Analysis of pulmonary pure ground-glass nodule in enhanced dual energy CT imaging for predicting invasive adenocarcinoma: comparing with conventional thin-section CT imaging

Abstract

Background: To investigate the value of dual energy computed tomography (DECT) parameters (including iodine concentration and monochromatic CT numbers) for predicting pure ground-glass nodules (pGGNs) of invasive adenocarcinoma (IA).Methods: A total of 55 resected pGGNs evaluated with both unenhanced thin-section CT (TSCT) and enhanced DECT scans were included. Correlations between histopathology [adenocarcinoma in situ (AIS), minimally IA (MIA), and IA] and CT scan characteristics were examined. CT scan and clinicodemographic data were investigated by univariate and multivariate analysis to identify features that helped distinguish IA from AIS or MIA.Results: Both normalized iodine concentration (NIC) of IA and slope of spectral curve [slope(k)] were not significantly different between IA and AIS or MIA. Size, performance of pleural retraction and enhanced monochromatic CT attenuation values of 120-140 keV were significantly higher for IA. In multivariate regression analysis, size and enhanced monochromatic CT number of 140 keV were independent predictors for IA. Using the two parameters together, the diagnostic capacity of IA could be improved from 0.697 or 0.635 to 0.713.Conclusions: DECT could help demonstrate blood supply and indicate invasion extent of pGGNs, and monochromatic CT number of higher energy (especially 140 keV) would be better for diagnosing IA than lower energies. Together with size of pGGNs, the diagnostic capacity of IA could be better. Several researches have used thin-section CT (TSCT) to distinguish IA from the preinvasive adenocarcinoma or MIA in terms of CT number and morphologic characteristics such as size, margin, bubble lucency, and solid proportion, and have indicated that the solid proportion has correlation with the degree of invasion of ground-glass nodules (GGNs) (4-9).Sometimes, GGNs would have no solid component, which are named pure GGNs (pGGNs). Most pGGNs tend to be preinvasive (1), while approximately 20-40% of pGGNs are pathologically malignant (10). Because of the limited resolution (0.2-0.3 mm) of CT images, stromal or myofibroblastic invasion of 5 mm or smaller in MIA or even IA greater than 5 mm in size may manifest as pGGN on high resolution CT (5). It has been proved that CT attenuation of IA is higher than its precursors (11), but there is no consensus over the cutoff of CT attenuation to indicate pGGN of IA. One study suggests that pGGNs with mean CT attenuation >−472 Hounsfield unit (HU) are more likely to be IA, with sensitivity of 75% and specificity of 81% (12). Angiogenesis is a fundamental process in the development of tumors, but enhancement characteristics of GGNs are often very difficult to assess because of low cellularity, and there are few researches about the enhancement characteristics of GGNs. Li et al. (13) found that the solid proportion of some GGNs (mostly in MIA or IA) would increase after contrast enhancement, and it could help for diagnosis of GGNs.Gemstone spectral imaging (GSI) analysis software is a specific tool in dual energy computed...

Comparison and Fusion of Deep Learning and Radiomics Features of Ground-Glass Nodules to Predict the Invasiveness Risk of Stage-I Lung Adenocarcinomas in CT Scan

“…Due to the different scanning parameters, the tube current, pixel spacing, and slice thickness of CT image was variety. Whether and how these scanning parameters affect the scheme performance have not been investigated in this study (29).…”

Is there any correlation between spectral CT imaging parameters and PD‐L1 expression of lung adenocarcinoma?

“…Third, the majority of selected cases in this study were elderly people with a mean age of 61.5 years, and younger patients should be included in future studies. Fourth, monochromatic CT number was measured only enhanced monochromatic spectral CT imaging at the energy level 40 and 70 keV based on previous studies, ignoring the other keV selection. Fifth, quantifying microvessel densities previously described in a previous study were not included in this study.…”

“…Spectral CT imaging has been applied in several of the studies on pulmonary nodules. Most researchers believe that quantitative parameters of spectral CT imaging have certain advantages in the differential diagnosis of benign and malignant pulmonary nodules . There is no study testing the association between the spectral CT imaging parameters and the PD‐L1 expression in lung adenocarcinoma.…”

Possibilities of Dualenergy Computed Tomography in the Differential Diagnosis of Focal Lesions of the Liver

“…Кроме того, выбрав область интереса (ROI) на йодной карте, можно измерить количество йода в ткани в мг/см 2 (или концентрацию йода в мг/мл в вокселе), тем самым количественно оценить накопление контрастного вещества, не прибегая к анализу усредненных значений рентгеновской плотности в единицах Хаунсфилда. Поскольку материал-специфические изображения йода (йодные карты) не зависят от присущего ткани затухания, они являются более надежным показателем контрастного усиления по сравнению с оценкой значений рентгеновской плотности при традиционных многофазных контрастных исследованиях [26,[30][31][32].…”

“…Применение ДЭКТ при диагностике очаговых образований печени. В большом количестве исследований показано значение низкоэнергетических ВМИ и йодных карт для идентификации опухолей различной локализации [2,3,6,7,14,18,22,27,32,[34][35][36][37]. Работы, посвященные дифференциальной диагностике образований печени, немногочисленны, и, главным образом, связаны с анализом концентрации йода в различных очагах.…”