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1.
Artigo em Inglês | MEDLINE | ID: mdl-38976037

RESUMO

PURPOSE: To systematically investigate kinetic metrics and metabolic trapping of [13N]NH3 in organs. METHODS: Eleven participants performed total-body [13N]NH3 dynamic positron emission tomography (PET). Regions of interest were drawn in organs to obtain time-to-activity curves (TACs), which were fitted with an irreversible two-tissue compartment model (2TC) to investigate constant rates K1, k2 and k3, and to calculate Ki. Additionally, one-tissue compartment model using full data (1TCfull) and the first four minutes of data (1TC4min) were fitted to TAC data. K1 and k2 were compared among different models to assess [13N]NH3 trapping in organs. RESULTS: Kinetic rates of [13N]NH3 varied significantly among organs. The mean K1 ranged from 0.049 mL/cm3/min in the muscle to 2.936 mL/cm3/min in the kidney. The k2 and k3 were lowest in the liver (0.001 min- 1) and in the pituitary (0.009 min- 1), while highest in the kidney (0.587 min- 1) and in the liver (0.800 min- 1), respectively. The Ki was largest in the myocardium (0.601 ± 0.259 mL/cm3/min) while smallest in the bone marrow (0.028 ± 0.022 mL/cm3/min). Three groups of organs with similar kinetic characteristics were revealed: (1) the thyroid, the lung, the spleen, the pancreas, and the kidney; (2) the liver and the muscle; and (3) the cortex, the white matter, the cerebellum, the pituitary, the parotid, the submandibular gland, the myocardium, the bone, and the bone marrow. Obvious k3 was identified in multiple organs, and significant changes of K1 in multiple organs and k2 in most organs were found between 2TC and 1TCfull, but both K1 and k2 were comparable between 2TC and 1TC4min. CONCLUSION: The kinetic rates of [13N]NH3 differed among organs with some have obvious 13N-anmmonia trapping. The normal distribution of kinetic metrics of 13N-anmmonia in organs can serve as a reference for its potential use in tumor imaging.

2.
J Nucl Cardiol ; 30(5): 1992-2002, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36929292

RESUMO

BACKGROUND: Whether physiological coronary diffuseness assessed by quantitative flow reserve (QFR) pullback pressure gradient (PPG) correlates with longitudinal myocardial blood flow (MBF) gradient and improves diagnostic performances for myocardial ischemia remains unknown. METHODS AND RESULTS: MBF was measured in mL g-1 min-1 with 99mTc-MIBI CZT-SPECT at rest and stress, corresponding myocardial flow reserve (MFR = MBF stress/MBF rest) and relative flow reserve (RFR = MBF stenotic area/MBF reference) were calculated. Longitudinal MBF gradient was defined as apical and basal left ventricle MBF gradient. △longitudinal MBF gradient was calculated by longitudinal MBF gradient at stress and rest. QFR-PPG was acquired from virtual QFR pullback curve. QFR-PPG significantly correlated with hyperemic longitudinal MBF gradient (r = 0.45, P = 0.007) and △longitudinal MBF gradient (stress-rest) (r = 0.41, P = 0.016). Vessels with lower RFR had lower QFR-PPG (0.72 vs. 0.82, P = 0.002), hyperemic longitudinal MBF gradient (1.14 vs. 2.22, P = 0.003) and △longitudinal MBF gradient (0.50 vs. 1.02, P = 0.003). QFR-PPG, hyperemic longitudinal MBF gradient and △longitudinal MBF gradient showed comparable diagnostic performances for predicting decreased RFR (area under curve [AUC]: 0.82 vs. 0.81 vs. 0.75, P = NS) or QFR (AUC: 0.83 vs. 0.72 vs. 0.80, P = NS). In addition, QFR-PPG and QFR in combination showed incremental value compared with QFR for predicting RFR (AUC = 0.83 vs. 0.73, P = 0.046, net reclassification index = 0.508, P = 0.001). CONCLUSION: QFR-PPG significantly correlated with longitudinal MBF gradient and △longitudinal MBF gradient when used for physiological coronary diffuseness assessment. All three parameters had high accuracy in predicting RFR or QFR. Adding physiological diffuseness assessment increased accuracy for predicting myocardial ischemia.


Assuntos
Doença da Artéria Coronariana , Reserva Fracionada de Fluxo Miocárdico , Hiperemia , Imagem de Perfusão do Miocárdio , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Angiografia Coronária/métodos , Reserva Fracionada de Fluxo Miocárdico/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Coração , Imagem de Perfusão do Miocárdio/métodos , Valor Preditivo dos Testes
3.
Clin Exp Med ; 20(4): 557-567, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32797371

RESUMO

Hepatic epithelioid hemangioendothelioma (HEHE) is a low-to-intermediate-grade malignant mesenchymal tumor. The diagnostic and prognostic values of 2-[18F] fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) to patients with HEHE have not been fully validated. Patient survival outcomes (including overall survival [OS] and progression-free survival [PFS]), lesions characteristics and semi-quantitative parameters, in terms of maximum standardized uptake value (SUVmax), peak SUV (SUVpeak), total lesion glycolysis (TLG) and metabolic tumor volume (MTV) on 18F-FDG PET/CT of 20 cases with HEHE were measured and analyzed. A total of 310 liver lesions were detected (excluding the diffuse-type lesions in 3 cases). Most lesions had higher SUVmax in delayed imaging than in early imaging (P = 0.013). Patients with multiple organs involved had higher death rate (P = 0.022), higher progression rate (P = 0.020), shorter OS (P = 0.011), larger lesion SUVmax (P = 0.048) and TLG (P = 0.033) than those with only liver involved. The area under curves (AUCs) from the receiver operating characteristic (ROC) curve analysis were 0.960, 0.949, 0.980 and 0.960 for SUVmax, SUVpeak, TLG and MTV, respectively, in predicting OS (P = 0.005, 0.008, 0.001 and 0.024, respectively). For predicting PFS, the AUCs were 0.791, 0.824, 0.857 and 0.813 (P = 0.036, 0.019, 0.010 and 0.024), respectively. Dual-time-point imaging may improve lesions detectability. Patients with multiple organ involved had worse prognosis. The higher SUVmax, SUVpeak, TLG and MTV of lesions, the worse prognosis of patients were found.


Assuntos
Hemangioendotelioma Epitelioide/diagnóstico por imagem , Hemangioendotelioma Epitelioide/mortalidade , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/mortalidade , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Adulto , Idoso , Feminino , Fluordesoxiglucose F18/farmacocinética , Seguimentos , Hemangioendotelioma Epitelioide/patologia , Hemangioendotelioma Epitelioide/terapia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Compostos Radiofarmacêuticos/farmacocinética , Carga Tumoral
4.
Mol Med Rep ; 16(3): 3680-3686, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28765926

RESUMO

The diagnosis of adult onset Still's disease (AOSD) is non­specific, and requires the exclusion of other diseases including infectious, inflammatory and malignant diseases. The current study aimed to summarize the imaging characteristics of fluorodeoxyglucose (18F­FDG) positron emission tomography (PET)/computerized tomography (CT) in patients with AOSD. The 18F­FDG PET/CT characteristic observations of 32 patients with definite AOSD were retrospectively reviewed based on visual interpretation and the semi­quantitative index of standard uptake value of maximum (SUVmax). Among 32 patients, no normal case was observed. Abnormal FDG accumulation by the spleen, bone marrow and lymph nodes was the main observation of the PET/CT images. Totals of 27 (84.4%) and 26 cases (81.3%) were identified with diffusely elevated FDG uptake by the spleen and bone marrow, respectively, and the average SUVmax was 4.2±1.1 and 4.6±0.6, respectively. A total of 20 cases (62.5%) showed lymphadenopathy with FDG uptake, with the range of SUVmax from 2.2­13.9. In addition, 7 patients (21.9%) were observed to exhibit effusion without FDG uptake, 1 case presented with abnormal FDG uptake by the skin, and another by the right shoulder joint. In addition, no abnormally elevated FDG uptake by the liver or large vessels was observed. Due to non­specific imaging features, 18F­FDG PET/CT could not be directly helpful in diagnosing AOSD. However, 18F­FDG PET/CT serves important roles in evaluating the involved extent of AOSD, and guiding the biopsy of lymph nodes, bone marrow or other tissues, which may aid in the development of novel clinical management strategies.


Assuntos
Glucose-6-Fosfato/análogos & derivados , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Doença de Still de Início Tardio/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/diagnóstico por imagem , Glucose-6-Fosfato/administração & dosagem , Humanos , Fígado/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Pessoa de Meia-Idade , Especificidade de Órgãos , Estudos Retrospectivos , Pele/diagnóstico por imagem , Baço/diagnóstico por imagem
5.
Clin Nucl Med ; 41(1): 72-3, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26359556

RESUMO

A 65-year-old man was diagnosed with hepatocellular carcinoma 4 years ago, for which he underwent interventional therapy and radiofrequency ablation after the right lobe partial hepatectomy. He was doing well, and an FDG PET/CT scan performed 1 year earlier did not reveal any hypermetabolic lesions. However, on recent examination, a soft tissue mass inside the oral cavity was found. 18F-FDG PET/CT imaging was performed to evaluate the possible metastasis. The images showed that the oral lesion was hypermetabolic. The pathology after biopsy confirmed oral metastasis from hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Bucais/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Idoso , Carcinoma Hepatocelular/patologia , Fluordesoxiglucose F18 , Humanos , Neoplasias Hepáticas/patologia , Masculino , Neoplasias Bucais/secundário , Imagem Multimodal , Compostos Radiofarmacêuticos
7.
Nanotechnology ; 21(17): 175101, 2010 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-20357413

RESUMO

The toxicity of polyethylene-glycol functionalized (PEGylated) multi-walled carbon nanotubes (MWCNTs) and non-PEGylated MWCNTs in vivo was evaluated and compared. Mice were exposed to MWCNTs by intravenous injection. The activity level of glutathione, superoxide dismutase and gene expression in liver, as well as some biochemical parameters and the tumor necrosis factor alpha level in blood were measured over 2 months. The pathological and electron micrographic observations of liver evidently indicate that the damage caused by non-PEGylated MWCNTs is slightly more severe than that of PEGylated MWCNTs, which means that PEGylation can partly, but not substantially, improve the in vivo biocompatibility of MWCNTs.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Fígado/efeitos dos fármacos , Nanotubos de Carbono/toxicidade , Polietilenoglicóis/toxicidade , Análise de Variância , Animais , Peso Corporal , Doença Hepática Crônica Induzida por Substâncias e Drogas/metabolismo , Histocitoquímica , Fígado/metabolismo , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Nanotubos de Carbono/química , Análise de Sequência com Séries de Oligonucleotídeos , Estresse Oxidativo , Polietilenoglicóis/química , Superóxido Dismutase/metabolismo , Testes de Toxicidade Crônica/métodos , Fator de Necrose Tumoral alfa/metabolismo
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