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1.
Medicine (Baltimore) ; 100(3): e23969, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33545981

RESUMO

ABSTRACT: This study aimed to evaluated the clinical impact of adding [11C] Pittsburgh compound-B (11C-PiB) PET for clinical diagnosis of mild cognitive impairment (MCI) to Alzheimer's disease (AD) dementia.Twenty six (mean age 78.5 ±â€Š5.18 years, 21 females) AD (n = 7), amnestic MCI (n = 12), non-amnestic MCI (n = 3), vascular dementia, progressive supranuclear palsy (PSP) with frontotemporal dementia (FTD), FTD (n = 1 each), and normal (n = 1) patients underwent 11C-PiB-PET, MRI, and SPECT scanning. 11C-PiB-PET was compared with MRI and SPECT for clinical impact.11C-PiB-PET showed positivity in 6, 9, and 0 of the AD, amnestic MCI, and non-amnestic MCI patients, respectively, and 0 of those with another disease. Parahippocampal atrophy at VSASD was observed in 5 AD patients, 6 amnestic and PiB-positive MCI patients, 1 amnestic and PiB-negative MCI patient, and 1 vascular dementia patient. Parietal lobe hypoperfusion in SPECT findings was observed in 6, 4, and 2 of those, respectively, as well as 1 each of non-amnestic MCI, vascular dementia, and normal cases. Sensitivity/specificity/accuracy for selecting PiB-positive patients among the 15 MCI patients for 11C-PiB-PET were 100% (9/9)/100% (6/6)/100% (15/15), for VSRAD were 66.7% (6/9)/83.3% (5/6)/73.3% (11/15), and for SPECT were 44.4% (4/9)/50.0% (3/6)/46.7% (7/15), while those were 88.9% (8/9)/33.3% (2/6)/66.7% (10/15)/for combined VSRAD and SPECT. 11C-PiB-PET accuracy was significantly higher than that of SPECT.11PiB-PET alone may be useful for selecting patients who will progress from MCI to AD in the future, although follow-up study is necessary to clarify the outcome of MCI patients.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Compostos de Anilina/uso terapêutico , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Tomografia por Emissão de Pósitrons/métodos , Tiazóis/uso terapêutico , Tomografia Computadorizada de Emissão de Fóton Único/métodos
3.
BMJ Case Rep ; 13(10)2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-33028572

RESUMO

A 13-year-old boy presented to hospital with 3-day self-limited fever, followed by dry cough, persistent asthenia and impaired general condition of 2 weeks' duration. Blood analyses showed a severe inflammatory status and chest X-ray images were consistent with bilateral COVID-19 pneumonia. He developed an acute respiratory failure that required paediatric intensive care admission and non-invasive ventilation. A targeted COVID-19 treatment was initiated with hydroxicloroquine, corticosteroids, enoxaparine and a single dose of tocilizumab. Repeated serological tests and real-time reverse transcription PCR for SARS-CoV-2 were negative. Other infectious pathogens were also ruled out. Thoracic high resolution CT showed an intense bilateral pulmonary dissemination with lytic vertebral bone lesions. After diagnostic investigations, Ewing's sarcoma with metastatic pulmonary dissemination was diagnosed. Nowadays, in the context of SARS-CoV-2 community pandemic, we cannot forget that COVID-19 clinical presentation is not specific and other entities can mimic its clinical features.


Assuntos
Infecções por Coronavirus/diagnóstico , Neoplasias Pulmonares , Nódulos Pulmonares Múltiplos , Pneumonia Viral/diagnóstico , Sarcoma de Ewing , Tomografia Computadorizada por Raios X/métodos , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica , Exame de Medula Óssea/métodos , Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/sangue , Infecções por Coronavirus/fisiopatologia , Diagnóstico Diferencial , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/fisiopatologia , Neoplasias Pulmonares/secundário , Masculino , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Nódulos Pulmonares Múltiplos/patologia , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/etiologia , Pneumonia Viral/fisiopatologia , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos
4.
Medicine (Baltimore) ; 99(36): e22038, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899061

RESUMO

The effectiveness of diethylenetriamine pentaacetic acid scan is regularly monitored for the assessment of any potential modifications in treatment responses or kidney functions in the pediatric population.This study attempts to compare the usefulness of diethylenetriamine pentaacetic acid and ultrasound imaging of renal disorders among paediatric patients.A retrospective observational study was conducted by enrolling 106 children. The demographic details such as: participant's age, gender, and the history of renal disease of each patient were recorded. Patients were administered radiopharmaceuticals in a fixed dose and were later subjected to computed tomography (CT) scan. The obtained data was analysed using descriptive statistics.Findings indicated increased sensitivity for CT (61.20%); whereas, a major decrease in specificity (23.68%) was observed. Comparison of Single-photon emission CT (SPECT) and CT findings revealed the increased sensitivity (90.90%) for ultrasound; whereas, there was a slight decrease in the specificity (40%) for SPECT. However, SPECT findings show 91% sensitivity among patients with 71.42% positive predictive value. Moreover, an increase in sensitivity for CT (61.20%), followed by a major decrease in specificity (23.68%) was observed.Ultrasonography has been proved to be the safest and the most effective method for the diagnosis and the treatment of most renal disorders, due to the higher predictive value of SPECT scans. It is thus suggested that patients with ureteral calculi should be diagnosed with renal scintigraphy and unenhanced helical computerized tomography.


Assuntos
Nefropatias/diagnóstico por imagem , Ácido Pentético/administração & dosagem , Cintilografia/métodos , Ultrassonografia/métodos , Cálculos Ureterais/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Nefropatias/fisiopatologia , Masculino , Medicina Nuclear/métodos , Valor Preditivo dos Testes , Compostos Radiofarmacêuticos/administração & dosagem , Estudos Retrospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos
5.
Neurology ; 95(6): e637-e642, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32636329

RESUMO

OBJECTIVE: To study neural networks involved in hyperkinetic seizures (HKS) using ictal SPECT. METHODS: We retrospectively identified 18 patients with HKS evaluated at the Cleveland Clinic between 2005 and 2015 with video-EEG monitoring and ictal SPECT. Semiology was confirmed by the consensus of 2 epileptologists' independent reviews and classified as type 1, 2, or 3 HKS. SPECT data were analyzed by 2 independent physicians using a z score of 1.5. Ictal hyperperfusion patterns for each group were analyzed visually and with SPM. Spatial normalization to Montreal Neurological Institute space for each patient's data was performed, followed by flipping of data from patients with left-sided ictal onset to the right side. Finally, an average z score map for each group was calculated. RESULTS: Visual analysis and SPM identified different patterns of ictal hyperperfusion in the 3 subtypes of HKS. Type 1 seizures showed hyperperfusion in a more anteriorly located network involving the anterior insula, orbitofrontal cortex, cingulate, and anterior perisylvian region and rostral midbrain. Type 2 seizures were associated with hyperperfusion in a more caudally located network involving the orbitofrontal cortex, cingulate (middle and posterior), basal ganglia, thalami, and cerebellum. Type 3 seizures showed a mixed pattern of SPECT hyperperfusion involving the temporal pole and anterior perisylvian region. CONCLUSIONS: Each of the 3 different semiologic subtypes of HKS is associated with distinct patterns of hyperperfusion, providing further insight into the neural networks involved. This knowledge may inform placement of invasive EEG electrodes in patients with HKS semiology undergoing presurgical evaluation.


Assuntos
Epilepsia Motora Parcial/diagnóstico por imagem , Hipercinese/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adolescente , Adulto , Mapeamento Encefálico , Circulação Cerebrovascular , Criança , Dominância Cerebral , Eletroencefalografia/métodos , Epilepsia Motora Parcial/classificação , Epilepsia Motora Parcial/fisiopatologia , Feminino , Humanos , Hipercinese/fisiopatologia , Masculino , Pessoa de Meia-Idade , Rede Nervosa/fisiopatologia , Cuidados Pré-Operatórios , Estudos Retrospectivos , Gravação em Vídeo/métodos , Adulto Jovem
6.
Clin Imaging ; 67: 136-142, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32622334

RESUMO

We report a marked abnormality in myocardial attenuation on non-gated contrast-enhanced CT in a patient with multiorgan sarcoidosis and correlate our findings with CMR, PET and SPECT. The noteworthy observation of myocardial hypoattenuation, in correspondence with the multimodality cardiovascular imaging findings, suggests that standard contrast-enhanced CT may provide information regarding tissue characterization. This report also demonstrates the independent clinical utility of CMR and PET in the evaluation and management of cardiac sarcoidosis.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Sarcoidose/diagnóstico por imagem , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Miocárdio , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodos
7.
Phys Med Biol ; 65(19): 195010, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32570222

RESUMO

In recent years, breast imaging using radiolabelled molecules has attracted significant interest. Our group has proposed a multi-pinhole molecular breast tomosynthesis (MP-MBT) scanner to obtain 3D functional molecular breast images at high resolutions. After conducting extensive optimisation studies using simulations, we here present a first prototype of MP-MBT and evaluate its performance using physical phantoms. The MP-MBT design is based on two opposing gamma cameras that can image a lightly compressed pendant breast. Each gamma camera consists of a 250 × 150 mm2 detector equipped with a collimator with multiple pinholes focusing on a line. The NaI(Tl) gamma detector is a customised design with 3.5 mm intrinsic spatial resolution and high spatial linearity near the edges due to a novel light-guide geometry and the use of square PMTs. A volume-of-interest is scanned by translating the collimator and gamma detector together in a sequence that optimises count yield from the scan region. Derenzo phantom images showed that the system can reach 3.5 mm resolution for a clinically realistic 99mTc activity concentration in an 11-minute scan, while in breast phantoms the smallest spheres visible were 6 mm in diameter for the same scan time. To conclude, the experimental results of the novel MP-MBT scanner showed that the setup had sub-centimetre breast tumour detection capability which might facilitate 3D molecular breast cancer imaging in the future.


Assuntos
Mama/diagnóstico por imagem , Câmaras gama/normas , Imagens de Fantasmas , Cintilografia , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Feminino , Humanos , Compostos Radiofarmacêuticos
9.
Clin Imaging ; 66: 1-6, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32413808

RESUMO

We report a case of symptomatic Oppenheimer ossicle in an 18-year-old male who presented with back pain. L5 pars interarticularis defect was suspected on initial lumbar spine radiographs. A subsequent technetium99m-methylene diphosphonate (Tc99m-MDP) bone scintigraphy with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed focal radiotracer uptake in an Oppenheimer ossicle in L2 vertebra. CT was negative for pars defect. Oppenheimer ossicle is a developmental variant resulting from an unfused accessory ossification center at the tip of the articular process. It is important to recognize this entity as a rare cause of low back pain. Focal tracer uptake can mimic changes from pars interarticularis defect on planar and SPECT images. SPECT/CT helps to resolve both entities. To our knowledge, this is also the first report in English literature describing a symptomatic Oppenheimer ossicle on a bone scan.


Assuntos
Dor Lombar/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Adolescente , Adulto , Difosfonatos , Fraturas Ósseas , Humanos , Dor Lombar/etiologia , Região Lombossacral , Masculino , Pessoa de Meia-Idade , Radiografia , Tomografia Computadorizada de Emissão de Fóton Único/métodos
10.
BMC Neurol ; 20(1): 192, 2020 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-32416724

RESUMO

BACKGROUND: Neuropathological data and nuclear medicine imaging show extensive serotonergic impairment in Parkinson's disease (PD). We undertook a case-controlled analysis of 123I-FP-CIT SPECT images to measure extrastriatal serotonergic transporters (SERT) in PD using the Parkinson's Progression Markers Initiative (PPMI) cohort. METHODS: We included all PD (n = 154) and Control subjects (n = 62) with available 123I-FP-CIT SPECT imaging and high-resolution T1-weighted MRI for coregistration (PD: mean age 61.6 years, 62% male, disease duration 26 months, MDS-UPDRS III score 22). 123I-FP-CIT SPECT images were processed with PETPVE12 using an exploratory voxel-wise analysis including partial-volume effect correction. Linear regressions were performed in the PD group to assess correlations between region of interest 123I-FP-CIT uptake and clinical motor and non-motor impairment. RESULTS: Compared to Controls, PD exhibited an uptake reduction in bilateral caudate nucleus, putamen, insula, amygdala and right pallidum (family-wise error (FWE)-corrected p <  0.05). While lower putaminal uptake on the contralateral side to clinically more affected side was associated with higher MDS-UPDRS III score (p = 0.022), we found a trend association between higher geriatric depression scale and lower pallidum uptake (p = 0.09). Higher SCOPA-AUT gastrointestinal subscore was associated with lower uptake in mean putamen and caudate nucleus (p = 0.01 to 0.03), whereas urological subscore was inversely correlated with mean caudate nucleus, putamen, and pallidum uptake (p = 0.002 to 0.03). REM sleep behaviour disorder screening questionnaire was associated with lower 123I-FP-CIT binding in caudate nucleus, putamen and pallidum (all p <  0.05). No significant association was found for Montreal Cognitive Assessment (all p > 0.45) or excessive daytime sleepiness (all p > 0.29). CONCLUSIONS: In addition to the well-established striatal deficit, this study provides evidence of a major extrastriatal 123I-FP-CIT impairment, and therefore of an altered serotonergic transmission in early PD.


Assuntos
Encéfalo/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Idoso , Encéfalo/metabolismo , Estudos de Casos e Controles , Estudos de Coortes , Progressão da Doença , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Radioisótopos do Iodo , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/metabolismo , Proteínas da Membrana Plasmática de Transporte de Serotonina/análise , Tropanos
11.
J Clin Neurosci ; 77: 123-127, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32389545

RESUMO

The aim of this work is to present whether SPECT 99mTc-HMPAO can be a method of examination to possibly differentiate the syndromes. 21 patients with PSP syndrome and 14 patients with corticobasal syndrome (CBS) were examined using SPECT 99mTc-HMPAO. Perfusion single photon emission computed tomography (SPECT) as a method of examination of progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) has not been extensively analyzed in contemporary literature. Recent criteria of PSP and CBS do not describe this method of examination as primary or additional. Extended analysis was done in the context of regions of interest affected by significant average hypoperfusion (>2 standard deviations). Differences between the syndromes were subsequently evaluated using the U-Mann-Whitney test. Lack of significant differences (p < 0.05) were observed in 92 out of 94 regions of interest. However, certain asymmetries were observed in a minority of regions in both of the syndromes. Additionally, the authors of the study verified possible differences of asymmetry of perfusion of both of the syndromes. The overlapping of clinical manifestations and locations of hypoperfusion leads to a question of whether the syndromes should be interpreted as separate entities or variants of the same disease.


Assuntos
Encéfalo/diagnóstico por imagem , Paralisia Supranuclear Progressiva/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Perfusão/métodos , Estatísticas não Paramétricas , Paralisia Supranuclear Progressiva/diagnóstico , Síndrome , Tecnécio Tc 99m Exametazima
12.
Curr Cardiol Rep ; 22(6): 43, 2020 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-32451746

RESUMO

PURPOSE OF REVIEW: The most pertinent clinical question in post-coronary computed tomography angiography (CCTA) patients is the assessment of the physiological significance of an anatomically identified stenosis. The clinical application of radionuclide MPI using single-photon emission computed tomography (SPECT) versus positron emission tomography (PET) in the evaluation and management of patients with an inconclusive CCTA is reviewed using a case-based approach. RECENT FINDINGS: Recent evidence suggests that CCTA is the most sensitive non-invasive test to exclude angiographic CAD and may be an effective first-line test especially among symptomatic low-intermediate risk patients. However, in the presence of angiographic atherosclerosis, its specificity and positive predictive value for identifying flow-limiting stenosis are modest. Radionuclide myocardial perfusion imaging offers accurate quantitative assessment of myocardial ischemia, which helps with risk stratification and patient management especially the potential need for revascularization. Routine accurate quantifications of myocardial blood flow and flow reserve are major advantages of PET MPI, which are especially useful when used in patients at intermediate-high clinical risk.


Assuntos
Doença da Artéria Coronariana/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Angiografia Coronária , Humanos , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X
13.
Clin Nucl Med ; 45(8): 588-593, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32404715

RESUMO

PURPOSE: The aim of the study is to evaluate the impact of myocardial I-metaiodobenzylguanidine (MIBG) in the diagnosis, clinical management, and differential diagnosis of Parkinson disease (PD) and non-PD parkinsonism. METHODS: The study enrolled 41 patients with parkinsonism. An initial diagnosis was reached after thorough clinical and imaging evaluation. After 2 to 5 years of follow-up, a final diagnosis was established. All patients underwent, soon after their initial visit, presynaptic striatal DaT scintigraphy with I-FP-CIT (DaTscan) and I-MIBG myocardial scintigraphy. DaTscan is not specific to distinguish among different types of neurodegenerative parkinsonism. I-MIBG myocardial scintigraphy displays the functional status of cardiac sympathetic nerves, which is reduced in PD/dementia with Lewy bodies (DLB) and normal in atypical parkinsonian syndromes and secondary or nondegenerative parkinsonism. RESULTS: No patients showed adverse effects during or after both scintigraphies. A positive DaTscan was found in all patients in the PD/DLB group (17/17) and in 15 of 24 patients in the non-PD group. Myocardial I-MIBG scintigraphy was associated with lower sensitivity (82% vs 100%) but higher specificity than DaTscan (79% vs 38%) in diagnosis PD/DLB from non-PD parkinsonism. A positive scan result on both techniques, to confirm diagnosis of PD/DLB, significantly improved the specificity of DaTscan, from 38% to 75%, with no reduction in sensitivity. CONCLUSIONS: Myocardial I-MIBG imaging provides complementary value to I-FP-CIT in the proper diagnosis, treatment plan, and differential diagnosis between PD and other forms of parkinsonism.


Assuntos
Imagem de Perfusão do Miocárdio/métodos , Doença de Parkinson/diagnóstico por imagem , Tomografia Computadorizada de Emissão de Fóton Único/métodos , 3-Iodobenzilguanidina , Idoso , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nortropanos , Compostos Radiofarmacêuticos , Tropanos
14.
J Surg Res ; 252: 216-221, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32289578

RESUMO

BACKGROUND: The addition of SPECT-CT to Tc-99 sestamibi has become a valuable tool for parathyroid localization in primary hyperparathyroidism (PHP). However, the enhanced sensitivity of this test can lead to unexpected and significant findings. We sought to identify the frequency and types of nonparathyroid detections by SPECT-CT. MATERIALS AND METHODS: With institutional approval, we reviewed all SPECT-CT studies performed for PHP between October 2012 and August 2018 for incidental nonparathyroid abnormalities. The electronic medical record was referenced to determine the type of lesion confirmed by additional evaluation. RESULTS: Among 2413 studies, 652 patients (27%) had 677 (28%) nonparathyroid findings. The most common were thyroid nodules (331/677, 49%), including 47 (6.9%) malignancies to date: 40 papillary thyroid cancers (11 microcarcinomas), five follicular thyroid cancers, one medullary carcinoma, and one noninvasive follicular thyroid neoplasm with papillary-like features. One hundred and seventy-seven patients had pulmonary nodules (26%), of whom nine were diagnosed with primary lung lesions (6 non-small-cell cancers, one small-cell cancer, one carcinoid, and one pulmonary sequestration). SPECT-CT revealed 14 patients (2.1%) with breast abnormalities, including three cancers. Nine patients (1.3%) demonstrated metastatic diseases within the lungs (4), bones (3), and mediastinum (2). One patient was diagnosed with follicular lymphoma. Two intracranial tumors were also identified, as well as dysplastic Barrett's esophagitis (1), hiatal hernia (20, 3%), and aortic aneurysm (13, 1.8%). In all, 72/677 (10.6%) PHP patients exhibited premalignant or malignant nonparathyroid SPECT-CT findings. CONCLUSIONS: In patients undergoing localization for PHP with Tc-99 sestamibi SPECT-CT, nonparathyroid findings are frequent (27%) and can lead to newly diagnosed malignant or premalignant lesions in at least 3% of patients to date.


Assuntos
Hiperparatireoidismo Primário/diagnóstico por imagem , Achados Incidentais , Neoplasias Pulmonares/epidemiologia , Neoplasias da Glândula Tireoide/epidemiologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Masculino , Glândulas Paratireoides/diagnóstico por imagem , Compostos Radiofarmacêuticos , Sensibilidade e Especificidade , Tecnécio Tc 99m Sestamibi , Neoplasias da Glândula Tireoide/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/estatística & dados numéricos
15.
Biochem J ; 477(7): 1261-1286, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32271883

RESUMO

Brown adipose tissue (BAT) has long been described according to its histological features as a multilocular, lipid-containing tissue, light brown in color, that is also responsive to the cold and found especially in hibernating mammals and human infants. Its presence in both hibernators and human infants, combined with its function as a heat-generating organ, raised many questions about its role in humans. Early characterizations of the tissue in humans focused on its progressive atrophy with age and its apparent importance for cold-exposed workers. However, the use of positron emission tomography (PET) with the glucose tracer [18F]fluorodeoxyglucose ([18F]FDG) made it possible to begin characterizing the possible function of BAT in adult humans, and whether it could play a role in the prevention or treatment of obesity and type 2 diabetes (T2D). This review focuses on the in vivo functional characterization of human BAT, the methodological approaches applied to examine these features and addresses critical gaps that remain in moving the field forward. Specifically, we describe the anatomical and biomolecular features of human BAT, the modalities and applications of non-invasive tools such as PET and magnetic resonance imaging coupled with spectroscopy (MRI/MRS) to study BAT morphology and function in vivo, and finally describe the functional characteristics of human BAT that have only been possible through the development and application of such tools.


Assuntos
Tecido Adiposo Marrom/metabolismo , Tecido Adiposo Marrom/anatomia & histologia , Tecido Adiposo Marrom/diagnóstico por imagem , Animais , Metabolismo Energético/fisiologia , Ácidos Graxos não Esterificados/metabolismo , Glucose/metabolismo , Humanos , Imagem por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Camundongos , Tomografia por Emissão de Pósitrons/métodos , Termogênese/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Triglicerídeos/metabolismo
16.
PLoS One ; 15(3): e0229366, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32142552

RESUMO

A Compton camera is a device for imaging a radio-source distribution without using a mechanical collimator. Ordered-subset expectation-maximization (OS-EM) is widely used to reconstruct Compton images. However, the OS-EM algorithm tends to over-concentrate and amplify noise in the reconstructed image. It is, thus, necessary to optimize the number of iterations to develop high-quality images, but this has not yet been achieved. In this paper, we apply a median filter to an OS-EM algorithm and introduce a median root prior expectation-maximization (MRP-EM) algorithm to overcome this problem. In MRP-EM, the median filter is used to update the image in each iteration. We evaluated the quality of images reconstructed by our proposed method and compared them with those reconstructed by conventional algorithms using mathematical phantoms. The spatial resolution was estimated using the images of two point sources. Reproducibility was evaluated on an ellipsoidal phantom by calculating the residual sum of squares, zero-mean normalized cross-correlation, and mutual information. In addition, we evaluated the semi-quantitative performance and uniformity on the ellipsoidal phantom. MRP-EM reduces the generated noise and is robust with respect to the number of iterations. An evaluation of the reconstructed image quality using some statistical indices shows that our proposed method delivers better results than conventional techniques.


Assuntos
Algoritmos , Simulação por Computador , Processamento de Imagem Assistida por Computador/métodos , Imagens de Fantasmas , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Humanos , Método de Monte Carlo , Reprodutibilidade dos Testes , Tomografia Computadorizada de Emissão de Fóton Único/métodos
17.
Intern Med ; 59(11): 1361-1371, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32161215

RESUMO

Objective There is no report on the risk stratification of major cardiac events (MCEs) with a combination of the Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score and ischemic reduction detected with rest 201Tl and stress 99mTc-tetrofosmin myocardial perfusion single-photon-emission computed tomography (SPECT) after revascularization in Japanese patients with coronary artery disease (CAD). Methods This was a retrospective study. The patients were followed up to confirm their prognosis for at least one year. Ischemia was evaluated based on the summed difference scores converted to the percentage of the total myocardium Safety Data Sheet (SDS%). The SYNTAX score and SDS% were calculated before and after revascularization. The endpoint was the occurrence of MCEs. Patients Study subjects were 293 patients who had a ≥75% stenotic lesion detected with coronary angiography following confirmation of ≥5% ischemia with SPECT, underwent revascularization, and thereafter received a re-evaluation with SPECT and coronary angiography. Results During the follow-up, 25 patients experienced MCEs of cardiac death (n=2), non-fatal myocardial infarction (n=3), and unstable angina pectoris (n=20). A receiver operating characteristic analysis indicated that the best cut-off values of the residual SYNTAX score and ΔSDS% were 12 and 5%, respectively, for the prediction of MCEs. The patients with a low residual SYNTAX score (<12) and high ΔSDS% (≥5%) had the best prognosis, while those with a high residual SYNTAX score (≥12) and low ΔSDS% (<5%) had the worst prognosis. Conclusion The combination of the residual SYNTAX score and ischemic reduction detected with nuclear cardiology is useful for predicting MCEs after revascularization.


Assuntos
Angiografia Coronária/métodos , Doença da Artéria Coronariana/cirurgia , Imagem de Perfusão do Miocárdio/métodos , Complicações Pós-Operatórias/diagnóstico , Prognóstico , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Grupo com Ancestrais do Continente Asiático , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
Rev. salud pública Parag ; 10(1): [P59-P65], mar. 2020.
Artigo em Espanhol | LILACS, BDNPAR | ID: biblio-1087931

RESUMO

nuclear permiten visualizar la estructura y función de un órgano, tejido, hueso o sistema dentro del cuerpo, entre ellos la glándula tiroidea, la cual puede presentar un nódulo tiroideo y este es importante diagnosticar por su potencial malignidad. Objetivo: Determinar las características funcionales de los nódulos tiroideos en 183 pacientes que asistieron al Servicio de Medicina Nuclear del Instituto de Investigaciones en Ciencias de la Salud - UNA durante el período de noviembre del 2016 - noviembre del 2019. Metodología: Fue utilizada la gammacámara SPECT doble cabezal, siguiendo protocolo estandarizado, con administración de pertecnetato de sodio. Resultados: Se observó que la gran mayoría de los pacientes corresponden al sexo femenino 89%, así como que el 64% provienen de la capital y del departamento central; las patologías detectadas corresponden a bocio en 82%, 15% a nódulos (hipercaptantes, hipocaptantes y autónomos) y casos particulares de tiroiditis, tiroides ectópica y adenoma tóxico. La medicina nuclear está directamente involucrada tanto en el diagnóstico como en el tratamiento de la enfermedad tiroidea, por lo que se requiere una comprensión de la fisiopatología y el manejo de los trastornos de la tiroides, de manera a que las políticas de salud pública sean implementadas para el fortalecimiento de la lucha contra estas enfermedades. Conclusión: El trabajo de investigación realizado comprobó que un mayoritario porcentaje de participantes de sexo femenino (89%), con enfermedades tiroideas asistieron al IICS/UNA, y que la frecuencia de bocio entre la totalidad de pacientes que participaron de este estudio fué de 151/183 (82%), los pacientes provenían en su mayoría de hospitales de referencia del departamento Central y coinciden con la localización geográfica de los domicilios de los pacientes, quienes provenían principalmente del mismo departamento Central 118/183 (64%), no obstante también participaron del trabajo de investigación pacientes provenientes de otros departamentos del país. Palabras claves: Diagnóstico, medicina nuclear, tiroides, tecnología nuclear en salud, SPECT


Introduction: The images obtained by nuclear medicine allow to visualize the structure and function of an organ, tissue, bone or system inside the body, including the thyroid gland, which can present a thyroid nodule and this is important to diagnose for its potential malignancy. Objective: To determine the functional characteristics of the thyroid nodules were determined in 183 patients, who attended the Nuclear Medicine Service at the Instituto de Investigaciones en Ciencias de la Salud during the period of November 2016 - November 2019. Methodology: It was used the dual head SPECT gamma camera following a standardized protocol with administration of sodium pertechnetate. Result: It was observed that most of the patients corresponded to the female sex 89 %, as well as that 64% came from the capital and the central department. The pathologies detected corresponded to goiter in 82%, 15% to nodules (hypercaptant, hypocaptant and autonoms) and particular cases of thyroiditis, ectopic thyroid and toxic adenoma. Nuclear medicine is directly involved both in the diagnosis and in the treatment of thyroid disease, therefore it requires an understanding of the pathophysiology and management of thyroid disorders in order that public health policies are implemented for strengthening the fight against these diseases. Conclusion: The research carried out showed that a majority percentage of female participants (89%), with thyroid diseases attended IICS / UNA, and the frequency of goiter among all patients who participated in this study was 151/183 ( 82%), the patients mostly they came the reference hospitals in the Central department and coincide with the geographic location of the patients' homes, who tested mainly from the same Central department 118/183 (64%), also participate in the research work patients from other departments of the country. Keywords: Diagnosis, nuclear medicine, thyroid, health technology, SPECT.


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Nódulo da Glândula Tireoide/diagnóstico por imagem , Paraguai , Doenças da Glândula Tireoide/diagnóstico por imagem , Estudos Transversais , Nódulo da Glândula Tireoide/fisiopatologia , Nódulo da Glândula Tireoide/epidemiologia , Distribuição por Sexo , Distribuição por Idade
19.
Jpn J Radiol ; 38(4): 343-357, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32043236

RESUMO

Radiolabeled tracers allow visualization of not only perfusion, but receptors, function, and metabolism as well. Although spatial resolution is lower than that of computed tomography and magnetic resonance imaging, positron emission tomography (PET) and single photon emission computed tomography (SPECT) have great potential for target-specific imaging. In this review, we discuss several SPECT and PET tracers used in brain imaging, specifically focusing on tracers currently available, or developed, in Japan. Several important and sophisticated methods exist for analysis of brain PET and SPECT images. Two of them, quantitative cerebral blood flow measurement and voxel-based statistical analysis are discussed in this review. The former method, which employs acetazolamide loading, is useful for evaluation of the brain perfusion reserve for ischemic brain diseases. The latter is useful in diagnosing dementing diseases. Additionally, great strides have been made in the development of the technology used in the scanners. New SPECT systems based on cadmium-zinc-telluride, PET/MRI, and semiconductor PET/CT may provide higher spatial resolution with an acquisition time shorter than ever before. Such developments of both tracers and scanners can be integrated for unprecedented imagery of the brain, providing valuable insight into underlying causes of some fatal brain disorders.


Assuntos
Encéfalo/diagnóstico por imagem , Medicina Nuclear/métodos , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Encéfalo/irrigação sanguínea , Cádmio/farmacocinética , Circulação Cerebrovascular , Humanos , Japão , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/instrumentação , Traçadores Radioativos , Telúrio/farmacocinética , Tomografia Computadorizada de Emissão de Fóton Único/instrumentação , Zinco/farmacocinética
20.
Circ Cardiovasc Imaging ; 13(2): e009769, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32069116

RESUMO

BACKGROUND: Measurement of myocardial blood flow (MBF) with single photon emission computed tomography (SPECT) is feasible using cardiac cameras with solid-state detectors. SPECT MBF has been shown to be accurate when compared with positron emission tomography MBF measured in the same patients. However, the value of a test result applied to an individual patient depends strongly on the precision or repeatability of the test. The purpose of our study is to measure the precision of SPECT MBF measurements using 99mTc-tetrofosmin and a solid-state cardiac camera. METHODS: SPECT MBF was measured in 30 patients and repeated at a mean interval of 18 days. MBF was evaluated from images with and without attenuation correction based on a separately acquired CT scan. The dynamic images were processed independently by 2 operators using in-house kinetic analysis software that applied a 1-tissue-compartment model. The K1 rate constant was converted to MBF using previously determined extraction fraction corrections. Correction for patient body motion was applied manually. RESULTS: The average coefficient of variation (COV) in the differences between the 2 MBF measurements was between 28% and 31%. The interobserver COV was between 11% and 15%. Myocardial flow reserve is the ratio of MBF measured at stress and rest, and the COV is correspondingly higher. The COV for the difference in repeated myocardial flow reserve was 33% to 38%, whereas the interobserver COV was 13% to 22%. CONCLUSIONS: The COV for the difference in SPECT MBF measurements obtained on separate days is 28% to 31%. The corresponding COV for myocardial flow reserve is 33% to 38%.


Assuntos
Doença da Artéria Coronariana/diagnóstico , Circulação Coronária/fisiologia , Vasos Coronários/diagnóstico por imagem , Compostos Organofosforados/farmacologia , Compostos de Organotecnécio/farmacologia , Fluxo Sanguíneo Regional/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Idoso , Doença da Artéria Coronariana/fisiopatologia , Vasos Coronários/fisiopatologia , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Curva ROC , Compostos Radiofarmacêuticos/farmacologia
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