O. Kenechi Nwawka

Ultrasound-guided needle localization to aid foreign body removal in pediatric patients.

Patients with podiatric foreign body injury commonly present to the emergency department. Often, the foreign object cannot be easily located or removed, and radiographs are frequently obtained to aid in localization. In cases requiring tissue dissection to remove the foreign bodies, accurate localization is required for safe removal of small and difficult to visualize bodies. We present 2 pediatric cases in which an ultrasound-guided needle localization technique was used to facilitate successful removal of small, difficult to visualize foreign bodies from the plantar foot. Ultrasound-guided needle localization reduced the required incision length and depth and helped to minimize the risk of damage to surrounding tissue.

Ultrasound-guided perineural injection for nerve blockade: Does a single-sided injection produce circumferential nerve coverage?

Our current clinical technique for sonographic‐guided perineural injection consists of two‐sided perineural needle placement to obtain circumferential distribution of the injectate. This study aimed to determine if a single‐side needle position will produce circumferential nerve coverage.

Ultrasound-Guided Peripheral Nerve Injection Techniques

OBJECTIVE Peripheral nerves are well seen using ultrasound (US) imaging, making US an ideal modality for image-guided nerve injections. This article provides a technical guide for common upper and lower extremity peripheral nerve injections, including the median, ulnar, and radial nerves in the upper extremity and the lateral femoral cutaneous, sciatic, common peroneal, tibial, and sural nerves in the lower extremity. CONCLUSION US is an effective modality for use in common upper and lower extremity peripheral nerve injections. With correct technique, peripheral nerve injections can be performed safely and are useful for both diagnostic evaluation of and therapy for peripheral neuropathy.

Imaging of Inflammatory Arthritis in Adults : Status and Perspectives on the Use of Radiographs, Ultrasound, and MRI

The term inflammatory arthritis encompasses a variety of conditions featuring synovial inflammation as a defining characteristic, with resultant local tissue damage occurring over time. These arthritides often share overlapping clinical and imaging characteristics, although the pattern of joint involvement, specific appearance of pathologic changes, and associated findings often allow imaging-based differentiation or individual arthritides.

Volume and Movement Affecting Flow of Injectate Between the Biceps Tendon Sheath and Glenohumeral Joint: A Cadaveric Study

OBJECTIVE The objective of our study was to determine if flow of injectate between the biceps tendon sheath and the glenohumeral joint is a function of injectate volume or of motion of the upper extremity. MATERIALS AND METHODS Sixteen upper-extremity fresh-frozen cadaveric specimens were used. Initially, three ultrasound-guided biceps tendon sheath injections were performed using 2, 5, and 10 mL of contrast material. Immediately after the injections, the specimens were imaged using CT. If contrast material was not visualized within the glenohumeral joint, the specimen was manipulated for 5 minutes and reimaged using CT to assess for contrast material within the joint. Five separate ultrasound-guided glenohumeral joint injections were also performed using 5 mL (three specimens), 10 mL (one specimen), and 15 mL (one specimen) of contrast material. The specimens underwent CT, and the presence or absence of contrast material in the biceps tendon sheath was documented before and after manipulation. Next, eight additional ultrasound-guided biceps tendon sheath injections were performed using 2 mL (six specimens) and 5 mL (two specimens) of contrast material. RESULTS The 5- and 10-mL biceps tendon sheath injection specimens and the 5-, 10-, and 15-mL glenohumeral joint specimens showed communicating contrast flow on the initial CT study. Only two of the seven 2-mL biceps tendon sheath injection specimens showed flow of contrast material into the glenohumeral joint from the biceps tendon sheath on the initial CT study; the remaining five specimens showed no communication even after manipulation. CONCLUSION Communication between the biceps tendon sheath and the glenohumeral joint may be a function of injectate volume rather than patient movement.

Membranous lipodystrophy: skeletal findings on CT and MRI

Membranous lipodystrophy, also known as Nasu–Hakola disease, is a rare hereditary condition with manifestations in the nervous and skeletal systems. The radiographic appearance of skeletal lesions has been well described in the literature. However, CT and MRI findings of lesions in the bone have not been documented to date. This report describes the radiographic, CT, MRI, and histopathologic skeletal findings in a case of membranous lipodystrophy. With corroborative pathologic findings, a diagnosis of membranous lipodystrophy on imaging allows for appropriate clinical management of disease manifestations.

Quantitative Ultrasound Assessment of the Achilles Tendon Under Varied Loads.

This Institutional Review Board–approved pilot study attempted to detect the correlation between ultrasound shear wave elastographic measures and tendon loads. Five male fresh‐frozen cadaveric Achilles tendons were loaded in 10‐N increments from 0 to 60 N. Shear wave velocity measurements within each Achilles tendon were obtained at each load in longitudinal and transverse orientations. Shear wave velocity measurements were correlated with tendon tension on both longitudinal and transverse plane imaging and showed moderate and strong positive correlation coefficients, respectively. Of note, limitations of the clinically available shear wave elastographic technology for measuring high velocities exist.

Ultrasound determination of presence, length and diameter of the palmaris longus tendon

Inadvertent median nerve harvest is a devastating complication of palmaris longus harvest. Accurate assessment of palmaris longus presence and dimensions preoperatively would minimize this risk and assure safe harvest. We hypothesized that ultrasound would accurately predict palmaris longus presence, length and diameter. Seventeen cadaveric forearms were studied using a LOGIQ-E9 ultrasound. Two radiologists assessed palmaris longus presence and dimensions. Each wrist was explored, and the tendon was harvested and measured. Inter-rater reliability and agreement between measurements was assessed. The palmaris longus was present in 13 of 17 forearms. Both radiologists correctly identified the tendon and its absence (sensitivity and specificity, 100%). Ultrasound assessment of palmaris longus dimensions significantly correlated with surgical measurements. Intraclass correlation coefficient between radiologists was 0.97. We conclude that ultrasound can determine palmaris longus presence and dimensions with excellent accuracy and inter-observer reliability. Ultrasound is useful for preoperative evaluation of the palmaris longus and its use will increase patient safety.

Sonographic Evaluation of Superficial Peroneal Nerve Abnormalities

OBJECTIVE The objective of this study was to review the anatomy of the superficial peroneal nerve (SPN) and describe the sonographic appearances of various abnormalities affecting it. We performed a retrospective chart review of ultrasound (US) examinations of the SPN performed from 2014 to 2016. CONCLUSION SPN abnormalities are well shown on US. Of 181 patients examined with US, the most commonly detected abnormality was scar encasement and neuroma or laceration.

Imaging of the Carpal Tunnel and Median Nerve

Carpal tunnel syndrome (CTS) is primarily a clinical diagnosis; however, recent advances in diagnostic imaging have increased the relevance of magnetic resonance imaging (MRI) and ultrasound (US) in the clinical evaluation. There are a variety of imaging findings of CTS that are well depicted on both modalities that have varied sensitivities and specificities. In MRI, the most commonly used criteria for CTS are increased median nerve size, median nerve flattening, median nerve signal change, and flexor retinaculum bowing. In ultrasound, measuring the cross-sectional area of the nerve at the level of the pisiform or carpal tunnel inlet detects CTS with a sensitivity and specificity that is similar to electrodiagnostic tests (EDTs). Both CT and ultrasound can aid in identifying alternative causes of nerve compression, such as ganglion cysts, masses, or flexor tenosynovitis. Future research in CTS imaging will include the use of MRI diffusion tensor imaging and ultrasound elastography.