SPECT/CT in der Handgelenkdiagnostik

CLINICAL/METHODICAL ISSUE: Hand and wrist pain remains a diagnostic challenge, both for hand surgeons and for radiologists. Especially chronic wrist pain is often hard to localize clinically and further cross-sectional imaging is often indispensable. STANDARD RADIOLOGICAL METHODS: The well-established standard for non-invasive diagnostic imaging in chronic wrist pain is magnetic resonance imaging (MRI). METHODICAL INNOVATIONS: Recently, state-of-the-art single photon emission computed tomography/computed tomography (SPECT/CT) systems have been introduced into the diagnostic array for musculoskeletal conditions. Besides morphological data SPECT/CT also provides metabolic information. PERFORMANCE: SPECT/CT allows an exact detection and precise anatomical mapping of different pathologies of the wrist, which is often crucial for therapy. ACHIEVEMENTS: In patients with chronic wrist pain, SPECT/CT is more specific than MRI. It is also beneficial in patients with posttraumatic conditions and metal implants and may serve as a problem-solving tool in difficult cases. PRACTICAL RECOMMENDATIONS: It is considered that SPECT/CT imaging is useful if MRI results are equivocal or present no clearly leading pathology. A primary examination with SPECT/CT seems to be a reasonable option for patients with certain bone pathologies, metal implants and non-specific wrist pain.     

MRI of the wrist

In the past, the diagnostic imaging algorithm for evaluating the painful wrist included initial plain radiographic examination followed by arthrography, tomography, bone scintigraphy, or computed tomography. In recent years, magnetic resonance imaging (MRI) has been proven efficacious for diagnosing a number of maladies of the bones, ligaments, and soft tissues. MRI can be of aid in evaluation of carpal instability, disorders of the triangular fibrocartilage, ulnar impaction syndrome, distal radioulnar joint (DRUJ) instability, fracture, avascular necrosis (AVN), tendinopathy, nerve entrapment syndromes, synovial abnormalities, and soft tissue masses.     

Cartilage imaging of the hand and wrist using 3-T MRI

The prevalence of osteoarthritis of the hand and wrist is high, and a thorough assessment of even subtle cartilage injuries is necessary before surgical interventions. Although magnetic resonance imaging (MRI) has been established as an important diagnostic tool for the evaluation of hand and wrist disorders, the focus has been on the assessment of the triangular fibrocartilage complex, tendons, ligaments, and the detection of avascular necrosis or occult fractures rather than on cartilage imaging. 3-T MR systems have become more and more widely available and yield an improved signal-to-noise ratio and thus a higher spatial resolution than 1.5-T systems. In principle, this should be especially beneficial for depicting the thin cartilage layers of the hand and wrist. This review focuses on cartilage imaging of the hand and wrist with 3-T MRI and addresses these four topics: (1) the advantages of 3-T versus 1.5- and 1-T MRI, (2) dedicated sequence protocols at 3 T including novel three-dimensional sequences, (3) imaging findings in common cases of overuse or sports injury, and (4) functional cartilage imaging techniques of the hand and wrist, for instance, delayed gadolinium-enhanced MRI of the cartilage.     

Magnetic resonance imaging of thehand and wrist

The application of magnetic resonance imaging (MRI) to the hand and wrist has lagged behind its use in larger joints. Recent advances in hardware and software technology have allowed faster imaging with excellent anatomic resolution. After routine radiography, MRI is the imaging procedure of choice for evaluation of chronic wrist pain. The most common indications for MRI within the hand and wrist include scapholunate-lunate ligament tears, triangular fibrocartilage complex (TFCC) tears, avascular necrosis, and soft tissue masses. MRI may occasionally help evaluate tendon abnormalities, atypical or postoperative recurrent carpal tunnel syndrome, and complications of inflammatory arthritides. Future applications of MRI will likely include improved anatomic imaging of smaller structures such as the lunatotriquetral ligament and the extrinsic ligaments, as well as MR angiography (MRA).     

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.     

Principles of tumor imaging

Tumors involving the upper extremity are not uncommon. Although there is a wide variety of lesions that may occur in the hand and wrist, there are certain lesions which have a predilection for this location. This chapter will highlight the spectrum of imaging modalities available for the evaluation of upper extremity tumors, providing imaging guidelines for optimum selection of radiological examinations. It presents an overview of imaging of the hand and wrist, emphasizing the fundamental principles inherent to tumor imaging. Modalities reviewed include nuclear scintigraphy, positron emission tomography, sonography, computed tomography, arteriography, magnetic resonance imaging, and magnetic resonance angiography.     

Principles of tumor imaging

Tumors involving the upper extremity are not uncommon. Although there is a wide variety of lesions that may occur in the hand and wrist, there are certain lesions which have a predilection for this location. This chapter will highlight the spectrum of imaging modalities available for the evaluation of upper extremity tumors, providing imaging guidelines for optimum selection of radiological examinations. It presents an overview of imaging of the hand and wrist, emphasizing the fundamental principles inherent to tumor imaging. Modalities reviewed include nuclear scintigraphy, positron emission tomography, sonography, computed tomography, arteriography, magnetic resonance imaging, and magnetic resonance angiography.     

Normal anatomy of the extrinsic capsular wrist ligaments by 3-T MRI and high-resolution ultrasonography

The anatomy of the extrinsic capsular wrist ligaments is complex. These ligaments are probably as important as the intrinsic interosseous ligaments for the maintenance of carpal stability. The extrinsic capsular wrist ligaments are frequently divided into dorsal, palmar, and collateral depending on their anatomical location. They have known origin and attachment sites with recognized anatomical variants. However, there is controversy in the literature related to their anatomy and nomenclature. In the past two decades, imaging has gained an important role in the evaluation of the extrinsic capsular wrist ligaments. Both 1.5-T magnetic resonance imaging (MRI) and magnetic resonance arthrography can provide good evaluation of the extrinsic capsular wrist ligaments; 3-T MRI with improved resolution provides better visualization of the same anatomical structures. Ultrasonography using high-resolution linear transducers allows good visualization of the extrinsic capsular wrist ligaments with results that are comparable with MRI. This article describes the normal anatomy of the dorsal, palmar, and collateral extrinsic capsular wrist ligaments on 3-T MRI and high-resolution ultrasonography.     

High-resolution outpatient imaging of the wrist

The authors describe their experience with magnetic resonance imaging (MRI) in the evaluation of pathologic conditions of the wrist in an outpatient setting. In that setting, because time and quality are both important factors, they have concentrated on developing protocols that will allow effective, time-efficient, high-resolution MRI of the wrist. With these wrist imaging protocols, they have evaluated the majority of commonly encountered pathologic conditions of the wrist. They have found that high-resolution images, which can be acquired in a very timely fashion when fast spin echo sequences are used in imaging protocols, will demonstrate the most common pathologic conditions, including triangular fibrocartilage and ligament tears in the wrist. They present the practical issues of patient position and imaging sequences as well as the imaging findings in those pathologic conditions.     

The carpal ligaments in MR arthrography of the wrist: correlation with standard MRI and wrist arthroscopy

We assessed the value of three-compartment magnetic resonance (MR) wrist arthrography in comparison with non-enhanced magnetic resonance imaging (MRI) for the evaluation of 13 individual wrist ligaments in 35 patients with refractory wrist pain. In 20 of these patients MR findings were correlated with the findings from multiportal wrist arthroscopy. For MR imaging (1.5-T magnet) a three-dimensional volume acquisition with a gradient-recalled echo sequence and 0.6-1.0 mm effective slice thickness was used. The delineation of individual wrist ligaments was rated as "good" in 10% of non-enhanced MR and 90% of MR arthrography images. Ligament evaluation was possible with high diagnostic confidence in 11% by non-enhanced MR imaging and 90% by MR arthrography. With wrist arthroscopy as the standard of reference, average sensitivities/specificities/accuracies for the diagnosis of full-thickness ligamentous defects were 0.81/0.75/0.77 for non-enhanced MR imaging and 0.97/0.96/0.96 for MR arthrography. Our findings suggest that MR arthrography is more accurate than standard MRI in delineating and evaluating the ligaments of the wrist.     

Pseudotumoral ganglion cyst of a finger with unexpected remote origin: multimodality imaging

The case of a ganglion cyst in the pulp of a fifth finger in an elderly woman initially mimicking a soft tissue tumor is described. Most typical sites of ganglion cysts are well documented at the wrist and in the vicinity of inter-phalangeal and metacarpo-phalangeal joints. In this case, ultrasonography (US) and magnetic resonance imaging (MRI) demonstrated a cystic lesion within the pulp of the fifth finger and indicated carpal osteoarthritis as the distant—and unexpected—origin of the lesion. The suggested diagnosis of ganglion cyst was confirmed by computed tomography arthrography (CT arthrography) of the wrist, which showed opacification of the cyst on delayed acquisitions after intra-articular injection into the mid-carpal joint, through the fifth flexor digitorum tendon sheath. The communications between the degenerative carpal joint, the radio-ulnar bursa, the fifth flexor digitorum tendon sheath and the pedicle of the cyst were well demonstrated.     

Radiological anatomy of the wrist]

The wrist is an articular complex composed of the radio-carpal, distal radio-ulnar and all of the carpal joints. Despite progress in imaging techniques, conventional radiology with plain x-rays and arthrography are still very widely used. Plain x-rays, numerous because of the anatomical complexity of the wrist, must be selected in relation to the clinical context and suspected diagnosis and must be performed according to a perfect technique. Contrast arthrography may be uni-, bi-, or tri-compartmental depending on the information required. It allows assessment of the integrity of the intra-articular synovial and ligamentous structures. The specific indications for computed tomography are uncommon, but those of MRI are becoming increasingly frequent due to refinement of the machines, especially the development of surface coils.     

Information that orthopedists still need to know and what is missing from the MR images of the wrist

Magnetic resonance imaging (MRI) has a very established role in imaging many pathologic conditions in the wrist. MRI provides useful clinical information regarding neoplastic processes. It also provides valuable information in the evaluation of tendons and synovium in rheumatoid arthritis. However, it has been and is less useful when early ligamentous injuries, including grade I and grade II scapholunate and lunotriquetral ligament lesions, are suspected. Also, information regarding cartilage injuries and degeneration, especially in wrist instabilities, would be more than desirable for treating orthopedists and hand surgeons. However, at the current stage, this information is missing, and only the more advanced changes are seen in MRI. This article describes and explains clinical entities in which that information would help patient care and management.     

Magnetic resonance imaging of the wrist: diagnostic performance statistics

AIM: To review the published diagnostic performance statistics for magnetic resonance imaging (MRI) of the wrist for tears of the triangular fibrocartilage complex, the intrinsic carpal ligaments, and for osteonecrosis of the carpal bones. MATERIALS AND METHODS: We used Medline and Embase to search the English language literature. Studies evaluating the diagnostic performance of MRI of the wrist in living patients with surgical confirmation of MR findings were identified. RESULTS: We identified 11 studies reporting the diagnostic performance of MRI for tears of the triangular fibrocartilage complex for a total of 410 patients, six studies for the scapho-lunate ligament (159 patients), six studies for the luno-triquetral ligament (142 patients) and four studies (56 patients) for osteonecrosis of the carpal bones. CONCLUSIONS: Magnetic resonance imaging is an accurate means of diagnosing tears of the triangular fibrocartilage and carpal osteonecrosis. Although MRI is highly specific for tears of the intrinsic carpal ligaments, its sensitivity is low. The diagnostic performance of MRI in the wrist is improved by using high-resolution T2* weighted 3D gradient echo sequences. Using current imaging techniques without intra-articular contrast medium, magnetic resonance imaging cannot reliably exclude tears of the intrinsic carpal ligaments. Hobby, J. L. (2001). Clinical Radiology, 56, 50-57.     

Advanced imaging of the wrist

Abnormalities of the wrist present a difficult diagnostic challenge requiring thorough evaluation of both osseous and soft-tissue structures. Advanced techniques such as scintigraphy, computed tomography, three-phase arthrography, and, most recently, magnetic resonance imaging have added greatly to our understanding of wrist pathology. This article discusses the application of these techniques in imaging the wrist.     

Clinical impact of MRI in acute wrist fractures

The purpose of this study was to evaluate the clinical impact of MRI in the early diagnosis of wrist trauma. High-resolution MR imaging was performed on a 1.5-T unit (Symphony Quantum, Siemens, Erlangen, Germany) using coronal and axial T1- and T2-weighted fat-saturated turbo-spin-echo sequence via a dedicated wrist coil within a mean of 6.6 days after initial radiographs in 54 patients (56 wrists) with clinical suspicion of wrist fractures and normal plain or indistinct radiographs. Initial radiographs were evaluated independently by two senior radiologists and the hand surgeon without knowledge of the MRI findings. The initial treatment protocol was based on evaluation of plain films and clinical findings by the hand surgeon. Treatment protocol was changed after MRI examination if necessary. In 31 of 56 wrists MRI findings resulted in a change of diagnosis. There were false-positive diagnoses on plain radiographs in nearly one half (n=25) of the patients. False-negative diagnoses on plain radiographs resulted in 6 cases. Magnetic resonance imaging detected additional injuries of soft tissue in more than one third (n=20). In 22 of 56 wrists the period of immobilization could be shortened or ended, in 12 of 56 it was prolonged, and in 3 of 56 a surgical intervention was necessary. In 19 wrists MRI had no therapeutic consequences. Our data demonstrate the high clinical impact of MRI in the detection of acute wrist fractures. We recommend MRI of the wrist immediately on the day of trauma if there is clinical suspicion and normal plain radiographs. Accurate diagnosis by MRI examination within the first days following trauma may reduce economic costs due to shortened immobilization time in cases with a suspected fracture but plain radiographs. Electronic Publication     

Atypical extraspinal musculoskeletal tuberculosis in immunocompetent patients: part II, tuberculous myositis, tuberculous bursitis, and tuberculous tenosynovites.

Tuberculosis involving the soft tissue from adjacent bone or joint is well recognized. However, primary tuberculous pyomyositis, tuberculous bursitis, and tuberculous tenosynovitis are rare entities constituting 1% of skeletal tuberculosis. Tuberculous tenosynovitis involves most commonly the tendon sheaths of the hand and wrist, and tuberculous bursitis occurs most commonly around the hip. The greater trochanteric bursa and the greater trochanter are the most frequent sites of tuberculous bursitis. Cases of primary tuberculous pyomyositis and tenosynovitis of the tendons of the ankle and foot are seldom reported in the radiology literature. All imaging modalities-plain radiography, bone scan, computed tomography, and magnetic resonance imaging (MRI)--provide information that is helpful in determining therapy. MRI in particular, with its multiplanar capabilities and superb contrast of soft tissue, can demonstrate the extent of the soft tissue mass and access the adjacent bones and joints. However, MRI has no diagnostic specificity in regard to tuberculosis, and in nonendemic areas, biopsy is strongly recommended. All patients in this review were permanent residents of North America or Western Europe and were immunocompetent. Examples of atypical presentations of the above entities are demonstrated.     

Magnetic resonance imaging of triangular fibrocartilage

Due to their small size and complex structure, diagnosing injury of the proximal wrist ligamentous structures can be challenging. The triangular fibrocartilage complex (TFCC) is an example of one such structure, for which lesions may be missed unless high-resolution magnetic resonance imaging (MRI) obtained via a standard matrix with a small field of view or high-resolution imaging matrix (small spatial scale matrix elements/large matrix size) is utilized. While there have been recent advances in increasing MRI spatial resolution, attempts at improved visualization by isolated increase in the spatial resolution will be ineffective if the signal-to-noise ratio (SNR) of the images obtained is low. Additionally, high contrast resolution is important to facilitate a more precise visualization of these structures and their pathology. Thus, a balance of the three important imaging factor qualifications of high spatial resolution, high SNR, and high contrast resolution must be struck for optimized TFCC and wrist imaging. The goal of this article, then, is to elucidate the theory and techniques of effective high-resolution imaging of the proximal ligamentous structures of the wrist, balancing SNR and high contrast resolution constraints, and focusing on imaging of the TFCC as a prototypical example.     

Imaging of the wrist with multichannel CT

Multichannel computed tomography (MCCT) can produce extremely thin, overlapping slices. This capability allows for the acquisition of essentially isotropic data sets. These isotropic data sets can be used to produce reformatted images in any plane with virtually no loss of spatial resolution. This, imaging can be done with a single acquisition. This high-resolution technique is particularly useful in the imaging of small body parts, such as the wrist, where fine detail in essential. Drawing on clinical examples, this article reviews the use of isotropic imaging in the wrist.     

Magnetic resonance imaging of the wrist

MR imaging of the wrist has the unique capability of simultaneously demonstrating bone and soft tissue structures. Its exquisite sensitivity for detecting bone marrow edema makes it an ideal screening tool for diagnosing radiographically occult osseous injuries and areas of AVN. This, together with its ability to provide a comprehensive, non-ivasive assessment of the ligaments, tendons, nerves, and components of the TFC make MRI a very powerful tool for evaluating patients with wrist pain of uncertain etiology. Its exact role in the work-up of these patients has not been entirely established, but with further advances in technology and the radiologist's understanding of wrist anatomy and pathology, MRI is assuming a more central role in this clinical setting.