Radiographic/MR Imaging Correlation of the Wrist.

In this review article, the authors discuss the imaging features of the most common pathologic conditions of the wrist by putting the emphasis on radiographic and MR imaging correlations. A topographic approach based on the 3 functional columns of the wrist (radial, central, and ulnar) serves as a framework. The pathologic conditions are classified, based on the structures involved, as fractures, ligament injuries, arthropathies, bone abnormalities, and tendinopathies. The authors describe and evaluate classic radiographic signs and explain how they correlate with MR imaging. The advantages and limitations of each technique are thoroughly discussed as well as other imaging modalities.

Recognizing the importance of an all-inclusive approach to brown bear conservation now and into the future.

In their critique of our recent article in Oecologia (Pigeon et al. Oecologia 181:1101-1116, 2016a) investigating the influence of ambient temperature on brown bear habitat selection, Ordiz et al. (2017, current issue) argue that we downplay the role of human disturbance on bear behavior, and that we wrongly report on the findings of Ordiz et al. (Oecologia 166:59-67, 2011). We argue that our previous article in Oecologia (Pigeon et al. 2016a) by no means downplays the influence of human factors on bear behavior, and that we correctly stated that Ordiz et al. (2011) did not adequately consider the potential influence of temperature on their findings. Finally, we stress the relevance of considering all-inclusive approaches to the common goal of successful wildlife conservation.

Staying cool in a changing landscape: the influence of maximum daily ambient temperature on grizzly bear habitat selection.

To fulfill their needs, animals are constantly making trade-offs among limiting factors. Although there is growing evidence about the impact of ambient temperature on habitat selection in mammals, the role of environmental conditions and thermoregulation on apex predators is poorly understood. Our objective was to investigate the influence of ambient temperature on habitat selection patterns of grizzly bears in the managed landscape of Alberta, Canada. Grizzly bear habitat selection followed a daily and seasonal pattern that was influenced by ambient temperature, with adult males showing stronger responses than females to warm temperatures. Cutblocks aged 0-20 years provided an abundance of forage but were on average 6 °C warmer than mature conifer stands and 21- to 40-year-old cutblocks. When ambient temperatures increased, the relative change (odds ratio) in the probability of selection for 0- to 20-year-old cutblocks decreased during the hottest part of the day and increased during cooler periods, especially for males. Concurrently, the probability of selection for 21- to 40-year-old cutblocks increased on warmer days. Following plant phenology, the odds of selecting 0- to 20-year-old cutblocks also increased from early to late summer while the odds of selecting 21- to 40-year-old cutblocks decreased. Our results demonstrate that ambient temperatures, and therefore thermal requirements, play a significant role in habitat selection patterns and behaviour of grizzly bears. In a changing climate, large mammals may increasingly need to adjust spatial and temporal selection patterns in response to thermal constraints.

The aponeurotic expansion of the supraspinatus tendon: anatomy and prevalence in a series of 150 shoulder MRIs.

OBJECTIVE: To describe the aponeurotic expansion of the supraspinatus tendon with anatomic correlations and determine its prevalence in a series of patients imaged with MRI. MATERIALS AND METHODS: In the first part of this HIPAA-compliant and IRB-approved study, we retrospectively reviewed 150 consecutive MRI studies of the shoulder obtained on a 1.5-T system. The aponeurotic expansion at the level of the bicipital groove was classified as: not visualized (type 0), flat-shaped (type 1), oval-shaped and less than 50% the size of the adjacent long head of the biceps section (type 2A), or oval-shaped and more than 50% the size of the adjacent long head of the biceps section (type 2B). In the second part of this study, we examined both shoulders of 25 cadavers with ultrasound. When aponeurotic expansion was seen at US, a dissection was performed to characterize its origin and termination. RESULTS: An aponeurotic expansion of the supraspinatus located anterior and lateral to the long head of the biceps in its groove was clearly demonstrated in 49% of the shoulders with MRI. According to our classification, its shape was type 1 in 35%, type 2A in 10 % and type 2B in 4%. This structure was also identified in 28 of 50 cadaveric shoulders with ultrasound and confirmed at dissection in 10 cadavers (20 shoulders). This structure originated from the most anterior and superficial aspect of the supraspinatus tendon and inserted distally on the pectoralis major tendon. CONCLUSION: The aponeurotic expansion of the supraspinatus tendon can be identified with MRI or ultrasound in about half of the shoulders. It courses anteriorly and laterally to the long head of the biceps tendon, outside its synovial sheath.

The deltoid, a forgotten muscle of the shoulder.

The deltoid is a fascinating muscle with a significant role in shoulder function. It is comprised of three distinct portions (anterior or clavicular, middle or acromial, and posterior or spinal) and acts mainly as an abductor of the shoulder and stabilizer of the humeral head. Deltoid tears are not infrequently associated with large or massive rotator cuff tears and may further jeopardize shoulder function. A variety of other pathologies may affect the deltoid muscle including enthesitis, calcific tendinitis, myositis, infection, tumors, and chronic avulsion injury. Contracture of the deltoid following repeated intramuscular injections could present with progressive abduction deformity and winging of the scapula. The deltoid muscle and its innervating axillary nerve may be injured during shoulder surgery, which may have disastrous functional consequences. Axillary neuropathies leading to deltoid muscle dysfunction include traumatic injuries, quadrilateral space and Parsonage-Turner syndromes, and cause denervation of the deltoid muscle. Finally, abnormalities of the deltoid may originate from nearby pathologies of subdeltoid bursa, acromion, and distal clavicle.

Subperiosteal hematoma of the iliac bone: imaging features of acute and chronic stages with emphasis on pathophysiology.

PURPOSE: The goal of this work is to describe the radiological appearance and clinical presentation of subperiosteal iliac hematoma and present a review of the literature. MATERIALS AND METHODS: We retrospectively reviewed the radiological and clinical files of 19 patients (age range: 12-75; mean: 47) who presented with acute or chronic subperiosteal iliac hematomas. Imaging findings and relevant clinical information were recorded. A thorough literature search was performed to find additional cases of this rare condition. RESULTS: Three young patients presented with acute subperiosteal iliac hematoma following a fall. Clinical presentation was characterized by pain and gait disturbance presumed to result from crural nerve compression. Unilateral or bilateral lenticular hematomas deep in the iliacus muscle were demonstrated by CT for all patients while MRI was also available for two of them. In 16 asymptomatic patients, chronic ossified subperiosteal iliac hematomas were incidentally detected by CT. Progressive ossification of acute hematoma was demonstrated at follow-up in two patients. CONCLUSIONS: Subperiosteal iliac hematoma is rare but has typical imaging findings that may present acutely in adolescents or chronically in asymptomatic adults.

Snapping biceps femoris tendon: a dynamic real-time sonographic evaluation.

Snapping of the distal arms of the biceps femoris tendon may explain pain and discomfort at the lateral aspect of the knee. We report two cases in which dynamic sonography was able to confirm the diagnosis and document which of the main arms was involved in the process.

Effectiveness of ultrasound-guided corticosteroid injection for the treatment of gluteus medius tendinopathy.

OBJECTIVE: The objective of our study was to evaluate the effectiveness of ultrasound-guided corticosteroid injection for the treatment of gluteus medius tendinopathy. SUBJECTS AND METHODS: We prospectively evaluated 54 consecutive patients (48 women, six men; mean age, 54.7 years; mean body mass index, 26 kg/m2) with a clinical diagnosis of gluteus medius tendinopathy. Pain assessment using a 10-cm visual analog scale (VAS) was obtained as part of the initial clinical evaluation of all patients. A hip ultrasound study was performed followed by a gluteus medius peritendinous ultrasound-guided injection of 30 mg of triamcinolone combined with 3 mL of bupivacaine 0.5% using an anterior oblique coronal plane. One month after treatment, participants were reassessed clinically, and they were asked to quantify their pain using the VAS pain score and their satisfaction with the outcome of the injection using a 4-point rating scale (very satisfied, somewhat satisfied, somewhat dissatisfied, or very dissatisfied). Statistical analysis included a paired Student's t test (comparison of pain levels before and after treatment, p=0.05) and a multivariate analysis of covariance. RESULTS: There was a 55% average reduction of pain level before versus after treatment (mean VAS pain score, 6.4 vs 2.9 cm, respectively; p<0.001). One month after treatment, 72% of the patients showed a clinically significant improvement in pain level, which was defined as a reduction in the VAS pain score of >or=30%. Seventy percent of patients were satisfied with the results of the intervention. No correlation was shown between treatment outcome and any of the clinical variables or ultrasound findings. CONCLUSION: Our study shows that a peritendinous ultrasound-guided corticosteroid injection may be an effective treatment of gluteus medius tendinopathy.

MDCT arthrography or MR arthrography for imaging the wrist joint?

Imaging of the wrist joint has been radically modified over the last decade, particularly since multidetector computed tomography (MDCT) arthrography and magnetic resonance (MR) arthrography have become widely available. These two modalities allow a confident assessment of ligament tears and potential diagnosis of associated abnormalities of cartilage, bone, and soft tissues. The interosseous scapholunate and lunotriquetral ligaments and the triangular fibrocartilage complex (TFCC) are the most important structures to consider. Precise analysis of their different lesions, including recognition of degenerative tears, is essential for guiding the treatment. After a brief overview of the different injuries of interosseous ligaments and cartilage, this article thoroughly exposes the technical aspects of wrist MDCT arthrography and MR arthrography, reviews their results, and discusses their performances in light of recent literature. Finally, we propose an imaging strategy to decide between MDCT arthrography and MR arthrography depending on the clinical query. Other imaging modalities are not forgotten in this strategy. The evaluation of ligamentous and TFCC pathology must always begin with conventional radiographs. Cineradiography, ultrasound, and standard MRI are also useful in selected cases.

Sonographic anatomy and dynamic study of the normal iliopsoas musculotendinous junction.

The objective of the study was to document the anatomy of the iliopsoas muscle at the level of the groin with the use of sonography. At the same time, behaviour of the muscle during external rotation-flexion and abduction was dynamically evaluated. Forty-two hips in 21 asymptomatic volunteers were studied in static and dynamic conditions. Four bundles of the iliopsoas muscle were identified in all patients. A fifth one was found in only two hips. During dynamic study, a snap was explained by the sudden release of the most medial fibres of the ilacus from an entrapment between the tendon and the superior pubic ramus in 40% of our asymptomatic hips. Anatomy of the iliopsoas muscle can be accurately depicted by sonography at the level of the groin. Snapping of the muscle is often encountered as a physiological finding.

"Tenomalacia": a new sonographic sign of tendinopathy?

The purpose of this study was to assess tendon compressibility with sonography in extensor tendinopathy and in asymptomatic extensor tendons of the elbow. Sonography of both elbows was performed in eight patients with a clinical diagnosis of unilateral lateral epicondylitis. Tendons were assessed for compressibility by measuring their thickness before and after compression with the transducer. The same manoeuvre was performed while tendon vascularity was assessed with colour Doppler. All eight cases showed increased compressibility of the common extensor tendon on the painful side compared to the asymptomatic side, as well as increased vascularity with compressible vessels on colour Doppler. Other signs of tendinopathy were hypoechogenicity (n = 8), loss of fibrillar pattern (n = 8), intratendinous calcifications (n = 1), partial tears (n = 3), and enthesophytes (n = 5). Increased tendon compressibility indicative of tendon softening or "tenomalacia" is a new sonographic sign of common extensor tendinopathy.

Atrophy and fatty infiltration of the supraspinatus muscle: sonography versus MRI.

OBJECTIVE: The objective of our study was to compare sonography with MRI for the evaluation of supraspinatus muscle atrophy and fatty infiltration. SUBJECTS AND METHODS: Forty-five shoulders in 39 patients who had undergone shoulder MRI for the assessment of rotator cuff disease were evaluated blindly with sonography. Supraspinatus muscle atrophy was quantitatively assessed by calculating the occupation ratio (cross-sectional surface area of the supraspinatus muscle belly divided by that of its fossa). This was done by reproducing on sonography the equivalent of the "Y" view on MRI. Fatty infiltration was assessed by evaluating supraspinatus muscle echogenicity compared with that of the trapezius muscle and pennate pattern. The occupation ratio and fatty infiltration of the supraspinatus muscle on sonography were compared with these findings on MRI. RESULTS: Occupation ratios calculated on sonography images ranged from 0.07 (severe atrophy) to 0.81 (normal) and correlated with the ratios calculated on MRI (R = 0.90; 95% CI, 0.83-0.95). All 20 shoulders with no fatty infiltration on MRI had normal echogenicity and a pennate pattern on sonography. Eight of the 10 shoulders with mild fatty infiltration on MRI had an effaced pennate pattern and mild hyperechogenicity on sonography. In 13 of the 15 shoulders with moderate to severe fatty infiltration on MRI, the pennate pattern was absent and marked hyperechogenicity was present on sonography. CONCLUSION: Our study suggests that there is a good correlation between sonography and MRI for the assessment of supraspinatus muscle atrophy and fatty infiltration.

The snapping iliopsoas tendon: new mechanisms using dynamic sonography.

OBJECTIVE: The purpose of our study was to describe new mechanisms responsible for the snapping iliopsoas tendon using dynamic sonography. MATERIALS AND METHODS: We reviewed the video recordings obtained during dynamic sonography studies used to establish the diagnosis of 18 snapping iliopsoas tendons in 14 patients (nine females and five males; age range, 13-50 years) who presented clinically with either unilateral (n = 10) or bilateral (n = 4) snapping hips. During dynamic imaging, the transducer was positioned in a transverse oblique plane just above the hip joint parallel to the pubic bone. For all patients, the hip movement that generated the snapping consisted of bringing the hip from flexion-abduction-external rotation back to the neutral position. RESULTS: In 14 of 18 hips, the snapping was provoked by the sudden flipping of the iliopsoas tendon around the iliac muscle, allowing abrupt contact of the tendon against the pubic bone and producing an audible snap. Other causes of snapping iliopsoas tendon were bifid tendon heads flipping over one another (n = 3) and iliopsoas tendon impinging over an anterior paralabral cyst (n = 1). CONCLUSION: New mechanisms of snapping iliopsoas tendon have been described using dynamic sonography. Sudden iliopsoas tendon flipping over the iliac muscle was the most common cause of snapping hip.

Ultrasound of ankle and foot: overuse and sports injuries.

Sports and overuse injuries of the ankle and foot are commonly encountered in clinical practice. Ultrasound (US) has been established as an excellent diagnostic modality for foot and ankle injuries, providing a rapid noninvasive, economical, and readily available tool that is well tolerated by the patient with acute or chronic pain. The opportunity for dynamic examination is another advantage of US in evaluating ankle and foot pathology, where maneuvers such as muscle contraction and stressing of the joint may be particularly helpful. In many cases, US can be used as a first-line and only imaging modality for diagnosis. This article focuses on ankle disorders related to sports or overuse that affect tendons, including tendinosis, tenosynovitis, paratendinitis, rupture, dislocation, and ligaments that are commonly torn. The sonographic features of certain common foot disorders related to physical activity and overuse are also discussed, including plantar fasciitis, Morton's neuroma, stress fractures, and plantar plate injury.

Cross-sectional imaging of internal derangement of the wrist with arthroscopic correlation.

Wrist arthroscopy has become an indispensable tool for the surgeon treating internal derangement of the wrist. The role of arthroscopy in both the diagnosis and treatment of intrinsic ligaments and triangular fibrocartilage complex (TFCC) pathology is well established. Arthroscopy remains a surgical procedure with potential complications, and it does not obviate the need for a careful history, physical examination, and conventional radiography. When the diagnosis remains unclear after these initial investigations, cross-sectional imaging studies play a valuable role in the assessment of internal derangement of the wrist. These studies include magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA), and computed tomography arthrography (CTA), the choice of which depends on the specific clinical query. The radiologist must have exact knowledge of the performance of each diagnostic test to select the appropriate one and interpret it in a clinically relevant manner. With continued refinements in the technological aspects of cross-sectional imaging, its potential to replace diagnostic arthroscopy will surely be realized in the near future. This article focuses on the role of cross-sectional imaging and arthroscopy in the evaluation and management of wrist internal derangement, namely of intrinsic ligaments and TFCC pathology.

Musculoskeletal sonography: a dynamic tool for usual and unusual disorders.

OBJECTIVE: The purpose of this study is to illustrate a wide variety of musculoskeletal disorders that can be diagnosed with dynamic sonography. CONCLUSION: Dynamic sonography is a useful tool for the evaluation of a variety of musculoskeletal disorders. Many of these disorders cannot be diagnosed by any other imaging method.

Sunitinib relieves renal cell carcinoma spinal cord compression.

A 66-year-old previously healthy female was diagnosed with renal cell carcinoma (RCC) metastic to the 4th, 6th and 12th thoracic vertebrae. Despite external beam radiotheraphy (20G in 5 fractions), she progressed to spinal cord compression within 4 weeks and was wheelchair bound. Radiation and surgery were not considered suitable, but sunitinib was initiated. After two 6-week sunitinib cycles, she is fully ambulatory. She reports grade I fatigue and occasional epistaxis, as sole side effects. This case demonstrates that despite the rapid progression of the disease, which escaped the effect of radiation within four weeks, sunitinib resulted in complete clinical symptom resolution, which was confirmed radiographically. Moreover, it appears that the novel therapies for metastatic RCC may restore quality and quantity of life to many of those, whose disease previously appeared too advanced to treat.