Objective To explore the clinical diagnostic value of chest CT in identifying tracheobronchial foreign body (TFB) in adults.

Methods A retrospective analysis was conducted on the clinical data of 37 patients diagnosed with TFB via electronic bronchoscopy at Beijing Tiantan Hospital, Capital Medical University, from January 2015 to December 2020. Thirty-seven patients included 28 males and 9 females, aged (56.2±13.2) years. Based on medical history, patients were divided into two groups: the definite foreign body aspiration history group and the no definite foreign body aspiration history group. The positive detection rate and localization accuracy of chest CT for TFB were assessed based on electronic bronchoscopy findings. Differences in CT values and positive detection rates among various types of foreign bodies were statistically compared. Intergroup comparisons of normally distributed measurement data were compared by ANOVA, counting data were analyzed with Fisher′s exact test.

Results  There were 25 cases (67.57%, 25/37) in group with definite foreign body aspiration history, and 12 cases (32.43%, 12/37) in group without definite foreign body aspiration history. Among the patients, 40.54% (15/37) had comorbid neurological disorders, and 78.38% (29/37) exhibited foreign bodies lodged in the right bronchial branches. Compared with electronic bronchoscopy, chest CT demonstrated a positive TFB detection rate of 89.19% (33/37) and a localization accuracy of 84.85% (28/33). No significant difference in CT positive detection rate was found between the definite foreign body aspiration history group (88.00%, 22/25) and the no definite foreign body aspiration history group (91.67%, 11/12) (Fisher′s exact test, P>0.05). The most common CT findings in TFB patients were obstructive pneumonia (64.86%, 24/37), followed by luminal stenosis (21.62%, 8/37), bronchiectasis (13.51%, 5/37), and bronchial wall thickening (5.41%, 2/37). The CT values of different foreign body types in descending order were bones or teeth (496.00±228.89) HU, plastic (136.00±141.08) HU, chili peppers (34.67±21.22) HU, and nuts (28.33±20.98) HU, there were statistical differences in CT values among different types of foreign body (F=9.181, P<0.001). The CT positive detection rates reached 100% for bones or teeth (19/19), plastic (3/3), and metal foreign bodies (2/2), but was lower for nuts (85.71%, 6/7) and chili peppers (50.00%, 3/6), there were statistical differences in CT positive detection rates among different types of foreign body (Fisher′s exact test, P=0.024).

Conclusions Chest CT is highly effective for detecting and localizing TFB in adults. Obstructive pneumonia is the predominant finding. The detection rate of TFB in adults by chest CT may be related to the type of foreign body. Attention should be paid to the fact that plant foreign bodies are easily missed.