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).     

Triangular fibrocartilage and intercarpal ligaments of the wrist: Does MR arthrography improve standard MRI?

The objective of this study was to assess the value of adding MR arthrography to standard MRI for patients with chronic wrist disorders. Thirty consecutive patients (age range, 19–73 years; mean, 36.2 years) were included in the investigation. The images were evaluated blindly and separately by two radiologists with regard to lesions of the scapholunate (SL) and lunotriquetral (LT) ligaments and the triangular fibrocartilage (TFC). Conventional two- or three-compartment arthrography was used as the standard of reference. For TFC lesions, standard MR images had a sensitivity of 92.3% (reader 1) and 84.6% (reader 2) and a specificity of 41.2% (reader 1) and 52.9% (reader 2). For MR arthrography, sensitivity was 84.6% (reader 1) and 84.6% (reader 2) and specificity was 88.2% (reader 1) and 100% (reader 2). For SL ligament tears, standard MRI had a sensitivity of 33.3% (reader 1) and 11.1% (reader 2) and a specificity of 47.6% (reader 1) and 57.1% (reader 2). For MR arthrography, sensitivity was 66.7% (reader 1) and 55.6% (reader 2) and specificity was 52.4% (reader 1) and 81.0% (reader 2). For LT ligament tears, standard MRI had a sensitivity of 28.6% (reader 1) and 35.7% (reader 2) and a specificity of 93.8% (reader 1) and 81.3% (reader 2). For MR arthrography, sensitivity was 35.7% (reader 1) and 23.1% (reader 2) and specificity was 93.8% (reader 1) and 94.1% (reader 2). In conclusion, the diagnostic performance of MRI in suspected lesions of the TFC and the SL and LT ligaments is improved by adding MR arthrography to the standard examination.     

Axial oblique MR imaging of the intrinsic ligaments of the wrist: initial experience

Objective To evaluate two separate MR sequences acquired in the axial oblique plane, parallel to the long axis of the scapholunate (SL) and lunotriquetral (LT) ligaments, to determine whether the addition of these sequences to the standard MR wrist examination improves visualization of the intrinsic ligaments, and the evaluation of their integrity. To our knowledge, this plane has not been described in the literature previously.Design and patients In total we evaluated 26 patients with chronic wrist pain or instability, referred for MR imaging following assessment by an orthopedic surgeon or physiatrist. All patients underwent initial conventional tri-compartment wrist arthrography, which served as the reference standard. This was immediately followed by MR arthrography, in the standard coronal and true axial planes, as well as in the axial oblique plane. The SL and LT ligaments were initially assessed for the presence or absence of tear, using the standard coronal and true axial sequences, and subsequently re-evaluated with the addition of the axial oblique planes.Results A total of ten intrinsic ligament tears were identified with conventional arthrography: six SL and four LT tears. Five of the six SL tears were identified on the standard sequences. All six were diagnosed with the addition of the oblique sequences. There were three false-positive SL tears identified using standard MR imaging, and two false-positives with the addition of the oblique sequences. No LT tear was identified on standard sequences, whereas all four were confidently seen with the addition of oblique images. No false-positives of the LT ligament were recorded with either standard or axial oblique sequences.Conclusion The study suggests that the addition of axial oblique MR sequences helps identify tears to the intrinsic ligaments of the wrist, particularly the LT ligament. In addition, the axial oblique images assist in localization of the tear.     

Role of MR imaging in chronic wrist pain

Magnetic resonance (MR) imaging for chronic wrist pain is challenging. Correct assessment of the triangular fibrocartilage, hyaline cartilage, ligaments, and tendons has become mandatory for comprehensive decision making in wrist surgery. The MR technique, potential and limits of MR imaging in patients with chronic wrist pain will be discussed. MR arthrography with injection of gadolinium-containing contrast material into the distal radioulnar joint is suggested for evaluation of the triangular fibrocartilage. The clinically meaningful ulnar-sided peripheral tears are otherwise hard to diagnose. The diagnostic performance of MR imaging for interosseous ligament tears varies considerably. The sensitivity for scapholunate ligament tears is consistently better than for lunotriquetral ligament tears. Gadolinium-enhanced MR imaging is considered to be the best technique for detecting established avascularity of bone, but the assessment of the MR results remains challenging. Most cases of ulnar impaction syndrome have characteristic focal signal intensity changes in the ulnar aspect of the lunate. Avascular necrosis of the lunate (Kienböck’s disease) is characterized by signal changes starting in the proximal radial aspect of the lunate. MR imaging is extremely sensitive for occult fractures. Questions arise if occult posttraumatic bone lesions seen on MR images only necessarily require the same treatment as fractures evident on plain films or computed tomography (CT) images. MR imaging and ultrasound are equally effective for detecting occult carpal ganglia. Carpe bossu (carpal boss) is a bony protuberance of a carpometacarpal joint II and III which may be associated with pain.     

Dynamic MR imaging and stress testing in glenohumeral instability: comparison with normal shoulders and clinical/surgical findings

Our objectives were to test the hypotheses that: 1) during shoulder motion, glenohumeral alignment differs between asymptomatic shoulders and those with symptomatic instability; 2) during magnetic resonance (MR)-monitored physical exam or stress testing, glenohumeral alignment differs between asymptomatic shoulders and those with instability; and 3) glenohumeral translation during MR stress testing correlates with findings of shoulder instability by clinical exam and exam under anesthesia (EUA). Using an open-configuration 0.5 T MR imaging (MRI) system, we studied symptomatic shoulders in 11 subjects and compared them to their contralateral asymptomatic shoulders. Each shoulder was studied during abduction/adduction and internal/external rotation to determine the humeral head position on the glenoid. An examiner also performed the MR stress test on each shoulder by applying manual force on the humeral head during imaging. All shoulders were assigned an instability grade from the MR stress test, and this grade was correlated with: 1) clinical exam grade assigned during preoperative assessment by an orthopedic surgeon and 2) intraoperative instability grade by EUA immediately preceding arthroscopy. With dynamic abduction and internal/external rotation, the humeral head remained centered on the glenoid in 9 of 11 shoulders, but in two subjects there were dramatic demonstrations of subluxation. With stress testing, a trend toward more joint laxity was demonstrated in symptomatic than in asymptomatic joints (P = 0.11). MR grading of instability correlated directly with clinical grading in six cases and underestimated the degree of instability relative to clinical exam in the other cases. MR instability grading systematically underestimated instability compared with EUA in 7 of the 10 cases that underwent surgical repair. We concluded that dynamic MR evaluation of glenohumeral alignment did not demonstrate abnormalities in symptomatic shoulders in 8 of 10 patients, whereas 2 patients showed dramatic findings of subluxation. Manual stress testing during dynamic MR examination showed a strong correlation with clinical instability grading. Dynamic shoulder MR examination during stress testing could, with further validation, become a useful adjunct to shoulder instability evaluations. J. Magn. Reson. Imaging 2001;13:748-756.     

Injuries of the lateral collateral ligaments of the ankle: assessment with MR imaging

The aim of this study was to evaluate the ability of MRI to display injuries of the lateral collateral ligamentous complex in patients with an acute ankle distorsion trauma. The MR examinations of 36 patients with ankle pain after ankle distorsion were evaluated retrospectively without knowledge of clinical history, outcome and/or operative findings. The examinations were performed on a 1.5-T whole-body imager using a flexible surface coil. The signs for ligamentous abnormality were as follows: complete or partial discontinuity, increased signal within, and irregularity and waviness of the ligament. The results were compared with operative findings in 18 patients with subsequent surgical repair. Eighteen patients with conservative therapy had a follow-up MR examination after 3 months. There was 1 sprain, 3 partial and 32 complete tears of the anterior talofibular ligament, and 5 sprains, 5 partial, and 7 complete tears of the calcaneofibular ligament. There were no lesions of the posterior talofibular ligament. Compared with surgery, MRI demonstrated in 18 of 18 cases the exact extent of anterior talofibular ligament injuries and underestimated the extent in 2 of 8 cases of calcaneofibular ligament injury. In patients with follow-up MRI after conservative therapy, a thickened band-like structure was found along the course of the injured ligament in 17 of 18 cases. The absence of ligament repair after conservative treatment was confirmed during operative revision in one case. The MRI technique allows for grading of the extent of injury of the lateral collateral ligamentous complex after acute ankle strain. It seems to be suitable for monitoring the healing process after conservative-functional treatment of ligament tears. Received: 29 June 1998; Revision received: 21 October 1998; Accepted: 22 October 1998     

Multidetector computed tomography in acute knee injuries: assessment of cruciate ligaments with magnetic resonance imaging correlation

Purpose: To evaluate whether non-contrast multidetector computed tomography (MDCT) for suspected acute knee fractures can also be used to evaluate cruciate ligament pathology.

Material and Methods: A total of 42 patients (17-65 years) underwent four-section MDCT. The images were independently evaluated at clinical workstations by four radiologists. They assessed the integrity (normal or torn) and the best slice direction (axial, sagittal, or coronal) for visualization of the cruciate ligaments. Magnetic resonance imaging (MRI), performed within 4 weeks (mean 6 days) in relation to MDCT, was considered the gold standard.

Results: Ligament integrity at MDCT: the mean interobserver proportion of agreement for a normal anterior cruciate ligament (ACL) was 0.73, for a torn ACL 0.41, for a normal posterior cruciate ligament (PCL) 0.96, and for a torn PCL 0.54. Interobserver variation for ACL was significant (P = 0.0136-0.0260), but insignificant for PCL (P = 0.3389-0.7212). Intra-observer variation was insignificant. Visualization was best in the axial and sagittal direction for ACL and PCL, respectively. At MRI, 29 normal, one partially, and 12 completely torn ACLs, and 37 normal, four partially and one completely torn PCL were found.

Conclusion: MDCT can detect an intact ACL and PCL with good specificity, accuracy, and negative predictive value. The assessment of torn ligaments is unreliable.     

The scapholunate interosseous ligament in MR arthrography of the wrist: correlation with non-enhanced MRI and wrist arthroscopy

 Objective. To compare three-compartment MR wrist arthrography with non-enhanced MRI in correlation with wrist arthroscopy, and to evaluate the potential of MR arthrography for consistently visualizing all parts of the scapholunate interosseous ligament of the wrist (SLIL) and exactly diagnosing the site and extent of SLIL defects. Design and Patients. In 41 patients with wrist pain (34 patients with wrist pain for more than 6 months) plain radiographs, stress views, non-enhanced MRI and three-compartment MR arthrography were done within 2 h of each other, using three-dimensional volume acquisition (0.6–1.0 mm effective slice thickness) with a gradient-recalled echo sequence and a 1.5-T magnet. The MR arthrography findings were compared with the findings from non-enhanced MRI and correlated with the arthroscopic findings in all patients. Results. The dorsal, central and palmar segments of the SLIL could be delineated exactly by MR arthrography in 95% of the patients; with non-enhanced MRI only 28% of SLIL segments were seen consistently. Demonstration of SLIL defects was possible with high diagnostic confidence in 42% of SLIL segments by non-enhanced MRI and in 94% by MR arthrography. With wrist arthroscopy as the standard of reference, sensitivity and specificity values for SLIL perforations were 52%/34% for non-enhanced MRI and 90%/87% for MR arthrography. Conclusions. MR arthrography, using three-dimensional volume acquisition with thin slices (0.6–1.0 mm), combines the advantages of three-compartment arthrography and non-enhanced MRI. It shows the precise location and magnitude of ligamentous defects of all parts of the SLIL, correlates well with wrist arthroscopy and has potential implications for diagnosis and treatment planning.     

Ultrasonographic evaluation of normal extrinsic and intrinsic carpal ligaments: preliminary experience

Objective To determine normal anatomy of extrinsic and intrinsic carpal ligaments at ultrasonography (US).Design and volunteers In the first part of the study, two musculoskeletal radiologists retrospectively reviewed in consensus the photographs of anatomic sections and dissections derived from 20 cadaveric wrists. This cadaveric study gave the two readers the opportunity to learn the anatomy and orientation of the various extrinsic and intrinsic carpal ligaments and, thus, to develop a US protocol to facilitate the recognition of each carpal ligament. In the second part of the study, these two radiologists prospectively and independently evaluated the visibility of extrinsic and intrinsic carpal ligaments in 30 wrists of volunteers, using the same US protocol.Results With regard to extrinsic carpal ligaments, the radioscaphocapitate ligament (partially visible, 38%; completely visible, 62%), the radiolunotriquetral ligament (partially visible, 27%; completely visible, 73%), the palmar ulnotriquetral ligament (partially visible, 12%; completely visible, 88%), and the dorsal radiotriquetral ligament (partially visible, 7%; completely visible, 93%) were visualized at US. The dorsal ulnotriquetral ligament (partially visible, 21%; completely visible, 74%), the ulnolunate ligament (partially visible, 5%; completely visible, 70%), and the radial collateral ligament (partially visible, 18%; completely visible, 12%) were more difficult to recognize. The radioscapholunate ligament was never seen. With regard to intrinsic carpal ligaments, the dorsal (partially visible, 11%; completely visible, 89%) and palmar (partially visible, 38%; completely visible, 62%) scaphotriquetral ligaments as well as the dorsal scapholunate ligament (partially visible, 3%; completely visible, 97%) were visualized at US. The dorsal lunotriquetral ligament (partially visible, 39%; completely visible, 61%) and the palmar scapholunate ligaments (partially visible, 12%; completely visible, 81%) were more difficult to recognize.Conclusion US may be helpful in identifying the major extrinsic and intrinsic carpal ligaments.     

In vitro and in vivo comparison of wrist MR imaging at 3.0 and 7.0 tesla using a gradient echo sequence and identical eight-channel coil array designs

Purpose

To evaluate in vivo MR imaging of the wrist at 3.0 Tesla (T) and 7.0T quantitatively and qualitatively.

Materials and Methods

To enable unbiased signal‐to‐noise ratio (SNR) comparisons, geometrically identical eight‐channel receiver arrays were used at both field strengths. First, in vitro images of a phantom bottle were acquired at 3.0T and 7.0T to obtain an estimate of the maximum SNR gain that can be expected. MR images of the dominant wrist of 10 healthy volunteers were acquired at both field strengths. All measurements were done using the same sequence parameters. Quantitative SNR maps were calculated on a pixel‐by‐pixel basis and analyzed in several regions‐of‐interest. Furthermore, the images were qualitatively evaluated by two independent radiologists.

Results

The quantitative analysis showed SNR increases of up to 100% at 7.0T compared with 3.0T, with considerable variation between different anatomical structures. The qualitative analysis revealed no significant difference in the visualization of anatomical structures comparing 3.0T and 7.0T MR images (P>0.05).

Conclusion

The presented results establish the SNR benefits of the transition from 3.0T to 7.0T for wrist imaging without bias by different array designs and based on exact, algebraic SNR quantification. The observed SNR increase nearly reaches expected values but varies greatly between different tissues. It does not necessarily improve the visibility of anatomic structures but adds valuable latitude for sequence optimization. J. Magn. Reson. Imaging 2011;33:661–667. © 2011 Wiley‐Liss, Inc.     

Enhanced MR imaging of tenosynovitis of hand and wrist in inflammatory arthritis

Objective The purpose of this study is to describe the appearance of tenosynovitis in various tendon groups in the wrist and hand and to compare MR enhanced and non-enhanced imaging evaluation of tenosynovitis of hand and wrist in inflammatory arthritis.Design and patients We reviewed 72 MRI studies of hands and wrists, including coronal, axial and sagittal images in 30 consecutive patients with inflammatory arthritis and tenosynovitis. We compared the degree of synovitis on T2-weighted vs contrast-enhanced T1-weighted images, using a predetermined scale. We also measured the extent of tenosynovitis in three dimensions. The tendons were assigned to volar, dorsal, ulnar and radial groups in the wrist and to extensor, flexor and thumb groups in the hand. Degree of tenosynovitis (graded 0–3), cross-sectional area and volume of the inflamed synovium in various tendon groups were then compared by statistical analysis.Results Review of the medical records revealed the following diagnoses in our patient population: rheumatoid arthritis (n=16), unspecified inflammatory polyarthritis (n=9), psoriatic arthritis (n=2), CREST syndrome (n=1), systemic lupus erythematosus (n=1), paraneoplastic syndrome with arthritis (n=1). The average T2 brightness scores and post-gadolinium enhancement scores were 1.0 and 1.7, respectively (P<0.001) in the wrist studies. The average T2 brightness scores and post-gadolinium enhancement scores were 0.7 and 1.4, respectively (P<0.001) in the hand studies. The average sensitivity of T2-weighted imaging for detection of tenosynovitis was 40% in the hand and 67% in the wrist tendons, when contrast-enhanced images were used as a reference. Carpal tunnel flexor tendons were the most frequently affected tendons of the wrist. The most frequently affected tendons of the hand were second and third flexor tendons. The hand flexors demonstrated higher degrees of enhancement and larger volumes of the inflamed tenosynovium than did the hand extensors and tendons of the thumb.Conclusion Enhanced MR imaging of the hand and wrist is a superior technique for detection of tenosynovitis. We observed carpal tunnel flexor tendons to be the most frequently affected tendons of the wrist. The flexor tendons of the second and third digits were the most frequently affected tendons of the hands. Higher contrast-enhancement scores and inflammation were noted in the hand flexor than in the extensor tendons.     

Distal intersection tenosynovitis of the wrist: a lesser-known extensor tendinopathy with characteristic MR imaging features

Objective To present the MRI imaging findings of extensor tenosynovitis at the distal intersection or crossover between the second (extensor carpi radialis longus (ECRL) and brevis (ECRB)) and third (extensor pollicis longus (EPL)) extensor compartment tendons, and the anatomical details that may play a role in the pathogenesis of this condition. Design and patients The imaging studies and clinical records of five patients (three females and two males, with ages ranging between 22 and 78 years; mean age, 49 years) presenting with pain on the dorsal and radial aspect of the wrist were reviewed by two musculoskeletal radiologists in consensus. Three cases were identified serendipitously during routine clinical reading sessions; a follow-up computerized database search for additional cases reported in the prior two years yielded two additional cases. The overall number of cases screened was 1,031. The diagnosis of tendinopathy affecting the second and third compartment extensor tendons was made on the basis of MRI findings and clinical follow-up, or synovectomy. Results All patients showed signs of tenosynovitis: in four patients both the tendons of the second and third extensor compartments were affected; the fifth patient showed signs of tenosynovitis of the EPL tendon, and tendinosis of the extensor carpi radialis tendons. Three patients showed tenosynovitis proximal and distal to the point of intersection; and in two of them, a discrete point of constriction was appreciated at the crossover site in relation to the extensor retinaculum. Two patients showed tenosynovitis limited to the segment distal to the point of decussation. Tendinosis tended to follow the presence of tenosynovitis. In one of the patients, subtendinous reactive marrow edema in Lister’s tubercle was noted. Conclusion Distal intersection tenosynovitis may be related to the biomechanical pulley effect exerted by Lister’s tubercle on the EPL tendon as it leaves the third compartment and crosses over the extensor carpi radialis tendons, as well as the constraining effect of the extensor retinaculum. These anatomical features determine the presence of characteristic MR imaging findings.     

Dynamic high-resolution ultrasound of intrinsic and extrinsic ligaments of the wrist: How to make it simple

Wrist ligaments are crucial structures for the maintenance of carpal stability. They are classified into extrinsic ligaments, connecting the carpus with the forearm bones or distal radioulnar ligaments, and intrinsic ligaments, entirely situated within the carpus. Lesions of intrinsic and extrinsic ligaments of the wrist have been demonstrated to occur largely, mostly in patients with history of trauma and carpal instability, or rheumatoid arthritis. Ultrasound allows for rapid, cost-effective, non-invasive and dynamic evaluation of the wrist, and may represent a valuable diagnostic tool. Although promising results have been published, ultrasound of wrist ligaments is not performed in routine clinical practice, maybe due to its technical feasibility regarded as quite complex. This review article aims to enlighten readers about the normal sonographic appearance of intrinsic and extrinsic carpal ligaments, and describe a systematic approach for their sonographic assessment with detailed anatomic landmarks, dynamic manoeuvres and scanning technique.     

Magnetic resonance imaging ofthe hand and wrist — clinical significance and impact

The clinical experience with magnetic resonance imaging (MRI) in the evaluation of the hand and wrist has beenrapidly expanding over the past few years. The use of dedicated surface coils has improved the ability of MRI to assess the soft tissue and osseous structures in this region. The evaluation of the patient with chronic hand and wrist pain can be a diagnostic dilemma. The anatomic complexity of the hand and wrist makes the pathological possibilities innumerable, ranging from tenosynovitis to osteonecrosis. MRI is invaluable in the detection of avascular necrosis of the carpus, and allows staging, determination of prognosis, and assessment of treatment. Carpal instability can be evaluated by this noninvasive modality, which provides information regarding ligament integrity as well as an assessment of'the articular surface. More recent application in the upper extremity has allowed the determination of flexor tendon integrity, and MR angiography can be used in the evaluation of vascular disorders of the hand. MRI has made a significant impact in our assessment and treatment of these various disorders of the hand and wrist. As the techniques are further refined, we can expect continued improvement in our diagnostic capabilities.     

Frequency and spectrum of abnormalities in the bone marrow of the wrist: MR imaging findings

Objective. To describe the frequency of marrow abnormalities on wrist MR imaging and the MR findings of these various abnormalities. Design and patients. Five hundred and nineteen patients were studied at 1.5 T. Two observers recorded the presence and location of avascular necrosis, occult fractures and arthritic edema [focal osteoarthritis, ulnolunate abutment, rheumatoid arthritis, septic arthritis, gouty arthritis and scapholunate advanced collapse (SLAC)]. Results and conclusion. One hundred and eighty-seven (36%) patients demonstrated marrow abnormalities in the wrist, of which 101 were diagnosed as arthritis [64 (34%) as focal osteoarthritis, 17 (9%) as ulnolunate abutment, 15 (8%) as rheumatoid arthritis, 2 as septic arthritis, 2 as SLAC, and 1 as gouty arthritis]. Seventy-two patients had occult fractures and in 27 patients avascular necrosis was seen. MR imaging can reveal various abnormalities in bone marrow of the wrist when findings on radiography are normal or equivocal. Received: 29 May 1998 Revision requested: 8 July 1998 Revision received: 8 December 1998 Accepted: 22 January 1999     

MR imaging of ulnar nerve entrapment secondary to an anomalous wrist muscle

MR imaging of an anomalous hypothenar adductor muscle causing isolated deep ulnar nerve branch compression and producing a purely motor neuropathy is presented. The muscle appears to represent a type 1 variant of the intrinsic anomalous hypothenar adductor muscle.     

Variations in meniscofemoral ligaments at anatomical study and MR imaging

Purpose To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging. Design Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus. Results At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27. Conclusion An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies. Received: 16 February 1998 Revision requested: 16 June 1998 Revision received: 6 October 1998 Accepted: 7 December 1998     

MR imaging of the normal sacroiliac joint with correlation to histology

Objective The microscopic study of the various components of joints provide a proper basis for understanding the nature of pathologic lesions to which they are subject and their imaging appearances. This study was designed to correlate MR imaging with a systematic histological study of the normal sacroiliac joint (SIJ), which to our knowledge is not available in the literature.Design and patients Five male cadavers, aged 20 to 45 years, and seven male and seven female volunteers, aged 23 to 44 years, were investigated with oblique transaxial and coronal MR imaging of the SIJs. A variety of sequences including pre- and post-contrast T1 fat-saturated studies in the volunteers were used. Cryosectioning was performed in six SIJs of the five cadavers and compared with the MR images for the microscopic joint anatomy and assessed for the presence of abnormalities resembling those associated with sacroiliitis.Results Throughout the SIJ, the hyaline cartilage of the sacral bone and the proximal third of the hyaline iliac cartilage was strongly attached to the surrounding stabilizing ligaments, forming wide margins of fibrocartilage. In the distal one-third of the joint only, the margins of the iliac joint facet resemble that of a synovial joint, which include an inner capsule with synovial cells. The MR anatomy of the ventral and dorsal aspects of the SIJ was only adequately visualized at oblique transaxial MR imaging. No contrast enhancement occurred in the synovial tissue or in the cartilaginous joint space. The dorsal transition between the proximal 2/3 and distal 1/3 of the cartilaginous joint was at microscopy rich in anatomical and histological variants, including osseous clefts, cartilage and subchondral defects, and vascular connective tissue in the bone marrow. These were all recognized at oblique transaxial MR imaging and in coronal MR sectioning may resemble abnormalities. Otherwise, no erosions, bone marrow abnormalities, bone sclerosis or abnormal contrast enhancement occurred in the normal joints.Conclusions The SIJ should be classified anatomically as a symphysis with some characteristics of a synovial joint being confined to the distal cartilaginous portion at the iliac side. Coronal MR imaging does not allow assessment of normal anatomy, variants or abnormalities of the ventral and dorsal margins of the cartilaginous SIJ.     

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.     

Evaluation of lesions of the internal ligaments of the wrist; conventional magnetic resonance imaging versus MR arthrography (MRA)

Objective

The aim of this study is to assess the diagnostic value of direct MR arthrography compared to conventional MR imaging in the diagnosis of different pathologic entities affecting the internal ligaments of the wrist mainly the scapholunate and lunotriquetral ligaments.

Subjects and methods

This study included 51 patients complaining of chronic wrist pain. Conventional MRI and MR arthrography (MRA) were done in all cases.

Results

A comparison of the sensitivity of conventional MRI versus MRA was done by correlating the final diagnosis of each modality with the results of arthroscopy. Regarding complete SLL tears, MRI revealed a SEN, SPE and ACC of 61.54%, 96.77%, and 86.36%, while MRA showed a SEN, SPE and ACC of 92.31%, 100%, and 97.73% respectively, partial SLL tears, un-enhanced MRI revealed SEN, SPE and ACC of 10%, 94.12%, and 75%, while MRA showed 66.67%, 85.71%, and 81.82% respectively, complete LTL tears un-enhanced MRI revealed a SEN, SPE, and ACC of 25%, 100%, and 79.5% respectively, while MRA showed 91.67%, 100%, and 97.73% respectively.

Conclusion

MR arthrography is a potent additional tool facilitating the diagnosis of different pathologic entities affecting the major internal ligaments of the wrist joint and helps to reduce arthroscopic interventions.