Artifacts in Musculoskeletal Ultrasonography

Abstract

).High-resolution ultrasonography (US) has proven to be a powerful diagnostic tool in the evaluation of musculoskeletal trauma including injuries of the tendons, ligaments, muscles, and nerves, as well as musculoskeletal diseases including joint effusions, synovitis, bursitis, articular erosions, joint bodies, soft tissue infections, and soft tissue tumors and tumor-like conditions. It can also diagnose radiographically occult fractures and joint and bone infections. 1 This imaging modality provides results in the diagnosis of musculoskeletal trauma and diseases comparable with MR imaging. 2 Rapid advances in US technologies in the past 10 years have resulted in significant improvement in image quality. Development of a variety of US transducers, compound imaging, improved focusing, and transducers with large and small fields of view are available for different musculoskeletal applications, resulting in better B-mode gray-scale image quality and information from Doppler imaging. AbstractDuring the past 2 decades, high-resolution ultrasonography (US) has been increasingly utilized in the diagnosis of musculoskeletal trauma and diseases with results comparable with MR imaging. US has an advantage over other cross-sectional modalities in many circumstances due to its superior spatial resolution and ability to allow dynamic assessment. When performing musculoskeletal US, the examiner has to be knowledgeable in the complex anatomy of the musculoskeletal system and US imaging technique. Additionally, he or she must be familiar with several common imaging artifacts in musculoskeletal US that may be mistaken for pathology, as well as several artifacts that frequently accompany pathologic conditions. These artifacts may occur with both Bmode gray-scale and Doppler imaging. In this article, we discuss common artifacts seen in musculoskeletal US and techniques to avoid or minimize these artifacts during clinical US examinations.

Musculoskeletal Imaging for Dermatologists: Techniques in the Diagnosis and Management of Psoriatic Arthritis

“…Conventional radiography is the most commonly used imaging technique for assessing structural damage in PsA [12,21]. Radiographs are especially useful in detecting bone erosion [26,44] Unable to detect intraosseous abnormalities due to active enthesitis, such as bone marrow edema [25,79] Assessment of preclinical PsA Nonionizing and noninvasive [26,44] Weak signals and artifacts due to small number of blood vessels in entheses and proximity to bone [32] Visualization of the peripheral joints and entheses for detection of enthesitis and assessment of synovial tissue, joint effusions, and erosions [23,25] Capability of real-time dynamic imaging of multiple joints/ enthuses [26,44] Lack of standardization among different machines [80] Identification of subclinical synovitis and tenosynovitis [25] Operator must be familiar with imaging artifacts that can cause misinterpretation or be mistaken for pathology [50,51] Measurement of abnormal vascularization (indicator of active inflammation) [31] Differentiation of subclinical enthesitis [14] and/or new bone formation, which tend to be seen in later stages of the disease, and can help visualize soft tissue swelling suggestive of dactylitis (Fig. 1) [12,22].…”

“…Another consideration is that the ultrasound examiner must be knowledgeable about imaging artifacts that can frequently occur. These artifacts can cause visualization of nonexistent structures or nonvisualization of existent structures and can also alter size, location, and brightness; this can lead to misinterpretation of results or mimic pathology in normal structures [ 50 ]. For example, fibrillary linear structures such as tendons or ligaments can appear hypoechoic if the ultrasound beam is not perpendicular during visualization; this could be misinterpreted as tendonitis or tears [ 51 ].…”

Diagnostic Utility of Superb Microvascular Imaging and Power Doppler Ultrasonography for Visualizing Enriched Microvascular Flow in Patients With Carpal Tunnel Syndrome

“…We found that both PDUS and SMI detected an increased blood flow signal in the CTS group, while CDUS did not. This limitation of CDUS may relate to artifacts such as the blooming effect ( 30 , 31 ), which can cause the relatively higher blood flow signal area in the control group compared with PDUS and SMI. We also found that the blood flow signal area measured using SMI had a relatively stronger correlation with the median nerve compression ratio and neuropathy severity (measured by NCS) compared with PDUS.…”

Artifacts in Musculoskeletal Ultrasonography: From Physics to Clinics

“…For instance, concerning nerve entrapment [ 15 ], measurement of the cross-sectional area is crucial for diagnosis. If the focal zone is not placed at the right depth, the epineurium will appear blurred [ 16 ]. Another example is imprecise differentiation of the neural fascicle of the deep radial nerve from the connective tissues in the supinator tunnel when the target/focus is placed at the far field ( Figure 2 B).…”