Introduction

This introductory chapter provides an overview of history and evolution of diagnostic and interventional pulmonology. It also provides an insight into the future development that are on the way to further refine the technique to provide maximum benefit in patient care. This chapter highlights about endobronchial ultrasound (EBUS) which combines traditional bronchoscopy with advanced ultrasound technology for real time visualization of airway and surrounding structures. The chapter outlines the anatomy of lymph node, principles of EBUS, clinical applications and its role in guided biopsies and staging. This chapter set the stage for deeper understanding of EBUS by the medical professionals and students.Modern technology has revolutionized the diagnostic and therapeutic aspect of medical sciences. Traditionally, lung and mediastinal lesions were diagnosed using non-invasive, minimally invasive, and surgical approach. It all started with Gustav Killian in 1876 who removed a pork bone from a farmer’s respiratory tract using an esophagoscope. Following his footsteps, Chevalier Jackson laid the milestone for rigid bronchoscope. The era of bronchoscope took a breakthrough when Shigeto Ikeda discovered flexible bronchoscope in the year 1967 which allowed us to investigate the airway mucosa.