Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow.Part I of this review can be found at:     

肘关节功能位CT扫描技术的应用

目的通过与传统肘关节CT扫描技术比较,探讨肘关节功能位CT扫描技术的应用价值。方法 45例患者采用仰卧位,患侧肘关节摆放成标准功能位进行扫描,再根据图像质量、各关节面显示的情况进行分级评估。结果显示肘关节上臂横断面图像,前臂长轴面图像;尺骨鹰嘴和肱骨滑车之间的关系显示清晰39例,良好5例,欠佳1例;尺桡关节显示清晰40例,良好4例,欠佳1例;肱桡关节显示清晰39例,良好5例,欠佳1例。结论肘关节功能位CT扫描技术较有利于直接显示肘关节的解剖结构,同时减少了扫描曝光时间,优于传统的扫描方式,可以作为肘关节CT扫描的首选方法。     

Evaluation of loose bodies in the elbow with MR imaging

The evaluation of loose bodies in the elbow is usually done by means of clinical examination, radiography, and postarthrographic computed tomography (CT). The authors review their experience with magnetic resonance (MR) imaging in place of postarthrographic CT for the evaluation of loose bodies in the elbow. The prospective interpretation of MR studies of the elbow in 20 patients was compared with arthroscopic findings. All elbows were imaged in multiple planes with thin sections, surface coils, and combinations of T1, T2, and proton-density weighting. The sensitivity for showing loose bodies with MR imaging was 100%, and the specificity was 67%. Because this was a nonblinded study, the results are biased and caution must be used when extrapolating these results to the general population. In this limited experience, MR imaging has reliably shown loose bodies in the elbow, and in the authors' institutions has replaced postarthrographic CT for that purpose.     

Fractures of the elbow and forearm

Fractures and dislocations of the elbow usually occur secondary to indirect trauma. In the adult, fractures of the distal humerus almost always involve the condyles. Fractures of the radial head and neck may be subtle, and the appearance of secondary signs, such as the elevated fat pads from an elbow joint effusion, may be diagnostically useful. Dislocations of the elbow can be associated with fractures, such as those involving the ulnar coronoid process. In children, the presence of epiphyseal and apophyseal ossification centers can confuse the inexperienced observer in the setting of elbow trauma. Osteochondral injury may be difficult to identify without adjunctive imaging techniques, such as magnetic resonance (MR) imaging. Soft tissue injury at the elbow is also well characterized by MR imaging. Fractures of a single forearm bone may occur in isolation, usually due to a direct blow, but these are usually associated with fracture of displacement of the other bone in that forearm.     

MR imaging of the elbow in baseball pitchers

Baseball pitcher throwing biomechanics are important to understanding the pathophysiology and magnetic resonance (MR) imaging appearances of injuries in baseball pitchers. Baseball pitchers experience repetitive excessive valgus forces at the elbow. Typical injuries are secondary to medial joint distraction, lateral joint compression, and rotatory forces at the olecranon. MR imaging is useful for evaluation of the elbow in baseball pitchers.     

Mr assessment of posttraumatic flexion contracture of the elbow

Reoperative assessment of posttraumatic flexion contracture of the elbow includes plain radiographs and tomograms, which are dif0cult to obtain in the coronal plane due to the contracture. We conducted this study to determine the uaefulness of MR haghg in the work-up of these patients. Twelve patients with flexion contracture of the elbow were studied. In addition to standard spin-echo sequences, a sagittally acquired spoiled gradient-recalled echo 3D data set of the flexed elbow was obtained and reformatted coronally using a curved plane of reconstruction. The MR hdings were compared to the plain filmrr. tomograms and surgical results. MRI allowed identification of loose bodies that were sometimes poorly visualized, or not seen. on plain films, and demonstrated degenerative changes eqdy as well M tomograms. MR showed soft tissue abnormalities including capsular and collateral ligament thickening. Cwillnear reconstructions were helpful in the assessment of collateral ligaments in patients with severe contractures. We conclude that MR is useful in the evaluation of elbow flexion contractures. particularly in assessing soft tissue causes.     

The effectiveness of diagnostic imaging methods for the assessment of soft tissue and articular disorders of the shoulder and elbow

There are no clear guidelines for diagnostic imaging of articular and soft tissue pathologies of the shoulder and elbow. Several methods are used, including magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and ultrasound (US). Their cost-effectiveness is still unclear. We performed a meta-analysis of the relevant literature and discussed the role of MR imaging of the shoulder and elbow compared with other diagnostic imaging modalities. For the shoulder impingement syndrome and rotator cuff tears, MRI and US have a comparable accuracy for detection of full-thickness rotator cuff tears. MRA and US might be more accurate for the detection of partial-thickness tears than MRI. Given the large difference in cost of MR and US, ultrasound may be the most cost-effective diagnostic method for identification of full-thickness tears in a specialist hospital setting (Evidence level 3). Both MRA and CT arthrography (CTA) are effective methods for the detection of labrum tears. More recently, multidetector CTA has offered the advantages of thinner slices than with MRA in a shorter examination time. Still, MRA has the advantage towards CTA to directly visualize the affected structures with a better evaluation of extent and location and to detect associated capsuloligamentous injuries. For the elbow pathologies, plain MRI or MRA have the advantage towards CTA to detect occult bone injuries. CTA is better for the assessment of the thin cartilage of the elbow. Both US and MRI are reliable methods to detect chronic epicondylitis; US is more available and far more cost-effective (Evidence level 2). MRA can differentiate complete from partial tears of the medial collateral ligament. US or MRI can detect partial and complete biceps tendon tears and/or bursitis. MRI can provide important diagnostic information in lesions of the ulnar, radial, or median nerve.     

Ultrasound of the elbow

The elbow is an important synovial hinge joint of the upper extremity. This joint represents a common site of musculoskeletal symptomatology, affecting all age groups. The advantages of ultrasound imaging of the elbow include easy availability, multiplanar capability and the ability to assess structures dynamically. Patient symptomatology and site of maximal tenderness can be directly correlated with imaging findings. Comparison is easily made with the contralateral side. Particular strengths include the ability to assess para-articular structures, such as regional tendons and ligaments, in addition to assessment of joint effusions, loose bodies and regional bursae. With operator experience and excellent technique, ultrasound is a valuable imaging tool for assessment of disorders of the elbow joint.     

MR imaging findings and MR criteria for instability in osteochondritis dissecans of the elbow in children

Purpose

Osteochondritis dissecans (OCD) of the elbow is an uncommon cause of elbow pain in adolescents and occurs at different locations in the elbow joint. Early diagnosis and treatment may prevent surgery. The aim of the study is to describe the MR imaging features of OCD at initial imaging, and to correlate these findings with surgical findings of stability and instability with arthroscopic findings as the reference standard.

Methods

Patients were identified through a keyword search of the radiology information system from 2000 to 2009. Twenty-five patients (26 elbows) with OCD of the elbow were identified (age 10.4–18 years, mean age 14 years). MR studies were retrospectively reviewed by two radiologists in consensus to define MR imaging findings and to determine the presence of previously described MR imaging criteria for OCD instability (i.e., high T2 signal rim, surrounding cysts, high T2 signal fracture line, fluid-filled osteochondral defect). Sensitivity of the individual and combined criteria was calculated.

Results

OCD occurred in the capitellum in 24 patients (92%), in the trochlea in 2 patients (8%) and radial head in 1 patient (4%). Loose bodies were identified in 11 (42%) patients. Eighteen patients demonstrated MRI findings in keeping with unstable lesions. In all 11 patients who had surgery the surgical findings of instability correlated with the MRI findings. When combined, the MR criteria were 100% sensitive for instability of OCD lesions of the elbow.

Conclusion

The vast majority of OCD of the elbow occurs in the capitellum. When used together, the MR criteria for instability were 100% sensitive for evaluation OCD lesions of the elbow.     

Magnetic resonance imaging of lateral epicondylitis of the elbow with a 0.2-T dedicated system

The purpose of this study was to evaluate MR imaging findings of the common extensor tendon in patients with lateral epicondylitis and asymptomatic volunteers studied on a 0.2-T dedicated system. In 23 patients (age range 29–58 years, mean age 47 years) with clinical symptoms of lateral epicondylitis MR imaging was performed using T1-, T2- and contrast-enhanced T1-weighted spin-echo sequences. In addition, the elbows of seven healthy volunteers (age range 22–29 years, mean age 25 years) and the symptom-free contralateral elbow of 11 of the 23 patients (age range 29–58 years, mean age 47 years) were studied as controls. Five patients were surgically treated after the MR examination and the results of histopathology were correlated with MR findings. Of the patients, 95.6 % showed intratendinous signal intensity changes on T1-weighted images on the symptomatic side. In 69.6 % signal alterations were observed on T2-weighted sequences and in 56.5 % an intratendinous contrast enhancement was present. Histopathology showed fibrovascular proliferation and fatty degeneration in patients with distinct signal intensity changes and contrast enhancement. Patients with only minor signal intensity changes on T1- and T2-weighted sequences and no contrast enhancement demonstrated fibrosclerotic degeneration and intratendinous cartilage formation in histopathology. The contralateral elbow showed signal intensity changes in 6 of 11 (54.5 %) cases on T1-weighted images and in 3 of 11 (27.3 %) on T2-weighted images. In the group of healthy volunteers minor signal intensity changes of the common extensor tendon could be seen in only 1 case. In patients with lateral epicondylitis of the elbow the type and extent of pathologic changes within the common extensor tendon can be evaluated using a dedicated low-field MR system. On the basis of MR imaging findings a more specified therapy planning among the variety of treatment modalities can be achieved. Received: 10 April 1998; Revision received: 13 October 1998; Accepted: 25 November 1998     

Imaging of the elbow

The imaging needs for diagnosis of abnormalities in and about the elbow are presently satisfied in most instances by plain film radiography. Arthrography with tomography and CT has enabled us to delineate the joint space and articular surfaces better. The sensitivity of radionuclide imaging allows early detection of disease processes but lacks specificity. The advantages of MR imaging in the musculoskeletal system should allow improved diagnostic imaging capability about the elbow as it has for other joints.     

High-resolution MR imaging of the elbow using a microscopy surface coil and a clinical 1.5 T MR machine: preliminary results

Objective To obtain high-resolution MR images of the elbow using a microscopy surface coil with a 1.5 T clinical machine and to evaluate the feasibility of its use for elbow injuries.Design and patients Five asymptomatic normal volunteers and 13 patients with elbow pain were prospectively studied with MR imaging using a microscopy surface coil 47 mm in diameter. High-resolution MR images using a microscopy coil were obtained with fast spin echo (FSE) proton density-weighted sequence, gradient recalled echo (GRE) T2*-weighted sequence, and short tau inversion recovery (STIR) sequence, with a 1–2 mm slice thickness, a 50–70 mm field of view, an imaging matrix of 140–224×512 using zero fill interpolation, and 2–6 excitations.Results High-resolution MR images of normal volunteers using a microscopy coil clearly showed each structure of the medial and lateral collateral ligaments on GRE T2*-weighted images and FSE proton-density weighted images. Partial medial collateral ligament injury, a small avulsion of the medial epicondyle, and osteochondritis dissecans were well demonstrated on high-resolution MR images.Conclusion High-resolution MR imaging of the elbow using a microscopy surface coil with a 1.5 T clinical machine is a promising method for accurately characterizing the normal anatomy of the elbow and depicting its lesions in detail.     

MR imaging of the elbow.

Of 27 patients who underwent magnetic resonance (MR) imaging of the elbow, 11 underwent elbow arthroscopy and/or an open surgical procedure. Surgical findings were compared with those from MR imaging. Five healthy volunteers also underwent MR imaging to demonstrate anatomic relationships. Transchondral fracture (osteochondritis dissecans) was identified in three of the 11 patients and was proved at surgery. Loose bodies were suspected at MR imaging in the three patients but were found in only two. One complete avulsion of the ulnar collateral ligament (UCL) and four cases of intact, thickened UCLs were identified at MR imaging and surgery. Loose bodies from the olecranon tip were found in three patients at surgery but were seen on MR images in only two. MR imaging depicted olecranal osteophytes in three cases, which were confirmed at surgery. Two complete avulsions of the biceps tendon and one partial triceps tendon tear were identified with MR imaging and proved at surgery. A postoperative soft-tissue infection and a synovial cyst were also seen at MR imaging and surgery. These results suggest that MR imaging is useful in the evaluation of the elbow.     

Magnetic resonance imaging of the elbow. Part I: Normal anatomy,imaging technique,and osseous abnormalities

Part I of this comprehensive review on magnetic resonance imaging of the elbow discusses normal elbow anatomy and the technical factors involved in obtaining high-quality magnetic resonance images of the elbow. Part I also discusses the role of magnetic resonance imaging in evaluating patients with osseous abnormalities of the elbow. With proper patient positioning and imaging technique, magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the osseous structures of the elbow. Magnetic resonance imaging can detect early osteochondritis dissecans of the capitellum and can be used to evaluate the size, location, stability, and viability of the osteochondritis dissecans fragment. Magnetic resonance imaging can detect early stress injury to the proximal ulna in athletes. Magnetic resonance imaging can detect radiographically occult fractures of the elbow in both children and adults. Magnetic resonance imaging is also useful in children to further evaluate elbow fractures which are detected on plain-film radiographs.Part II of this review can be found at:     

Simultaneous ipsilateral elbow and forearm fractures in children: a retrospective review

The aim is to evaluate the incidence of simultaneous ipsilateral forearm fractures in pediatric patients who present with elbow fractures and to attempt to identify patients who might be at greater risk of this type of injury. All pediatric patients with elbow radiographs during a 3-month period were retrospectively reviewed. One hundred sixty patients were identified. Sixty-one of the 160 were diagnosed with elbow fractures. Of these, 7 had a simultaneous ipsilateral forearm fracture (12.3%). Of the 7 patients with simultaneous fractures, all had supracondylar fractures; 4 were displaced elbow fractures and 3 were nondisplaced. Although our initial experience is limited, there appears to be a fairly high incidence of ipsilateral forearm fractures in pediatric patients with elbow fractures. All of these cases involved a supracondylar fracture, and over 50% showed displaced fractures. We conclude that in preadolescent patients with elbow fractures, simultaneous forearm fracture should be considered, and clinical and or radiographic evaluation of the forearm may be warranted. Electronic Publication     

Dynamic sonography with valgus stress to assess elbow ulnar collateral ligament injury in baseball pitchers

Sonography is a valuable method for imaging superficial tendons and ligaments. The ability to obtain comparison images easily with dynamic stress allows assessment of ligament and tendon integrity. We studied the medial elbow joints of two baseball pitchers using MR imaging and dynamic sonography. Both sonography and MR imaging identified the ulnar collateral ligament tears. Dynamic sonography uniquely demonstrated the medial joint instability.     

MR arthrography of elbow: evaluation of the ulnar collateral ligament of elbow

 Objective. The purpose of this study was to evaluate ulnar collateral ligament (UCL) injury of the elbow in throwing athletes by MRI and MR arthrography. Design. Ten elbows of throwing athletes were examined on both plain MRI and MR saline arthrography and the injuries subsequently surgically proven. Spin-echo (SE) T1-weighted and fast SE T2-weighted coronal images were obtained. Results. The UCL was unclear in all ten cases on T1-weighted MRI. In five cases an avulsion fracture was also found on T1-weighted MRI. On T2-weighted MRI, abnormal high-intensity areas were identified in or around the UCL. On T2-weighted MR arthrography images, extracapsular high-intensity areas, which represent extracapsular leakage, were found in four of five cases with avulsion fracture. At surgery, all these four cases showed avulsion fractures with instability; the other case had a fracture but it was stable and adherent to the humerus. On T2-weighted MR arthrography images, an extracapsular high-intensity area was found in one of the five cases without avulsion fracture. At surgery this patient had a complete tear of the UCL itself. Conclusion. MR arthrography provided additional information for evaluating the degree of UCL injury.     

Magnetic resonance (MR) imaging of the shoulder, elbow, and wrist

Thorough knowledge of small structures in the joints is becoming important as the resolution of magnetic resonance (MR) imaging has improved during the past decade. The author discusses the MR anatomy and pathology of three representative structures in the joints of the upper extremities: the labral-ligamentous complex of the shoulder, ulnar collateral ligament(UCL) of the elbow, and triangular fibrocartilage complex(TFCC) of the wrist. The labral-ligamentous complex is composed of the anterior labrum and three glenohumeral ligaments. Because of their similar MR appearance, the labral sulcus is difficult to differentiate from traumatic detachment of the labrum, even with the aid of MR arthrography. Insertion of the UCL to the medial condyle in the growing elbow presents different MR appearances according to age. Acute and chronic UCL tears are commonly seen in elbows with medial tension overload and are well depicted with three-dimensional Fourier transform(3DFT) gradient-echo images. 3DFT images are the most suitable for observation of the TFCC as well. Since abnormally high signals of the articular disc suggestive of tear are often seen in asymptomatic subjects, MR imaging may not reliably be used to differentiate clinically significant tears from asymptomatic defects. In this review article, the author emphasizes developmental anatomy and normal variations in the interpretation of MR images.     

Throwing injury of the elbow: Assessment with gradient three-dimensional,Fourier transform gradient-echo and short tau inversion recovery images

We assessed MR findings of throwing injuries occurring in the elbow joint using three-dimensional Fourier transform (3DFT) and short tau inversion recovery (STIR) images. MR images of 63 elbows in 63 male patients aged from 10 to 32 years (mean age, 15 years 11 months) suffering from throwing injury were visually analyzed. The sequences used for the study were axial 3DFT and coronal STIR. Full-thickness tears were demonstrated in 34 elbows and undersurface tears of the ulnar collateral ligament (UCL) were demonstrated in five elbows. Thirty loose bodies were detected in 14 elbows. Cartilaginous damage due to osteochondral injury was depicted in 21 elbows. Multiplanar reformatted images using the 3DFT data set were useful for assessing torn UCLs, intraarticular loose bodies, and capitellar fragments. Full-thickness tears and undersurface tears of the UCL could be differentiated with STIR images. 3DFT and STIR sequences depict various aspects of throwing injuries occurring in the elbow.