Combination of positron emission tomography/computed tomography and chest thin-layer high-resolution computed tomography for evaluation of pulmonary nodules

Abstract

This study aimed to analyze the imaging findings of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and chest thin-layer high-resolution computed tomography (HRCT), correlate the maximum standardized uptake value (SUVmax), and the pathological type of benign or malignant pulmonary nodules (PNs), and assess the diagnostic accuracy in differentiating malignant from benign PNs.A retrospective review of 18F-FDG PET/CT scans from 88 patients with PNs confirmed by pathology or clinical follow-up were included. They both accepted PET/CT and HRCT scan conventional. The final results were determined by a combination of PET/CT and HRCT. Independent samples t test was used for statistical analysis. Receiver operating curves (ROC) were generated and the optimal threshold of SUVmax was determined.The sensitivity, specificity, and accuracy of HRCT, PET/CT, and PET/CT combined with HRCT in the diagnosis of PNs were 83.3%, 70%, 77.3%; 91.7%, 62.5%, 78.4%; and 95.8%, 75%, 86.4%, respectively. The SUVmax of malignant nodules was significantly higher than that of benign nodules, and the difference was statistically significant (t = –5.668, P < .001). In the subgroup analysis, the SUVmax of squamous cell carcinoma was higher than that of the denocarcinoma (t = –5.442, P < .001), and that of bronchioloalveolar carcinoma (t = 4.678, P < .001), the difference were both statistically significant. There were both no significant difference between adenocarcinoma and bronchioloalveolar carcinoma (t = 0.36, P = .722), tuberculosis and inflammatory nodules (t = –0.18, P = .858). Higher the value of SUVmax, greater the risk of malignancy. However, when the SUVmax ranges between 2.5 and 8.0, the lesion may be benign or malignant, and a comprehensive evaluation using combination methods with HRCT are required. When SUVmax <2.5, there is still a 9.5% chance of PN malignancy. ROC curve shows SUVmax >3.635 as the best threshold, and the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PET/CT in diagnosis of PNs were 83.3%, 62.5%, 79.2%, 71.7%, and 71.4%, respectively.PET/CT combined with HRCT should be advocated to improve the sensitivity, specificity, and accuracy of PET/CT in diagnosis of PNs.

Solitary Pulmonary Nodule: Morphological Effects on Metabolic Activity Assessment

“…The highest diagnostic accuracy was found with SUV max threshold of 4 (sensitivity, specificity and accuracy of 85%). ROC analysis in a study with 88 SPNs by Hou et al (25) showed SUV max >3.635 as the best threshold value for SPNs (sensitivity 83.3%, sensitivity 62.5%, accuracy 79.2%). In our study, ROC analysis demonstrated (AUC=0.950±0.027; p<0.001) SUV max cut-off value as 4.39 for malignant nodules, similar with the study by Grgic et al (10) and higher than the study by Hou et al (25) (sensitivity 93.6%, specificity 89.5% and accuracy 92.9%).…”

Pulmonary Lymphangitic Carcinomatosis: Diagnostic Performance of High-Resolution CT and18F-FDG PET/CT in Correlation with Clinical Pathologic Outcome

“…Quantitative 18 F-FDG PET/CT of peritumoral areas should hence be part of the initial imaging workup of patients with primary lung cancer. However, CT images should always be checked before peritumoral SUV is measured, to avoid misinterpreting peritumoral infiltrates for another etiology, such as infection (27). In hybrid imaging, acquisition of HRCT images during a single contrast-enhanced 18 F-FDG PET/ HRCT examination should be the next step to optimize patients' evaluation and minimize costs and needs to be investigated further.…”

The Added Value of [18F]FDG PET/CT in the Management of Invasive Fungal Infections

“…The lung is the most common site of IFIs. Some authors have recommended the combination of HR CT and FDG PET/CT when evaluating pulmonary lesions to increase sensitivity and specificity [22]. A previous report demonstrated [ 18 F]FDG uptake in IFI lesions that were not seen on the corresponding CT [23].…”