Computed Tomography in Adults with Bronchiectasis and Nontuberculous Mycobacterial Pulmonary Disease: Typical Imaging Findings

Sabine Dettmer,Jan Fuge,Felix C Ringshausen,Tobias Welte,Jessica Rademacher,Hannah Louise Maske,Frank Wacker

doi:10.3390/jcm10122736

Abstract

Among patients with bronchiectasis, nontuberculous mycobacterial pulmonary disease (NTM-PD) ranged between 1 and 6% and it is suspected that its prevalence is underestimated. Our aim was to evaluate differences in computed tomography (CT) features in patients with bronchiectasis, with and without NTM-PD, in order to facilitate earlier diagnosis in the future. In addition, we evaluated longitudinal changes after successful NTM-PD treatment. One hundred and twenty-eight CTs performed in adults with bronchiectasis were scored for the involvement, type, and lobar distribution of bronchiectasis, bronchial dilatation, and bronchial wall thickening according to Reiff. In addition, associated findings, such as mucus plugging, tree-in-bud, consolidations, ground-glass opacities, interlobular thickening, intralobular lines, cavities, and atelectasis, were registered. Patients with NTM-PD (n = 36), as defined by ATS/IDSA diagnostic criteria, were compared to bronchiectasis patients without NTM-PD (n = 92). In twelve patients with an available consecutive CT scan after microbiological cure of NTM-PD imaging findings were also scored according to Kim and compared in the course. In patients with NTM-PD, there was a higher prevalence of bronchiectasis in the middle lobes (p < 0.001), extended bronchiolitis (p = 0.032) and more small and large nodules (p < 0.001). Furthermore, cavities turned out to be larger (p = 0.038), and walls thickened (p = 0.019) and extended (p = 0.016). Patients without NTM more often showed peripheral ground-glass opacities (0.003) and interstitial changes (p = 0.001). CT findings decreased after successful NTM-PD treatment in the follow-up CT; however, without statistical significance for most features (p = 0.056), but bronchiolitis was the only significantly reduced score item (p = 0.043). CT patterns in patients with bronchiectasis and NTM-PD differ from those of patients with bronchiectasis without NTM-PD, although the findings are non-specific radiological features. Follow-up CT findings after microbiological cure differed interindividual regarding the decline in imaging features. Our findings may help practitioners to identify NTM-PD in patients with bronchiectasis. Further research is needed regarding the use of CT as a potential imaging biomarker for the evaluation of treatment response.

Highlights

Introduction distributed under the terms andNontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause opportunistic infection in humans [1]
0.42 in the left lower lobe/0.56 in the right lower lobe in patients with vs. 1.11/1.14 in patients without nontuberculous mycobacterial pulmonary disease (NTM-PD), both p < 0.001) and bronchial dilatation
The lobar distribution differed significantly between patients with and those without NTM-PD: bronchiectasis in patients with NTM-PD was found predominantly in the middle lobe (56% of patients with versus 13% of patients without NTM-PD, p < 0.001), whereas non-NTM bronchiectasis was found predominantly in the lower lobes (25% of patients with versus 55 % of patients without NTM-PD, p = 0.002) (Table 3)

Summary

Introduction

Nontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause opportunistic infection in humans [1]. Due to NTM (NTM-PD), is a rare, chronic, and slowly progressive disease [1]. The most common species that causes this disease is mycobacterium avium complex (MAC), followed by mycobacterium conditions of the Creative Commons. The incidence of NTM-PD is expected to increase worldwide. In the USA, incidence increased from 3.13 per 100,000 in 2008 to 4.73 per 100,000 in 2015, among women and older age groups [2]. The use of a machine learning-based algorithm applied to German statutory health insurance claims data predicted a 9-fold increase in incidence rates, suggesting that a relevant number of patients with NTM-PD remains undetected [3]

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