Pulmonary Densitovolumetry Using Computed Tomography in Patients with Nontuberculous Mycobacteria: Correlation with Pulmonary Function Tests

Abstract

Background. Since nontuberculous mycobacterial pulmonary disease (NTM-PD) is a condition with increasing morbidity, a more detailed knowledge of radiological aspects and pulmonary function plays a relevant role in the diagnosis and appropriate therapeutic management of these patients. Objectives. The purpose of this study was to evaluate changes in lung parenchyma through computed tomography (CT) densitometry and, secondarily, to analyze its correlation with pulmonary function testing (PFT) in patients with NTM-PD. Methods. This is a cross-sectional study in which 31 patients with NTM-PD and 27 controls matched by sex, age, and body mass index underwent CT pulmonary densitovolumetry and pulmonary function tests including spirometry and body plethysmograph. Results. Based on the total lung volume (TLV) and total lung mass (TLM) measurements, the cumulative mass ratios were calculated for 3% (M3), 15% (M15), 85% (M85), and 97% (M97) of the TLV. We also calculated the complement, which is represented by TLM (100%) minus the mass of 15% (C85) or 3% (C97) of the TLV. Patients with NTM-PD presented lower values ​​of M3 and M15 than controls, with greater significant differences in the apical third and middle third measurements. Compared to controls, patients with NTM-PD showed higher values ​​of C85 and C97, although significant differences were observed only in the basal third measurements. There were negative correlations of total lung capacity with M3 and M15 in the middle third and apical third measurements. There were positive correlations of residual volume and airway resistance with M3 at the apical third measurement. Conclusions. Patients with NTM-PD show reduced lung mass and increased lung mass in the apical and basal regions of the lungs, respectively. Furthermore, there is a relationship between lung mass measurements and pulmonary function parameters.

The thickness of erector spinae muscles can be easily measured by computed tomography for the assessment of physical activity: An observational study

“…In some patients who are difficult to treat by chemotherapy, surgical treatment should be considered. [ 20 , 36 ] Patients with NTM pulmonary diseases showed lower FVC and FEV 1 values than healthy controls, [ 37 ] and the disease severity can affect body weight and nutrition status. [ 38 ] In our study, the physical activity of patients with NTM pulmonary diseases might be related to skeletal muscle mass.…”

Radiology of Bronchiectasis

“…Upper lobes 14 Upper lobes 15 Nontuberculous mycobacterial disease LML, RML and RUL 16 Upper lobes 17 RUL, RML and LML 13 RUL, RML and LML 18 Primary ciliary dyskinesia RML, middle and lower lobes 19 LML 20…”

Non-tuberculous mycobacterial lung disease: a brief review focusing on radiological findings

“…The loss of lung mass volume is also a characteristic that is frequently identified among the radiological findings of patients with lung diseases. De Marca et al (2019) suggested that there is a relationship between mass and lung functions, however, this relationship is not yet fully elucidated 53 . Although all the findings described above are not specific towards a definitive NTM-LD diagnosis, it is described in the literature that the disease form with nodular infiltrates and bronchiectasis frequently affects the middle lobe and lingula regions 37,41 .…”

“…The loss of lung mass volume is also a characteristic that is frequently identified among the radiological findings of patients with lung diseases. De Marca et al (2019) suggested that there is a relationship between mass and lung functions, however, this relationship is not yet fully elucidated 53 .…”