Preface

In the past 20 years, remarkable technologic advances in CT imaging have revolutionized noninvasive imaging of all thoracic structures, including the airways. CT has assumed a central position in the modern management of both focal and diffuse airway diseases. The combination of thin collimation and helical acquisition during a single breath-hold at full inspiration multidetector CT (MDCT) provides high-resolution volumetric data sets that allow the generation of high-quality multiplanar and three-dimensional images of the airways. Accurate assessment and anatomical display of proximal and distal airways are routinely obtained. In addition, dynamic acquisition during a forced expiratory maneuver is highly appreciated to detect and assess obstruction on small airways and abnormal collapse of large airways.

Nowadays, MDCT is used not only to detect neoplastic and non-neoplastic endotracheal and endobronchial lesions and to assess the extent of tracheobronchial stenosis for planning treatment and follow-up, but also to diagnose and assess the extent of bronchiectasis and small-airway disease, and, in addition, to detect bronchial fistula, cysts, or dehiscences.

In parallel, there have also been important advances in diagnostic and interventional bronchoscopy and surgery. In this respect, the information provided by CT has become increasingly essential for establishing accurate diagnoses, for guiding and planning procedures, and for assessing response to therapy. Recent improvement in image analysis techniques has made possible accurate and reproducible quantitative analysis of airway wall and lumen areas, as well as lung volume and attenuation, leading to better insights in physiopathology of obstructive lung disease, particularly chronic obstructive pulmonary disease and asthma.

The authors of this issue of Radiologic Clinics of North America were chosen for their focused expertise in airway imaging. I thank those chest radiologists for sharing their experience and insights to provide a comprehensive update on practical imaging for airway disease. While high-resolution CT and MDCT have tremendously improved our ability to assess large- and small-airway diseases, I anticipate even more developments in the future. Rapid-volume scanning and new postprocessing techniques may promote sophisticated functional imaging and advanced interventions. MR imaging in this respect may become an additional modality to MDCT.