Color Doppler US Pulmonary Artery Vessel Signal: A Sign for Predicting the Benign Lesions

Abstract

The lung cancer blood supply originates from the bronchial artery. If vessel signals within pulmonary lesions can be confirmed to be those of the pulmonary artery, color Doppler ultrasound (US) should be able to predict and differentiate benign lesions from lung cancers. Two hundred sixty-four patients with abutting thoracic lesions (including 125 lung cancers and 139 benign lesions) underwent color Doppler US examinations. A pulsatile flow, with the vessel signal length on sonographic appearance ≥1 cm demonstrated by color Doppler US, was arbitrarily defined as a pulmonary artery vessel signal. Of the 264 thoracic lesions, 73 (58%) lung cancers and 107 (77%) benign lesions had detectable color Doppler US pulsatile flow vessel signals. Analyzing the pulsatile flow vessel signals, the color Doppler US pulmonary artery vessel signal was present in 74 (53%) benign lesions, but was found in only two (2%) lung cancers of a specific alveolar cell carcinoma with lobar consolidation. Using the pulmonary artery vessel signal, color Doppler US can be valuable in predicting and differentiating benign lesions from lung cancers (p < 0.0001, sensitivity = 0.53, specificity = 0.98 and positive likelihood ratio 26.5). In conclusion, color Doppler US pulmonary artery vessel signal sign is useful in predicting and differentiating benign lesions from lung cancers. (E-mail: [email protected])

Introduction

Image [fluoroscopy, computed tomography (CT), ultrasound (US)]-guided percutaneous transthoracic needle biopsy is a well-documented technique for diagnosing thoracic tumors (Ikezoe et al 1990, Yang et al 1992). For malignant tumors or lung cancers, the diagnostic yields of image-guided percutaneous transthoracic needle biopsy are all ≥90% in published papers (Ikezoe et al 1990, Yang et al 1992). Nevertheless, some pulmonary benign lesions are difficult to diagnose accurately by image examinations alone and/or by image-guided percutaneous needle biopsy. Clinically, it is very important to determine the nature of thoracic lesions to make an appropriate therapeutic decision. Therefore, in the case of benign pulmonary lesions, especially lesions mimicking lung cancers, some semi-invasive or invasive procedures, such as thoracoscopic biopsy or surgical resection, are sometimes necessary to make a confirmative diagnosis and to exclude the possibility of lung cancers.

Lung cancers are always supplied by the bronchial artery system. Thus, previously pulmonary and bronchial angiograms were used to diagnose and differentiate lung cancers from benign lesions (Lyons and Vertova 1958, Ney et al 1972, Viamonte 1965). Among the imaging modalities used in chest medicine, color Doppler ultrasound (US) has been applied to assess the vessel signals in thoracic lesions (Gorg et al 2003, Gorguner et al 2003, Hsu et al 1998, Hsu et al 1996, Yuan et al 2000). Thus, from our viewpoint and experience, color Doppler US, being able to assess the vessel signals of thoracic lesions, should be able to predict and differentiate benign lesions from lung cancers.

Herein, we describe our findings regarding the clinical application of the color Doppler US pulmonary artery vessel signal. Color Doppler US pulmonary artery vessel signal is defined as a pulsatile flow, with the vessel signal length on sonographic appearance ≥1 cm demonstrated smoothly by color Doppler US. Using this pulmonary artery vessel signal, color Doppler US can easily and quickly predict and differentiate pulmonary benign lesions from lung cancers with high specificity and without any risk.