Imaging of MSK infections in the ER

Musculoskeletal infections in the ER are not an uncommon presentation. The clinical context is critical in determining the suspicion for infection and degree of tissue involvement which can involve all layers from the skin to bones. The location, extent, and severity of clinically suspected infection directly relate to the type of imaging performed. Uncomplicated cellulitis typically does not require any imaging. Localized and superficial infections can mostly be evaluated with ultrasound. If there is a diffuse site (an entire extremity) or suspected deeper involvement (muscle/deep fascia), then CT is accurate in diagnosing, widely available, and performed quickly. With potential osseous involvement, MRI is the gold standard for diagnosing acute osteomyelitis; however, it has the drawbacks of longer scan times, artifacts including patient motion, and limited availability.

ACR Appropriateness Criteria® Chronic Hand and Wrist Pain: 2023 Update

Chronic hand and wrist pain is a common presenting complaint. The intricate anatomy results in a variety of pain generators-multiple bones, articular cartilage, intrinsic ligaments, triangular fibrocartilage complex, joint capsules and synovium, tendons and tendon sheaths, muscles, and nerves-in a compact space. The need for imaging and the choice of the appropriate imaging modality are best determined by the patient's presentation, physical examination, and the clinician's working differential diagnosis. Radiography is usually appropriate as the initial imaging study in the evaluation of chronic hand or wrist pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Superficial Radial Neuropathy due to Anatomic Variation: A Case Report

Superficial radial neuropathy is a purely sensory neuropathy, usually caused by nerve entrapment in the distal forearm. We report a case of superficial radial neuropathy caused by the anomalous course of the superficial radial nerve, which was found to be spirally encircling the brachioradialis tendon in the distal forearm. To the best of our knowledge, this is the first report of an anatomical variant of the superficial radial nerve that causes neuropathy.

Identification of potential diagnostic biomarkers for tenosynovial giant cell tumour by integrating microarray and single-cell RNA sequencing data

PURPOSE

Tenosynovial giant cell tumour (TGCT) is a benign hyperplastic and inflammatory disease of the joint synovium or tendon sheaths, which may be misdiagnosed due to its atypical symptoms and imaging features. We aimed to identify biomarkers with high sensitivity and specificity to aid in diagnosing TGCT.

METHODS

Two scRNA-seq datasets (GSE210750 and GSE152805) and two microarray datasets (GSE3698 and GSE175626) were downloaded from the Gene Expression Omnibus (GEO) database. By integrating the scRNA-seq datasets, we discovered that the osteoclasts are abundant in TGCT in contrast to the control. The single-sample gene set enrichment analysis (ssGSEA) further validated this discovery. Differentially expressed genes (DEGs) of the GSE3698 dataset were screened and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of DEGs were conducted. Osteoclast-specific up-regulated genes (OCSURGs) were identified by intersecting the osteoclast marker genes in the scRNA-seq and the up-regulated DEGs in the microarray and by the least absolute shrinkage and selection operator (LASSO) regression algorithm. The expression levels of OCSURGs were validated by an external dataset GSE175626. Then, single gene GSEA, protein-protein interaction (PPI) network, and gene-drug network of OCSURGs were performed.

RESULT

22 seurat clusters were acquired and annotated into 10 cell types based on the scRNA-seq data. TGCT had a larger population of osteoclasts compared to the control. A total of 159 osteoclast marker genes and 104 DEGs (including 61 up-regulated genes and 43 down-regulated genes) were screened from the scRNA-seq analysis and the microarray analysis. Three OCSURGs (MMP9, SPP1, and TYROBP) were finally identified. The AUC of the ROC curve in the training and testing datasets suggested a favourable diagnostic capability. The PPI network results illustrated the protein-protein interaction of each OCSURG. Drugs that potentially target the OCSURGs were predicted by the DGIdb database.

CONCLUSION

MMP9, SPP1, and TYROBP were identified as osteoclast-specific up-regulated genes of the tenosynovial giant cell tumour via bioinformatic analysis, which had a reasonable diagnostic efficiency and served as potential drug targets.

Magnetic Resonance Imaging (MRI) Findings in a Case of Pigmented Villonodular Synovitis of the Knee

Pigmented villonodular synovitis (PVNS) is a rare benign condition of tenosynovial proliferation that mostly affects the knee joint. In this case report, we present a 39-year-old female with a ten-year history of gradual progression in the size of painful soft tissue swelling in her left knee. Our case report emphasizes the MRI's ability to provide detailed information on tendon sheath and synovium involvement, as well as extensive extra-articular involvement and hemosiderin deposition.

Ultrasonography of fibroma of the tendon sheath in the hand and wrist

BACKGROUND

The purpose of our study was to explore the sonographic characteristics of fibromas of the tendon sheath of the hand and wrist and to evaluate the value of high frequency ultrasound in the diagnosis of FTS.

METHODS

We retrospectively reviewed the sonography of 42 patients with surgically proven FTS, including one with a relapsing tumor (43 lesions in total). The location, size, distribution, relationship with the surrounding tissue, two-dimensional gray-scale sonographic appearance and internal color blood flow of all lesions were analysed.

RESULTS

The maximum diameter ranged from 0.4 to 2.8 cm, with an average of 1.5 ± 0.6 cm. Twenty-eight lesions (65%) were associated with an adjacent tendon, while the other 15 lesions (35%) were next to the joint. Spindle or oval lesions were common, followed by irregular shape. The nodules with clear boundaries were hypoechoic and had posterior echo enhancement. Thirty-seven lesions (86%) were homogeneous, while 6 lesions (14%) had cystic components with no echo inside. Seventeen lesions (40%) had a large amount of blood flow. Nine lesions (20%) had a small amount of blood flow. The other 17 lesions (40%) had no significant blood flow.

CONCLUSIONS

The diagnosis of fibroma of the tendon sheath can be considered when ultrasound examination reveals a focal nodular mass adjacent to a tendon sheath with homogeneous hypoechogenicity and no or small or large amounts of blood flow.

Ultrasound of the Hook of Hamate Region: Pictorial Review

The hook of hamate is a complex anatomical region with many small but important structures. A sound knowledge of anatomy along with a systematic ultrasound technique can help delineate a variety of disorders. In this pictorial review, we discuss the ultrasound anatomy and the possible pathologies that can be encountered in this region.

Tendons and Tendon Sheaths of the Hand - An Update on MRI

BACKGROUND

 The tendons of the hand run in close proximity to each other and within retinacular tunnels adjacent to articular joints, while forming intersections in characteristic locations. The enclosing tendon sheaths are often sites of systemic or infectious inflammation.

METHOD

 This review article outlines the different entities of tendon and tendon sheath pathology and their manifestation in the hands. Diagnostic findings in tendon and tendon sheath disorders are illustrated using MRI imaging and discussed in context with the current literature.

RESULTS AND CONCLUSION

 Overuse may cause stenosis in the fibrous outer layer of the retinacula and the A1 annular ligaments as well as tendinosis. In contrast, proliferative tenosynovitis is a disease of the synovial inner layer of the tendon sheath with tendon infiltration and tendinitis. Pyogenic tenosynovitis favors the flexor compartments. Because of the narrow spaces in the hand, a high-resolution MRI technique must be used.

KEY POINTS

  · Diseases of the tendons and tendon sheaths may have a mechanical, degenerative, metabolic, systemic inflammatory, or infectious etiology.. · Fibrous tunnels and bony prominences in close proximity to crossing tendons predispose to mechanical tendon irritation at typical sites of the hand.. · Stenosing tenovaginitis occurs in the fibrous layer of the extensor retinaculum or the A1 annular pulleys. The most frequent manifestations are the "trigger finger" and de Quervain disease.. · Proliferative tenosynovitis affects the synovial layer of the tendon sheaths before infiltrating the tendons. The classic representative is rheumatoid arthritis..

CITATION FORMAT

· Schmitt R, Hesse N, Grunz JP. Tendons and Tendon Sheaths of the Hand - An Update on MRI. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1826-1007.

Rice bodies in the wrist

Rice bodies are a rare finding in medicine and offer a therapeutic challenge. As their occurrence varies over multiple rheumatic as well as infectious diseases, multiple hypotheses have been made about their origin. While rice bodies are most frequently reported in the shoulder and knee joints, flexor tendon synovitis with accompanying rice bodies is rarer. We report a case of extensive flexor tenosynovitis with rice bodies in the wrist in a 90-year-old patient with seronegative rheumatoid arthritis. The patient reported a 5-month history of painful swelling of the right wrist. Ultrasound showed pronounced swelling of the synovial tissue of the flexor tendons. Laboratory test were negative for rheumatology tests with normal C-reactive protein and sedimentation rates. T2-weighted magnetic resonance imaging demonstrated an extensive synovitis reaching from the distal forearm into the hand with inclusions, better known as rice bodies. Synovectomy including carpal tunnel release was performed with dissection of the mass revealing an extensive synovitis with a multitude of rice bodies. Histopathology showed lymphohistiocytic infiltrates consistent with rheumatoid nodules. After surgery, the patient regained full function of the wrist within 2 weeks without any pain or remaining mass in the affected limb.

How to Report: Wrist MRI

Knowledge of the imaging anatomy of the wrist is essential for reporting magnetic resonance imaging (MRI). This familiarity should include the carpal bones, tendons (extensor and flexor compartments), triangular fibrocartilage complex (TFCC), intrinsic and extrinsic ligaments, and nerves, especially the median and ulnar nerves. Limitations of MRI in visualizing these structures, particularly the intrinsic ligaments and the TFCC, need to be considered. This article outlines the main features to comment on when reporting common conditions of the wrist on MRI, with some examples of terminology that can be used to describe these abnormalities.

Sonography of tendon pathology in the hand and wrist

Traumatic and non-traumatic tendon lesions are common at the wrist and hand. For the diagnosis, therapy management, and long-term prognosis of tendon lesions, a detailed understanding of the complex anatomy and knowledge of typical injury patterns is crucial for both radiologists and clinicians. Improvements in high-resolution ultrasound are producing high-quality images of the superficial tendinous and peritendinous structures. Thus, ultrasound is a valuable first-choice tool for visualizing traumatic, inflammatory, and degenerative conditions of the extensor and flexor tendons, particularly with the advantage of possible dynamic examination. The additional use of duplex-Doppler and power Doppler ultrasound imaging is recommended for detection of tenosynovitis in overuse injury, inflammatory disease, infection, and after traumatic conditions. In traumatic tendon injuries, knowing the precise injury zone is important for treatment decision-making. In cases of tendon rupture, the radiologist should report the tear type (i.e., complete or partial-thickness) and assess the degree of tendon retraction and associated avulsion injury, including the degree of fragment displacement. The function of intact flexor tendons may be impaired by thickening, strain, or rupture of corresponding annular pulleys. This review describes in detail the typical ultrasound imaging features of common pathologies of hand and wrist tendons, including annular pulley lesions.

Pulley, Flexor, and Extensor Tendon Injuries of the Hand

Tendon injuries represent the second most common injury of the hand (after fractures) and are a common scanning indication in radiology. Pulley injuries are very frequent in rock climbers with the A2 pulley the most commonly affected. Tendon and pulley injuries can be reliably evaluated using ultrasound (US) and magnetic resonance imaging (MRI). US can be postulated as a first-line imaging modality, allowing dynamic examination. MRI is essential for cases with ongoing diagnostic doubt post-US and also for preoperative pulley reconstruction assessment.

Integrated thermoacoustic and ultrasound imaging based on the combination of a hollow concave transducer array and a linear transducer array

To integrate the high resolution of ultrasound imaging (UI) and the high tissue specificity of thermoacoustic imaging (TAI) and to achieve an easy and precise co-registration of the two different imaging modalities, we present and demonstrate a hybrid thermoacoustic and ultrasound (TA/US) imaging system based on the combination of a novel hollow concave array and a commercial linear array. This TA/US imaging system can provide enhanced imaging of both tissues' mechanical and dielectric properties. We verified the effective imaging performance of the hybrid TA/US system using tissue phantom experiments.In vivoTA/US imaging of the wrist and foot in healthy volunteers was also demonstrated using the hybrid system. This hollow concave array provided enhanced imaging performance for TAI because of its wide angular coverage with an optimal center frequency, showing a large effective imaging field of view (FOV) and improved images with high contrast and superior quality. Compared with stand-alone UI or TAI, the hybrid TA/US imaging presented more complete tissue anatomical structures, like skin, muscles, tendons, blood vessels, and bones for possible human disease diagnosis, although the US image quality using the hybrid system was slightly lower because the distance between the tissue and commercial ultrasound array was not ideal. This study suggests that the hybrid TA/US imaging approach has the potential to become a clinical tool for diagnosis of diseases in the wrist and foot.

3T Magnetic Resonance Imaging of the Wrist Tendons

Magnetic resonance imaging (MRI) is frequently used in the imaging evaluation of wrist pain. The complex anatomy of the wrist can be demonstrated by MRI. Three tesla (3 T) MRI offers increased signal-to-noise ratio relative to 1.5 T MRI allowing for higher soft tissue contrast and better spatial resolution. The resulting increase in conspicuity of fine anatomic detail may improve the detection and characterization of wrist pathology. In this article, we will review the anatomy, normal variants, and common pathologies of the wrist tendons as evaluated on 3 T MRI.

Multimodality Pitfalls of Wrist Imaging With a Focus on Magnetic Resonance Imaging: What the Radiologist Needs to Know

Numerous pitfalls are frequently encountered at multimodality imaging of the wrist, which may mimic various tendinous, osseous, capsuloligamentous, muscular, and neurovascular pathologic conditions. These pitfalls may be secondary to variant anatomy, artifactual due to magnetic resonance imaging or sonographic technique, or represent varying ranges of structure-specific normal including a spectrum of findings associated with aging in asymptomatic subjects. When an imaging finding of questionable significance is encountered, it is critical that the interpreting radiologist make every attempt to review any relevant clinical information in an effort to determine whether the imaging findings in question may account for the patient's presenting symptomology. In order to accurately diagnose true pathology at wrist imaging, it is imperative that the radiologist be familiar with the pitfalls discussed throughout this manuscript that may mimic disease. This familiarity will allow the radiologist to provide a more useful report for referring providers focusing on true pathology while eliminating potentially confusing or misleading findings which are inconsistent with the patient's clinical presentation.

Unusual, but important, peri- and extra-articular manifestations of rheumatoid arthritis: a pictorial essay

Ultrasonography is a useful technique to detect soft tissue changes of rheumatoid arthritisnot only synovitis, but also tenosynovitis, bursitis, and enthesitis-even at a subclinical stage. However, radiologists tend to focus on synovitis in daily practice, and unusual peri- or extra-articular manifestations of rheumatoid arthritis are difficult to detect at the initial presentation. This pictorial essay describes a broad spectrum of ultrasonographic findings in tendons, bursae, ligaments, subcutaneous tissues, bones, and nerves to assist in the accurate diagnosis of rheumatoid arthritis.

Magnetic resonance imaging of the wrist and hand

The anatomy of the wrist and hand is complex and contains numerous small structures. Magnetic resonance imaging (MRI) is often an ideal imaging modality in the assessment of various traumatic and pathologic conditions of this region, and it is frequently performed after initial radiographs. In this manuscript we describe the normal anatomy, imaging techniques, and MRI findings of various traumatic and pathologic conditions of the wrist and hand including occult fractures, osteonecrosis, ligamentous and tendon injuries, and entrapment neuropathies.

Imaging of the Hand and Wrist

Imaging plays a key role in the evaluation and treatment planning of hand and wrist injuries in athletes. Depending on the suspected injury, a combination of conventional radiographs, computed tomography, magnetic resonance imaging, magnetic resonance arthrography, and/or ultrasound may be indicated. This article reviews the strengths and limitations of these imaging modalities and how they can be utilized in commonly encountered clinical questions.

Imaging of ulnar-sided wrist pain

Ulnar-sided wrist pain is a complex entity to diagnose clinically and frequently requires imaging to help confirm or determine the diagnosis. This article reviews the imaging and the logical imaging pathway of the common causes of ulnar-sided wrist pain, and illustrates various pathologies. It also discusses appropriate imaging modalities for various conditions. The causes of ulnar-sided wrist pain are stratified according to the affected anatomical structures, such as bony, soft tissue or neurovascular aetiologies. This review provides a handy imaging framework for non-radiologist clinicians of the common conditions producing ulnar-sided wrist pain. A linked article (10.12968/hmed.2019.80.8.456) detailing the diagnosis of ulnar-sided wrist pain is included in this issue.

Imaging musculoskeletal soft tissue infections

Musculoskeletal soft tissue infections are not uncommonly encountered in both the clinic and Emergency Department setting. The clinical diagnosis is not always evident as these infections can have variable presentations depending on the duration and depth of disease extension through the soft-tissue layers. Imaging often plays an important role in diagnosing the infection, defining the extent of involvement, directing tissue sampling, and in monitoring treatment response. After initial radiographs, ultrasound (US) is often the next modality utilized to evaluate patients with suspected soft tissue infections given its low cost, availability, portability, and potential for real-time guidance of fluid aspiration. The widespread use of cross-sectional imaging with magnetic resonance imaging (MRI) and computed tomography (CT) has greatly increased the radiological diagnosis in conditions where US may be limited. In addition, CT and MRI allow a thorough evaluation of disease extension, including assessment of joint spaces, tendons, and osseous changes indicative of bone involvement. This review will focus on the radiological findings of soft tissue infections on US, CT, and MRI.

Desmoplastic fibroblastoma mimicking tenosynovial giant cell tumor encasing a tendon of the foot

Desmoplastic fibroblastoma is an uncommon, benign fibrous soft tissue tumor that usually occurs in the arms, shoulders, neck, hands, and feet in the fifth to seventh decades of life. In general, it is commonly located in the subcutaneous tissue and skeletal muscle. The authors report an unusual case of a desmoplastic fibroblastoma mimicking tenosynovial giant cell tumor encasing a tendon of the foot in a 72-year-old woman. Ultrasonography revealed an inhomogeneously hypoechoic lobulated soft tissue lesion completely wrapped around the extensor digitorum longus tendon. Color Doppler study revealed increased vascularity in the internal and peripheral portions of the lesion. Magnetic resonance imaging revealed a well-defined, lobulated soft tissue mass encasing the extensor digitorum longus tendon with predominantly isointense signal with some areas of hypointense signal on T1-weighted images, predominantly hyperintense signal with some areas of hypointense signal on T2-weighted images, and inhomogeneous enhancement on fat-suppressed contrast-enhanced T1-weighted images. Surgical excision was performed, and the mass was diagnosed on pathological examination as a desmoplastic fibroblastoma. There has been no previously published radiologic case of a desmoplastic fibroblastoma encasing a tendon of the foot in the literature.

Technical Note: Anti-phase microwave illumination-based thermoacoustic tomography of in vivo human finger joints

PURPOSE

Thermoacoustic tomography (TAT) has been studied to image joints. While several joint tissues could be thermoacoustically imaged, tendons and bone could not be recovered completely or clearly. The purpose of this study was to overcome this limitation.

METHODS

We developed a novel TAT system based on anti-phase microwave illumination method to image the proximal interphalangeal joint and middle phalanx of a right middle finger from a healthy volunteer. The performance of this new system for imaging joints and tendons was compared with that by in-phase microwave illumination and a conventional pyramidal horn antenna.

RESULTS

Anti-phase microwave illumination can produce relatively homogeneous electric (E)-Field distributions inside the joint tissues. The homogeneous E-Field distributions can enhance the detectability of flexor tendon and extensor tendon. Anti-phase microwave illumination could image the flexor tendon, and extensor tendon and bone, which were not clearly imaged by the in-phase microwave illumination or by the horn antenna. The images generated by the in-phase microwave illumination and pyramidal horn antenna were almost identical in terms of the tissue types they imaged.

CONCLUSIONS

Anti-phase illumination can overcome the limitation associated with the conventional TAT by adding the ability of completely delineating tendons and bone in the joints. This study paves the way for us to continue the study and to validate its utility in detection of joint diseases.

Enhancement of Musculoskeletal Radiology Resident Education with the Use of an Individual Smart Portable Ultrasound Device (iSPUD)

RATIONALE AND OBJECTIVES

Many medical specialties have incorporated portable ultrasound into their educational curriculum. Our objective was to determine the utility of an individual smart portable ultrasound device (iSPUD) as an educational tool in resident and fellowship Musculoskeletal Radiology training.

MATERIALS AND METHODS

After Institutional Review Board approval, volunteer radiology trainees were instructed to use the iSPUD (Philips Lumify ultrasound probe and Samsung Galaxy Tab S2 8 inch tablet), asked to identify 10 wrist structures with the iSPUD and completed a Likert scale-based, pretest survey. Trainees were then given the iSPUD for 3 days of independent scanning practice. Afterward, trainees were asked to identify the same 10 wrist structures with the iSPUD and to complete a Likert scale-based, post-test survey.

RESULTS

Twenty trainees volunteered to participate. Trainee performance on the 10-wrist structure identification test with the iSPUD resulted in a pretest mean number correct of 2.5 ± 2.16 and a post-test mean number correct of 9.85 ± 0.37 (p < 0.001). On the pretest survey, 68.42% (13/20) had never performed and 42.11% (8/20) had never interpreted a musculoskeletal ultrasound. On the post-test survey, 18/20 (94.74%) strongly agreed that access to an iSPUD would improve their ability to perform musculoskeletal ultrasound, improve ultrasound-guided interventional skills, and help them become better Radiologists.

CONCLUSION

The use of an iSPUD as a tool in Musculoskeletal Radiology resident and fellow education can improve clinical ultrasound skills, build trainee technical confidence during diagnostic ultrasound procedures, and help trainees achieve their goal of becoming a competent Radiologist.

Thermoacoustic Tomography of In Vivo Human Finger Joints

OBJECTIVE

the purpose of this study was to demonstrate the potential of thermoacoustic tomography (TAT) to reveal anatomic structures of in vivo human finger joints.

METHODS

all the participating volunteers provided written informed consent. Eight healthy middle and index fingers from five volunteers were imaged in vivo by our TAT imaging system. Axial T1-weighted MR imaging (3.0 T) was used to validate the TAT findings. Comparative analyses between TAT and MRI images were performed in two dimension for all the fingers imaged. Three-dimensional (3-D) images and animations were also obtained for some of the fingers thermoacoustically scanned.

RESULTS

various intra- and extra-articular tissues were identified in TAT images in high fidelity. These TAT images matched well with the MRI images. Both the 3-D images and animations effectively displayed the extension and transformation of the entire finger along the axis.

CONCLUSION

TAT can noninvasively visualize anatomic structures of the finger joints based on the electrical properties of the joint tissues. The results obtained indicate that TAT may have the potential to contribute to the detection of joint and bone diseases.

SIGNIFICANCE

this study represents the first for TAT of in vivo human joints and fingers. This study reveals that TAT can effectively recover both soft and hard tissues of the healthy interphalangeal joints, which provides a foundation for its clinical application to detection and diagnosis of joint and bone diseases.

Diagnosing extensor carpi ulnaris tendon dislocation with dynamic rotation MRI of the wrist

OBJECTIVE

The purpose of this study was to retrospectively correlate the kinematic dynamic rotation MRI (DR-MRI) of the wrist for assessment of extensor carpi ulnaris (ECU) tendon subluxation and dislocation.

MATERIAL AND METHODS

The presence of an ECU tendon subluxation or dislocation on the DR-MRI report was correlated to findings of the surgical report.

RESULTS

DR-MRI findings showed an ECU subluxation in 12 cases and an ECU dislocation in 13 cases. Surgery showed an ECU subluxation in 13 cases and an ECU dislocation in 12 cases (ĸ = 0.92).

CONCLUSION

DR-MRI is a feasible method to visualize ECU tendon subluxation and dislocation.

Sonography of Non-neoplastic Disorders of the Hand and Wrist Tendons

Tendon disorders commonly cause hand and wrist disability and curtail the performance of work-related duties or routine tasks. Imaging is often needed for diagnosis, but it requires knowledge of the complex anatomic structures of the tendons of the hand and wrist as well as familiarity with related disorders. This review article aims to provide medical professionals with guidelines for the sonographic assessment of the tendons of hand and wrist and related disorders. Sonographic features of tendon disorders affecting the hand and wrist are described here, specifically: infectious tenosynovitis; tendon rupture or tearing; stenosing forms of tenosynovitis such as De Quervain disease and trigger finger; intersection syndrome; insertional tendinopathy; several forms of tendinous instability such as extensor carpi ulnaris instability, climber finger, and boxer knuckle; and tendinopathy in inflammatory rheumatic diseases. Postsurgical evaluation of the hand and wrist tendons is also discussed, including the healthy and pathologic appearances of operated tendons as well as impingement from orthopedic hardware. In conclusion, sonography is effective in assessing the tendons of the hand and wrist and related disorders and represents a valuable tool for diagnosis.

MRI of the Extensor Tendons of the Wrist

OBJECTIVE

This article reviews the normal anatomy of the extensor tendons of the wrist as well as the clinical presentation and MRI appearances of common tendon abnormalities, such as tears, tenosynovitis, intersection syndromes, and associated or predisposing osseous findings. Treatment options are also discussed.

CONCLUSION

We review the anatomy and normal MRI appearance of the clinically important dorsal extensor tendons of the wrist, in addition to the spectrum of abnormalities associated with these tendons.

Variations of anatomy on MRI of the first extensor compartment of the wrist and association with DeQuervain tenosynovitis

OBJECTIVE

To study anatomical variations on MRI of the first extensor compartment of the wrist in DeQuervain tenosynovitis (DQT).

MATERIALS AND METHODS

A retrospective search for DQT patients yielded 47 subjects (51 ± 15 years, 36 female, 11 male). The age-matched control group (normal first extensor compartment) was 49 ± 15 years (29 female, 18 male). Two independent readers reviewed: the number of abductor pollicis longus (APL) tendon slips, tendon sheath septations (compartmentalization), and APL and EPB cross-sectional area (CSA) at the radial styloid. A tendon slip was defined as a discrete structure for ≥5 contiguous slices with its own insertion.

RESULTS

The distribution of APL tendon slips was different for the DQT and control groups (Reader 1/Reader 2: P = 0.0001 and 0.001). The most common arrangement for both groups was two APL tendon slips. One tendon slip was less common (P = 0.03 and 0.1) and compartmentalization was more common (P = 0.003; < 0.0001) for the DQT group than the control group. There was no difference in tendon slip insertions on one or multiple bones (P = 0.1; 0.7). APL and EPB compartment CSAs were also higher for the DQT group (combined first extensor compartment area: 21.3 ± 7.6 mm²; 21.0 ± 7.1) than the control group (17.2 ± 3.8; 17.1 ± 3.9) (P = 0.002; 0.002).

CONCLUSION

We found a statistically significantly increased proportion of supernumerary tendon slips and compartmentalization of the first extensor compartment in patients with DQT and greater CSA of the first extensor compartment at the radial styloid, consistent with previous anatomical, surgical, and ultrasound studies.