Analysis of the Internal Structure of Peripheral Pulmonary Lesions Using Endobronchial Ultrasonography: Methods and Equipment
Correlation Between the Preoperative EBUS Images and the Histopathologic Findings: Bronchoscopy was performed with a flexible bronchoscope under local anesthesia without sedation. The miniature probe was inserted into bronchi that were suspected to lead to the lesions visualized by plain roentgenography or CT scanning. The probe was introduced up to the point at which the operator felt resistance to further advancement of the probe, and scanning was performed while the probe was withdrawn to obtain EBUS images. Surgery specimens were fixed in formalin and cut into 2-mm-thick slices, and the EBUS findings were correlated with the histopathology or hematoxylin-eosin-stained specimens to identify the anatomy that produced the EBUS images.
Typing of 124 Lesions Based on the Internal Structure by EBUS: Peripheral pulmonary lesions were classified based on their internal structure, focusing on internal echoes and the architecture of blood vessels, bronchi, and hyperechoic patterns.
Images of the peripheral pulmonary lesion also were obtained by high-resolution CT (HRCT) scanning. Anti allergy Source The HRCT scanning technique uses 2-mm collimation, a sharp algorithm, a 120-kV peak, 250 mA/s, and a 2-s scan. HRCT scanning was started 60 s after the continuous infusion of contrast material (2 mL/s) was initiated. Informed consent was obtained from all the subjects.
EBUS was performed using an endoscopic ultrasound system (EU-M30; Olympus; Tokyo, Japan) equipped with a 20-MHz mechanical radial probe with an external diameter of 2.5 mm (UM-3R; Olympus) or 2.0 mm (UM-4R; Olympus) [Fig 1].
Beyond the level of the subsubsegmental branches, the probe, with the external diameter of 2.5 mm, came in contact with the inner surface of the bronchus circumferentially, making the use of a balloon (which is needed for the central bronchi) unnecessary. The peripheral bronchi were flexible enough to allow the probe to be guided easily into the subpleural regions. In cases in which the lesions were in S1 or S1 + 2, the hard tip of the 2.5-mm probe was too long, making it difficult to insert this probe into right B1 or left B1 + 2, which have sharp bifurcation angles. In these cases, it was easier to advance the 2.0-mm probe.
Figure 1. A miniature probe. This probe is a 20-MHz mechanical radial type with an external diameter of 2.5 mm (UM-3R; Olympus) or 2.0 mm (UM-4R; Olympus).