Human-recognizable CT image features of subsolid lung nodules associated with diagnosis and classification by convolutional neural networks

Objectives The interpretability of convolutional neural networks (CNNs) for classifying subsolid nodules (SSNs) is insufficient for clinicians. Our purpose was to develop CNN models to classify SSNs on CT images and to investigate image features associated with the CNN classification. Methods CT images containing SSNs with a diameter o

tumor atelectasis gives rise to a solid appearance in pulmonary adenocarcinomas on hr ct

Abstract Introduction Ground glass opacities on HR-CT scan, if malignant on histological examination, correlate with adenocarcinoma in situ. Solid appearance on HR-CT is often considered an invasive component. This study aims to compare radiological features on HR-CT and histological features of primary adenocarcinomas in resection specimens in order to demonstrate the presence of tumor atelectasis in ground glass nodules, part solid and solid nodules. Materials and Methods HR-CT imaging was evaluated, and lung nodules were classified as ground glass nodule, part solid nodule and solid nodule, while adenocarcinomas were classified according to WHO classification. Lepidic growth pattern with collapse was considered if reduction of air in the histological section was present, with maintained pulmonary architecture (without signs of pleural or vascular invasion). Results Radiological and histological features were compared in 47 lesions of 41 patients. The number of ground glass, part solid and solid nodules were 2, 8 and 37, respectively. Lepidic growth pattern with collapse was observed in both ground glass nodules, 7 out of 8 (88%) part solid and 24 out of 37 (65%) solid lesions. Remarkably, more than 50% of adenocarcinomas with solid appearance on HR-CT showed a pre-existing pulmonary architecture with adenocarcinoma with a predominant lepidic growth pattern. In these cases, the solid component can be explained by tumor related collapse in vivo (tumor atelectasis on radiology). Conclusion Tumor atelectasis is a frequent finding in pulmonary adenocarcinomas and results in solid appearance on HR-CT. A solid appearance on HR-CT can not only be attributed to invasion, as has been the assumption until now

Conventional CT and PET/CT imaging in the evaluation and management of subsolid pulmonary nodules: an overview of the literature and author recommendations

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Nodular Ground-Glass Opacities on Thin-section CT: Size Change during Follow-up and Pathological Results

OBJECTIVE: To evaluate the inter-group differences in growth and the pathological results of nodular ground-glass opacities (GGOs) according to their size and focal solid portions. MATERIALS AND METHODS: Ninety-six nodular GGOs in 55 individuals followed by CT for at least one month from an initial chest CT were included. Forty nodular GGOs in 30 individuals were pathologically confirmed to be: adenocarcinoma (n = 15), bronchioloalveolar carcinoma (BAC) (n = 11), atypical adenomatous hyperplasia (AAH) (n = 8), focal interstitial fibrosis (n = 5) and aspergillosis (n = 1). Lesions were categorized based on high-resolution CT findings: pure nodular GGO (PNGGO) 10 mm, mixed nodular GGO (MNGGO) 10 mm. In each group, the change in size during the follow-up period, the pathological results and the rate of malignancy were evaluated. RESULTS: Three MNGGO lesions, and none of the PNGGO, grew during the follow-up period. Resected PNGGOs 10 mm were focal interstitial fibrosis (n = 4), AAH (n = 2), BAC (n = 2), and adenocarcinoma (n = 2). Resected MNGGOs 10 mm were adenocarcinoma (n = 11), BAC (n = 3), and aspergillosis (n = 1). CONCLUSION: Mixed nodular GGOs (MNGGOs) had the potential for growth; most were pathologically adenocarcinoma or BAC. By contrast, PNGGOs were stable for several months to years; most were AAH, BAC, or focal interstitial fibrosis.This study is supported by Seoul National University Hospital Research Grant (04- 2006-044-0)

Intraoperative ultrasonographic localization of pulmonary ground-glass opacities

ObjectivesGround-glass opacities are typically difficult to inspect and to palpate during video-assisted thoracic surgery. We therefore examined whether ultrasonographic assessments could localize ground-glass opacities and help to achieve adequate resection margins.MethodsAn intraoperative ultrasonographic procedure was prospectively performed on 44 patients harboring ground-glass opacities of less than 20 mm in diameter to localize these lesions and to achieve adequate margins. We also examined whether there were any complications resulting from the intraoperative ultrasonogram, such as lung injury, heart injury, or arrhythmia. We excluded patients with both asthma and chronic obstructive pulmonary disease from this study inasmuch as the intraoperative ultrasonographic procedure is more difficult to interpret when residual air is present in the lung.ResultsA total of 53 ground-glass opacities were successfully identified by intraoperative ultrasonography without any complications. Of the 20 mixed ground-glass opacities that we examined, 15 were found on palpation. However, only 4 (12.1%) of the 33 pure ground-glass opacities could be palpated. In all instances in which complete collapse of the lung was achieved (30/53 of these cases), high-quality echo images were obtained. Additionally, a strong correlation was found between the resection margins measured by ultrasonogram and the margins determined by histologic examination in the resected lung specimens (r2 = 0.954, P < .001).ConclusionsIntraoperative ultrasonography can both safely and effectively localize pulmonary ground-glass opacities in a completely deflated lung. This procedure is also useful for the evaluation of surgical margins in a resected lung. Hence, ultrasonography may assist surgeons to perform minimally invasive lung resections with clear surgical margins during the treatment of solitary lung ground-glass opacity

Analysis of the imaging and clinical features of subsolid pulmonary nodules in stage IA non-small cell lung cancer

The subsolid pulmonary nodules (SSPNs) in the imaging diagnosis of stage IA non-small cell lung cancer (NSCLC) is very important since they are closely related to early lung cancer. The CT imaging and pathology data of 230 patients with solitary pulmonary nodules (SPNs) who underwent thoracoscopic treatment at Guizhou Provincial People’s Hospital between July 2021 and June 2022 were collected. Based on postoperative pathology, the patients were divided into a benign group and a stage IA NSCLC group. The imaging and clinical features of SPNs in stage IA NSCLC were analysed. A total of 230 patients with SPNs were enrolled. There were 146 cases of SSPNs (including 34 cases of pure ground-glass opacities (pGGOs) and 112 cases of mixed GGOs (mGGOs)), and the incidence rate was significantly higher in the stage IA NSCLC group than in the benign group [96.7% (146/151) vs. 74.7% (59/79), P&lt;0.05]. The overall malignancy rate of subsolid nodules was 71.2% (146/205); the malignancy rate of mGGO lesions was higher (75.2%) than that of pGGO lesions (60.7%) and solid nodules (20%). Malignant subsolid nodules mostly occurred in middle-aged women, mostly in the upper lobe of the lungs, with unclear edges and lobular signs, and accompanied by spur signs and pleural indentation signs (P&lt;0.05). SSPNs are an important sign of lung cancer, and mGGO lesions have the highest malignant tendency. CT imaging findings such as unclear lesion edges, lobular signs, and pleural indentation signs are important for determining benign and malignant SSPNs. CT imaging manifestations are helpful for correctly assessing the nature of early SSPNs so that patients can receive timely and effective treatment