Yonago Acta medica 1996;39:183–187
Dynamic Study of the Tracheal Cavity by Fast MRI with Coughing in Patients with Tracheomalacia
Yuji Suto, Shuji Sugihara, Kotaro Yoshida, Takashi Kato, Masayuki Kamba and Yoshio Ohta
Department of Radiology, Faculty of Medicine, Tottori University, Yonago 683, Japan
Fast magnetic resonance imaging (MRI) with coughing was performed in 3 patients with tracheomalacia (TM) and 10 healthy volunteers, and its usefulness was evaluated. Twenty serial images were obtained using two-dimensional-turbo fast low angle shot (FLASH) sequences and the image data were transferred to a graphic workstation connected on-line. The maximum and minimum cross-sectional areas of the trachea were measured during deep breathing (forced expiration and inspiration) and during coughing, and the collapsibility index (CI) = [(maximum cross-sectional area - minimum cross-sectional area)/maximum cross-sectional area] × 100 (%) was calculated. In the healthy volunteers, CI was 36 ± 15% (mean ± SD) during forced expiration and inspiration and 48 ± 15% during coughing, and the difference was not significant. In the TM patients, it was 68 ± 6% and 85 ± 5%, respectively, with the value during coughing being significantly higher (P = 0.019). CI was significantly higher in the TM patients than in the normal volunteers both during forced expiration and inspiration (P = 0.006) and during coughing (P = 0.002). Fast MRI with coughing may facilitate the evaluation of the tracheal collapsibility in TM.
Key words: dynamic study; fast MR imaging; trachea; tracheomalacia
