 85% for Sulesomab and 77% for 67Ga. Image interpretation for Sulesomab in this group of patients is occasionally suboptimal when imaging is performed at 3 hours post injection. High vascular background in the early images may obscure infection especially in small bones. Practically, scintigraphy with Sulesomab is fast and simple due to ease of labeling, no ex-vivo handling of blood, low radiation and provides rapid diagnosis. The diagnosis of osteomyelitis obtained by the antibody fragment scintigraphy influences the management (guided biopsy) and therapy. In several patients, imaging with Sulesomab was able to rule out osteomyelitis, helping to avoid useless antibiotic therapy and its associated side effects.


Subject(s)
Antibodies, Monoclonal , Diabetic Foot/diagnostic imaging , Gallium Radioisotopes , Osteomyelitis/diagnostic imaging , Aged , Aged, 80 and over , Antibodies, Monoclonal, Murine-Derived , Diabetic Foot/complications , Female , Humans , Male , Middle Aged , Radiography , Radionuclide Imaging , Reproducibility of Results
9.
Br J Surg ; 92(3): 362-9, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15672427

ABSTRACT

BACKGROUND: The aim of this study was to assess the additional value of information provided by positron emission tomography (PET) with [(18)F]fluoro-2-deoxy-D-glucose (FDG) over that provided by computed tomography (CT) in patients with resectable liver metastases from colorectal cancer. METHODS: Between October 2001 and November 2002, a prospective double-blind comparison of preoperative FDG-PET and thoracoabdominal CT was performed in 53 patients with potentially resectable liver metastases from colorectal cancer. All resected metastases were subjected to histological examination. RESULTS: Histological examination confirmed the presence of malignant or benign lesions detected by PET and/or CT in 95 per cent of instances. Overall sensitivity (78 per cent) and accuracy (88 per cent) of PET were equivalent to those of CT (76 and 86 per cent respectively). The sensitivity of PET was equivalent to that of CT for hepatic sites (both 79 per cent), but was superior for extrahepatic abdominal sites (63 and 25 per cent respectively). PET provided additional information in five patients, mainly by revealing abdominal extrahepatic metastases, but falsely upstaged three patients. CONCLUSION: Whole-body FDG-PET may identify unrecognized extrahepatic metastases in patients with potentially resectable liver metastases imaged by CT. However, additional information provided by PET is not as reliable as suggested by earlier retrospective studies.


Subject(s)
Colorectal Neoplasms , Fluorodeoxyglucose F18 , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/secondary , Positron-Emission Tomography/methods , Radiopharmaceuticals , Adult , Aged , Double-Blind Method , Female , Humans , Male , Middle Aged , Prospective Studies , Tomography, X-Ray Computed/methods
10.
Neuroradiology ; 44(7): 610-6, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12136364

ABSTRACT

Our purpose was to assess the usefulness of diffusion- and perfusion-weighted MRI for the detection of ischaemic brain damage in patients with suspected vasospasm after subarachnoid haemorrhage (SAH). We studied 11 patients admitted with a ruptured aneurysm of the anterior circulation and suspected of intracranial vasospasm on clinical examination and transcranial Doppler sonography (TCD). All were investigated by technetium-hexamethyl-propylene amine oxime (Tc-HMPAO) single photon emission computed tomography (SPECT) and diffusion and perfusion-weighted MRI (DWI, PWI) within 2 weeks of their SAH. Trace images and TTP maps were interpreted by two examiners and compared with clinical and imaging follow-up. PWI revealed an area of slowed flow in seven patients, including four with major and three with minor hypoperfusion on SPECT. In two patients, PWI did not demonstrate any abnormality, while SPECT revealed major hypoperfusion in one and a minor deficit hypoperfusion in the other. Two patients with high signal on DWI had a permanent neurological deficit.


Subject(s)
Brain/pathology , Magnetic Resonance Imaging , Subarachnoid Hemorrhage/diagnosis , Tomography, Emission-Computed, Single-Photon , Vasospasm, Intracranial/diagnosis , Adult , Aneurysm, Ruptured/complications , Blood Flow Velocity , Brain/diagnostic imaging , Cerebrovascular Circulation , Female , Humans , Intracranial Aneurysm/complications , Male , Middle Aged , Radiopharmaceuticals , Subarachnoid Hemorrhage/complications , Subarachnoid Hemorrhage/diagnostic imaging , Technetium Tc 99m Exametazime , Ultrasonography, Doppler, Transcranial , Vasospasm, Intracranial/diagnostic imaging , Vasospasm, Intracranial/etiology
11.
Eur J Nucl Med ; 28(10): 1505-11, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11685493

ABSTRACT

The aim of this prospective study was to assess pulmonary and intestinal permeability (PP and IP, respectively) in patients with alcoholic liver cirrhosis (ALC). Thirty-five non-smoking patients with biopsy-proven ALC were included (mean grade B in Child's classification). None had a previous history of pulmonary disease and all had a normal chest radiograph and computed tomography scan. Lung function tests and bronchoalveolar lavage (BAL) were also performed. The PP was studied by measuring the lung to blood clearance of inhaled 99mTc-DTPA aerosol. Clearance half-time (T 1/2, in minutes) and residual activity (RA in %) were obtained from exponential fitting of the right pulmonary clearance curve. IP was concurrently evaluated by measuring the urinary recovery of ingested 51Cr-EDTA, according to Bjarnason's technique and expressed as a percentage of the total oral dose. Results were compared with those obtained in non-smoking healthy control subjects. PP was significantly (P<0.05) increased in patients with ALC (T 1/2 65.9 +/- 32.2 min, RA 87.1% +/- 6.7%) versus control subjects (T 1/2 85.2 +/- 20.8 min, RA 92.8% +/- 2.6%). IP was not significantly different between patients and controls (2.39% +/- 2.20% vs 1.74% +/- 0.81%). A significant correlation (P<0.05) was found between PP and total cell number in BAL and total lymphocyte number in BAL. In conclusion, in patients with ALC, PP is increased without any association with IP, the severity of cirrhosis according to Child's classification or the results of pulmonary function tests. These findings may reflect primary involvement of the alveolar epithelium. In patients with ALC, PP is correlated with total cell number and total lymphocyte number. Increased PP may be due to activated cytotoxic lymphocytes and/or abnormal macrophage activity.


Subject(s)
Intestinal Mucosa/metabolism , Liver Cirrhosis, Alcoholic/metabolism , Lung/metabolism , Adult , Female , Humans , Male , Middle Aged , Permeability , Prospective Studies
12.
Dement Geriatr Cogn Disord ; 12(6): 371-8, 2001.
Article in English | MEDLINE | ID: mdl-11598308

ABSTRACT

The identification of new nosological forms such as Lewy body disease (LBD) requires a re-evaluation of the patterns observed in brain functional imaging in the various forms of dementia. We studied 60 demented patients, divided into three groups and fulfilling the clinical criteria for Alzheimer's disease (AD), LBD and frontotemporal dementia (FTD), using Tc-HMPAO and a brain-dedicated SPECT system. After normalisation we applied a cut-off at two levels according to previously established criteria. We reaffirmed the already established data concerning FTD (mainly a bilateral frontal decrease) and for LBD (a severe diffuse decrease in the frontal regions and also in the posterior association cortex). In contrast, the decrease in AD was strictly limited to the parieto-occipital cortex, irrespective of the severity of the cognitive decline. We hypothesise that the major simplification concerning the pattern observed in AD can be explained by the fact that patients suffering from LBD have previously been included in the groups of AD patients.


Subject(s)
Alzheimer Disease/diagnostic imaging , Brain/diagnostic imaging , Dementia/diagnostic imaging , Lewy Body Disease/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Alzheimer Disease/physiopathology , Cerebrovascular Circulation , Dementia/physiopathology , Diagnosis, Differential , Female , Humans , Lewy Body Disease/physiopathology , Male , Middle Aged , Neurodegenerative Diseases/diagnostic imaging , Radiopharmaceuticals , Retrospective Studies , Technetium Tc 99m Exametazime
13.
Rev Neurol (Paris) ; 157(2): 187-97, 2001 Feb.
Article in French | MEDLINE | ID: mdl-11283465

ABSTRACT

We have investigated the cortical and subcortical regional cerebral blood flow (rCBF) disorders resulting from infarcts of the anterior choroidal artery (AChA), and correlations with the severity of lesions, the physical and cognitive deficits, and the functional impairment. Eighteen patients presenting with recent anterior choroidal artery infarct without any other brain injury were examined at the secondary phase post-stroke using the single photon emission computed tomography technique and 133 Xenon inhalation. The rCBF and asymmetry indexes (AI) were calculated for 12 symmetrical hemispheric areas, and the cerebellum. The AI values were compared with those of 24 control subjects. The severity of the lesions was evaluated from CT scans or MRI. The neurological status (Orgogozo scale, walking disorders, MMSE, attention impairment, aphasia) and disability (functional independance measure: FIM) were assessed for each patient at the same time period. The relationships between rCBF disorders and brain lesions, and between the results of clinical investigations and rCBF disorders and brain lesions were assessed by linear regression analyses (stepwise variable selections, p=0.05). The AI values were significantly increased in the cerebral hemispheres, and this was most severe in the internal capsule (direct effect of the lesion) and the dorsolateral hemispheric cortex (diaschisis). Individual evaluations showed that AI were significantly increased in 13 patients in at least one ROI of the cerebral hemispheres, and in 3 patients in the internal capsule. Stepwise variable selections revealed that AI were best explained by the severity of the lesions in the internal capsule and the internal temporal area. The AI of the external temporal area and the internal capsule also helped explain the clinical (physical and cognitive) deficits. Thus, AChA infarcts may have relatively large effects on the central part of the lateral and dorsal cortex of the ipsilateral hemisphere. Subcortical and cortical consequences both contribute to explain the motor and cognitive deficits and disability.


Subject(s)
Cerebral Arteries/pathology , Cerebral Arteries/physiopathology , Cerebral Infarction/pathology , Cerebral Infarction/physiopathology , Cerebrovascular Circulation/physiology , Choroid Plexus/blood supply , Aged , Cerebral Infarction/diagnosis , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Regional Blood Flow , Tomography, Emission-Computed, Single-Photon , Tomography, X-Ray Computed , Xenon Radioisotopes
14.
J Neurol Neurosurg Psychiatry ; 69(5): 661-3, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11032624

ABSTRACT

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.


Subject(s)
Alzheimer Disease/diagnostic imaging , Dementia/diagnostic imaging , Frontal Lobe/diagnostic imaging , Technetium Tc 99m Exametazime , Temporal Lobe/diagnostic imaging , Brain/diagnostic imaging , Discriminant Analysis , Humans , Multivariate Analysis , Tomography, Emission-Computed, Single-Photon
15.
Rev Neurol (Paris) ; 156(10): 811-83, 2000 Oct.
Article in French | MEDLINE | ID: mdl-11033516

ABSTRACT

The aim of this study was to investigate relations between neuropsychological disorders resulting from rupture of aneurysms of the anterior communicating artery, regional cerebral blood flow anomalies and brain lesions revealed on MRI. Blood flow was analyzed in 22 consecutive patients at least 3 weeks after surgery using single photon emission computed tomography. Flow values were calculated in 10 regions of interest on each side of the brain. Attention, motor control, executive functions, short-term and long-term learning (verbal, visuo-spatial), categorical evocation, general intellectual performances were investigated. Flow drop was observed over frontal areas, which predominated on the right side. The correlation analyses showed that


Subject(s)
Aneurysm, Ruptured/physiopathology , Aneurysm, Ruptured/psychology , Intracranial Aneurysm/physiopathology , Intracranial Aneurysm/psychology , Neuropsychological Tests , Aged , Aneurysm, Ruptured/diagnosis , Attention , Cerebral Arteries , Cerebral Cortex/blood supply , Cerebrovascular Circulation , Female , Follow-Up Studies , Humans , Intracranial Aneurysm/diagnosis , Learning , Magnetic Resonance Imaging , Male , Memory , Middle Aged , Motor Activity , Retrospective Studies , Tomography, Emission-Computed
16.
Rev Neurol (Paris) ; 156(12): 1113-9, 2000 Dec.
Article in French | MEDLINE | ID: mdl-11139727

ABSTRACT

Ictal SPECT is a valuable method for the presurgical exploration of partial epilepsy. (99m)Tc Ethyl Cysteinate Dimer stable during 6h has contributed to develop ictal studies to evaluate the location of partial seizure. The aim of this study was to investigate some factors playing a possible role on the regional increase of cerebral blood flow (rCBF) Twenty-three patients with refractory partial epilepsy (temporal epilepsy n=16, extratemporal epilepsy n=7) were included. All the patients underwent a presurgical evaluation (phase I) during a week with detailed clinical history, cranial magnetic resonance imaging, monitoring EEG and video. Ictal and interictal SPECT were performed using a fast rotating brain dedicated camera (TOMOMATIC 564) in a quiet and normally illuminated room with controlled EEG (interictal) or video EEG (ictal); Scanning was started one hour after injection of ECD Tc administered in IV a few seconds after the electrical onset seizure. Slices parallel to the long axis of the temporal lobe were reconstructed. SPECT images were evaluated after normalisation. This study shows that


Subject(s)
Brain/blood supply , Cerebrovascular Circulation , Epilepsies, Partial/diagnostic imaging , Epilepsies, Partial/physiopathology , Tomography, Emission-Computed, Single-Photon/methods , Adolescent , Adult , Age of Onset , Brain/diagnostic imaging , Cysteine/analogs & derivatives , Electroencephalography , Epilepsy, Temporal Lobe/diagnostic imaging , Epilepsy, Temporal Lobe/physiopathology , Humans , Organotechnetium Compounds , Radiopharmaceuticals , Regional Blood Flow , Sensitivity and Specificity , Video Recording
17.
J Nucl Med ; 40(6): 956-62, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10452310

ABSTRACT

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.


Subject(s)
Alzheimer Disease/diagnostic imaging , Brain/diagnostic imaging , Cerebrovascular Circulation , Parkinson Disease/diagnostic imaging , Tomography, Emission-Computed, Single-Photon , Aged , Cerebral Cortex/diagnostic imaging , Data Interpretation, Statistical , Diagnosis, Differential , Humans , Middle Aged , Radiopharmaceuticals , Technetium Tc 99m Exametazime
18.
Neurochirurgie ; 45(2): 110-7, 1999 May.
Article in French | MEDLINE | ID: mdl-10448650

ABSTRACT

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.


Subject(s)
Brain Neoplasms/diagnostic imaging , Brain/pathology , Glioma/diagnostic imaging , Neoplasm Recurrence, Local/diagnostic imaging , Radiation Injuries/diagnostic imaging , Technetium Tc 99m Sestamibi , Tomography, Emission-Computed, Single-Photon , Aged , Astrocytoma/diagnostic imaging , Astrocytoma/pathology , Astrocytoma/radiotherapy , Biopsy , Brain/diagnostic imaging , Brain Neoplasms/pathology , Brain Neoplasms/radiotherapy , Choroid Plexus Neoplasms/diagnostic imaging , Choroid Plexus Neoplasms/pathology , Choroid Plexus Neoplasms/radiotherapy , Cranial Irradiation/adverse effects , Diagnosis, Differential , Evaluation Studies as Topic , False Negative Reactions , False Positive Reactions , Female , Glioblastoma/diagnostic imaging , Glioblastoma/pathology , Glioblastoma/radiotherapy , Glioma/pathology , Glioma/radiotherapy , Humans , Male , Middle Aged , Necrosis , Oligodendroglioma/diagnostic imaging , Oligodendroglioma/pathology , Oligodendroglioma/radiotherapy , Prospective Studies , Radiation Injuries/etiology , Retrospective Studies , Sensitivity and Specificity , Stereotaxic Techniques
19.
J Nucl Med ; 40(5): 721-9, 1999 May.
Article in English | MEDLINE | ID: mdl-10319742

ABSTRACT

UNLABELLED: The aim of this study was to evaluate regional and remote diaschisis of inferior brain stem or cerebellar infarcts in 25 patients presenting with relatively limited lesions. Patients presented with medullary, pontine or cerebellar infarction. METHODS: Lesions were evaluated on MRI (0.5 T). Regional cerebral blood flow (rCBF) was assessed by means of SPECT, after injection of 9rmTc-hexamethyl propyleneamine oxime (HMPAO) and, when possible, inhalation of 133Xe in the same session. For each method, asymmetry indices (Als), comparing contralateral to ipsilateral rCBF values, were calculated in four areas of each cerebral hemisphere and in the cerebellum and later compared with values obtained in healthy subjects (P = 0.05). RESULTS: Higher rCBF values were observed in the contralateral cerebellum in 2 of 7 patients with selective lateral medullary lesions, and cerebellar Als were significantly increased. When a cerebellar infarct was associated with a lateral medullary lesion, the cerebellar and contralateral hemispheric asymmetries were more severe. Unilateral paramedian pontine infarcts had more frequent consequences on the cerebellum (2 of 3 cases), with rCBF or tracer uptake being reduced in the ipsilateral or the contralateral lobe. Inverse cerebral hemispheric asymmetry could then be observed. Bilateral pontine lesions were difficult to evaluate. Using 99mTc-HMPAO, discrete cerebellar asymmetry was observed in 3 of 6 cases. Pure cerebellar infarcts in the posterior inferior cerebellar artery territory were always associated with a severe ipsilateral flow drop in the cerebellum, and contralateral hemispheric diaschisis was frequent (3 of 4 patients), predominating in the frontotemporal cortex and subcortical structures. This was also more obvious using 99mTC-HMPAO than 133Xe. Variance analysis showed that hemispheric diaschisis was more severe in mixed brain stem and cerebellar infarcts than in pure cerebellar or brain stem lesions. Furthermore, cerebellar and hemispheric AI values were not correlated with measurements of clinical deficits, disability or handicap. CONCLUSION: Unilateral and limited inferior brain stem lesions can have ipsi- or contralateral consequences on the cerebellum and cerebral hemispheres rCBF. These remote effects are related to lesions of the main pathways joining these structures, resulting in deactivation and, in some cases, overactivation. Contrary to what has been suggested, consequences on cerebral hemispheres are more severe in mixed cerebellar and brain stem infarcts than in pure cerebellar lesions.


Subject(s)
Cerebellar Diseases/diagnostic imaging , Cerebral Infarction/diagnostic imaging , Cerebrovascular Circulation/physiology , Technetium Tc 99m Exametazime , Tomography, Emission-Computed, Single-Photon , Adult , Cerebellar Diseases/physiopathology , Cerebral Infarction/physiopathology , Female , Humans , Male , Medulla Oblongata/blood supply , Middle Aged , Pons/blood supply , Radiopharmaceuticals , Xenon Radioisotopes
20.
Rev Neurol (Paris) ; 154(5): 401-7, 1998 Jun.
Article in French | MEDLINE | ID: mdl-9773071

ABSTRACT

A case of unilateral infarct in the territory of the left internal cerebral vein, severely disturbing cognitive processes, and more especially recall in verbal memory, is reported. This 22-year-old patient survived a left thalamic and striato-capsular infarct related to a straight sinus and left internal cerebral vein thrombosis. Motor and functional recovery was fair, despite late dystonia. At the secondary phase post-stroke, cognitive disorders were severe, including increased short-term forgetting and episodic (anterograde and retrograde) and semantic amnesia. One year later, a residual deficit of verbal recall was observed, which participated in the anterograde and retrograde amnesia. Recognition was well preserved. This case showed that: (1) internal cerebral vein thrombosis can have severe consequences on cognition and memory, and that late prognosis is not as fair as has been previously reported in selected patients, and (2) left diencephalic structures are specifically associated with recollection of verbal information from long-term memory.


Subject(s)
Cerebral Infarction/psychology , Cerebral Veins , Cognition Disorders/etiology , Memory , Verbal Learning , Adult , Brain/diagnostic imaging , Brain/pathology , Cerebral Infarction/diagnostic imaging , Cerebral Infarction/pathology , Cognition Disorders/diagnostic imaging , Cognition Disorders/pathology , Corpus Striatum/diagnostic imaging , Corpus Striatum/pathology , Female , Humans , Intelligence Tests , Magnetic Resonance Imaging , Thalamus/diagnostic imaging , Thalamus/pathology , Tomography, X-Ray Computed
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