Ultrasound of the Gruberi Bursa With Cadaveric and MRI Correlation.

OBJECTIVE: The purpose of this study was to describe the appearance and ultrasound characteristics of the Gruberi bursa using a cadaveric model and retrospective ultrasound imaging review. MATERIALS AND METHODS: For the cadaveric study, ultrasound of the dorsolateral ankle of a foot-ankle specimen was performed and was followed by injection of latex between the extensor digitorum longus (EDL) tendons and the talus and dissection. For the ultrasound imaging review, the radiology database was searched for ultrasound studies performed from September 15, 2000, through April 1, 2015, to identify subjects with a dorsolateral foot or ankle fluid collection detected on ultrasound. Images were retrospectively reviewed to characterize the location and size of the fluid collection, assess for the number of locules, and evaluate the compressibility of the fluid collection. It was determined whether the ultrasound findings were significantly different from chance: CI and p values were obtained from performing a test for one proportion. RESULTS: Dissection of a cadaveric specimen revealed latex within a well-defined region between the EDL tendons and the dorsolateral talus; this location is consistent with a Gruberi bursa. For the image review, the imaging examinations of 162 subjects (age range, 16-88 years; 31 male subjects and 131 female subjects) were reviewed. On the ultrasound images, a fluid collection with its epicenter between the dorsolateral talus and EDL was found in 93% of ankles. Of the fluid collections identified on ultrasound, 98% were unilocular and 94% were anechoic. Of these fluid collections, 133 were assessed for compressibility, and 89% were compressible. The positive findings for a Gruberi bursa that were different from chance (p < 0.0001) were a fluid collection being located between the EDL tendons and the dorsolateral talus and being unilocular, anechoic, and compressible. CONCLUSION: The Gruberi bursa characteristically is located between the EDL and the talus; on ultrasound, the Gruberi bursa is most commonly unilocular, anechoic, and compressible.

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.

Ultrasound Findings of Delayed-Onset Muscle Soreness.

The purpose of this series was to retrospectively characterize the ultrasound findings of delayed-onset muscle soreness (DOMS). The Institutional Review Board approved our study, and informed consent was waived. A retrospective search of radiology reports using the key phrase "delayed-onset muscle soreness" and key word "DOMS" from 2001 to 2015 and teaching files was completed to identify cases. The sonograms were reviewed by 3 fellowship-trained musculoskeletal radiologists by consensus. Sonograms were retrospectively characterized with respect to echogenicity (hypoechoic, isoechoic, or hyperechoic), distribution of muscle involvement, and intramuscular pattern (focal versus diffuse and well defined versus poorly defined). Images were also reviewed for muscle enlargement, fluid collection, muscle fiber disruption, and increased flow on color or power Doppler imaging. There were a total of 6 patients identified (5 male and 1 female). The average age was 22 years (range, 7-44 years). Of the 6 patients, there were a total of 11 affected muscles in 7 extremities (1 bilateral case). The involved muscles were in the upper extremity: triceps brachii in 27% (3 of 11), biceps brachii in 18% (2 of 11), brachialis in 18% (2 of 11), brachioradialis in 18% (2 of 11), infraspinatus in 9% (1 of 11), and deltoid in 9% (1 of 11). On ultrasound imaging, the abnormal muscle was hyperechoic in 100% (11 of 11), well defined in 73% (8 of 11), poorly defined in 27% (3 of 11), diffuse in 73% (8 of 11), and focal in 27% (3 of 11). Increased muscle size was found in 82% (9 of 11) and minimal hyperemia in 87.5% (7 of 8). The ultrasound findings of DOMS include hyperechoic involvement of an upper extremity muscle, most commonly appearing well defined and diffuse with increased muscle size and minimal hyperemia.

Knee MRI: Vascular Pathology.

OBJECTIVE: Patients who undergo knee MRI for presumed musculoskeletal disease can have unexpected vascular findings or pathology in the imaged field. Some vascular processes are limb threatening and affect treatment planning and patient outcome. CONCLUSION: Unexpected vascular findings on knee MRI can range from incidental to symptomatic and can include such processes as variant anatomy, aneurysm, traumatic injury, and neoplasm. The assessment for vascular pathology should be a key component of every radiologist's search pattern when evaluating knee MRI.

Ultrasound of the thumb ulnar collateral ligament: technique and pathology.

OBJECTIVE: The ulnar collateral ligament (UCL) serves an important role in stabilizing the thumb metacarpophalangeal (MCP) joint. The adductor pollicis aponeurosis lies superficial to the UCL, and plays an important role in the pattern of injury and treatment of UCL tears. Ultrasound is a cost-effective and accurate method to evaluate the UCL, allowing dynamic imaging and contralateral comparison in the setting of acute injury. The purpose of this video article is to show the optimal technique for sonographic evaluation of the UCL. CONCLUSION: UCL tears are common injuries involving the base of the thumb, and correct diagnosis of a Stener lesion aids in timely surgical management. Performing ultrasound evaluation in the long axis with use of dynamic imaging allows excellent visualization of the UCL and adductor pollicis aponeurosis. With application of appropriate technique, ultrasound is highly accurate in diagnosing Stener lesions.

Sonography of the accessory head of the biceps brachii.

Anatomic variations in the anterior aspect of the shoulder, such as an accessory head of the biceps brachii muscle, are not uncommon. The magnetic resonance imaging and arthroscopic appearance of the accessory head of the biceps brachii has been recently described. This series demonstrates the sonographic appearance of the accessory head of the biceps brachii in the bicipital groove. It is an asymptomatic, flat, echogenic structure with average measurements of 7.7 × 1.2 mm in cross section. Knowledge of this anatomic variant can avoid the misdiagnosis of a longitudinal split tear and improve the accuracy of sonography.

Value of ultrasound before joint aspiration.

OBJECTIVE: The purpose of this article is to illustrate and discuss the value of ultra-sound screening before joint aspiration. CONCLUSION: Before joint aspiration, ultrasound assessment of the overlying and surrounding soft tissues requires little time and is relatively inexpensive. Bursal fluid collections, soft-tissue abscesses, and other fluid collections that would be undetected with fluoroscopy or blind aspiration can thus be identified. Ultrasound screening before joint aspiration can aid diagnosis and decrease the risk of iatrogenic complications.

The role of sonography in differentiating full versus partial distal biceps tendon tears: correlation with surgical findings.

OBJECTIVE: The purpose of this study was to determine the accuracy of ultrasound for distinguishing complete rupture of the distal biceps tendon versus partial tear and versus a normal biceps tendon. Surgical findings were used as the reference standard in cases of tear. Clinical follow-up was used to assess the normal tendons. MATERIALS AND METHODS: The study population consisted of 45 consecutive elbow ultrasound cases with surgical confirmation and six cases of a clinically normal distal biceps tendon that underwent elbow ultrasound for suspicion of injury to a structure other than the biceps tendon. Cases underwent consensus review by two fellowship-trained musculoskeletal radiologists. Tendons were classified as normal biceps tendon, partial tear, or complete tear. The presence or absence of posterior acoustic shadowing at the distal biceps tendon was also assessed. The ultrasound findings were then compared with the surgical findings and clinical follow-up. RESULTS: Ultrasound showed 95% sensitivity, 71% specificity, and 91% accuracy for the diagnosis of complete versus partial distal biceps tendon tears. Posterior acoustic shadowing at the distal biceps had sensitivity of 97% and accuracy of 91% for indicating complete tear versus partial tear and sensitivity of 97%, specificity of 100%, and accuracy of 98% for indicating complete tear versus normal tendon. CONCLUSION: Ultrasound can play a role in the diagnosis of elbow injuries when a distal biceps brachii tendon tear is suspected.

Extra-abdominal desmoid tumor with osseous involvement.

Deep fibromatoses, or desmoid tumors, arise from connective tissue. Imaging can frequently suggest the diagnosis of these aggressive, benign neoplasms. Cross-sectional imaging commonly demonstrates an enhancing solid mass that resembles scar tissue, typically without osseous involvement. We report a case of an extra-abdominal desmoid tumor involving the teres minor muscle in a symptomatic 42-year-old woman with unusual features of medullary involvement and negative nuclear beta-catenin staining.

Sonography of partial-thickness tears of the distal triceps brachii tendon.

OBJECTIVES: The purpose of this study was to retrospectively characterize the sonographic appearance of partial-thickness distal triceps brachii tendon tears. METHODS: After Institutional Review Board approval, sonographic records were searched for patients who had an unequivocal partial-thickness triceps tendon tear at surgery or magnetic resonance imaging. Sonograms were retrospectively characterized for tendon discontinuity of the superficial or deep layers, tendon retraction, osseous fracture fragments, and joint effusion. Imaging findings were then compared with clinical, imaging, and surgical results. RESULTS: Five patients had a partial-thickness distal triceps brachii tendon tear at surgery (n = 4) or magnetic resonance imaging (n = 1). All cases only involved the superficial tendon layer (combined long and lateral heads) with retraction of a fractured olecranon enthesophyte fragment. The deep tendon layer (medial head) was intact in all cases with no joint effusion. CONCLUSIONS: Partial-thickness distal triceps brachii tendon tears have a characteristic appearance with selective superficial tendon retraction and olecranon enthesophyte avulsion fracture.

Sonography of benign palpable masses of the elbow.

The purpose of this pictorial essay is to show the sonographic appearances of benign masses found in and around the elbow, including fat-containing tumors, fibrous tumors, vascular lesions, selected skin lesions, and other miscellaneous lesions. Sonographic features, including the use of dynamic and color Doppler imaging, can be helpful in characterizing these masses and in narrowing the differential diagnosis.

Entrapment neuropathies I: upper limb (carpal tunnel excluded).

Several entrapment neuropathies of the upper extremity can cause hypoechoic swelling and nerve compression as seen at ultrasound. The ulnar nerve can be compressed at the cubital tunnel of the elbow and Guyon's canal at the wrist. The deep branch of the radial nerve can be compressed at the supinator muscle at the elbow, and the superficial radial nerve may be compressed at the dorsal wrist (Wartenberg's syndrome). In addition to compression at the carpal tunnel, the median nerve may be compressed at the elbow, related to a supracondylar process or by the pronator teres. Knowledge of these key anatomical sites of potential nerve compression is essential for accurate diagnosis of entrapment neuropathies.

The sternoclavicular joint: can imaging differentiate infection from degenerative change?

OBJECTIVE: The purpose of this study was to determine if there are imaging and clinical findings that can differentiate a septic sternoclavicular joint from a degenerative one. MATERIALS AND METHODS: Search of radiology reports from 2000-2007 revealed 460 subjects with imaging of the sternoclavicular joint, of whom 38 had undergone aspiration or biopsy. The final study group consisted of nine subjects with pathologic proof of sternoclavicular joint infection and ten subjects with pathologic and clinical findings excluding infection consistent with degenerative change. Available ultrasound, computed tomography (CT), and magnetic resonance (MR) images were retrospectively reviewed, and echogenicity, capsular distention, erosions, cysts, hyperemia or enhancement, and intensity of bone marrow signal were recorded. Clinical data were also reviewed. FINDINGS: The findings significantly associated with sternoclavicular joint infection included degree and extent of capsular distention. With infection, average joint distention was 14 mm (range 10-20 mm) and extended over the sternum and clavicle in 60% compared to 5 mm (range 3-8 mm) with degeneration only extending over the clavicle. Other findings significantly associated with infection included bone marrow fluid signal on magnetic resonance imaging (MRI), elevated Westergren red blood cell sedimentation rate, and fever. The two findings significantly associated with degeneration were subchondral cysts on CT and female gender. Other imaging and clinical variables showed no significant differences between infection and degenerative change. CONCLUSION: The clinical and imaging findings significantly associated with sternoclavicular joint infection included joint capsule distention of 10 mm or greater, extension over both the clavicle and sternum, adjacent fluid signal bone marrow replacement, elevated Westergren red blood cell sedimentation rate, and fever.

Sonographic evaluation of Lisfranc ligament injuries.

OBJECTIVE: This study characterized the sonographic appearances of Lisfranc injuries. METHODS: Sonography reports (2000-2007) were searched for "Lisfranc," resulting in 10 patients. Sonographic images of affected and asymptomatic contralateral feet were reviewed, recording the thickness of the dorsal ligament between the first (medial) cuneiform (C1) and second metatarsal (M2) ligaments, distance between C1 and M2, and change in this distance with weight bearing, hyperemia, and fractures. Correlations were made to clinical, surgical, and other imaging findings. RESULTS: In 5 asymptomatic feet, the dorsal C1-M2 ligament was 0.9 to 1.2 mm thick, and the C1-M2 distance was 0.5 to 1 mm. Of the symptomatic feet, 1 group (n=3) had normal sonographic findings (thickness, 0.9-1.1 mm; distance, 0.6-0.7 mm; all had normal radiographic findings and follow-up, and 1 had normal magnetic resonance imaging [MRI] findings). Another group (n=3) had abnormal hypoechogenicity and thickening of the dorsal C1-M2 ligament (1.4-2.3 mm), a normal C1-M2 distance (0.6-0.7 mm), and no widening with weight bearing (1 of 1), consistent with a ligament sprain (1 had normal computed tomographic [CT] findings, and all had uneventful follow-up). The third group (n=4) had nonvisualization of the dorsal C1-M2 ligament, an increased C1-M2 distance of 2.5 to 3.1 mm, and further widening with weight bearing (3 of 4) from Lisfranc ligament disruption (shown at surgery in 2, MRI in 1, and CT in 1). CONCLUSIONS: Nonvisualization of the dorsal C1-M2 ligament and a C1-M2 distance of 2.5 mm or greater were indirect signs of a Lisfranc ligament tear. Dynamic evaluation with weight bearing showed widening of the space between C1 and M2.

Medical Leadership: A Manifesto for Radiologists.

Leadership is much discussed but also often misunderstood. For radiologists, leadership may seem irrelevant or, even worse, an onerous addition to their busy careers. It is important that radiologists understand the relevance and importance of good leadership for the success of departments and groups. There are many obstacles to radiologists becoming effective leaders, including personal resistance that is due to myths and misunderstandings, the time and effort (and money) required to learn to lead well, as well as others including the shift in perspective that comes from focusing on organizational success rather than individual career success. This manifesto will explore the what, the why, and the how of becoming a leader in radiology and why it is critical for individuals, their organizations, academic departments, private practice groups, and others, as well as the larger house of radiology.

Ultrasound of the hindfoot and midfoot.

Ultrasound has demonstrated great utility and accuracy for imaging the hindfoot and midfoot. Its advantages include its capacity to allow evaluation during dynamic maneuvers, imaging of patients who cannot undergo MR imaging, and real-time evaluation of the symptomatic site. It can also reveal abnormalities that are not apparent during static imaging. This article makes the case that radiologists should continue to be experts in all aspects of musculoskeletal imaging, including ultrasound or the business will be taken over by other specialties. If musculoskeletal ultrasound is lost, additional modalities such as MR imaging may be lost as well. Radiologists, with their expertise and years of training, are uniquely suited to apply this versatile modality to foot and ankle pathology.

Sonography of fat necrosis involving the extremity and torso with magnetic resonance imaging and histologic correlation.

OBJECTIVE: The purpose of this study was to describe the sonographic appearance of pathologically proven isolated fat necrosis involving the extremities or torso with magnetic resonance imaging (MRI) correlation. METHODS: A query of the Department of Pathology database at our institution for the diagnosis of fat necrosis resulted in 1539 cases. Review of the cases and medical records excluded cases without sonographic imaging, those involving the breast, and those within or adjacent to a primary process, including masses or prior surgery, which resulted in a total of 5 cases of primary fat necrosis, 2 of which were evaluated with MRI. Sonograms were reviewed by 2 musculoskeletal radiologists and characterized with regard to location, echogenicity, shadowing, posterior through-transmission, a hypoechoic rim or halo, definition of borders, homogeneity, a mass effect, and vascularity. The patient medical records, histologic results, and MRI findings were also reviewed. RESULTS: Of the 5 cases of isolated fat necrosis, 2 involved the torso and 3 the lower extremities. On sonography, all were located in the subcutaneous fat; 2 were isoechoic; 3 were hyperechoic; 2 had a hypoechoic halo; none showed shadowing or posterior through-transmission; 2 were well defined; 3 were masslike; 4 were heterogeneous; and 2 showed increased flow on color or power Doppler imaging. Magnetic resonance imaging showed an intermediate signal and either diffuse or ring enhancement. CONCLUSIONS: Isolated fat necrosis of the extremities and torso had 2 sonographic appearances, which included a well-defined isoechoic mass with a hypoechoic halo and a poorly defined hyperechoic region in the subcutaneous fat.