Developments in musculoskeletal ultrasound and clinical applications

Utility of Handheld Ultrasound in Identifying Millimeter-Sized Vasculature in Living and Cadaveric Subjects

Objective This study aims to investigate the utility of handheld, Bluetooth-capable ultrasound in identifying millimeter-sized vasculature in both living and cadaveric subjects. Methods Using handheld, linear ultrasound probes, the carpal tunnel of 87 living individuals (174 forearms) was assessed for the presence of a persistent median artery (PMA). Radial, ulnar, and persistent median arterial diameters were measured, along with forearm circumference. Using the same probes, 46 cadaveric forearms were assessed for the presence of a "potential" PMA. Those same forearms were subsequently dissected to confirm the presence of the artery.  Results A PMA was identified in 3.4% of individuals (1.7% of forearms). Radial, ulnar, and persistent median arterial diameters were 2.12 ± 0.40 mm, 1.89 ± 0.41 mm, and 0.82 ± 0.33 mm, respectively. The radial artery was significantly larger than the ulnar artery (p < 0.0001). In cadaveric subjects, four "potential" PMAs were identified by pre-dissection ultrasound. Upon dissection, only one of the "potential" PMAs was confirmed, and three previously unidentified PMAs were identified.  Conclusions The prevalence of PMA in living subjects was lower than previously reported. Additionally, handheld ultrasound had low accuracy in identifying PMAs in cadavers prior to dissection. This could be an indication that current handheld ultrasound lacks the sensitivity to identify millimeter-sized vasculature, such as a PMA. In both populations of subjects, key, non-anomalous anatomy was readily seen, indicating the utility of handheld ultrasound in the proper context.

Application of ultrasound to monitor in vivo residual bone movement within transtibial prosthetic sockets

Transtibial prosthetic users do often struggle to achieve an optimal prosthetic fit, leading to residual limb pain and stump-socket instability. Prosthetists face challenges in objectively assessing the impact of prosthetic adjustments on residual limb loading. Understanding the mechanical behaviour of the pseudo-joint formed by the residual bone and prosthesis may facilitate prosthetic adjustments and achieving optimal fit. This study aimed to assess the feasibility of using B-mode ultrasound to monitor in vivo residual bone movement within a transtibial prosthetic socket during different stepping tasks. Five transtibial prosthesis users participated, and ultrasound images were captured using a Samsung HM70A system during five dynamic conditions. Bone movement relative to the socket was quantified by tracking the bone contour using Adobe After-Effect. During the study a methodological adjustment was made to improve data quality, and the first two participants were excluded from analysis. The remaining three participants exhibited consistent range of motion, with a signal to noise ratio ranging from 1.12 to 2.59. Medial-lateral and anterior-posterior absolute range of motion varied between 0.03 to 0.88 cm and 0.14 to 0.87 cm, respectively. This study demonstrated that it is feasible to use B-mode ultrasound to monitor in vivo residual bone movement inside an intact prosthetic socket during stepping tasks.

Muscle Architecture and Subcutaneous Fat Measurements of Rectus Femoris and Vastus Lateralis at Optimal Length Aided by a Novel Ultrasound Transducer Attachment

Purpose: This cross-sectional study determines the sensitivity of muscle architecture and fat measurements of the rectus femoris (RF) and vastus lateralis (VL) muscles from ultrasound images acquired with varying transducer tilt, using a novel transducer attachment, in healthy adults. Secondary objectives were to estimate intrarater and interrater reliability of image measurement and acquisition, respectively. Methods: Thirty healthy adults participated (15 women and 15 men; 25 [SD 2.5] y). Ultrasound image acquisition was conducted by two raters at different transducer tilts relative to the skin: estimated perpendicular, and five measured angles (80°, 85°, 90°, 95°, 100°) using the transducer attachment. Muscle thickness (MT), subcutaneous fat thickness (FT), pennation angle (PA), and fascicle length (FL) were measured. Sensitivity and reliability were assessed using intra-class correlation coefficients (ICCs) and standard error of measurements (SEMs). Results: MT and FT for RF and VL were not sensitive to transducer tilt. However, PA and FL were sensitive to transducer tilt. MT and FT for both muscles showed high ICCs and low SEMs for intrarater and interrater reliability. For PA of both muscles, standardizing transducer tilt improved interrater ICCs and lowered SEMs. Conclusion: MT and FT measurements of RF and VL acquired at 60° knee flexion are robust to varying transducer tilt angles. PA measurements benefit from standardizing transducer tilt.

Iatrogenic Nerve Injuries of the Upper Extremity: A Critical Analysis Review

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Iatrogenic nerve injuries may occur after any intervention of the upper extremity.

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Causes of iatrogenic nerve lesions include direct sharp or thermal injury, retraction, compression from implants or compartment syndrome, injection, patient positioning, radiation, and cast/splint application, among others.

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Optimal treatment of iatrogenic peripheral nerve lesions relies on early and accurate diagnosis.

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Advanced imaging modalities (e.g., ultrasound and magnetic resonance imaging) and electrodiagnostic studies aid and assist in preoperative planning.

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Optimal treatment of iatrogenic injuries is situation-dependent and depends on the feasibility of direct repair, grafting, and functional transfers.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part I: Extraarticular Pathologies

The first part of the guidelines and recommendations for musculoskeletal ultrasound, produced under the auspices of the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB), provides information about the use of musculoskeletal ultrasound for assessing extraarticular structures (muscles, tendons, entheses, ligaments, bones, bursae, fasciae, nerves, skin, subcutaneous tissues, and nails) and their pathologies. Clinical applications, practical points, limitations, and artifacts are described and discussed for every structure. After an extensive literature review, the recommendations have been developed according to the Oxford Centre for Evidence-based Medicine and GRADE criteria and the consensus level was established through a Delphi process. The document is intended to guide clinical users in their daily practice.

Assessment of lower limb peripheral nerves with ultrasound in patients with traumatic amputation

Objectives

This study aims to assess the sciatic nerve (SN), common peroneal nerve (CPN), and tibial nerve (TN) by ultrasound in patients with traumatic lower limb amputation (LLA) and to examine the possible relationship between ultrasonographic and clinical findings.

Patients and methods

This cross-sectional study included a total of 33 male patients (mean age: 36.6±8.7 years; range, 21 to 48 years) who had LLA due to traumatic injury between May 2019 and April 2020. Amputation and prosthesis use and functional K level of activity were recorded. Ultrasound examinations were performed to measure the cross-sectional areas (CSAs) of the SN, CPN, and TN bilaterally at the same levels. The values from the normal sides were accepted as controls.

Results

The CSA values were greater on the amputated sides than the non-amputated sides for SN (p=0.001), TN (p=0.001), and CPN (p=0.015), regardless of the activity level. The amputated side SN (p=0.001), TN (p=0.001), and CPN (p=0.016) were thicker in patients with level of K4 activity than the non-amputated side. For the patients with K3 activity level, larger TN CSA values were determined on the amputated side, compared to those at the K4 level (p=0.035). The SN was found to be greater in patients using microprocessor-controlled knee prosthesis (p=0.032) and TN was larger in hypobaric sealing membrane users on the amputated sides (p=0.041).

Conclusion

The SN, CPN, and TN were found to be larger in all patients on the amputated sides and in patients with K4 activity level. Based on these findings, the K3 activity level and the use of hypobaric sealing membrane seems to affect the CSA values of TN. Additionally, the use of microprocessor knee prosthesis affects the CSA values of SN. We believe that these results may be essential for the analysis or prediction of lower extremity nerve involvement according to the K activity level and the use of prosthesis in patients with traumatic LLA.

Ultrasound shear wave elastography of the anterior talofibular and calcaneofibular ligaments in healthy subjects

Aim of study

Most sprained lateral ankle ligaments heal uneventfully, but in some cases the ligament’s elastic function is not restored, leading to chronic ankle instability. Ultrasound shear wave elastography can be used to quantify the elasticity of musculoskeletal soft tissues; it may serve as a test of ankle ligament function during healing to potentially help differentiate normal from ineffective healing. The purpose of this study was to determine baseline shear wave velocity values for the lateral ankle ligaments in healthy male subjects, and to assess inter-observer reliability.

Material and methods

Forty-six ankles in 23 healthy male subjects aged 20–40 years underwent shear wave elastography of the lateral ankle ligaments performed by two musculoskeletal radiologists. Each ligament was evaluated three times with the ankle relaxed by both examiners, and under stress by a single examiner. Mean shear wave velocity values were compared for each ligament by each examiner. Inter-observer agreement was evaluated.

Results

The mean shear wave velocity at rest for the anterior talofibular ligament was 2.09 ± 0.3 (range 1.41–3.17); and for the calcaneofibular ligament 1.99 ± 0.36 (range 1.29–2.88). Good inter-observer agreement was found for the anterior talofibular ligament and calcaneofibular ligament shear wave velocity measurements with the ankle in resting position. There was a significant difference in mean shear wave velocities between rest and stressed conditions for both anterior talofibular ligament (2.09 m/s vs 3.21 m/s; p <0.001) and calcaneofibular ligament (1.99 m/s vs 3.42 m/s; p <0.0001).

Conclusion

Shear wave elastography shows promise as a reproducible method to quantify ankle ligament stiffness. This study reveals that shear waves velocities of the normal lateral ankle ligaments increased with applied stress compared to the resting state.

US-guided high-volume injection for Achilles tendinopathy

Achilles tendinopathy is a common overuse condition affecting the adult population. The incidence is on the rise because of greater participation of people in recreational or competitive sporting activities. Chronic Achilles tendinopathy occurs most commonly in the tendon’s mid-portion, and it is challenging to manage, leading to significant patient morbidity. Despite conservative management many patients still require surgical intervention. The mechanism underlying pain is not entirely understood; however, high-resolution color Doppler ultrasound has shown that neovascularisation could be involved. Minimally-invasive treatments for chronic Achilles tendinopathy may prevent the need for surgery when conservative methods have failed. Ultrasound provides an option to guide therapeutic interventions accurately, so that treatment is delivered to the desired site of pathology. High-volume image-guided injection is a relatively new technique where a high volume of liquid is injected between the anterior aspect of the Achilles tendon and the Kager’s fat pad, used to strip away the neovascularity and disrupt the nerve ingrowth seen in chronic cases of Achilles tendinopathy. High-volume image-guided injection has shown promising results in terms of reducing pain and improving function in patients where conservative measures have failed. This review aims to describe the fundamental technical factors, and investigate the efficacy of high-volume image-guided injection with reference to the available literature.

MR imaging of inherited myopathies: a review and proposal of imaging algorithms

PURPOSE OF REVIEW

The aims of this review are to discuss the imaging modalities used to assess muscle changes in myopathies, to provide an overview of the inherited myopathies focusing on their patterns of muscle involvement in magnetic resonance imaging (MR), and to propose up-to-date imaging-based diagnostic algorithms that can help in the diagnostic workup.

CONCLUSION

Familiarization with the most common and specific patterns of muscular involvement in inherited myopathies is very important for radiologists and neurologists, as imaging plays a significant role in diagnosis and follow-up of these patients.

KEY POINTS

• Imaging is an increasingly important tool for diagnosis and follow-up in the setting of inherited myopathies. • Knowledge of the most common imaging patterns of muscle involvement in inherited myopathies is valuable for both radiologists and neurologists. • In this review, we present imaging-based algorithms that can help in the diagnostic workup of myopathies.

Diagnostic accuracy of examination tests for lateral elbow tendinopathy (LET) - A systematic review

BACKGROUND

Reviews on the diagnostic performance of the examination tests for lateral elbow tendinopathy (LET) based on updated context-specific tools and guidelines are missing.

PURPOSE

To review the diagnostic accuracy of examination tests used in LET.

DESIGN

Systematic review following PRISMA-DTA guidelines.

METHODS

We searched MEDLINE, PubMed, CINAHL, EMBASE, PEDro, ScienceDirect, and Cochrane Library databases. The QUADAS-2 checklist was used to assess the methodological quality of the eligible studies. We included diagnostic studies reporting the accuracy of physical examination tests or imaging modalities used in patients with LET.

RESULTS

Twenty-four studies with 1370 participants were identified reporting the diagnostic performance of Ultrasound Imaging (USI) (18 studies), physical examination tests (2 studies) and Magnetic Resonance Imaging (MRI) (4 studies). Most studies (97%) were assessed with "unclear" or "high risk" of bias. Sonoelastography showed the highest sensitivity (75- 100%) and specificity (85- 96%). Grayscale with or without Doppler USI presented poor to excellent values (sensitivity: 53%-100%, specificity: 42%-90%). MRI performed better in the diagnosis of tendon thickening and enthesopathy (sensitivity and specificity: 81%-100%). The Cozen's test reported high sensitivity (91%) while a grip strength difference of 5%-10% between elbow flexion and extension showed high sensitivity (78%-83%) and specificity (80%-90%).

CONCLUSIONS

Cozen's test and grip strength measurement present high accuracy in the diagnosis of LET but are poorly investigated. USI and MRI provide variable diagnostic accuracy depending on the entities reported and should be recommended with caution when differential diagnosis is necessary. Substantial heterogeneity was found in inclusion criteria, operator/ examiner, mode of application, type of equipment and reference standards across the studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID CRD42020160402.

Assessment of neovascularization during bone healing using contrast-enhanced ultrasonography in a canine tibial osteotomy model: a preliminary study

Blood perfusion of skeletal muscle and callus was evaluated using contrast-enhanced ultrasonography (CEUS) in a canine osteotomy model to determine the applicability of CEUS in the assessment of neovascularization during fracture healing and to compare the vascular signals on CEUS between external skeletal fixation and cast-applied dogs. In 6 Beagle dogs, a simple transverse osteotomy was performed at the left tibial shaft and external skeletal fixation (n = 3) or a cast (n = 3) was applied. Radiography, power Doppler ultrasonography (power Doppler), and CEUS were performed until complete union was achieved. On CEUS, vascular changes were quantitatively evaluated by measuring peak intensity (PI) and time to PI in the soft tissue and callus and by counting the vascular signals. Vascular signals from the soft tissue were detected on power Doppler and CEUS on day 2. Significantly more vascular signals were detected by CEUS than by power Doppler. On CEUS, PI in the surrounding soft tissue was markedly increased after the fracture line appeared indistinctively changed on radiography in all dogs. In the cast-applied dogs, vascular signals from the periosteal and endosteal callus were detected on CEUS before mineralized callus was observed on radiography. CEUS was useful in assessing the vascularity of soft tissue and callus, particularly in indirect fracture healing, and provided indications of a normally healing fracture.

Difference-Frequency Ultrasound Imaging With Non-Linear Contrast

Conventional ultrasound imaging is based on the scattering of sound from inhomogeneities in the density and the speed of sound and is often used in medicine to resolve pathologic compared to normal tissue. Here we demonstrate a difference-frequency ultrasound (dfUS) imaging method that is based on the interaction of two sound pulses that propagate non-collinearly and intersect in space and time. The dfUS signal arises primarily from the second-order non-linear coefficient, a contrast mechanism that differs from linear and harmonic US imaging. The distinct contrast mechanism allows dfUS to image anatomic features that are not identifiable in conventional US images of salmon and pig kidney tissue. Further, dfUS produces enhanced contrast of glioblastoma tumor implanted in the mouse brain, revealing its potential for improving medical diagnosis. Progress towards a real-time system is discussed.

Reliability of Quantitative Assessment of Distal Radioulnar Joint Stability With Force-Monitor Ultrasonography

The purpose of this study was to evaluate the reliability of ultrasound assessment of the displacement-force relationships for distal radioulnar joint (DRUJ) stability. Non-dominant wrists of 10 healthy male subjects were evaluated by force-monitor ultrasonography. This apparatus was developed to apply cyclic compression to the wrist with pre-determined transducer displacement conditions in the range of 0.1-3.0 mm. The subject's wrist was placed on the table with the forearm in the pronated position. The transducer was placed on the dorsal surface of the distal radius and ulna, perpendicular to the long axis of the forearm. The center of the ulnar head was at the DRUJ level. The distance between the dorsal surface of the distal radius and the ulnar head was measured at an initial and a pressed-down position. Changes in radioulnar displacement, force to the wrist and the displacement/force ratio were evaluated. The measurements were performed independently by two raters. The intra-class correlation coefficients (ICCs) for the radioulnar displacement were 0.76, 0.68, and 0.93, in the 1.0, 2.0, and 3.0 mm transducer displacement conditions, respectively. The ICCs for the force to the wrist were 0.18, 0.67, and 0.34, in different transducer displacement conditions, respectively. The ICCs for the displacement/force ratios were 0.68, 0.67, and 0.97, in different transducer displacement conditions, respectively. The highest ICC for the radioulnar displacement and the displacement/force ratio was observed in the 3.0 mm displacement condition. This assessment of displacement-force relationships may be useful to quantify DRUJ stability. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2053-2060, 2019.

Strain Ratio Measurements of Patellar and Achilles Tendons With Different Reference Regions in Healthy Volunteers

Strain ratio measurements of tendons vary because of the reference tissue selection. The main purpose of this study is to highlight, in detail, the numeric variability attributable to the use of various reference materials on strain ratio measurements of patellar and Achilles tendons. Measurements were performed at the proximal, middle and distal thirds of the patellar and Achilles tendons on the dominant site of healthy volunteers. A total of 3 references were used: the Hoffa's fat pad for the patellar tendon, the Kager's fat pad for the Achilles tendon, subcutaneous tissue and Aquaflex gel pads (Parker Laboratories, Fairfield, NJ, USA) for both tendons. Although the same methods were used by the same physician for each tendon site on repeated measurements, strain ratio values had numeric variability with various reference materials in each measurement. Therefore, comparison of numeric strain ratio results of various studies with various reference materials could confuse the clinical interpretations of these numeric data, and, using a reference material with standard stiffness like Aquaflex ultrasound gel pads, should be considered by verifying these results with further studies.

3D Ultrasound Imaging of Residual Limbs With Camera-Based Motion Compensation

Ultrasound is a cost-effective, readily available, and non-ionizing modality for musculoskeletal imaging. Though some research groups have pursued methods that involve submerging the transducer and imaged body segment into a water bath, many limitations remain in regards to acquiring an unloaded volumetric image of an entire human limb in a fast, safe, and adequately accurate manner. A 3D dataset of a limb is useful in several rehabilitative applications including biomechanical modeling of soft tissue, prosthetic socket design, monitoring muscle condition and disease progression, bone health, and orthopedic surgery. This paper builds on previous work from our group and presents the design, prototyping, and preliminary testing of a novel multi-modal imaging system for rapidly acquiring volumetric ultrasound imagery of human limbs, with a particular focus on residual limbs for improved prosthesis design. Our system employs a mechanized water tank setup to scan a limb with a clinical ultrasound transducer and 3D optical imagery to track motion during a scan. The iterative closest point algorithm is utilized to compensate for motion and stitch the images into a final dataset. The results show preliminary 2D and 3D imaging of both a tissue-mimicking phantom and residual limbs. A volumetric error compares the ultrasound image data obtained to a previous MRI method. The results indicate potential for future clinical implementation. Concepts presented in this paper could reasonably transfer to other imaging applications such as acoustic tomography, where motion artifact may distort image reconstruction.

Are Ultrasound Measurements of Achilles Tendon Size Reliable? A Systematic Review of Rater Reliability

Ultrasound measurements of Achilles tendon size are used to assess the tendon's response to exercise, aging, rehabilitation, tendon loading and healing. It is important to understand and minimise the measurement error that occurs with these measurements. This review identified and synthesised studies reporting on intra- and inter-rater reliability of ultrasound measurements of Achilles tendon size. Analysis of 21 studies revealed that good to excellent intra- and inter-rater reliability can be achieved for ultrasound measurements of Achilles tendon size. Reliability can be optimised by using one experienced operator, standardising transducer pressure and orientation and averaging two or three measurements. There was a high risk of methodological bias across the included studies. Reporting of reliability studies needs to be improved by the use of existing reporting guidelines and expansion of these guidelines to include important elements of ultrasound imaging.

Tendinopathy: Investigating the Intersection of Clinical and Animal Research to Identify Progress and Hurdles in the Field

Biological treatments, surgical interventions, and rehabilitation exercises have been successfully used to treat tendinopathy, but the development of effective treatments has been hindered by the lack of mechanistic data regarding the pathogenesis of the disease. While insightful, clinical studies are limited in their capacity to provide data regarding the pathogenesis of tendinopathies, emphasizing the value of animal models and cell culture studies to fill this essential gap in knowledge. Clinical pathological findings from imaging studies or histological analysis are not universal across patients with tendinopathy and have not been clearly associated with the onset of symptoms. There are several unresolved controversies, including the cellular changes that accompany the tendinopathic disease state and the role of inflammation. Additional research is needed to correlate the manifestations of the disease with its pathogenesis, with the goal of reaching a field-wide consensus on the pathology of the disease state. Such a consensus will allow standardized clinical practices to more effectively diagnose and treat tendinopathy.

Ultrasound elastography: compression elastography and shear-wave elastography in the assessment of tendon injury

Ultrasound elastography (USE) is a recent technology that has experienced major developments in the past two decades. The assessment of the main mechanical properties of tissues can be made with this technology by characterisation of their response to stress. This article reviews the two major techniques used in musculoskeletal elastography, compression elastography (CE) and shear-wave elastography (SWE), and evaluates the studies published on major electronic databases that use both techniques in the context of tendon pathology. CE accounts for more studies than SWE. The mechanical properties of tendons, particularly their stiffness, may be altered in the presence of tendon injury. CE and SWE have already been used for the assessment of Achilles tendons, patellar tendon, quadriceps tendon, epicondylar tendons and rotator cuff tendons and muscles. Achilles tendinopathy is the most studied tendon injury with USE, including the postoperative period after surgical repair of Achilles rupture tendon. In relation to conventional ultrasound (US), USE potentially increases the sensitivity and diagnostic accuracy in tendinopathy, and can detect pathological changes before they are visible in conventional US imaging. Several technical limitations are recognised, and standardisation is necessary to ensure repeatability and comparability of the results when using these techniques. Still, USE is a promising technique under development and may be used not only to promote an early diagnosis, but also to identify the risk of injury and to support the evaluation of rehabilitation interventions. KEY POINTS: • USE is used for the assessment of the mechanical properties of tissues, including the tendons. • USE increases diagnostic performance when coupled to conventional US imaging modalities. • USE will be useful in early diagnosis, tracking outcomes and monitoring treatments of tendon injury. • Technical issues and lack of standardisation limits USE use in the assessment of tendon injury.

Chronic kidney disease: considerations for monitoring skeletal muscle health and prescribing resistance exercise

Skeletal muscle wasting has gained interest as a primary consequence of chronic kidney disease (CKD) due to the relationship between skeletal muscle mass, mortality and major adverse cardiovascular events in this population. The combination of reductions in physical function, skeletal muscle performance and skeletal muscle mass places individuals with CKD at greater risk of sarcopenia. Therefore the monitoring of skeletal muscle composition and function may provide clinical insight into disease progression. Dual-energy X-ray absorptiometry and bioelectrical impedance analysis are frequently used to estimate body composition in people with CKD within clinical research environments, however, their translation into clinical practice has been limited. Proxy measures of skeletal muscle quality can be obtained using diagnostic ultrasound, providing a cost-effective and accessible imaging modality to aid further clinical research regarding changes in muscle composition. Clinicians and practitioners should evaluate the strengths and limitations of the available technology to determine which devices are most appropriate given their respective circumstances. Progressive resistance exercise has been shown to improve skeletal muscle hypertrophy of the lower extremities, muscular strength and health-related quality of life in end-stage renal disease, with limited evidence available in CKD predialysis. Fundamental principles (i.e. specificity, overload, variation, reversibility, individuality) can be used in the development of more advanced programs focused on improving specific neuromuscular and functional outcomes. Future research is needed to determine the applicability of skeletal muscle monitoring in clinical settings and the feasibility and efficacy of more advanced resistance exercise approaches in those with CKD predialysis.

Distal Forearm Fracture Open Reduction-Internal Fixation: Sonographic Detection of Hardware Malalignment and Associated Tendon Injuries Missed by Radiography

Tendon injury is a known complication of distal radius fracture plate and screw fixation. Targeted musculoskeletal sonography is uniquely capable of assessing both tendon integrity and hardware abnormalities not recognized on radiographs. Each of the 3 patients described presented with pain after an open reduction-internal fixation following a distal forearm fracture. In each patient, radiographic findings, specifically the hardware position, were interpreted as normal. Important radiographically occult observations were subsequently made with sonography, including 3 proud screws and tendon injuries, all of which required surgical treatment. This case series demonstrates the clinical utility of musculoskeletal sonography in symptomatic patients after distal radius open reduction-internal fixation with negative radiographic findings. In our practice, sonography has been the most useful modality for precluding missing or delaying the diagnosis and treatment of these hardware complications. We advocate its use as an adjunct in any department performing musculoskeletal imaging.

Intraoperative Ultrasound for Peripheral Nerve Applications

Offering real-time, high-resolution images via intraoperative ultrasound is advantageous for a variety of peripheral nerve applications. To highlight the advantages of ultrasound, its extraoperative uses are reviewed. The current intraoperative uses, including nerve localization, real-time evaluation of peripheral nerve tumors, and implantation of leads for peripheral nerve stimulation, are reviewed. Although intraoperative peripheral nerve localization has been performed previously using guide wires and surgical dyes, the authors' approach using ultrasound-guided instrument clamps helps guide surgical dissection to the target nerve, which could lead to more timely operations and shorter incisions.

Ultrasound imaging of the distal radioulnar joint: a new method to assess ulnar radial translation in forearm rotation

A cross-sectional reliability study was conducted with 23 normal participants to establish normal values, and the repeatability and validity of distal radioulnar joint translation measurements using ultrasound imaging. Static transverse images of maximal supination, neutral and maximal pronation were examined to assess translation, using a method consistent with the rheumatoid arthritis subluxation ratio. Translation while gripping a 1 kg weight in supinated and pronated positions was then compared with non-gripping translation. There was significantly more ulnar radial translation found with pronation than supination, when compared with neutral. Gripping in pronation did not produce statistically significant changes in translation, whereas the changes produced by gripping in supination were significant. Internal consistency was deemed very high and the rheumatoid arthritis subluxation ratio values measured using ultrasound imaging were consistent with previously documented values measured by computerized tomography. This study demonstrated that translational movement of the distal radioulnar joint can be reliably detected in healthy participants using ultrasound imaging. This may reduce dependency on other imaging modalities to diagnose distal radioulnar joint instability.

LEVEL OF EVIDENCE

2.

Juvenile idiopathic arthritis: what is the utility of ultrasound?

Juvenile idiopathic arthritis (JIA) is a heterogeneous condition and an important cause of acquired disability in children. Evidence supports early treatment to prevent future complications. This relies on prompt diagnosis, achieved by a high index of clinical suspicion and supportive evidence, including the detection of joint and or tendon inflammation. Ultrasound is a readily accessible, well-tolerated, safe and accurate modality for assessing joints and the surrounding soft tissues. It can also be used to guide therapy into those joints and tendon sheaths resistant to systemic treatments. Ultrasound imaging is highly operator dependent, and the developing skeleton poses unique challenges in interpretation with sonographic findings that can mimic pathology and vice versa. Ultrasound technology has been rapidly improving and is more accessible than ever before. In this article, we review the normal appearances, highlight potential pitfalls and present the key pathological findings commonly seen in JIA.

Current and Prospective Use of Musculoskeletal Diagnostic Ultrasound Imaging at Chiropractic Teaching Institutions: A Worldwide Survey of Diagnostic Imaging Staff

OBJECTIVE

The purpose of this study was to survey the use of musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) at chiropractic educational programs worldwide and to elicit opinions of academic diagnostic imaging staff of its prospective use at their teaching institutions.

METHODS

An electronic questionnaire was delivered in 2014 using SurveyMonkey and notifications were disseminated by e-mail to 127 diagnostic imaging staff at chiropractic programs worldwide. The questionnaire consisted of 27 items using multiple-choice, Likert-type, and open-ended questions. Descriptive statistics were used for basic demographic data and the results of the numerical scales used in each item.

RESULTS

Fifty-nine respondents (46.5%) from 24 (24/41) chiropractic programs returned questionnaires. The reported use of MSK-DUSI at chiropractic programs is low (n = 5/24); however, respondents from 9 institutions stated that it is planned to be implemented. Few respondents stated they had formal MSK-DUSI qualifications (4/59); however, 7 respondents stated they were in the process of becoming certified. Most respondents expressed an interest in the prospect of incorporating MSK-DUSI at their chiropractic program. Sixty-five percent stated that chiropractic programs should provide MSK-DUSI training to chiropractic students, and 75% of respondents stated that chiropractic programs should be providing accredited postgraduate MSK-DUSI courses.

CONCLUSIONS

The current use of MSK-DUSI among chiropractic programs that responded to this survey is low. The opinions of diagnostic imaging staff who responded suggest a positive attitude to its use and possible growth in its use if foundational work, including gaining funding, accreditation, and acceptance of within the scope of chiropractic practice, is undertaken.

US of the Peripheral Nerves of the Upper Extremity: A Landmark Approach

Ultrasonography (US) has become a first-line modality for the evaluation of the peripheral nerves of the upper extremity. The benefits of US over magnetic resonance (MR) imaging include higher soft-tissue resolution, cost effectiveness, portability, real-time and dynamic imaging, and the ability to scan an entire extremity quickly and efficiently. US can be performed on patients who are not eligible for MR imaging. Metallic implant artifacts are usually not problematic. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Any abnormal findings can be easily compared with the contralateral side. The published literature has shown that US has demonstrated clinical utility in patients with suspected peripheral nerve disease by guiding diagnostic and therapeutic decisions as well as by confirming electrodiagnostic findings. Common indications for upper extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, and tumor. US of the upper extremity is most commonly performed to evaluate carpal and cubital tunnel syndrome. It is important for the radiologist or sonographer to have a detailed knowledge of anatomy and specific anatomic landmarks for each nerve to efficiently and accurately perform an examination. The goal of this article is to introduce readers to the basics of US of the peripheral nerves of the upper extremity with a focus on the median, ulnar, and radial nerves. Common sites of disease and the location of important anatomic landmarks will be reviewed.

Effects of Cigarette Smoking on Elastographic Strain Ratio Measurements of Patellar and Achilles Tendons

OBJECTIVES

The aim of this study was to explore the sonographic and elastographic properties of patellar and Achilles tendons in smoking and nonsmoking otherwise healthy adults.

METHODS

We conducted a level 3 case-control analytical study. Smoking and nonsmoking volunteers (>18 years) without musculoskeletal system disorders were included in the study. Demographic characteristics and smoking habits (pack-years) were recorded. Proximal, middle, and distal third thicknesses of the patellar and Achilles tendons were measured by B-mode sonography. Strain ratio measurements of the same regions were measured by real-time ultrasound elastography.

RESULTS

A total of 69 participants (57 male and 12 female; mean age ± SD, 35.5 ± 7.8 years) were evaluated in the study. Smoking (n = 35) and nonsmoking (n = 34) groups had no significant differences in terms of age, body mass index, sex, and activity level (all P > .05). Proximal, middle, and distal thirds of the patellar and Achilles tendons were significantly thinner in the smoking group (all P < .05). Furthermore, strain ratio measurements in the same regions were significantly lower in the smoking group (all P< .05). Patellar tendon thicknesses and strain ratios had negative correlations with the smoking amount (all P < .05).

CONCLUSIONS

Thickness and strain ratio measurements of patellar and Achilles tendons were reduced (thinner and harder tendons) in smokers. Clinical implications of these morphologic and elastographic changes should be investigated in future studies.

High-Resolution US of Rheumatologic Diseases

For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

Update in Musculoskeletal Ultrasound Research

CONTEXT

Musculoskeletal ultrasound (US) research is expanding due to increased clinical utility of sonography.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Ultrasound is widely applied in musculoskeletal imaging and sports medicine. The real-time capabilities and favorable cost profile of US make it ideal for use in diagnosis of musculoskeletal conditions. The enthusiasm for the use of US in musculoskeletal imaging has led to an increase in US research to broaden its applications.

CONCLUSION

Several recent advances have been made in conventional and novel US imaging techniques, quantitative US imaging, and US-guided interventions.

STRENGTH OF RECOMMENDATIONS TAXONOMY SORT

C.

Sonographic evaluation of athletic pubalgia

Athletic pubalgia, or "sports hernia", represents a constellation of pathologic conditions occurring at and around the pubic symphysis. These injuries are primarily seen in athletes or those involved in athletic activity. In this article, we review the sonographic appearance of the relevant complex anatomy, scanning technique for ultrasound evaluation of athletic pubalgia, and the sonographic appearances of associated pathologic conditions.

Return to clinical in contrast to serologically-based diagnoses

The future of rheumatology is predicated upon a return to basics. The advent and facile availability of laboratory testing led to reduction of emphasis on clinical skills. Recognition that immunologic abnormalities are not limited to individuals who clearly have related pathology provides new motivation for reorientation of training programs to assure that graduates have appropriate information gathering, diagnostic and procedural skills. Inadequate accessibility to rheumatologic care requires innovative approaches and especially training and educating those individuals who provide primary care. While the rheumatologist can elicit the patient’s history remotely, telerheumatology will be feasible only when the individual interacting physically with the patient has confidence in their examination skills and when those skills have been validated. Named syndromes or diseases will be modified to avoid impugning the individual or compromising their future access to health, disability and life insurance. Interventions will be pursued in a more cost-effective, evidence-based manner. The future of rheumatology is dependent upon the rheumatologist’s ability to amortize the inadequate reimbursement for direct patient interaction, depending on skills of interpretation of standard X-rays, ultrasound performance and results.

US of the Peripheral Nerves of the Lower Extremity: A Landmark Approach

Ultrasonography (US) is commonly used to assess the peripheral nerves of the lower extremity because of its many advantages over magnetic resonance (MR) imaging. The most obvious advantages over MR imaging are superior soft-tissue resolution, low cost, portability, lack of magnetic susceptibility artifact, and the ability to image patients who cannot undergo MR imaging. US has been shown to have equal specificity and greater sensitivity than MR imaging in the evaluation of peripheral nerves. Additional benefits are the capability of real-time and dynamic imaging, and the ability to scan an entire extremity quickly without the need for a patient to lie motionless for long periods of time, as with MR imaging. Any abnormal findings can be easily compared against the contralateral side. Published literature has shown that US has clinical utility in patients suspected of having peripheral nerve disease: US can be used to guide diagnostic and therapeutic decisions, as well as help confirm electrodiagnostic findings. Common indications for lower extremity peripheral nerve US are the evaluation for injury due to penetrating trauma, entrapment by scar tissue, or tumor. To confidently perform US of the peripheral nerves of the lower extremity, it is important to gain a thorough knowledge of anatomic landmarks and the course of each nerve. Readers who may not be familiar with US will be introduced to the basics of scanning the peripheral nerves of the lower extremity. Important anatomic landmarks and common sites of injury and entrapment will be reviewed.

Efficacy of ultrasound elastography in detecting active myositis in children: can it replace MRI?

BACKGROUND

Juvenile idiopathic inflammatory myopathy is a rare yet potentially debilitating condition. MRI is used both for diagnosis and to assess response to treatment. No study has evaluated the performance of US elastography in the diagnosis of this condition in children.

OBJECTIVE

To assess the performance of compression-strain US elastography in detecting active myositis in children with clinically confirmed juvenile idiopathic inflammatory myopathy and to compare its efficacy to MRI.

MATERIALS AND METHODS

Children with juvenile idiopathic inflammatory myopathy underwent non-contrast MR imaging as well as compression-strain US elastography of the quadriceps muscles. Imaging findings from both modalities were compared to each other as well as to the clinical determination of active disease based on physical examination and laboratory data. Active myositis on MR was defined as increased muscle signal on T2-weighted images. Elastography images were defined as normal or abnormal based on a previously published numerical scale of muscle elastography in normal children. Muscle echogenicity was graded as normal or abnormal based on gray-scale sonographic images.

RESULTS

Twenty-one studies were conducted in 18 pediatric patients (15 female, 3 male; age range 3-19 years). Active myositis was present on MRI in ten cases. There was a significant association between abnormal MRI and clinically active disease (P = 0.012). US elastography was abnormal in 4 of 10 cases with abnormal MRI and in 4 of 11 cases with normal MRI. There was no association between abnormal elastography and either MRI (P > 0.999) or clinically active disease (P > 0.999). Muscle echogenicity was normal in 11 patients; all 11 had normal elastography. Of the ten patients with increased muscle echogenicity, eight had abnormal elastography. There was a significant association between muscle echogenicity and US elastography (P < 0.001). The positive and negative predictive values for elastography in the determination of active myositis were 75% and 31%, respectively, with a sensitivity of 40% and specificity of 67%.

CONCLUSION

Compression-strain US elastography does not accurately detect active myositis in children with juvenile idiopathic inflammatory myopathy and cannot replace MRI as the imaging standard for detecting myositis in these children. The association between abnormal US elastography and increased muscle echogenicity suggests that elastography is capable of detecting muscle derangement in patients with myositis; however further studies are required to determine the clinical significance of these findings.

Real-time sonoelastography of the quadriceps tendon in patients undergoing chronic hemodialysis

OBJECTIVES

This study aimed to compare sonoelastographic findings for the quadriceps tendon in patients with chronic renal failure who were in a dialysis program to findings in a control group.

METHODS

Fifty-three randomly allocated patients (mean age, 54.3 years; range, 27-86 years) with chronic renal failure who were in a dialysis program 3 days a week between January and May 2012 were included. The measurements were performed in both knees of 53 patients undergoing dialysis and 25 individuals in the control group. The tendons were classified as follows: type 1, very stiff tissue (blue); type 2, stiff tissue (blue-green); and type 3, intermediate tissue (green-yellow) according to color mapping.

RESULTS

The mean quadriceps tendon thicknesses in the patient group were 4.9 mm (range, 1.9-6.5 mm) for the right knee and 4.9 mm (1.4-6.5 mm) for the left knee; the values in the control group were 5.4 mm (3.6-7.0 mm) for the right knee and 5.4 mm (3.4-7.0 mm) for the left knee. The mean elasticity scores in the patient group were 3.14 (1.03-5.23) for the right knee and 3.33 (1.29-5.00) for the left knee; in the control group, the values were 3.79 (1.73-5.23) and 3.69 (1.23-5.53) for the right and left knees, respectively (right knee, P = .025; left knee, P = .018; Mann-Whitney U test). The quadriceps tendons were significantly thinner in the patient group (right knee, P = .054; left knee, P = .015; Mann-Whitney U test).

CONCLUSIONS

Quadriceps tendons in patients with chronic renal failure are thinner and have lower elasticity scores compared to controls.

Contrast-enhanced ultrasonography to assess blood perfusion of skeletal muscles in normal dogs

This study evaluated perfusion of skeletal muscle using contrast enhanced ultrasonography in humerus, radius, femur and tibia in normal dogs. Contrast enhanced ultrasonography for each region was performed after injecting 0.5 mL and 1 mL of contrast medium (SonoVue) in every dog. Blood perfusion was assessed quantitatively by measuring the peak intensity, time to the peak intensity and area under the curve from the time-intensity curve. Vascularization in skeletal muscle was qualitatively graded with a score of 0-3 according to the number of vascular signals. A parabolic shape of time-intensity curve was observed from muscles in normal dogs, and time to the peak intensity, the peak intensity and area under the curve of each muscle were not significantly different according to the appendicular regions examined and the dosage of contrast agent administered. This study reports that feasibility of contrast enhanced ultrasonography for assessment of the muscular perfusion in canine appendicular regions.

Navigational ultrasound imaging: A novel imaging tool for aiding interventional therapies of equine musculoskeletal injuries

REASONS FOR PERFORMING STUDY

Navigational ultrasound imaging, also known as fusion imaging, is a novel technology that allows real-time ultrasound imaging to be correlated with a previously acquired computed tomography (CT) or magnetic resonance imaging (MRI) study. It has been used in man to aid interventional therapies and has been shown to be valuable for sampling and assessing lesions diagnosed with MRI or CT that are equivocal on ultrasonography. To date, there are no reports of the use of this modality in veterinary medicine.

OBJECTIVES

To assess whether navigational ultrasound imaging can be used to assist commonly performed interventional therapies for the treatment of equine musculoskeletal injuries diagnosed with MRI and determine the appropriateness of regional anatomical landmarks as registration sites.

STUDY DESIGN

Retrospective, descriptive clinical study.

METHODS

Horses with musculoskeletal injuries of the distal limb diagnosed with MRI scheduled for ultrasound-guided interventional therapies were evaluated (n = 17 horses with a total of 29 lesions). Anatomical landmarks used for image registration for the navigational procedure were documented. Accuracy of lesion location and success of the procedure were assessed subjectively and described using a grading scale.

RESULTS

All procedures were accurately registered using regional anatomical landmarks and considered successful based on our criteria. Anatomical landmarks were described for each lesion type. The addition of navigational imaging was considered to greatly aid the procedures in 59% of cases and added information to the remainder of the procedures. The technique was considered to improve the precision of these interventional procedures.

CONCLUSIONS

Navigational ultrasound imaging is a complementary imaging modality that can be used for the treatment of equine soft tissue musculoskeletal injuries diagnosed with MRI.

Educational benefits of fusing magnetic resonance imaging with sonograms

PURPOSE

To investigate whether providing sonographic (US)/MRI fusion images will enhance the ability of medical students and radiology residents to identify MSK anatomy on sonograms alone.

METHODS

Medical students (n = 31) and radiology residents (n = 23) were each randomly divided into two groups: Group A and Group B. Subjects in Group A were shown 10 MSK sonograms with arrows pointing to a specific anatomic structure or anatomic region. Subjects in Group B were shown the exact same 10 annotated sonograms as Group A as well as an additional fusion image consisting of an MRI of the same anatomy in the same plane fused with the sonogram without arrows. Sonograms and MRI were obtained from adult patients who consented to have their images used. The anatomic regions included the shoulder, hip, and pelvis. Both groups were given the same 10-question multiple choice examination to identify the anatomic structure that the arrow was marking on the sonogram. The transducer's location was given for every question. One minute was allowed to answer each question. The Wilcoxon rank sum test was used to assess if there was a difference between Group A and Group B in both the medical student and the radiology resident cohorts.

RESULTS

Medical students: subjects in Group A (n = 16) gave the correct answers in 33.8% of the cases (54/160). Subjects in Group B (n = 15) gave correct answers in 26.0% of the cases (39/150) (p value <0.110). Radiology residents: subjects in Group A (n = 11) gave correct answers in 40.9% of the cases (45/110). Subjects in Group B (n = 12) gave correct answers in 72.5% of the cases (87/120) (p value <0.001).

CONCLUSION

The addition of a fusion MRI/US image enhances radiology residents' ability to identify MSK US anatomy accurately compared with the sonogram alone. The medical students, however, did not show improvement with the addition of the fusion MRI/sonogram. 2014.

The diagnostic test accuracy of ultrasound for the detection of lateral epicondylitis: a systematic review and meta-analysis

BACKGROUND

The purpose of this study was to determine the diagnostic test accuracy of ultrasound for the detection of lateral epicondylitis.

METHODS

An electronic search of databases registering published (MEDLINE, EMBASE, CINAHL, AMED, Cochrane Library, ScienceDirect) and unpublished literature was conducted to January 2013. All diagnostic accuracy studies that compared the accuracy of ultrasound (index test) with a reference standard for lateral epicondylitis were included. The methodological quality of each of the studies was appraised using the QUADAS tool. When appropriate, the pooled sensitivity and specificity analysis was conducted.

RESULTS

Ten studies investigating 711 participants and 1077 elbows were included in this review. Ultrasound had variable sensitivity and specificity (sensitivity: 64%-100%; specificity: 36%-100%). The available literature had modest methodological quality, and was limited in terms of sample sizes and blinding between index and reference test results.

CONCLUSIONS

There is evidence to support the use of ultrasound in the detection of lateral epicondylitis. However, its accuracy appears to be highly dependent on numerous variables, such as operator experience, equipment and stage of pathology. Judgement should be used when considering the benefit of ultrasound for use in clinical practice. Further research assessing variables such a transducer frequency independently is specifically warranted.

LEVEL OF EVIDENCE

Level II.

Are multiple platelet-rich plasma injections useful for treatment of chronic patellar tendinopathy in athletes? a prospective study

BACKGROUND

Chronic patellar tendinopathy (PT) is one of the most common overuse knee disorders. Platelet-rich plasma (PRP) appears to be a reliable nonoperative therapy for chronic PT.

PURPOSE

To evaluate clinical and radiological outcomes of 3 consecutive ultrasound (US)-guided PRP injections for the treatment of chronic PT in athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 28 athletes (17 professional, 11 semiprofessional) with chronic PT refractory to nonoperative management were prospectively included for US-guided pure PRP injections into the site of the tendinopathy. The same treating physician at a single institution performed 3 consecutive injections 1 week apart, with the same PRP preparation used. All patients underwent clinical evaluation, including the Victorian Institute of Sport Assessment-Patella (VISA-P) score, visual analog scales (VAS) for pain, and Lysholm knee scale before surgery and after return to practice sports. Tendon healing was assessed with MRI at 1 and 3 months after the procedure.

RESULTS

The VISA-P, VAS, and Lysholm scores all significantly improved at the 2-year follow-up. The average preprocedure VISA-P, VAS, and Lysholm scores improved from 39 to 94 (P < .001), 7 to 0.8 (P < .0001), and 60 to 96 (P < .001), respectively, at the 2-year follow-up. Twenty-one of the 28 athletes returned to their presymptom sporting level at 3 months (range, 2-6 months) after the procedure. Follow-up MRI assessment showed improved structural integrity of the tendon at 3 months after the procedure and complete return to normal structural integrity of the tendon in 16 patients (57%). Seven patients did not recover their presymptom sporting level (among them, 6 were considered treatment failures): 3 patients returned to sport at a lesser level, 1 patient changed his sport activity (for other reasons), and 3 needed surgical intervention.

CONCLUSION

In this study, application of 3 consecutive US-guided PRP injections significantly improved symptoms and function in athletes with chronic PT and allowed fast recovery to their presymptom sporting level. The PRP treatment permitted a return to a normal architecture of the tendon as assessed by MRI.

Advances in noninvasive functional imaging of bone

The demand for functional imaging in clinical medicine is comprehensive. Although the gold standard for the functional imaging of human bones in clinical settings is still radionuclide-based imaging modalities, nonionizing noninvasive imaging technology in small animals has greatly advanced in recent decades, especially the diffuse optical imaging to which Britton Chance made tremendous contributions. The evolution of imaging probes, instruments, and computation has facilitated exploration in the complicated biomedical research field by allowing longitudinal observation of molecular events in live cells and animals. These research-imaging tools are being used for clinical applications in various specialties, such as oncology, neuroscience, and dermatology. The Bone, a deeply located mineralized tissue, presents a challenge for noninvasive functional imaging in humans. Using nanoparticles (NP) with multiple favorable properties as bioimaging probes has provided orthopedics an opportunity to benefit from these noninvasive bone-imaging techniques. This review highlights the historical evolution of radionuclide-based imaging, computed tomography, positron emission tomography, and magnetic resonance imaging, diffuse optics-enabled in vivo technologies, vibrational spectroscopic imaging, and a greater potential for using NPs for biomedical imaging.

Ultrasound elastography in children: establishing the normal range of muscle elasticity

BACKGROUND

Ultrasound elastography allows assessment of tissue elasticity. To the best of our knowledge, the elastography appearance of muscles in normal children has not been described.

OBJECTIVE

To determine the US elasticity of muscles in children at rest and following exercise.

MATERIALS AND METHODS

Cine elastography of biceps brachii and rectus femoris muscles was obtained at rest and after exercise in 42 healthy children (23 males, 19 females; mean: 11.2 ± 4.4 years, range: 2-18 years). Elastography scores were assigned to each clip based on a five-point color scale. Mean elastography scores and standard deviations were calculated and resting and postexercise elastography scores were compared.

RESULTS

Resting muscle elasticity was lower in the biceps brachii than in the rectus femoris (P = 0.008), and higher in the dominant than in the nondominant biceps brachii (P < 0.032). Rectus femoris elasticity was higher in males than females (P = 0.051). Postexercise muscle elasticity significantly increased in both the dominant and nondominant biceps brachii (P < 0.001) and in the rectus femoris (P < 0.001). There was no significant gender-related difference in postexercise muscle elasticity. Biceps brachii elasticity decreased and rectus femoris elasticity increased with increasing body mass index. Younger subjects had a greater change in muscle elasticity with exercise.

CONCLUSION

Resting muscle elasticity in children is significantly lower in the biceps brachii than in the rectus femoris and in the nondominant biceps brachii than in the dominant biceps brachii. Elasticity significantly increases immediately postexercise in both muscle groups; resting differences between biceps brachii and rectus femoris elasticity, and dominant and nondominant biceps brachii elasticity, do not persist after exercise. The change in muscle elasticity with exercise is higher in younger children.

3D imaging options and ultrasound contrast agents for the ultrasound assessment of pediatric rheumatic patients

The application of 3D imaging in pediatric rheumatology helps to make the assessment of inflammatory changes more objective and to estimate accurately their volume and the actual response to treatment in the course of follow-up examinations. Additional interesting opportunities are opened up by the vascularity analysis with the help of power Doppler and color Doppler in 3D imaging. Contrast-enhanced ultrasound examinations enable a more sensitive assessment of the vascularity of inflamed structures of the locomotor system, and a more accurate analysis of treatment's effect on changes in vascularity, and thereby the inflammation process activity, as compared to the classical options of power and color Doppler. The equipment required, time limitations, as well as the high price in the case of contrast-enhanced ultrasound, contribute to the fact that the 3D analysis of inflammatory changes and contrast-enhanced ultrasound examinations are not routinely applied for pediatric patients.

Advanced imaging in gout

OBJECTIVE

The purpose of this article is to describe the role of advanced imaging using ultrasound, CT, and MRI in the assessment and diagnosis of gout.

CONCLUSION

Dual-energy CT can quantitatively identify monosodium urate crystal deposits with high sensitivity and specificity within joints, tendons, and periarticular soft tissues. There are several characteristic ultrasound imaging findings, which include visualization of echogenic monosodium urate crystal deposition, tophus, and adjacent erosions. MRI is sensitive in showing soft-tissue and osseous abnormalities of gout, although the imaging findings are not specific. Gout commonly involves specific joints and anatomic structures, and knowledge of these sites and imaging appearances are clues to the correct diagnosis.

Comprehensive musculoskeletal sonographic evaluation of the hand and wrist

Sonography is widely used for evaluation of hand and wrist lesions. The easy accessibility, cost-effectiveness, and good diagnostic accuracy of sonography coupled with the numerous benefits of real-time imaging make it desirable. The aim of this article is to describe the typical sonographic appearances of lesions in the hand and wrist that are encountered frequently in routine clinical practice, such as inflammatory arthropathies, tumors, traumatic injuries, foreign bodies, and nerve entrapment syndromes. Relevant anatomy, scanning methods, and recent developments in musculoskeletal sonography are also discussed.

Muscle injuries: ultrasound evaluation in the acute phase

Muscle injuries can be classified as extrinsic or intrinsic injuries as well as contusions and lacerations, and clinical assessment is composed of the history and physical examination. Diagnostic imaging, particularly ultrasound (US) examination, is essential to a correct assessment of the severity of the injury and to exclude important complications as these two elements influence treatment decisions, prognosis and time to return to unrestricted physical activity. This paper presents the main clinical and US features of acute muscle injuries.

Detection of peripheral nerve pathology: comparison of ultrasound and MRI

OBJECTIVE

To compare accuracy of ultrasound and MRI for detecting focal peripheral nerve pathology, excluding idiopathic carpal or cubital tunnel syndromes.

METHODS

We performed a retrospective review of patients referred for neuromuscular ultrasound to identify patients who had ultrasound and MRI of the same limb for suspected brachial plexopathy or mononeuropathies, excluding carpal/cubital tunnel syndromes. Ultrasound and MRI results were compared to diagnoses determined by surgical or, if not performed, clinical/electrodiagnostic evaluation.

RESULTS

We identified 53 patients who had both ultrasound and MRI of whom 46 (87%) had nerve pathology diagnosed by surgical (n = 39) or clinical/electrodiagnostic (n = 14) evaluation. Ultrasound detected the diagnosed nerve pathology (true positive) more often than MRI (43/46 vs 31/46, p < 0.001). Nerve pathology was correctly excluded (true negative) with equal frequency by MRI and ultrasound (both 6/7). In 25% (13/53), ultrasound was accurate (true positive or true negative) when MRI was not. These pathologies were typically (10/13) long (>2 cm) and only occasionally (2/13) outside the MRI field of view. MRI missed multifocal pathology identified with ultrasound in 6 of 7 patients, often (5/7) because pathology was outside the MRI field of view.

CONCLUSIONS

Imaging frequently detects peripheral nerve pathology and contributes to the differential diagnosis in patients with mononeuropathies and brachial plexopathies. Ultrasound is more sensitive than MRI (93% vs 67%), has equivalent specificity (86%), and better identifies multifocal lesions than MRI. In sonographically accessible regions ultrasound is the preferred initial imaging modality for anatomic evaluation of suspected peripheral nervous system lesions.