Volumetric Imaging of Lung Tissue at Micrometer Resolution: Clinical Applications of Micro-CT for the Diagnosis of Pulmonary Diseases

Abstract

Micro-computed tomography (micro-CT) is a promising novel medical imaging modality that allows for non-destructive volumetric imaging of surgical tissue specimens at high spatial resolution. The aim of this study is to provide a comprehensive assessment of the clinical applications of micro-CT for the tissue-based diagnosis of lung diseases. This scoping review was conducted in accordance with the PRISMA Extension for Scoping Reviews, aiming to include every clinical study reporting on micro-CT imaging of human lung tissues. A literature search yielded 570 candidate articles, out of which 37 were finally included in the review. Of the selected studies, 9 studies explored via micro-CT imaging the morphology and anatomy of normal human lung tissue; 21 studies investigated microanatomic pulmonary alterations due to obstructive or restrictive lung diseases, such as chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, and cystic fibrosis; and 7 studies examined the utility of micro-CT imaging in assessing lung cancer lesions (n = 4) or in transplantation-related pulmonary alterations (n = 3). The selected studies reported that micro-CT could successfully detect several lung diseases providing three-dimensional images of greater detail and resolution than routine optical slide microscopy, and could additionally provide valuable volumetric insight in both restrictive and obstructive lung diseases. In conclusion, micro-CT-based volumetric measurements and qualitative evaluations of pulmonary tissue structures can be utilized for the clinical management of a variety of lung diseases. With micro-CT devices becoming more accessible, the technology has the potential to establish itself as a core diagnostic imaging modality in pathology and to enable integrated histopathologic and radiologic assessment of lung cancer and other lung diseases.

Keywords: chronic obstructive lung diseases; interstitial lung diseases; lung cancer; micro-CT; pulmonary imaging.

Figure 1

Flowchart of the systematic scoping review in accordance with PRISMA guidelines [13].

Figure 2

Included study characteristics. (A) Number of scanned specimens according to the topic assessed, (B) Micro-computed tomography scanners utilized, and (C) Geographical distribution of included studies.

Figure 3

Micro-CT imaging of human lung tissue specimens. Resected lung tissue specimen (A) is scanned through micro-computed tomography (micro-CT) scanner (B) and 3D images of high spatial resolution are generated after reconstruction (C). Herein, 3D micro-CT images of terminal bronchioles and pulmonary acini are displayed (C left), in comparison with illustrated CT-derived low attenuation cluster analysis of the airway tree (C right).