Contrast-Enhanced Sonography as Guidance for Transthoracic Biopsy of a Peripheral Lung Lesion with Large Necrotic Areas

In recent years, sonography has gained increasing appreciation as a useful tool for various diseases of the chest and in particular as reliable and safe guidance for transthoracic biopsy of peripheral lung masses. When the lesions are in contact with pleura, sonographically guided percutaneous biopsy is as effective as computed tomographically guided biopsy and offers a number of advantages, such as real-time monitoring of the tip of the needle throughout the procedure and the ability of being performed in bedridden patients. The recent introduction of real-time, low-mechanical-index, contrast-specific sonographic techniques, producing images based on nonlinear acoustic effects of the interaction of ultrasound with microbubble contrast agents, has greatly increased the diagnostic performance of conventional sonography in liver imaging. These techniques enable characterization of several focal liver lesions and detection of lesions that are not depicted on conventional sonography. Moreover, the ability of these techniques to show microcirculation allows imaging of perfused tissues, enabling differentiation of viable from necrotic portions of hepatocellular carcinoma lesions. Although most studies about these new contrast-specific techniques have been focused on the liver, promising results have also been reported in other areas, such as the kidney and breast. We report a case in which contrast-enhanced sonography played a key role as guidance for successful percutaneous biopsy of a peripheral lung lesion after conventional sonographically guided biopsy failed in yielding adequate and diagnostic sampling.