White, Darin B

Abstract OBJECTIVES The aim of this study is to evaluate the efficacy of chest computed tomography (CT) to predict the pathological stage of thymic epithelial tumours (TET) using the recently introduced tumour, node and metastasis (TNM) staging with comparison to the modified Masaoka staging. METHODS Preoperative chest CT examinations in cases of resected TET with sampled lymph nodes (2006–2016) were retrospectively reviewed by 2 thoracic radiologists and radiologically (r) staged using both staging systems. A thoracic pathologist reviewed all cases for the pathological (p) stage. Concordance between r-staging and p-staging was assessed by % agreement and unweighted kappa statistics. Associations between r-stage and p-stage with outcomes were assessed using the Cox proportional hazards regression. RESULTS Sixty patients with TET were included (47 thymomas, 12 thymic carcinomas and 1 atypical carcinoid tumour). Sixteen patients (26.7%) had received neoadjuvant therapy. Fifty-four patients (90.0%) had complete resection. The overall agreement between the r-stage and p-stage was 66.7% (κ = 0.46) for TNM staging and 46.7% (κ = 0.30) for modified Masaoka staging. Agreement between r-assessment and p-assessment of the T, N and M components of the TNM stage was 61.7% (κ = 0.28), 86.7% (κ = 0.48) and 98.3% (κ = 0.88), respectively. CT overstaged 12 patients (20.0%) for TNM staging and 12 patients (20.0%) for modified Masaoka staging and understaged 8 (13.3%) and 20 (33.3%) patients for TNM staging modified Masaoka staging, respectively. The r-TNM staging accuracy was lower for patients with neoadjuvant therapy (50.0% with vs 72.7% without). During a median follow-up of 2.6 years (range 0.1–10.5 years), 12 patients had metastases and/or recurrence; 11 patients died (4 of disease). The r-TNM stage and modified Masaoka stage were associated with overall survival and progression-free survival (P < 0.001). CONCLUSIONS Preoperative chest CT is able to accurately predict p-TNM stage in two-thirds of surgically resected TET, with an agreement between radiological staging and pathological staging superior to the modified Masaoka staging.

Purpose: Differentiating between systemic sclerosis-related interstitial lung disease (SSc-ILD) and idiopathic pulmonary fibrosis (IPF) is important because of the differences in workup, prognosis, and treatment. However, there is much overlap in the appearance of these 2 entities on high-resolution computed tomography. We propose that inflammation and/or fibrosis focally or disproportionately involving the bilateral anterolateral upper lobes and posterosuperior lower lobes [“Four Corners” Sign (FCS)] is specific for SSc-ILD. Materials and Methods: Randomized high-resolution computed tomography studies from 74 IPF and 73 SSc-ILD cases were evaluated by 2 thoracic radiologists blinded to all patient data. For each case the reviewers noted whether the FCS was present and assigned a confidence level on the basis of a 7-point Likert scale. The same process was then performed on a randomized external validation group of 42 SSc-ILD and 42 IPF cases. Results: For Likert scores of 6 or 7 (“mostly agree” or “entirely agree” that the FCS is present, respectively) the sensitivity in SSc was 16.4% (95% confidence interval, 9.7%, 26.6%), specificity 100.0% (95% confidence interval, 95.1%, 100.0%). There was a significant association between a confidently present FCS and SSc compared with a confidently present FCS and IPF (P=0.0003). Analysis on an external validation group of 42 SSc and 42 IPF cases conferred similarly high specificity for SSc in cases characterized as FCS with high confidence. Conclusion: The FCS, a pattern of focal or disproportionate inflammation and/or fibrosis involving the bilateral anterolateral upper lobes and posterosuperior lower lobes, is specific for SSc-ILD when readers are confident of its presence.

Despite its nonionizing technique and exquisite soft tissue characterization, noncardiovascular, and nonmusculoskeletal magnetic resonance imaging (MRI) of the chest has been considered impractical due to various challenges such as respiratory motion, cardiac motion, vascular pulsatility, air susceptibility, and paucity of signal in the lung. With advances in MRI, it is now possible to perform diagnostically useful and good quality MRIs of the chest, but literature on subspecialized chest MRI practices is limited. The purpose of this manuscript is to describe the rationale, nuances, and logistics that went into developing such a practice in the Division of Thoracic Radiology at our institution. The topics addressed include technical and clinical considerations, support at administrative and clinical levels, protocol development, and economic considerations compared with conventional practices. Various MRI techniques are also specifically discussed to facilitate chest MRI at other sites. Although chest MRI is used in a relatively small number of patients at this point, in certain patients, chest MRI can provide additional information to optimize medical management. A few clinical cases illustrate the quality and clinical utility of chest MRI. Given recent advances in MRI techniques, it is now an opportune time to develop a chest MRI practice.