Physics of Ultrasound
KEY POINTS • Ultrasonic waves are elastic, mechanical waves. • Ultrasound imaging is safe and noninvasive. • Imaging provides real-time visualization. • Contrast imaging improve vascular detection. Characteristics of Ultrasound…
Purchasing Ultrasound Equipment
KEY POINTS • Consider the range of clinical indications first when selecting an ultrasound system. • The nature and location of your practice dictate the selection of stationary, mobile, or…
Pitfalls in Doppler Ultrasound
KEY POINTS • Common artifacts related to machine settings are focusing, random noise, aliasing, motion, blooming, and mirroring. • A common artifact related to the surrounding tissue is reverberation. •…
Anatomy for Needle Electromyography
Upper Extremity Median Nerve Abductor Pollicis Brevis (APB) ( Figure 13–1A,B ) Innervation: * All cross-section anatomy figures adapted from: A Cross-Section Anatomy by Eycleshymer & Schoemaker, D Appleton Century…
Basics of Electricity and Electronics for Electrodiagnostic Studies
In the office, hospital, and home, we are surrounded by equipment, appliances, and many other devices powered by electricity. Although knowledge of electricity and electronics is not needed to watch…
Lumbosacral Plexopathy
The anterior rami of the L1–S3 roots come together to form the lumbosacral plexus, from which all major lower extremity nerves are derived. Disorders of the lumbosacral plexus are distinctly…
Proximal Neuropathies of the Shoulder and Arm
Electromyographers occasionally are called on to evaluate the proximal nerves in the shoulder and arm. Isolated lesions of these nerves, including the suprascapular, axillary, musculocutaneous, long thoracic, and spinal accessory,…
Neuromuscular Junction Disorders
Disorders affecting the neuromuscular junction (NMJ) are among the most interesting and rewarding seen in the electromyography (EMG) laboratory. These disorders are generally pure motor syndromes that usually preferentially affect…
