Bronchoscopic Ultrasonography in the Diagnosis of Lung Cancer

An ultrasonic bronchoscope has been newly developed for diagnosisand lymph node staging in the hilum and mediastium. The instrumentcomprises an Echo-camera, SSD-630 (Aloka), and a transbronchialultrasonic probe similar to the currently used videobronchoscope.The scope is equipped with an ultrasonic transducer in its tip.The maximum diameter of the probe head is 6.3 mm and that ofthe transducer, 5.0 mm. The frequency employed is 7.5 Megahertz(MHz) and the direction of scanning is parallel to the bronchoscopicaxis. The device can easily be introduced into the lobar bronchusunder topical anesthesia in a similar procedure to that usedfor routine videobronchoscopy. The location of the transducerin the airway is confirmed by monitoring endoscopic images ona TV monitor screen. With the device, 25 patients, who had giventheir consent for the ultrasonographic study beforehand, wereexamined during the twomonth period, January and February, 1992.Vessels such as the thoracic aorta, pulmonary artery and truncusbrachiocephalicus were good landmarks for diagnosis. Lung cancerwas detected in five patients by biopsy, three malignant lesionsin the hilum were diagnosed by videobronchoscopy while two malignantlesions in the periphery were confirmed by bronchoscopic ultrasonographyas anterior mediastinal lymph node swellings.