Ultrasound Artifacts Classification, Applied Physics With Illustrations, and Imaging Appearances Somnath J. Prabhu, MD,* Kalpana Kanal, PhD,Þ Puneet Bhargava, MD,þ Sandeep Vaidya, MD,§ and Manjiri K. Dighe, MDþ Abstract: Ultrasound has become a widely used diagnostic imaging modality in medicine because of its safety and portability. Because of rapid advances in technology, in recent years, sonographic imaging quality has significantly increased. Despite these advances, the potential to encounter artifacts while imaging remains. This article classifies both common and uncommon gray-scale and Doppler ultrasound artifacts into those resulting from physiology and those caused by hardware. A brief applied-physics explanation for each artifact is listed along with an illustrated diagram. The imaging appearance of artifacts is presented in case examples, along with strategies to minimize the artifacts in real time or use them for clinical advantage where applicable. Key Words: ultrasound, artifacts, physics, Doppler, illustrations (Ultrasound Quarterly 2014;30:145Y157)
ltrasonography has become an indispensible and widely used modality in diagnostic imaging because of its safety, portability, and cost-effectiveness.1 Gray-scale ultrasound provides cross-sectional imaging information without the use of ionizing radiation. Doppler evaluation of hemodynamics provides useful information regarding the presence or the absence of blood flow, flow direction, and velocity, and spectral wave-form analysis allows for evaluation of blood flow parameters over time. In recent years, sonographic image quality has significantly been enhanced by the use of all-digital high-frequency transducers, harmonic imaging, and spatial compounding.2 Despite these advances, the potential to encounter imaging artifacts, which can confound image interpretation, remains. Moreover, some of these advances themselves produce unique artifacts. The ultrasonologist should be aware of them and recognize when they occur. Understanding the physics principles behind imaging artifacts will enable the ultrasonologist to capture artifactfree images and, in many cases, use these artifacts to make a clinical diagnosis.
Received for publication May 8, 2013; accepted August 4, 2013. *Department of Radiology, †Department of Radiology, Division of Diagnostic Physics, ‡Department of Radiology, Division of Body Imaging, and §Department of Radiology, Division of Interventional Radiology, University of Washington, Seattle, WA. The authors declare no conflict of interest. Reprints: Manjiri K. Dighe, MD, Department of Radiology, Division of Body Imaging, University of Washington, 1959 NE Pacific St, Seattle WA 98195 (e