RESUMO
BACKGROUND AND PURPOSE: Recommendations for using fluorodeoxyglucose positron emission tomography (FDG-PET) to support the diagnosis of dementing neurodegenerative disorders are sparse and poorly structured. METHODS: Twenty-one questions on diagnostic issues and on semi-automated analysis to assist visual reading were defined. Literature was reviewed to assess study design, risk of bias, inconsistency, imprecision, indirectness and effect size. Critical outcomes were sensitivity, specificity, accuracy, positive/negative predictive value, area under the receiver operating characteristic curve, and positive/negative likelihood ratio of FDG-PET in detecting the target conditions. Using the Delphi method, an expert panel voted for/against the use of FDG-PET based on published evidence and expert opinion. RESULTS: Of the 1435 papers, 58 papers provided proper quantitative assessment of test performance. The panel agreed on recommending FDG-PET for 14 questions: diagnosing mild cognitive impairment due to Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) or dementia with Lewy bodies (DLB); diagnosing atypical AD and pseudo-dementia; differentiating between AD and DLB, FTLD or vascular dementia, between DLB and FTLD, and between Parkinson's disease and progressive supranuclear palsy; suggesting underlying pathophysiology in corticobasal degeneration and progressive primary aphasia, and cortical dysfunction in Parkinson's disease; using semi-automated assessment to assist visual reading. Panellists did not support FDG-PET use for pre-clinical stages of neurodegenerative disorders, for amyotrophic lateral sclerosis and Huntington disease diagnoses, and for amyotrophic lateral sclerosis or Huntington-disease-related cognitive decline. CONCLUSIONS: Despite limited formal evidence, panellists deemed FDG-PET useful in the early and differential diagnosis of the main neurodegenerative disorders, and semi-automated assessment helpful to assist visual reading. These decisions are proposed as interim recommendations.
Assuntos
Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Demência/diagnóstico por imagem , Fluordesoxiglucose F18 , Doenças Neurodegenerativas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Consenso , Diagnóstico Diferencial , Humanos , Medicina Nuclear , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Prionopathy is the cause of 62% of the rapidly progressive dementias (RPD) in which a definitive diagnosis is reached. The variability of symptoms and signs exhibited by the patients, as well as its different presentation, sometimes makes an early diagnosis difficult. METHODS: Patients withdiagnosis of definite or probable prionopathy during the period 1999-2012 at our hospital were retrospectively reviewed.The clinical features and the results of the complementary tests (14-3-3 protein, EEG, MRI, FDG-PET, and genetic analysis) were evaluated in order to identify some factors that may enable an earlier diagnosis to be made. RESULTS: A total of 14 patients are described: 6 with definite sporadic Creutzfeldt-Jakob (sCJD) disease, 3 with probable sCJD, 4 with fatal familial insomnia, and 1 with the new variant. The median age at diagnosis was 54 years old. The mean survival was 9.5 months. Mood disorder was the most common feature, followed by instability and cognitive impairment. 14-3-3 protein content in the cerebrospinal fluid was positive in 7 of 11 patients, and the EEG showed typical signs in 2 of 12 patients. Neuroimaging (FDG-PET, MRI) studies suggested the diagnosis in 13 of the 14 patients included. CONCLUSIONS: Most patients presenting with RPD suffer from a prion disease. In our series the most useful complementary tests were MRI and FDG-PET, being positive in 13 of the 14 patients studied.
Assuntos
Síndrome de Creutzfeldt-Jakob/diagnóstico , Insônia Familiar Fatal/diagnóstico , Neuroimagem , Adulto , Idoso , Encéfalo , Demência/etiologia , Diagnóstico Diferencial , Imagem de Difusão por Ressonância Magnética , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Prion diseases are neurodegenerative disorders resulting from the accumulation of a misfolded isoform of the cellular prion protein (PrPc). They can occur as acquired, sporadic, or hereditary forms. Although prion diseases show a wide range of phenotypic variations, pathological features and clinical evolution, they are all characterised by a common unfavourable course and a fatal outcome. REVIEW SUMMARY: Some variants, such as kuru, have practically disappeared, while others, for example the variant Creutzfeldt-Jakob (vCJD) or those attributable to iatrogenic causes, are still in force and pose a challenge to current medicine. There are no definitive pre-mortem diagnostic tests, except for vCJD, where a tonsil biopsy detects 100% of the cases. For this reason, diagnostic criteria dependent on statistical probability have had to be created. These require complementary examinations, such as an electroencephalogram (EEG) or the detection of 14-3-3 protein in cerebrospinal fluid (CSF). Only the pulvinar sign in magnetic resonance imaging (MRI) has been included as a vCJD diagnostic criterion. The present review discusses neuroimaging findings for each type of prion disease in patients with a definitive histopathological diagnosis. CONCLUSIONS: The aim is to define the usefulness of these complementary examinations as a tool for the diagnosis of this family of neurodegenerative diseases.
Assuntos
Encéfalo/patologia , Doenças Priônicas/patologia , Proteínas 14-3-3/líquido cefalorraquidiano , Síndrome de Creutzfeldt-Jakob/diagnóstico , Síndrome de Creutzfeldt-Jakob/patologia , Eletroencefalografia , Doença de Gerstmann-Straussler-Scheinker/diagnóstico , Doença de Gerstmann-Straussler-Scheinker/patologia , Humanos , Insônia Familiar Fatal/diagnóstico , Insônia Familiar Fatal/patologia , Kuru/diagnóstico , Kuru/patologia , Imageamento por Ressonância Magnética , Neuroimagem , Proteínas PrPC/líquido cefalorraquidiano , Proteínas PrPC/metabolismo , Doenças Priônicas/diagnósticoRESUMO
Autoimmune encephalitis are brain inflammatory processes that are classified into two main groups according to the underlying pathogenic mechanism: antibodies to intracellular antigens (paraneoplastic) and antibodies to extracellular or neuronal surface antigens. The clinical manifestations of autoimmune encephalitis are very varied and non-specific. Complementary tests included in its clinical diagnosis include determination of antibodies in serum or cerebrospinal fluid and magnetic resonance imaging (MRI). MRI may show characteristic patterns such as mesial temporal involvement, although in some cases it may be normal or non-specific. 18F-Fluorodeoxyglucose PET/CT (18F-FDG PET/CT) imaging may be helpful in cases of paraneoplastic autoimmune encephalitis to find the primary tumor. In autoimmune encephalitis mediated by antibodies to extracellular antigens, 18F-FDG PET/CT shows distinctive patterns that can aid clinical diagnosis. This continuing education aims to present in a clear and easy-to-understand way, the clinical features of autoimmune encephalitis, the difficulties in clinical diagnosis and the patterns seen on MRI and 18F-FDG PET/CT.
Assuntos
Encefalite , Doença de Hashimoto , Anticorpos , Encefalite/diagnóstico por imagem , Fluordesoxiglucose F18 , Doença de Hashimoto/diagnóstico por imagem , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia ComputadorizadaRESUMO
Neuroimaging using both functional and structural examinations like positron emission tomography (PET), single photon emission tomography (SPECT), computed tomography (CT) and magnetic nuclear imaging (MRI) provide supportive information of great importance for the diagnosis and treatment of patients with central nervous system disorders. Therefore, they have become commonplace in clinical practice and basic biomedical research. In recent years we have seen the development of multimodality equipment that enables PET or SPECT to be combined with a CT structural image. Moreover, experimental equipment combining PET and MRI has now been developed. Additionally, methodological features that provide a higher image quality, and analysis tools for objective quantification and interpretation have been refined. This article reviews the technical aspects of those imaging methods, highlighting the most significant and recent advances in the development of neuroimaging.
Assuntos
Doenças do Sistema Nervoso Central/diagnóstico , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodosRESUMO
Normalization of neuroimaging studies to a stereotaxic space allows the utilization of standard volumes of interest (VOIs) and voxel-based analysis (SPM). Such spatial normalization of PET and MRI studies requires a high quality template image. The aim of this study was to create new MRI and PET templates of (18)F-DOPA and (11)C-(+)-alpha-dihydrotetrabenazine ((11)C-DTBZ) of the Macaca fascicularis brain, an important animal model of Parkinson's disease. MRI template was constructed as a smoothed average of the scans of 15 healthy animals, previously transformed into the space of one representative MRI. In order to create the PET templates, (18)F-DOPA and (11)C-DTBZ PET of the same subjects were acquired in a dedicated small animal PET scanner and transformed to the created MRI template space. To validate these templates for PET quantification, parametric values obtained with a standard VOI-map applied after spatial normalization to each template were statistically compared to results computed using individual VOIs drawn for each animal. The high correlation between both procedures validated the utilization of all the templates, improving the reproducibility of PET analysis. To prove the utility of the templates for voxel-based quantification, dopamine striatal depletion in a representative monkey treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was assessed by SPM analysis of (11)C-DTBZ PET. A symmetric reduction in striatal (11)C-DTBZ uptake was detected in accordance with the induced lesion. In conclusion, templates of M. fascicularis brain have been constructed and validated for reproducible and automated PET quantification. All templates are electronically available via the internet.
Assuntos
Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Di-Hidroxifenilalanina/análogos & derivados , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Tetrabenazina/análogos & derivados , Animais , Radioisótopos de Carbono , Macaca fascicularis , Compostos Radiofarmacêuticos , Valores de Referência , Técnica de SubtraçãoRESUMO
A 64-year-old woman presented with a 6-month history of right-sided continuous headache, without autonomic symptoms and complete response to indomethacin. Clinical examination and structural brain imaging were normal. A diagnosis of hemicrania continua (HC) was made. We sought to determine the brain structures active during the pain in a patient who met all of the diagnostic criteria for HC with the exception of autonomic symptoms. A brain positron emission tomography study was performed during pain, and completely pain-free after indomethacin administration. Comparing the pain with pain-free states, the region of the dorsal pons was significantly activated. There was no activation in the hypothalamus, as previously reported in HC with autonomic symptoms. Although definitive conclusions can not be drawn from a single observation, the lack of autonomic symptoms along with the absence of hypothalamic activation suggests that the clinical presentation may predict the pattern of brain activation in primary headache syndromes.
Assuntos
Transtornos da Cefaleia/fisiopatologia , Ponte/patologia , Encéfalo/diagnóstico por imagem , Tronco Encefálico/patologia , Feminino , Transtornos da Cefaleia/diagnóstico , Humanos , Hipotálamo/patologia , Pessoa de Meia-Idade , Tomografia por Emissão de PósitronsRESUMO
BACKGROUND: Easily accessible biomarkers are needed for the early identification of individuals at risk of developing Alzheimer's disease (AD) in large population screening strategies. OBJECTIVES: This study evaluated the potential of plasma ß-amyloid (Aß) biomarkers in identifying early stages of AD and predicting cognitive decline over the following two years. DESIGN: Total plasma Aß42/40 ratio (TP42/40) was determined in 83 cognitively normal individuals (CN) and 145 subjects with amnestic mild cognitive impairment (a-MCI) stratified by an FDG-PET AD-risk pattern. RESULTS: Significant lower TP42/40 ratio was found in a-MCI patients compared to CN. Moreover, a-MCIs with a high-risk FDG-PET pattern for AD showed even lower plasma ratio levels. Low TP42/40 at baseline increased the risk of progression to dementia by 70%. Furthermore, TP42/40 was inversely associated with neocortical amyloid deposition (measured with PiB-PET) and was concordant with the AD biomarker profile in cerebrospinal fluid (CSF). CONCLUSIONS: TP42/40 demonstrated value in the identification of individuals suffering a-MCI, in the prediction of progression to dementia, and in the detection of underlying AD pathology revealed by FDG-PET, Amyloid-PET and CSF biomarkers, being, thus, consistently associated with all the well-established indicators of AD.
Assuntos
Doença de Alzheimer/líquido cefalorraquidiano , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Diagnóstico Precoce , Fragmentos de Peptídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Compostos de Anilina/metabolismo , Apolipoproteínas E/genética , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Biomarcadores/metabolismo , Estudos de Casos e Controles , Disfunção Cognitiva/sangue , Estudos Transversais , Feminino , Fluordesoxiglucose F18/metabolismo , Genótipo , Humanos , Masculino , Neuroimagem , Fragmentos de Peptídeos/líquido cefalorraquidiano , Fosforilação , Placa Amiloide/metabolismo , Tomografia por Emissão de Pósitrons , Sintomas Prodrômicos , Tiazóis/metabolismo , Proteínas tau/líquido cefalorraquidianoRESUMO
BACKGROUND: amyloid-PET reading has been classically implemented as a binary assessment, although the clinical experience has shown that the number of borderline cases is non negligible not only in epidemiological studies of asymptomatic subjects but also in naturalistic groups of symptomatic patients attending memory clinics. In this work we develop a model to compare and integrate visual reading with two independent semi-quantification methods in order to obtain a tracer-independent multi-parametric evaluation. METHODS: We retrospectively enrolled three cohorts of cognitively impaired patients submitted to 18F-florbetaben (53 subjects), 18F-flutemetamol (62 subjects), 18F-florbetapir (60 subjects) PET/CT respectively, in 6 European centres belonging to the EADC. The 175 scans were visually classified as positive/negative following approved criteria and further classified with a 5-step grading as negative, mild negative, borderline, mild positive, positive by 5 independent readers, blind to clinical data. Scan quality was also visually assessed and recorded. Semi-quantification was based on two quantifiers: the standardized uptake value (SUVr) and the ELBA method. We used a sigmoid model to relate the grading with the quantifiers. We measured the readers accord and inconsistencies in the visual assessment as well as the relationship between discrepancies on the grading and semi-quantifications. CONCLUSION: It is possible to construct a map between different tracers and different quantification methods without resorting to ad-hoc acquired cases. We used a 5-level visual scale which, together with a mathematical model, delivered cut-offs and transition regions on tracers that are (largely) independent from the population. All fluorinated tracers appeared to have the same contrast and discrimination ability with respect to the negative-to-positive grading. We validated the integration of both visual reading and different quantifiers in a more robust framework thus bridging the gap between a binary and a user-independent continuous scale.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Placa Amiloide/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Estudos de Coortes , Europa (Continente)/epidemiologia , Feminino , Radioisótopos de Flúor/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Placa Amiloide/metabolismo , Tomografia por Emissão de Pósitrons/tendências , Estudos RetrospectivosRESUMO
AIM: This study evaluates the utility of (11)C-(+)-alpha -dihydrotetrabenazine ((11)C-(+)DTBZ) in the quantification of dopaminergic innervation by positron emission tomography (PET) in rat and monkey, two animal species used as animal models of Parkinson's disease. MATERIAL AND METHODS: Healthy control animals (n = 10) and the effect of 6-hydroxidopamine (6-OHDA) neurotoxic were studied in rats. (18)F-DOPA PET studies and digital quantitative autoradiography were also carried out. Studies with Macaca fascicularis were performed in control and 1-methyl 4-phenyl 1, 2, 3, 6-tetrahydropyridine (MPTP) treated animals. RESULTS: In both species high quality images were generated in which clear uptake of (11)C-(+)DTBZ was found in the striatum. (11)C-(+)DTBZ uptake quantification was estimated by creating parametric images and binding potential (BP) calculation. BP in control rats was 1.10 +/- 0.16 (mean +/- standard deviation [SD], whereas 6-OHDA produced a decrease in the uptake depending on the lesion degree. Images obtained with (18)F-DOPA were not adequate for the analysis as they did not discriminate the stratum whereas digital quantitative autoradiography studies confirmed the high affinity of striatum by (11)C-(+)DTBZ. In monkeys, final BP values were 1.31 and 1.06 and MPTP treatment reduced uptake by 40 %. CONCLUSIONS: The quality of PET images and the decrease of uptake in 6-OHDA and MPTP lesions show that (11)C-(+)DTBZ is an adequate radiotracer for the study of dopaminergic innervation in these animal models.
Assuntos
Doença de Parkinson/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Receptores Dopaminérgicos , Tetrabenazina/análogos & derivados , Animais , Macaca fascicularis , Masculino , RatosRESUMO
UNLABELLED: Dihydrotetrabenazine (2-hydroxy-3-isobutyl-9,10-dimethoxy-1,3,4,6,7-hexahydro-11bH-benzo[a]-quinolizine, DTBZ) has become the ideal radioligand for the presynaptic vesicular monoamine transporter VMAT2 based on its high binding affinity and optimal lipophilicity. OBJECTIVE: To develop an automatic procedure for labelling DTBZ with carbon-11, which has been shown to be a highly effective marker for in vivo studies of neuronal losses in animal models with Parkinson's disease using positron emission tomography (PET). MATERIALS AND METHODS: We have developed a new fully automated synthesis procedure to obtain 11C-(+)DTBZ quickly and simply through labelling the precursor -(+)desmethyldihy-drotetrabenazine- at room temperature in the presence of dimethyl sulfoxide (DMSO) and potassium hydroxide (KOH), using 11CH3I as primary precursor. The final purification was carried out by solid phase extraction using commercially available cartridges and the residual solvents (DMSO and ethyl ether) were eliminated by evaporation. RESULTS: The whole procedure was automated, and after 54 syntheses, an average production of 1.94 GBq of sterile, pyrogen-free 11C-(+)DTBZ with a radiochemical purity > 99 % was obtained with 5 minutes irradiation and 6 minutes of synthesis after 11CH3I production. 11C-(+)DTBZ binding to presynaptic dopamine nerve terminals has been demonstrated by MicroPET studies in Wistar rats and M. Fascicularis monkeys. CONCLUSIONS: This new synthesis procedure is quick and simple, due to optimised techniques, which have allowed elimination of residual solvents based on their polarity for the final purification. It is also applicable to other automatic syntheses for obtaining compounds labelled by methylation reactions.
Assuntos
Radioisótopos de Carbono , Tomografia por Emissão de Pósitrons/métodos , Terminações Pré-Sinápticas/diagnóstico por imagem , Ensaio Radioligante , Compostos Radiofarmacêuticos/síntese química , Tetrabenazina/análogos & derivados , Proteínas Vesiculares de Transporte de Monoamina/análise , Automação , Cromatografia Líquida de Alta Pressão , Dimetil Sulfóxido , Dopamina , Contaminação de Medicamentos , Endotoxinas/análise , Éter , Humanos , Marcação por Isótopo/métodos , Terminações Pré-Sinápticas/química , Terminações Pré-Sinápticas/ultraestrutura , Controle de Qualidade , Receptores Pré-Sinápticos/química , Solventes , Tetrabenazina/síntese químicaRESUMO
Alzheimer's disease (AD) is a neurodegenerative condition characterized by progressive cognitive decline and memory loss, and is the most common form of dementia. Amyloid plaques with neurofibrillary tangles are a neuropathological hallmark of AD that produces synaptic dysfunction and culminates later in neuronal loss. Amyloid PET is a useful, available and non-invasive technique that provides in vivo information about the cortical amyloid burden. In the latest revised criteria for the diagnosis of AD biomarkers were defined and integrated: pathological and diagnostic biomarkers (increased retention on fibrillar amyloid PET or decreased Aß1-42 and increased T-Tau or P-Tau in CSF) and neurodegeneration or topographical biomarkers (temporoparietal hypometabolism on 18F-FDG PET and temporal atrophy on MRI). Recently specific recommendations have been created as a consensus statement on the appropriate use of the imaging biomarkers, including amyloid PET: early-onset cognitive impairment/dementia, atypical forms of AD, mild cognitive impairment with early age of onset, and to differentiate between AD and other neurodegenerative diseases that occur with dementia. Amyloid PET is also contributing to the development of new therapies for AD, as well as in research studies for the study of other neurodegenerative diseases that occur with dementia where the deposition of Aß amyloid is involved in its pathogenesis. In this paper, we review some general concepts and study the use of amyloid PET in depth and its relationship with neurodegenerative diseases and other diagnostic techniques.
Assuntos
Doença de Alzheimer/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Peptídeos beta-Amiloides , Humanos , Tomografia por Emissão de Pósitrons/métodos , Guias de Prática Clínica como AssuntoRESUMO
Early-onset Alzheimer disease (EOAD), which presents in patients younger than 65 years, has frequently been described as having different features from those of late-onset Alzheimer disease (LOAD). This review analyses the most recent studies comparing the clinical presentation and neuropsychological, neuropathological, genetic, and neuroimaging findings of both types in order to determine whether EOAD and LOAD are different entities or distinct forms of the same entity. We observed consistent differences between clinical findings in EOAD and in LOAD. Fundamentally, the onset of EOAD is more likely to be marked by atypical symptoms, and cognitive assessments point to poorer executive and visuospatial functioning and praxis with less marked memory impairment. Alzheimer-type features will be more dense and widespread in neuropathology studies, with structural and functional neuroimaging showing greater and more diffuse atrophy extending to neocortical areas (especially the precuneus). In conclusion, available evidence suggests that EOAD and LOAD are 2 different forms of a single entity. LOAD is likely to be influenced by ageing-related processes.
Assuntos
Idade de Início , Envelhecimento , Doença de Alzheimer/classificação , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/diagnóstico por imagem , HumanosRESUMO
PURPOSE: Gastroenteropancreatic neuroendocrine tumors are a heterogeneous group of low incidence neoplasms characterized by a low proliferative activity and slow growth. Their response to targeted therapies is heterogeneous and often does not lead to tumor shrinkage. Thus, evaluation of the therapeutic response should differ from other kind of tumors. METHODS: To answer relevant questions about which techniques are best in the assessment of progression or treatment response a RAND/UCLA-based consensus process was implemented. Relevant clinical questions were listed followed by a systematic search of the literature. The expert panel answered all questions with recommendations, combining available evidence and expert opinion. Recommendations were validated through a questionnaire and a participatory meeting. RESULTS: Expert recommendations regarding imaging tools for tumor assessment and evaluation of progression were agreed upon. Available imaging techniques were reviewed and recommendations for best patient monitoring practice and the best way to evaluate treatment response were formulated.
Assuntos
Neoplasias Intestinais/diagnóstico por imagem , Neoplasias Intestinais/patologia , Tumores Neuroendócrinos/diagnóstico por imagem , Tumores Neuroendócrinos/patologia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/patologia , Diagnóstico por Imagem/métodos , Progressão da Doença , HumanosRESUMO
OBJECTIVE: To determine the status of neuroimaging studies of Nuclear Medicine in Spain during 2013 and first quarter of 2014, in order to define the activities of the neuroimaging group of the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM). MATERIAL AND METHODS: A questionnaire of 14 questions was designed, divided into 3 parts: characteristics of the departments (equipment and professionals involved); type of scans and clinical indications; and evaluation methods. The questionnaire was sent to 166 Nuclear Medicine departments. RESULTS: A total of 54 departments distributed among all regions completed the questionnaire. Most departments performed between 300 and 800 neuroimaging examinations per year, representing more than 25 scans per month. The average pieces of equipment were three; half of the departments had a PET/CT scanner and SPECT/CT equipment. Scans performed more frequently were brain SPECT with 123I-FP-CIT, followed by brain perfusion SPECT and PET with 18F-FDG. The most frequent clinical indications were cognitive impairment followed by movement disorders. For evaluation of the images most sites used only visual assessment, and for the quantitative assessment the most used was quantification by region of interest. CONCLUSIONS: These results reflect the clinical activity of 2013 and first quarter of 2014. The main indications of the studies were cognitive impairment and movement disorders. Variability in the evaluation of the studies is among the challenges that will be faced in the coming years.
Assuntos
Neuroimagem/tendências , Serviço Hospitalar de Medicina Nuclear/estatística & dados numéricos , Medicina Nuclear/tendências , Transtornos Cognitivos/diagnóstico por imagem , Equipamentos Médicos Duráveis/estatística & dados numéricos , Epilepsia/diagnóstico por imagem , Humanos , Transtornos Mentais/diagnóstico por imagem , Transtornos dos Movimentos/diagnóstico por imagem , Doenças do Sistema Nervoso/diagnóstico por imagem , Neuroimagem/instrumentação , Neuroimagem/estatística & dados numéricos , Cintilografia/estatística & dados numéricos , Compostos Radiofarmacêuticos , Espanha , Inquéritos e Questionários , Recursos HumanosRESUMO
The cases of three children, 16, 12, and 12 years of age, who suffered sudden confusional state and cortical blindness lasting 12 to 30 minutes while under treatment with high-dose methotrexate, cyclophosphamide, and dactinomycin for a lower limb osteosarcoma are reported. Transient neuropsychologic deficits arose after the acute phase of treatment: left hemispatial neglect and constructive apraxia (Patient 1); constructive apraxia (Patient 2); and constructive apraxia and alexia without aphasia (Patient 3). The three patients recovered completely from all their deficits within the time frame of 3 hours to 2 weeks. Arterial hypertension and hypomagnesemia were found during the acute phase in all patients. In Patients 2 and 3, magnetic resonance imaging revealed increased parieto-occipital T(2) signal involving gray and white matter. In Patients 1 and 2, HmPAO-SPECT revealed parieto-occipital hypoperfusion that resolved a few days later. The alterations detected by neuroimaging were concurrent with the appearance and disappearance of the clinical symptoms. Such transient acute episodes have been named occipital-parietal encephalopathy. On the basis of our clinical, laboratory, and neuroimaging findings, an explanation for the origin of this syndrome, a migrainelike mechanism, triggered by chemotherapy-induced hypomagnesemia, is proposed.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Síndromes Neurotóxicas/etiologia , Osteossarcoma/tratamento farmacológico , Doença Aguda , Adolescente , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Criança , Ciclofosfamida/efeitos adversos , Dactinomicina/efeitos adversos , Feminino , Humanos , Hipertensão/induzido quimicamente , Deficiência de Magnésio/induzido quimicamente , Masculino , Metotrexato/efeitos adversos , Síndromes Neurotóxicas/diagnóstico por imagem , Síndromes Neurotóxicas/patologia , Compostos Radiofarmacêuticos , Indução de Remissão , Síndrome , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
An esophagobronchial fistula developed in a patient who had well-differentiated squamous carcinoma of the lung that was treated with chemotherapy. Because the esophagobronchial fistula could not be surgically repaired, it was isolated with a mechanical stitch above and below it. Forty-eight hours after initiation of enteral nutrition, a perfusion lung scan was performed because of clinical suspicion of pulmonary embolism. Because the scan showed reduced pulmonary radioactivity and accumulation of activity in the kidneys and spine, an arteriovenous shunt was suspected. However, subsequent digital subtraction angiography ruled out this possibility and a recurrence of the esophagobronchial fistula was confirmed with an esophagogram. The unusual extrapulmonary activity could be related to a reversible capillary shunt in the pulmonary vasculature, secondary to acute respiratory distress syndrome.
Assuntos
Pulmão/diagnóstico por imagem , Síndrome do Desconforto Respiratório/diagnóstico por imagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Fístula Brônquica/complicações , Carcinoma de Células Escamosas/tratamento farmacológico , Fístula Esofágica/complicações , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Pneumonia Aspirativa/complicações , Cintilografia , Recidiva , Síndrome do Desconforto Respiratório/etiologia , Agregado de Albumina Marcado com Tecnécio Tc 99mRESUMO
INTRODUCTION AND OBJECTIVES: The purpose of this study is to show our experience in clinical dynamic cardiomyoplasty. PATIENTS, MATERIALS AND METHODS: Six patients with end-stage heart failure and 2 patients with left ventricular aneurysm underwent dynamic cardiomyoplasty using the latissimus dorsi muscle. The latissimus dorsi was electrically conditioned before the procedure through a lead placed under local anesthesia and connected to an external cardiac pace-maker. Surgical technique--including dissection of the latissimus dorsi and encircling of the ventricles with the muscle flap--was performed in general terms as described at the Broussais Hospital. In the first 3 patients a bipolar lead connected to a single impulse generator was used. In the other 5 patients a train of impulses cardiomyostimulator was used. Changes in systolic function were studied through Doppler-echocardiography and radionuclide studies. Changes in diastolic function were evaluated through E wave velocity and deceleration time. RESULTS: Mean follow up was 9 +/- 5.7 months. No early deaths were recorded. One patient underwent emergency surgery, one week after the procedure, because of a tear of the patch used to close the wall defect after left ventricular aneurysm resection. In 2 patients a subcutaneous serous collection secondary to muscle dissection was evacuated. One patient died due to a stroke 4 months after the procedure. Another patient died after an unsuccessful coronary transluminal percutaneous angioplasty 11 months after the procedure. An improved functional class was observed in all patients. No changes in systolic function were observed after surgery when the cardiomyoestimulator was turned-off either with echocardiography (26.7 +/- 8.6 vs 24.8 +/- 5.8% [NS]) or radionuclides (24.5 +/- 9.5 vs 20.2 +/- 8.3% [NS]). When the cardiomyostimulator was turned-on a statistically significant increase of the left ventricular ejection fraction was observed either with echocardiography (24.8 +/- 5.8 vs 37 +/- 10.3%; p < 0.05) or radionuclides (20.2 +/- 8.3 vs 33.3 +/- 12.2%; p < 0.05). This significant increase of the ejection fraction has been observed in subsequent studies. Nevertheless the differences when the cardiomyostimulator is turned-on and turned-off have decreased several months after the procedure. A significant increase of the left ventricular outflow velocity (cm/seg) was observed when the generator was turned-on (57.7 +/- 20.4 vs 75.1 +/- 17.8%; p < 0.01). A significant increase of the dP/dt (mmHg/seg) was observed when the generator was turned-on (706.3 +/- 291.5 vs 592.6 +/- 181.6%; [NS]). No significant changes were observed on E wave velocity. A significant decrease of the deceleration time was observed several months after the procedure (p < 0.05). CONCLUSIONS: We believe that dynamic cardiomyoplasty is a safe and valid surgical procedure for some patients with end stage cardiomyopathies as well as in association with Jatene's technique for the management of left ventricular aneurysms. An improvement in functional class is present and a significant increase of the left ventricular systolic function. Nevertheless it is necessary to find new systolic parameters, independent of volumetric calculations, to evaluate the mechanical support of the muscle as well as to determine the long-term pattern of electrical stimulation.
Assuntos
Procedimentos Cirúrgicos Cardíacos/métodos , Aneurisma Cardíaco/cirurgia , Insuficiência Cardíaca/cirurgia , Retalhos Cirúrgicos , Adulto , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Músculos , Resultado do Tratamento , Função Ventricular EsquerdaRESUMO
OBJECTIVE: The aim of this study is to evaluate the contribution of the Cedars-Sinai quantification tomographic method (CS) in the diagnosis and localization of ischemic areas in coronary artery disease (CAD) and to optimize the threshold values proposed by CS. PATIENTS AND METHODS: Fifty patients with clinical suspicion of CAD performed a maximal stress test by cycloergometer; thallium myocardial tomographic images were obtained; applying the CS program afterwards. The sensitivity and specificity variations obtained by changing the criteria for extent of myocardial hypoperfusion (range 1% to 100%) were used to calculate the new thresholds (CS-I), using the results of coronariographic studies as a reference. The data determined by qualitative analysis were compared with that obtained by quantitative analysis by means of CS and CS-I using coronary angiography as the standard of reference. RESULTS: The coronary angiography showed coronary disease in 37 patients. The sensitivity for the diagnosis of CAD was superior using CS (97%) at the expense of low specificity (15%) which nevertheless improved with CS-I (54%). For the location of CAD, the visual analysis was statistically significant (p < 0.05) in the left anterior descending and right coronary arteries, CS being superior in the diagnosis of 3 vessel disease. CONCLUSIONS: The quantification of tomographic studies with thallium by means of CS needs a readjustment of the thresholds. The tested values (CS-I) improved the CS results, although they require prospective validation. Quantitative study permits the confirmation of visual findings, being a complementary method that can be rapidly and easily interpreted, although it is not recommended as a single technique for the diagnosis of coronary disease.