Preoperative assessment of pleural adhesion by Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) with Adaptive Iterative Dose Reduction using Three-Dimensional processing (AIDR-3D)

Abstract Purpose To assess the feasibility of Four-Dimensional Ultra-Low-Dose Computed Tomography (4D-ULDCT) for distinguishing pleural aspects with localized pleural adhesion (LPA) from those without. Methods Twenty-seven patients underwent 4D-ULDCT during a single respiration with a 16 cm-coverage of the body axis. The presence and severity of LPA was confirmed by their intraoperative thoracoscopic findings. A point on the pleura and a corresponding point on the outer edge of the costal bone were placed in identical axial planes at end-inspiration. The distance of the two points (PCD), traced by automatic tracking functions respectively, was calculated at each respiratory phase. The maximal and average change amounts in PCD (PCD MCA and PCD ACA ) were compared among 110 measurement points (MPs) without LPA, 16 MPs with mild LPA and 10 MPs with severe LPA in upper lung field cranial to the bronchial bifurcation (ULF), and 150 MPs without LPA, 17 MPs with mild LPA and 9 MPs with severe LPA in lower lung field caudal to the bronchial bifurcation (LLF) using the Mann-Whitney U test. Results In the LLF, PCD ACA as well as PCD MCA demonstrated a significant difference among non-LPA, mild LPA and severe LPA (18.1 ± 9.2, 12.3 ± 6.2 and 5.0 ± 3.3 mm) ( p   0.05). Also in the ULF, PCD ACA showed a significant difference among three conditions (9.2 ± 5.5, 5.7 ± 2.8 and 2.2 ± 0.4 mm, respectively) ( p MCA for mild LPA was similar to that for non-LPA (12.3 ± 5.9 and 17.5 ± 11.0 mm). Conclusions Four D-ULDCT could be a useful non-invasive preoperative assessment modality for the detection of the presence or severity of LPA.