ABSTRACT
OBJECTIVE: To study the morphological alteration of the diaphragm with three-dimensional reconstruction in patients with chronic obstructive pulmonary disease (COPD), and to evaluate the relationship between morphological parameters and pulmonary function. METHODS: Subjects were consecutively recruited in Shanghai East Hospital of Tongji University from July 2010 to April 2011. They were divided into a COPD (30 males) group, including mild (n = 10), moderate (n = 10), and severe/very severe (n = 10), and a control group (20 males); with the age of the subjects ranging from 45 to 80 years old. The subjects were asked to take pulmonary function test. Each subject underwent CT scanning in residual volume (RV) and total lung capacity (TLC) phases. The imaging of CT scanning was used to reconstruct three-dimensional diaphragm with the special computer software. The length of total diaphragm (Ldi), including the part of the zone apposition (Lap) and part of the dome (Ldo) under coronal (C) and sagittal (S) were observed. The surface area of the diaphragm (Adi), surface area (Aap) of the zone of apposition and surface area (Ado) of the dome were measured as well. In addition, the relationship between morphological indexs and pulmonary function were evaluated. RESULTS: In RV phase, compared with the control, Ldi and Lap were significantly lower in COPD, S-Ldi: (23.3 ± 2.9) cm vs (31.1 ± 4.3) cm (t = 4.12, P < 0.05); S-Lap: (5.4 ± 1.9) cm vs (12.7 ± 2.0) cm, (t = 6.96, P < 0.05); the difference was more obvious in sagittal slices as compared to the coronal slices. The reduction of S-Ldi was more pronounced in the part of S-Lap. In RV phase, Adi and Aap were also significant lower in COPD, Adi: (571 ± 119) cm(2) vs (811 ± 95) cm(2) (t = 4.06, P < 0.05). Aap: (270 ± 99) cm(2) vs (471 ± 61) cm(2) (t = 4.33, P < 0.05). Aap decreased more significantly, and accounted for the most part of reduction of Adi. There was a significant positive correlation between Aap and S-Lap with pulmonary function (r = 0.577 - 0.787, all P < 0.05), especially for Aap (r = 0.787). In TLC phase, only C-Ldi and C-Lap decreased significantly (t = 3.08, t = 2.80 respectively, all P < 0.05). CONCLUSIONS: The diaphragmatic length and surface area decreased in patients with COPD, which were more pronounced in the part of the zone of apposition and occurred during RV phase. The dimension of the zone of apposition could be a parameter to reflect the severity of the disease.
