Clinical Applications of Color Doppler Ultrasound in Chest Medicine

The wide application of recent advances in chest ultrasound has enabled color Doppler ultrasound (CDUS) to be used in evaluating thoracic lesions. Clinically, CDUS is helpful in assessing vessel signals within the thoracic lesions, differentiating lung cancers from benign lesions, assessing the neovascularity of lung cancers, diagnosing congenital vascular abnormalities (pulmonary sequestration and arteriovenous malformation), and avoiding the complication of US-guided needle biopsy injury to the great vessels. The CDUS “fluid color sign” can be used to detect minimal pleural effusion in thoracocentesis, and the CDUS “pulmonary artery vessel signal” is useful in predicting pulmonary benign lesions. Though CDUS still has some limitations in its capability to image vessel signals, the development of power Doppler US (US angiography) has improved images of vessel signals without angle limitation, and the newly developed dynamic flow US produces superior imaging quality with less color noise and blooming effect. The broad application and potential extension of CDUS in thoracic diseases has made CDUS a powerful and necessary imaging modality in chest medicine, especially in guiding transthoracic percutaneous needle biopsy of thoracic lesions and aiding in the differentiation of anatomic tissue.