171 research outputs found

    Squelette homotopique 3D pour le traitement et l'analyse du ventricule gauche en SPECT

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    Des images tomoscintigraphiques sont la reprĂ©sentation 3D de la distribution d'un traceur dans le ventricule gauche (VG). Le but de notre Ă©tude est de rĂ©ussir Ă  quantifier les dĂ©fauts de fixations (zones d'attĂ©nuation) reprĂ©sentatifs d'une pathologie. Le squelette 3D du VG est utilisĂ© pour reconstituer la forme originale du VG. Pour combler les lacunes liĂ©es aux pathologies, le squelette est complĂ©tĂ© conformĂ©ment Ă  un modĂšle. Un algorithme fondĂ© sur la thĂ©orie de l'incertain (logique floue) utilise le squelette ainsi complĂ©tĂ© pour gĂ©nĂ©rer une nouvelle image avec un contraste plus Ă©levĂ©. Cette nouvelle image peut ĂȘtre plus facilement segmentĂ©e, et le VG est considĂ©rĂ© dans son intĂ©gralitĂ©. Le VG peut alors ĂȘtre entiĂšrement quantifiĂ©

    Diagnostic interventions in nuclear medicine

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    Diagnostic interventions in nuclear medicine may be defined as the coadministration of a nonradioactive drug or application of a physical stimulus or physiologic maneuver to enhance the diagnostic utility of a nuclear medicine test. The rationale for each interventional maneuver follows from the physiology or metabolism of the particular organ or organ system under evaluation. Diagnostic inference is drawn from the pattern of change in the biodistribution of the tracer in response to the intervention-induced change in metabolism or function.In current practice, the most commonly performed interventional maneuvers are aimed at studies of the heart, genitourinary system, hepatobiliary system, and gastrointestinal tract. The single most commonly performed interventional study in the United States is the stress Thallium-201 myocardial perfusion scan aimed at the diagnosis of coronary artery disease. The stress portion of the study is accomplished with dynamic leg exercise on a treadmill and is aimed at increasing myocardial oxygen demands. Areas of myocardium distal to hemodynamically significant lesions in the coronary arteries become ischemic at peak stress due to the inability of the stenotic vessel to respond to the oxygen demand/blood flow needs of the myocardium. Ischemic areas are readily recognized as photopenic defects on scans obtained immediately after exercise, with "normalization" upon delayed imaging.Diuresis renography is aimed at the differential diagnosis of hydroureteronephrosis. By challenging the urinary tract collecting structures with an augmented urine flow, dilated, unobstructed systems can be differentialed from systems with significant mechanical obstruction. Obstructed systems have a low ability to respond even after effective diuresis, resulting in a characteristic prolonged retention of the radiotracer.Hepatobiliary interventions are most commonly employed in the clinical setting of suspected acute cholecystitis. Administering a cholecystogogue before a hepatobiliary tracer promotes visualization of the gallbladder by causing it to go through a contraction/filling cycle in gallbladder by causing it to go through a contraction/filling cycle in which the filling phase occurs during maximum exposure to the radionuclide. This maneuver can convert a false positive study that suggests the presence of acute cholecystitis to a true negative study. Other gastrointestinal interventions are aimed at enhancing the detection of gastroesophageal reflux and gastrointestinal bleeding.Many new interventions have been developed that are currently aimed at research problems rather than clinical problems. Elegant studies eliciting cortical activation in response to visual, auditory, and cognitive stimulae have been described for the brain and show clinical promise for the future. New interventions are also under investigation for the heart and kidney. The development of new tracers and instrumentation will continue to be paralleled by the development of new interventional maneuvers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28098/1/0000545.pd

    Étude d'un dĂ©tecteur CMOS hybride Ă  semi-conducteur et comptage de photons (application Ă  l'imagerie X)

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    CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

    Place de la TEP-TDM dans la prise en charge des cancers du col et du corps utérins et de l'ovaire (expérience clermontoise)

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    Le but de cette Ă©tude rĂ©trospective Ă©tait de dĂ©terminer la place de la TEP-TDM dans la prise en charge des cancers du col et du corps utĂ©rins et de l'ovaire. Les comptes-rendus des 188 TEP-TDM rĂ©alisĂ©es dans notre service depuis 2004 ont Ă©tĂ© analysĂ©s. Au vu des rĂ©sultats obtenus et des donnĂ©es les plus rĂ©centes de la littĂ©rature, il semble que les indications dans lesquelles cette technique puisse ĂȘtre utilisĂ©e soient plus larges que les simples options actuellement reconnues dans les Standards, Options, Recommandations. Ainsi l'utilisation de la TEP-TDM pour le bilan d'extension initial ou d'une rĂ©cidive avĂ©rĂ©e d'un cancer du col de l'utĂ©rus tend Ă  devenir un standard. L'apport de la TEP-TDM pour la dĂ©tection des rĂ©cidives des cancers ovariens semble aussi Ă©vident. Les performances de la TEP-TDM nous paraissent suffisantes pour proposer son emploi pour le bilan d'extension d'une rĂ©cidive avĂ©rĂ©e d'un cancer de l'ovaire et pour l'Ă©valuation de la rĂ©ponse au traitement. La TEP-TDM apparaĂźt utile pour le bilan d'extension initial des cancers du corps utĂ©rin ne pouvant pas bĂ©nĂ©ficier de lymphadĂ©nectomie (patientes obĂšses ou consultant aprĂšs hystĂ©rectomie). Elle peut par ailleurs jouer un rĂŽle en cas de suspicion de rĂ©cidive en permettant de distinguer les cicatrices post-thĂ©rapeutiques de rĂ©elles lĂ©sions nĂ©oplasiques. L'intĂ©rĂȘt de la TEP-TDM dans ces indications doit bien sĂ»r ĂȘtre confirmĂ© par des Ă©tudes prospectives regroupant des effectifs plus importants. L'Ă©tendue des situations oĂč la TEP-TDM est potentiellement utile n'est donc pas encore stabilisĂ©e.CLERMONT FD-BCIU-SantĂ© (631132104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

    EVALUATION PAR TRAITEMENT DE L'IMAGE DE LA CINETIQUE CARDIAQUE EN TEMP SYNCHRONISEE A L'ECG (DOCTORAT)

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    CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

    Impact du mode d'acquisition 2D versus 3D sur les examens TEP

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    CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
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