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1.
Medicine (Baltimore) ; 100(35): e26961, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477126

RESUMO

BACKGROUND: The quantification of heterogeneity for the striatum and whole brain with F-18 FP-CIT PET images will be useful for diagnosis. The index obtained from texture analysis on PET images is related to pathological change that the neuronal loss of the nigrostriatal tract is heterogeneous according to the disease state. The aim of this study is to evaluate various heterogeneity indices of F-18 FP-CIT PET images in the diagnosis of Parkinson's disease (PD) patients and to access the diagnostic accuracy of the indices using machine learning (ML). METHODS: This retrospective study included F-18 FP-CIT PET images of 31 PD and 31 age-matched health controls (HC). The volume of interest was delineated according to iso-contour lines around standardized uptake value (SUV) 3.0 g/ml for each region of the striatum by PMod 3.603. One hundred eight heterogeneity indices were calculated using CGITA to find indices from which the PD and HC were classified using statistical significance. PD group was classified by constructing a 2-dimensional or 3-dimensional phase space quantifier using these heterogeneity indices. We used 71 heterogeneity indices to classify PD from HC using ML for dimensional reduction. RESULTS: The heterogeneity indices for classifying PD from HC were size-zone variability, contrast, inverse difference-moment, and homogeneity in the order of low P value. Three-dimensional quantifiers composed of normalized-contrast, code-similarity, and contrast were more clearly classified than 2-dimensional ones. After 71-dimensional reduction using PCA, classification was possible by logistic regression with 91.3% accuracy. The 2 groups were classified with an accuracy of 85.5% using the support vector machine and 88.4% using the random forest. The classification accuracy using the eXtreme Gradient Boosting was 95.7%, and feature importance was highest in order of SUV bias-corrected kurtosis, size-zone-variability, intensity-variability, and high-intensity-zone-variability. CONCLUSION: It was confirmed that PD patients is more clearly classified than the conventional 2-dimensional quantifier by introducing a 3-dimensional phase space quantifier. We observed that ML can be used to classify the 2 groups in an easy and explanatory manner. For the discrimination of the disease, 24 heterogeneity indices were found to be statistically useful, and the major cut-off values of 3 heterogeneity indices were size-zone variability (1906.44), intensity variability (129.21), and high intensity zone emphasis (800.29).


Assuntos
Doença de Parkinson/diagnóstico , Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Idoso , Feminino , Fluordesoxiglucose F18/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Neuroimagem/estatística & dados numéricos , Doença de Parkinson/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Estudos Retrospectivos
2.
Medicine (Baltimore) ; 100(35): e27055, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34477136

RESUMO

ABSTRACT: This study aimed to assess the longitudinal changes in amyloid beta (Aß) deposition in cortical regions with [11C]-PIB PET in initially amyloid-negative non-demented subjects and evaluate whether amyloid-negative subjects convert to amyloid-positive.Sixteen cognitively normal (CN) and 7 mild cognitive impairment (MCI) subjects (aged 60-75 years), who were amyloid-negative at baseline, underwent 60-minute dynamic [11C]-PIB PET and cognitive assessment over 5.0 to 9.4 years of a long follow-up, and the apolipoprotein-E (APOE) genotype was assessed. Regions of interest were defined in the bilateral cortex on coregistered MRI. Quantitative analysis of [11C]-PIB was performed using the distribution value ratio (DVR). Longitudinal changes in global and regional PIB DVRs were evaluated in the same regions, and the annual rate of change in the PIB DVR was calculated.Seven (30.4%) of 23 initially amyloid-negative non-demented subjects converted to globally amyloid-positive (global PIB DVR ≥1.40) over a follow-up of 6.5 ±â€Š1.4 years (converter). The global PIB DVR in converters increased from 1.22 ±â€Š0.07 at baseline to 1.63 ±â€Š0.15 (n = 7, P < .01) at last follow-up, and an annual increase of global PIB DVR was 0.057 ±â€Š0.019/year (n = 7, P < .01). In contrast, the global PIB DVR in the remaining 16 subjects was 1.15 ±â€Š0.07 at baseline and did not change over a follow-up period (stable). The APOE ε4 allele was present in 4 (57.1%) of the 7 converters, differing from 2 (12.5%) of 16 stable subjects (Fisher's exact test, P < .05). Three amyloid-negative MCI subjects had an annual increase in global PIB DVR above 0.061/year and became positive at 2.8 ±â€Š0.5 years of follow-up, which was faster than 5.0 ±â€Š2.0 years in 4 CN subjects. The regional PIB DVR that increased early above the regional positivity threshold was most frequently found in the right lateral temporal cortex (71.4%), followed by the left frontal cortex (41.8%).Our results suggest that the initially amyloid-negative CN and MCI subjects, especially with APOE ε4, can become globally amyloid-positive over a longer time, based on early regional Aß deposition in the lateral temporal cortex and/or frontal cortex.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/análise , Placa Amiloide/complicações , Idoso , Doença de Alzheimer/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placa Amiloide/fisiopatologia , Tomografia por Emissão de Pósitrons/métodos , Tomografia por Emissão de Pósitrons/estatística & dados numéricos
3.
World J Surg Oncol ; 19(1): 262, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470640

RESUMO

BACKGROUND: This study aimed to investigate the correlation between miRNA-216b expression in patients with non-small cell lung cancer (NSCLC) and 18F-fluorodeoxyglucose (FDG) uptake by PET/CT and to explore the clinical application value of 18F-FDG PET/CT in miRNA-216b based on therapy for NSCLC. METHODS: Eighty patients with NSCLC and 40 healthy subjects were enrolled in our study. The SUVmax of the lesion area by PET/CT imaging was calculated. SUVmax represented the highest concentration of 18F-FDG in the lesion. The expression of miRNA-216b in the plasma and fiber bronchoscopic puncture of NSCLC patients was detected by RT qPCR. Then Pearson correlation analysis was used to analyze the correlation between miRNA-216b expression and 18F-FDG uptake in patients with different types of NSCLC. RESULTS: Compared with healthy subjects, SUVmax of early adenocarcinoma and advanced adenocarcinoma were increased. Compared with healthy subjects, SUVmax of early squamous and advanced squamous were increased. And the SUVmax content of advanced adenocarcinoma and squamous cell carcinoma was higher than that of early adenocarcinoma and squamous cell carcinoma. Compared with healthy subjects, the expression of miRNA-216b in the plasma of patients with early and advanced adenocarcinoma was reduced, and the expression of miRNA-216b in the plasma of patients with early and advanced squamous cell carcinoma was reduced. Compared with adjacent tissues, the expression of miRNA-216b in early adenocarcinoma tissues and advanced adenocarcinoma tissues was reduced, and the expression in early squamous cell carcinoma and advanced squamous cell carcinoma was reduced. Pearson correlation analysis showed a negative correlation between SUVmax and miRNA-216b (plasma and tissue) in patients with four types of NSCLC. CONCLUSION: miRNA-216b expression was negatively correlated with 18F-FDG uptake in NSCLC. miRNA-216b could be used for the classification and staging of non-small cell lung cancer. 18F-FDG PET/CT may be used to evaluate the therapeutic response in application of miRNA-216b-based cancer treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Fluordesoxiglucose F18/farmacocinética , Neoplasias Pulmonares , MicroRNAs , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Carcinoma Pulmonar de Células não Pequenas/genética , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/genética , MicroRNAs/genética , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Prognóstico , Compostos Radiofarmacêuticos
4.
ACS Chem Neurosci ; 12(18): 3410-3417, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34469110

RESUMO

Adenosine receptor (AR) radiotracers for positron emission tomography (PET) have provided knowledge on the in vivo biodistribution of ARs in the central nervous system (CNS), which is of therapeutic interest for various neuropsychiatric disorders. Additionally, radioligands that can image changes in endogenous adenosine levels in different physiological and pathological conditions are still lacking. The binding of known antagonist adenosine A1 receptor (A1R) radiotracer, [11C]MDPX, failed to be inhibited by elevated endogenous adenosine in a rodent PET study. Since most of the known AR PET radiotracers were antagonists, we propose that an A1R agonist radioligand may possess higher sensitivity to measure changes in endogenous adenosine concentration. Herein, we report our latest findings toward the development of a full agonist adenosine A1 radioligand for PET. Based on a 3,5-dicyanopyridine template, 16 new derivatives were designed and synthesized to optimize both binding affinity and functional activity, resulting in two full agonists (compounds 27 and 29) with single-digit nanomolar affinities and good subtype selectivity (A1/A2A selectivity of ∼1000-fold for compound 27 and 29-fold for compound 29). Rapid O-[11C]methylation provided [11C]27 and [11C]29 in high radiochemical yields and radiochemical purity. However, subsequent brain PET imaging in rodents showed poor brain permeability for both radioligands. An in vivo PET study using knockout mice for MDR 1a/a, BCRP, and MRP1 indicated that these compounds might be substrates for brain efflux pumps. In addition, in silico evaluation using multiparameter optimization identified high molecular weight and high polar surface area as the main molecular descriptors responsible for low brain penetration. These results will provide further insight toward development of full agonist adenosine A1 radioligands and also highly potent CNS A1AR drugs.


Assuntos
Proteínas de Neoplasias , Agonistas do Receptor Purinérgico P1 , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Adenosina , Animais , Camundongos , Tomografia por Emissão de Pósitrons , Distribuição Tecidual
5.
Nat Commun ; 12(1): 5255, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489438

RESUMO

Monocytes are part of the mononuclear phagocytic system. Monocytes play a central role during inflammatory conditions and a better understanding of their dynamics might open therapeutic opportunities. In the present study, we focused on the characterization and impact of monocytes on brown adipose tissue (BAT) functions during tissue remodeling. Single-cell RNA sequencing analysis of BAT immune cells uncovered a large diversity in monocyte and macrophage populations. Fate-mapping experiments demonstrated that the BAT macrophage pool requires constant replenishment from monocytes. Using a genetic model of BAT expansion, we found that brown fat monocyte numbers were selectively increased in this scenario. This observation was confirmed using a CCR2-binding radiotracer and positron emission tomography. Importantly, in line with their tissue recruitment, blood monocyte counts were decreased while bone marrow hematopoiesis was not affected. Monocyte depletion prevented brown adipose tissue expansion and altered its architecture. Podoplanin engagement is strictly required for BAT expansion. Together, these data redefine the diversity of immune cells in the BAT and emphasize the role of monocyte recruitment for tissue remodeling.


Assuntos
Tecido Adiposo Marrom/citologia , Monócitos/fisiologia , Adiponectina/genética , Tecido Adiposo Marrom/fisiologia , Animais , Diferenciação Celular/genética , Contagem de Leucócitos , Macrófagos/citologia , Macrófagos/fisiologia , Glicoproteínas de Membrana/metabolismo , Camundongos Transgênicos , Monócitos/citologia , Tomografia por Emissão de Pósitrons , Receptores CCR2/genética , Receptores CCR2/metabolismo
6.
Croat Med J ; 62(4): 310-317, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34472733

RESUMO

AIM: To investigate the diagnostic accuracy of O-(2-[18F]-fluoroethyl)-L-tyrosine (18F-FET) and fluoromethyl-(18F)-dimethyl-2-hydroxyethyl-ammonium chloride (18F-FCH) computed tomography (CT) in patients with primary low-grade gliomas (LGG). METHODS: The study enrolled patients with magnetic resonance imaging (MRI)-suspected LGG. Patients underwent both 18F-FET and 18F-FCH positron emission tomography (PET)-CT. Brain PET-CT was performed according to standard protocol - 20 minutes after intravenous injection of 185 MBq of 18F-FET and 185 MBq of 18F-FCH PET. Surgery and pathohistological diagnosis were performed in the next two weeks. RESULTS: We observed significantly better concordance between tumor histology and 18F-FET PET (weighted Kappa 0.74) compared with both 18F-FCH (weighted Kappa 0.15) and MRI (weighted Kappa 0.00). Tumor histology was significantly associated with 18F-FET (odds ratio 12.87; 95% confidence interval [CI], 0.49-333.70; P=0.013, logistic regression analysis). Receiver operating characteristic curve analysis comparing 18F-FCH (area under the curve [AUC] 0.625, 95% CI 0.298-0.884) and 18F-FET (AUC 0.833, 95% CI 0.499-0.982) showed better diagnostic properties of 18F-FET (AUC difference 0.208, 95% CI -0.145 to 0.562, P=0.248). CONCLUSION: Performing PET-CT in patients with newly diagnosed LGG should be preceded by a selection of an appropriate radiopharmaceutical. 18F-FET seems to be more accurate than 18F-FCH in the LGG diagnosis.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/diagnóstico por imagem , Colina/análogos & derivados , Glioma/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Projetos Piloto , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Tirosina
7.
Alzheimers Res Ther ; 13(1): 150, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488875

RESUMO

BACKGROUND: Aging is associated with declining protective immunity and persistent low-grade inflammatory responses, which significantly contribute to Alzheimer's disease (AD) pathogenesis. Detecting aging-related cerebral vulnerability associated with deterioration of the immune system requires from non-invasive biomarkers able to detect failures in the brain-immunity connection. Reduced levels of salivary lactoferrin (sLF), an iron-binding protein with immunomodulatory activity, have been related to AD diagnosis. However, it remains unknown whether decreased sLF is associated with increased cortical amyloid-beta (Aß) load and/or with loss of cortical integrity in normal aging. METHODS: Seventy-four cognitively normal older adults (51 females) participated in the study. We applied multiple linear regression analyses to assess (i) whether sLF is associated with cortical Aß load measured by 18F-Florbetaben (FBB)-positron emission tomography (PET), (ii) whether sLF-related variations in cortical thickness and cortical glucose metabolism depend on global Aß burden, and (iii) whether such sLF-related cortical abnormalities moderate the relationship between sLF and cognition. RESULTS: sLF was negatively associated with Aß load in parieto-temporal regions. Moreover, sLF was related to thickening of the middle temporal cortex, increased FDG uptake in the posterior cingulate cortex, and poorer memory. These associations were stronger in individuals showing the highest Aß burden. CONCLUSIONS: sLF levels are sensitive to variations in cortical Aß load, structural and metabolic cortical abnormalities, and subclinical memory impairment in asymptomatic older adults. These findings provide support for the use of sLF as a non-invasive biomarker of cerebral vulnerability in the general aging population.


Assuntos
Doença de Alzheimer , Lactoferrina , Idoso , Envelhecimento , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides/metabolismo , Feminino , Humanos , Tomografia por Emissão de Pósitrons
8.
J Coll Physicians Surg Pak ; 31(9): 1102-1104, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34500530

RESUMO

Cardiac lymphomas, either primary or secondary, are mostly of B-cell lineage; among which, diffuse large B-cell lymphoma (DLBCL) is the most common. Secondary involvement of the heart is usually a late manifestation of disseminated lymphoma. Patients may be asymptomatic or may have non-specific symptoms, particularly when cardiac involvement is not extensive. A 22-year male patient presented with four months' history of progressive enlargement of left cervical lymph nodes with intermittent fever along with dysphagia and left ear pain. Positron-emission tomography (PET)/computed tomography (CT) scan revealed abnormal fluorodeoxyglucose (FDG) uptake in multiple systemic locations including inferior wall of the myocardium. Subsequently, cardiac MRI showed left ventricular posterolateral wall abnormal area of delayed enhancement, corresponding to the FDG uptake on PET CT scan. Patient had remission after completion of standard chemotherapy protocol for the management of DLBCL with acceptable toxicity. Key Words: Diffuse large B-cell lymphoma (DLBCL), Secondary, Heart, Chemotherapy.


Assuntos
Linfoma Difuso de Grandes Células B , Compostos Radiofarmacêuticos , Fluordesoxiglucose F18 , Humanos , Linfoma Difuso de Grandes Células B/diagnóstico por imagem , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Imageamento por Ressonância Magnética , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons
9.
ACS Chem Neurosci ; 12(18): 3335-3346, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34449193

RESUMO

Selective inhibition of glycine transporter 1 (GlyT1) has emerged as a potential approach to alleviate N-methyl-d-aspartate receptor (NMDAR) hypofunction in patients with schizophrenia and cognitive decline. ALX5407 is a potent and selective inhibitor of GlyT1 derived from the metabolic intermediate sarcosine (N-methylglycine) that showed antipsychotic potential in a number of animal models. Whereas clinical application of ALX5407 is limited by adverse effects on motor performance and respiratory function, a suitably radiolabeled drug could represent a promising PET tracer for the visualization of GlyT1 in the brain. Herein, [18F]ALX5407 and the corresponding methyl ester, [18F]ALX5406, were prepared by alcohol-enhanced copper mediated radiofluorination and studied in vitro in rat brain slices and in vivo in normal rats. [18F]ALX5407 demonstrated accumulation consistent with the distribution of GlyT1 in in vitro autoradiographic studies but no brain uptake in µPET experiments in naïve rats. In contrast, the methyl ester [18F]ALX5406 rapidly entered the brain and was enzymatically transformed into [18F]ALX5407, resulting in a regional accumulation pattern consistent with GlyT1 specific binding. We conclude that [18F]ALX5406 is a promising and easily accessible PET probe for preclinical in vivo imaging of GlyT1 in the brain.


Assuntos
Proteínas da Membrana Plasmática de Transporte de Glicina , Pró-Fármacos , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Humanos , Tomografia por Emissão de Pósitrons , Ratos , Receptores de N-Metil-D-Aspartato/metabolismo , Sarcosina
10.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(4): 1181-1186, 2021 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34362500

RESUMO

OBJECTIVE: To investigate the prognostic value of metabolic parameters of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in diffuse large B-cell lymphoma (DLBCL). METHODS: The clinical data of 58 patients with DLBCL who were examined by 18F-FDG PET/CT before treatment and confirmed by pathology were analyzed retrospectively. The relationships between maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and clinical factors were analyzed. Kaplan Meier method, Log-rank test and multivariate Cox regression were used to analyze the relationships between metabolic SUVmax, MTV, TLG and times of total overall survival (OS) and progression-free survival (PFS). RESULTS: The SUVmax, MTV and TLG of 58 DLBCL patients were 21.45 (10.26-42.38), 27.30 (14.20-133.25) cm3 and 322.85 (47.35-1438.20), respectively. Univariate analysis showed that large mass, Ann Arbor stage, international prognostic index, MTV and TLG were the factors influencing OS and PFS in DLBCL patients (P<0.05), while lactate dehydrogenase and SUVmax were the factors influencing PFS only (P<0.05). Multivariate analysis showed that MTV (HR=2.974, 95%CI: 1.803-7.225)/(HR=3.925, 95%CI: 1.973-8.246) and TLG (HR=2.583, 95%CI: 1.192-5.316)/(HR=2.874, 95%CI: 1.538-6.483) were independent risk factors for OS and PFS in DLBCL patients (P<0.05), and international prognostic index (HR=2.490, 95%CI: 1.150-4.962) was independent risk factor for OS in DLBCL patients (P<0.05). CONCLUSION: MTV and TLG are independent risk factors for OS and PFS in patients with DLBCL, which may be valuable for prognosis of patients with DLBCL.


Assuntos
Fluordesoxiglucose F18 , Linfoma Difuso de Grandes Células B , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons , Prognóstico , Estudos Retrospectivos
11.
J Int Med Res ; 49(7): 3000605211032859, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34334002

RESUMO

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a benign, self-limiting inflammatory disorder of unknown etiology and pathogenesis. This report presents a rare case involving a man with 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) hypermetabolism caused by KFD mimicking malignant lymphoma. The PET/CT maximum intensity projection showed multiple hypermetabolic lymphadenopathies and homogeneous FDG uptake in the bone marrow and spleen. Malignant lymphoma was initially suspected. The patient then underwent excision biopsy of one enlarged right cervical lymph node that was selected because it showed the highest FDG uptake in PET/CT, and examination of this biopsy specimen confirmed the diagnosis of KFD. PET/CT is useful for assessing the general condition of patients and can help to select lymph nodes for excision biopsy based on the highest FDG uptake. However, KFD can predispose to localized FDG uptake and limit the specificity of PET/CT by mimicking malignancy. Thus, positive results of PET/CT should be interpreted with caution.


Assuntos
Linfadenite Histiocítica Necrosante , Linfoma , Fluordesoxiglucose F18 , Linfadenite Histiocítica Necrosante/diagnóstico por imagem , Humanos , Linfonodos/diagnóstico por imagem , Linfoma/diagnóstico por imagem , Masculino , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons
14.
Medicina (Kaunas) ; 57(8)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34441015

RESUMO

Backgroundand objectives: The clinical assessment of therapeutic response in pyogenic vertebral osteomyelitis (PVO) has been usually performed based on the changes of clinical symptoms and blood inflammatory markers. Recently, 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) has emerged as an alternative independent method. We analyzed the validity of the clinical assessment for detecting residual PVO based on 18F-FDG-PET. Materials and Methods: This study was conducted with 53 patients confirmed as lumbar PVO under retrospective design. All patients underwent clinical assessment using clinical symptoms and C-reactive protein (CRP) for therapeutic response after parenteral antibiotic therapy, which led to the decision of placement in the uncontrolled (group UC) or controlled (group C) group. The validity of clinical assessment was analyzed based on the cut-off values of FDG uptake for detecting residual PVO as references, which are already established in the previous literature. Results: The mean duration of parenteral antibiotic therapy and recurrence rate were 42.19 ± 15.84 (21-89) days and 9.4% (5/53), respectively. 18F-FDG-PETs were performed at 80 rounds of clinical assessment on 37.40 ± 13.15 (21-83) days of parenteral antibiotic therapy and divided: 31 into group UC and 49 into group C, according to the decisions of clinical assessment. Based on the cut-off values of FDG uptake, clinical assessment showed 48.4-58.1% of false positive for residual PVO in group UC. However, 18F-FDG-PET showed 8.2% (4/49) of false negative for residual PVO in group C, which led to recurrences. Conclusions: Clinical assessment using clinical symptoms and CRP for evaluating therapeutic response in PVO is still a useful method in terms of similar recurrence rate compared to 18F-FDG-PET. However, the high rate of false positive for residual PVO can prolong the use of unnecessary antibiotics and overall treatment period.


Assuntos
Fluordesoxiglucose F18 , Osteomielite , Proteína C-Reativa , Humanos , Osteomielite/diagnóstico por imagem , Osteomielite/tratamento farmacológico , Tomografia por Emissão de Pósitrons , Estudos Retrospectivos
15.
Medicina (Kaunas) ; 57(8)2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34441062

RESUMO

Monoclonal gammopathy of undetermined significance (MGUS) is a highly prevalent condition with the possible risk of progression to multiple myeloma (MM) or a lymphoproliferative neoplasm in a small percentage of patients. Fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) or positron emission tomography/magnetic resonance imaging (PET/MRI) are imaging methods increasingly used in patients with MM. The aim of this communication is to underline that, taking into account current evidence-based data, compared to MM the role of 18F-FDG PET/CT or PET/MRI in MGUS is still undetermined and more studies should be performed before suggesting 18F-FDG PET/CT or PET/MRI for evaluation of MM progression in patients with MGUS.


Assuntos
Fluordesoxiglucose F18 , Gamopatia Monoclonal de Significância Indeterminada , Humanos , Imageamento por Ressonância Magnética , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Tomografia por Emissão de Pósitrons
16.
Sensors (Basel) ; 21(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34451008

RESUMO

The purpose of this study was to investigate the feasibility of a time-of-flight (TOF) brain positron emission tomography (PET) providing high-quality images. It consisted of 30 detector blocks arranged in a ring with a diameter of 257 mm and an axial field of view of 52.2 mm. Each detector block was composed of two detector modules and two application-specific integrated circuit (ASIC) chips. The detector module was composed of an 8 × 8 array of 3 × 3 mm2 multi-pixel photon counters and an 8 × 8 array of 3.11 × 3.11 × 15 mm3 lutetium yttrium oxyorthosilicate scintillators. The 64-channel individual readout ASIC was used to acquire the position, energy, and time information of a detected gamma ray. A coincidence timing resolution of 187 ps full width at half maximum (FWHM) was achieved using a pair of channels of two detector modules. The energy resolution and spatial resolution were 6.6 ± 0.6% FWHM (without energy nonlinearity correction) and 2.5 mm FWHM, respectively. The results of this study demonstrate that the developed TOF brain PET could provide excellent performance, allowing for a reduction in radiation dose or scanning time for brain imaging due to improved sensitivity and signal-to-noise ratio.


Assuntos
Fótons , Tomografia por Emissão de Pósitrons , Encéfalo/diagnóstico por imagem , Eletrônica , Estudos de Viabilidade
17.
Radiol Clin North Am ; 59(5): 693-703, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34392913

RESUMO

Precision medicine integrates molecular pathobiology, genetic make-up, and clinical manifestations of disease in order to classify patients into subgroups for the purposes of predicting treatment response and suggesting outcome. By identifying those patients who are most likely to benefit from a given therapy, interventions can be tailored to avoid the expense and toxicity of futile treatment. Ultimately, the goal is to offer the right treatment, to the right patient, at the right time. Lung cancer is a heterogeneous disease both functionally and morphologically. Further, over time, clonal proliferations of cells may evolve, becoming resistant to specific therapies. PET is a sensitive imaging technique with an important role in the precision medicine algorithm of lung cancer patients. It provides anatomo-functional insight during diagnosis, staging, and restaging of the disease. It is a prognostic biomarker in lung cancer patients that characterizes tumoral heterogeneity, helps predict early response to therapy, and may direct the selection of appropriate treatment.


Assuntos
Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Imagem Molecular/tendências , Tomografia por Emissão de Pósitrons/tendências , Medicina de Precisão/tendências , Fluordesoxiglucose F18 , Humanos , Interpretação de Imagem Assistida por Computador , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/tendências , Compostos Radiofarmacêuticos
18.
Radiol Clin North Am ; 59(5): 725-735, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34392915

RESUMO

Imaging plays an integral role in the clinical care of patients with breast cancer. This review article focuses on the use of PET imaging for breast cancer, highlighting the clinical indications and limitations of 2-deoxy-2-[18F]fluoro-d-glucose (FDG) PET/CT, the potential use of PET/MRI, and 16α-[18F]fluoroestradiol (FES), a newly approved radiopharmaceutical for estrogen receptor imaging.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/tendências , Feminino , Fluordesoxiglucose F18 , Humanos , Imageamento por Ressonância Magnética , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos
19.
Radiol Clin North Am ; 59(5): 835-852, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34392922

RESUMO

Cardiovascular disease is the leading cause of death worldwide. Given the increased availability of radiopharmaceuticals, improved positron emission tomography (PET) camera systems and proven higher diagnostic accuracy, PET is increasingly utilized in the management of various cardiovascular diseases. PET has high temporal and spatial resolution, when compared to Single Photon Emission Computed Tomography. In clinical practice, hybrid imaging with sequential PET and Computed Tomography acquisitions (PET/CT) or concurrent PET and Magnetic Resonance Imaging are standard. This article will review applications of cardiovascular PET/CT including myocardial perfusion, viability, cardiac sarcoidosis/inflammation, and infection.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Imagem de Perfusão do Miocárdio/tendências , Tomografia por Emissão de Pósitrons/tendências , Cardiomiopatias/diagnóstico por imagem , Fluordesoxiglucose F18 , Humanos , Miocardite/diagnóstico por imagem , Compostos Radiofarmacêuticos , Sarcoidose/diagnóstico por imagem
20.
Radiol Clin North Am ; 59(5): 853-874, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34392923

RESUMO

PET/MR imaging is in routine clinical use and is at least as effective as PET/CT for oncologic and neurologic studies with advantages with certain PET radiopharmaceuticals and applications. In addition, whole body PET/MR imaging substantially reduces radiation dosages compared with PET/CT which is particularly relevant to pediatric and young adult population. For cancer imaging, assessment of hepatic, pelvic, and soft-tissue malignancies may benefit from PET/MR imaging. For neurologic imaging, volumetric brain MR imaging can detect regional volume loss relevant to cognitive impairment and epilepsy. In addition, the single-bed position acquisition enables dynamic brain PET imaging without extending the total study length which has the potential to enhance the diagnostic information from PET.


Assuntos
Imageamento por Ressonância Magnética/tendências , Imagem Multimodal/tendências , Tomografia por Emissão de Pósitrons/tendências , Imagem Corporal Total/tendências , Humanos , Compostos Radiofarmacêuticos
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