Sonography of Common Peripheral Nerve Disorders With Clinical Correlation
Sonography is now considered an effective method to evaluate peripheral nerves. Low cost, high resolution, the ability to image an entire limb in a short time, and dynamic assessment are several of the positive attributes of sonography. This article will review the normal appearance of peripheral nerves as shown with sonography. In addition, the most common applications for sonography of the peripheral nerves will be reviewed, which include entrapment neuropathies, intraneural ganglion cyst, nerve trauma, and peripheral nerve sheath tumors. Clinical information related to nerve disorders is also included, as it provides valuable information that can be obtained during sonographic examinations, increasing diagnostic accuracy.
Ultrasound-Guided Nerve Blocks in Emergency Medicine Practice
Objectives—The purpose of this study was to investigate the current practice of ultrasound (US)-guided regional anesthesia at academic emergency departments, including education, protocols, policies, and quality assessment.
Methods—We conducted a cross-sectional study. A questionnaire on US-guided nerve blocks was electronically sent to all emergency US directors and emergency US fellowship directors.
Results—A total of 121 of 171 academic institutions with an emergency medicine residency program participated in this study, representing a 71% response rate. Eighty-four percent (95% confidence interval [CI], 77%–91%) of programs perform US-guided nerve blocks at their institutions. The most common type of nerve block performed is a forearm nerve block (ulnar, median, or radial). The most common indication for US-guided nerve blocks is fracture pain management. Only 7% (95% CI, 2%–12%) of programs have a separate credentialing pathway for US-guided nerve blocks. Regarding quality assessment review of US-guided nerve blocks, none of the programs have a separate program in place. In 57% (95% CI, 48%–66%) of programs, it is a component of the emergency US quality assessment program. Eighty-four percent (95% CI, 77%–90%) of programs do not have specific agreements with other specialty services with regard to performing US-guided nerve blocks in the emergency department. The most common educational methods used to teach US-guided nerve blocks are didactic sessions, at 67% (95% CI, 59%–75%); online resources, at 54% (95% CI, 45%–63%); and supervised training with real patients, at 48% (95% CI, 39%–57%).
Conclusions—Ultrasound-guided nerve blocks are performed at most academic emergency departments. However, there is a substantial variation in the practices and policies within these institutions.
Portable A-Mode Ultrasound for Body Composition Assessment in Adolescents
Objectives—Ultrasound (US) imaging is a low-cost, highly feasible alternative method for monitoring the nutritional status of a population; however, only a few studies have tested the body composition agreement between US and reference standard methods, especially in adolescents. The purposes of this study were to assess the agreement of portable US with a reference standard method, dual-energy x-ray absorptiometry (DXA), for body fat percentage (BF%) in adolescents and to verify whether the use of a new mathematical model, based on the anatomic thickness obtained by US, is capable of improving BF% prediction.
Methods—This research was a descriptive study. Measures of total body mass, BF% on DXA, and BF% on US were collected from 105 adolescents.
Results—The participants included 71 male adolescents (median age ± interquartile range, 14.0 ± 2.0 years) and 34 female adolescents (13.0 ± 2.3 years). Ultrasound yielded significantly lower BF% values than DXA for male (mean ± SD, US, 9.6% ± 6.6%; DXA, 20.0% ± 7.2%; R= 0.848; P< .05) and female (US, 22.5% ± 5.7%; DXA, 30.3% ± 4.9%; R = 0.495; P < .05) participants. In addition, Bland-Altman analysis showed low concordance. When a multivariate regression was tested, the results improved for both sexes (US, 20.3% ± 4.6%; R= 0.848; P= .503) and female participants (US, 29.0% ± 5.7%; R = 0.712; P = .993) with a standard estimate of error of 1.57%.
Conclusions—This study has shown that US applied in a specific regression for BF% prediction in adolescents has a strong correlation with DXA as well as concordance with Bland-Altman analysis.
Three-Dimensional Sonography of Biliary Tract Disorders
In this pictorial essay, we review the 3-dimensional sonographic appearance of the normal gallbladder and biliary tree, as well as the appearance of congenital and acquired biliary tract disorders. Using examples, we demonstrate the advantage of 3-dimensional scanning compared with 2-dimensional sonography and, even in certain cases, magnetic resonance cholangiopancreatography.