Ultrasonography has multiple advantages over traditional radiologic imaging modalities when used for interventional procedures. It allows improved visualization of the anatomy while avoiding ionizing radiation and risks associated with contrast use. It has proved superiority at accuracy of delivery and procedural effectiveness over blind procedures when used in association with interventional pain procedures. Although limited in its ability to see through bony structures, ultrasound has utility in visualizing soft tissues and vascular structures in anatomic regions of interest resulting in increased use for posterior neuraxial, periaxial, peripheral nerve and joint-related structures. Current evidence for use in these settings is presented here. In some cases, optimal utility may be improved by combining ultrasonography with other imaging modalities.
KEYWORDS• chronic pain management
Advantages of ultrasound imagingInterventional pain procedures were traditionally performed under fluoroscopic (FS), computed tomography (CT) or MRI guidance. The use of ultrasound (US) to perform injections for chronic pain has significantly increased in the past decade [1,2]. This increase is attributed to its multiple advantages over other imaging modalities including ease of performance, absence of ionizing radiation, better visualization of soft tissue (i.e., muscle, ligament) and blood vessels, real time visualization of needle advancement and, at times, the ability to observe the spread of injectate [3]. US
Practice points• Use of ultrasound in medicine has grown with smaller size equipment, increased portability and decreased cost.• Ultrasound has multiple advantages over radiographic imaging when used for interventional pain procedures.• Sonography is useful for medial branch blocks and intra-articular facet blocks in the cervical and lumbar spine but there is little evidence to support its use in the thoracic spine.• Ultrasonography is limited in utility for many types of axial injections because of bony and acoustic shadowing artifact but it does show some promise with transforaminal epidurals or selective nerve root blocks.• Ultrasound guidance is effective in preventing soft tissue and vascular injury in stellate ganglion blocks compared with blind techniques. Soft tissue and vascular anomalies can be identified that fluoroscopic technique will miss.• Ultrasound improves accuracy and efficacy in ilioinguinal, iliohypogastric and genitofemoral blocks for inguinal and testicular pain.• Lateral femoral cutaneous nerve injections are more accurate under ultrasound guidance, especially given the anatomic variation the nerve exhibits in cadaver dissections.• Injections into the knee, shoulder and hip joints are more successful when performed using ultrasound.For reprint orders, please contact: reprints@futuremedicine.com