Current perspectives on the advantages of 3-T MR imaging of the wrist

Peripheral tear of the triangular fibrocartilage complex: diagnostic accuracy of magnetic resonance imaging and diagnostic performance of the primary and secondary signs

OBJECTIVE

This study is to assess the diagnostic performance of magnetic resonance imaging (MRI) findings for type 1B triangular fibrocartilage complex (TFCC) tear of the wrist.

MATERIALS AND METHODS

This study retrospectively enrolled 78 patients to examine the diagnostic performance of preoperative MRI examinations in patients with type 1B TFCC tears. Thirty-nine participants had confirmed type 1B TFCC tear. The control group included 39 patients who were randomly selected from 1157 patients who underwent MRI for wrist pain. Both groups underwent a review of 19 MRI findings by two independent radiologists, and the correlation between each diagnostic finding and type 1B TFCC tear was assessed using the chi-squared test. The 19 MRI findings comprised eight primary signs of abnormalities in the distal or proximal lamina, in conjunction with 11 secondary signs suggestive of abnormalities in the surrounding structures.

RESULTS

The TFCC tear group demonstrated a significantly higher incidence of two primary MRI signs, i.e., fiber discontinuity and signal alteration in the distal lamina, as observed by both readers (R1, 74.4% vs. 38.5%, p = 0.003, and 87.2% vs. 43.6%, p < 0.001; R2, 74.4% vs. 35.9%, p = 0.001, and 87.2% vs. 53.8%, p < 0.003, respectively). Reader 2 identified a higher prevalence of two additional primary MRI signs: fiber discontinuity and signal alteration in the proximal lamina (all p < 0.05). None of the 11 secondary MRI signs demonstrated statistically significant associations with type 1B TFCC.

CONCLUSION

MRI manifestations of fiber discontinuity and signal alteration in the distal lamina may provide predictive markers for type 1B TFCC wrist tear.

3T Magnetic resonance imaging and computed tomography of the bovine carpus

Background

Lameness in cattle is a major health problem and causes great economic losses. Carpal injury is a common cause of forelimb lameness in cattle. Radiography and/or ultrasonography of the carpus is a challenge due to complex anatomy of the joint. Additional imaging using computed tomography (CT) or magnetic resonance imaging (MRI) may be indispensable for reaching a decisive diagnosis. Precise evaluation of the clinical CT and MRI images necessitates an in-depth knowledge of the normal CT and MRI tissue variants. Therefore, our purpose was to provide a detailed description of the normal CT and MRI appearance of the osseous and soft tissue structures of twelve cadaveric bovine carpi using CT and 3 Tesla MRI. Carpi were frozen, transected in sagittal, dorsal and transverse planes then adjoined to their corresponding CT and MRI images.

Results

The clinically significant articular and peri-articular structures of the bovine carpus were identified and characterized on the CT and MRI images. CT images provided a remarkable delineation of the cortical, subchondral, and cancellous bone. The high-field 3 Tesla MRI offered high definition and distinction of the delicate soft tissues of the bovine carpus.

Conclusions

3 Tesla high-field MRI offers new opportunities in soft tissue tomography but cannot be compared with CT in terms of bone imaging. Clinicians have to determine whether CT, MRI or both imaging techniques are required in clinical situations.

How to Report: Wrist MRI

Knowledge of the imaging anatomy of the wrist is essential for reporting magnetic resonance imaging (MRI). This familiarity should include the carpal bones, tendons (extensor and flexor compartments), triangular fibrocartilage complex (TFCC), intrinsic and extrinsic ligaments, and nerves, especially the median and ulnar nerves. Limitations of MRI in visualizing these structures, particularly the intrinsic ligaments and the TFCC, need to be considered. This article outlines the main features to comment on when reporting common conditions of the wrist on MRI, with some examples of terminology that can be used to describe these abnormalities.

Accuracy of magnetic resonance imaging of the wrist for clinically important lesions of the major interosseous ligaments and triangular fibrocartilage complex; correlation with radiocarpal arthroscopy

OBJECTIVE

To demonstrate the utility of MRI in separating clinically relevant from minor or incidental lesions of the triangular fibrocartilage complex and the major interosseous ligaments in the wrist.

MATERIALS AND METHODS

In this retrospective study, we identified 89 patients and correlated MRI finding with subsequent arthroscopy. Triangular fibrocartilage complex abnormalities have been subdivided into disc lesions-central and radial-or ulnar-sided tears according to MRI appearances and surgical findings as the clinical and surgical approach is very different. Interosseous ligament tears were subdivided into partial or complete, highlighting the principle of recognising surgically relevant lesions.

RESULTS

For simple central to radial tears and perforations of the triangular fibrocartilage complex, MRI was 98.3% accurate. MRI identified all peripheral triangular fibrocartilage complex tears seen at arthroscopy; however, the specificity of 66.7% may reflect partly the use of arthroscopy limited to the radiocarpal joint. MRI proved 95.4% accurate for surgically relevant scapholunate interosseous ligament tears and was highly accurate at separating limited from complete lunotriquetral interosseous ligament tears showing 100% accuracy for complete tears.

CONCLUSIONS

The study shows excellent correlation between MRI and arthroscopic findings that determine surgical relevance with a very high sensitivity for triangular fibrocartilage complex lesions and accurate separation of minor versus surgically relevant ligamentous tears.

Distal Radioulnar Joint Instability and Associated Injuries: A Literature Review

The distal radioulnar joint (DRUJ) allows supination and pronation of the distal forearm and wrist, an integral motion in everyday human activity. DRUJ injury and chronic instability can be a significant source of morbidity in patients' lives. Although often linked with distal radius fractures, DRUJ injury may occur in a variety of other upper extremity injuries, as well as an isolated pathology. Diagnosis of this injury requires the clinician to have a high index of suspicion and low threshold for clinical testing and further imaging of the DRUJ. The purpose of this article is to provide a review on DRUJ anatomy and biomechanics, to discuss common diagnostic and treatment modalities, and to identify common injuries associated with DRUJ instability.

Comparison of visibility of ulnar sided triangular fibrocartilage complex (TFCC) ligaments between isotropic three-dimensional and two-dimensional high-resolution FSE MR images

OBJECTIVES

Assessment of the ulnar attachment of the triangular fibrocartilage complex (TFCC) in a neutral forearm position remains challenging. Our study aims to evaluate the visibility of ulnar sided TFCC on 3 T MRI and compare isotropic 3D FSE sequences utilizing multiplanar reformation (MPR) with standard high-resolution 2D FSE sequences.

METHODS

Ninety-nine MRI wrist studies in patients with wrist pain were retrospectively analyzed. Patients were scanned with a neutral forearm position and reviewed with isotropic 3D coronal FSE proton density-weighted images (PDWI) and 2D coronal FSE PDWI. MPR was used for 3D assessment. Visibility of the dorsal radioulnar ligament (DRUL), triangular ligament (TL), and volar radioulnar ligament (VRUL) was assessed by three raters utilizing a five-point grading scale. Grades were compared between 2D and 3D sequences. Intrarater and interrater reliability for the delineation of anatomic structures was measured by Spearman's rank correlation coefficient, Cohen's kappa, and percentage of exact agreement/agreement within a range of ±1 score point.

RESULTS

Visibility grades in 3D were statistically significantly higher than those in 2D in all ligaments by all raters (p < 0.01). In Spearman's rank correlation coefficient and Cohen's kappa analysis, interrater correlations and agreements are variable but tended to be higher on 3D than on 2D. Both 2D and 3D sequences showed high intrarater exact agreement in all ligaments (80-91 % on 2D and 88-95 % on 3D). All exact interrater agreements on 3D were acceptable for TL (83-93 %) and acceptable to close to acceptable for VRUL (72-96 %).

CONCLUSION

The utilization of isotopic 3D imaging combined with MPR function significantly improves visibility of ulnar attachment of the TFCC.

Assessment of Articular Cartilage Disorders After Distal Radius Fracture Using Biochemical and Morphological Nonenhanced Magnetic Resonance Imaging

PURPOSE

To assess radiocarpal articular cartilage after distal radius fracture, with and without intra-articular extension, compared with healthy controls using multiparametric, nonenhanced magnetic resonance imaging (MRI).

METHODS

In this prospective study, multiparametric MRI of the radiocarpal articular cartilage was performed in 26 participants (16 males and 10 females; mean age, 39.5 ± 14.7 years; range, 20-70 years) using 3T MRI. The cohort consisted of 14 patients with a distal radius fracture and 12 healthy volunteers. The radiocarpal articular cartilage was assessed using morphological (Double Echo Steady-State [DESS] and True Fast Imaging With Steady-State Precession [TrueFISP]) and biochemical (T2∗) MRI sequences without an intravenous contrast agent. The modified Outerbridge classification system for morphological analyses and region-of-interest biochemical analysis were applied to assess the degree of articular cartilage damage in each patient.

RESULTS

Morphological articular cartilage assessment showed no difference between the DESS sequence and the reference standard, TrueFISP. In the morphological (DESS and TrueFISP) and biochemical (T2∗) assessments, patients with intra-articular fractures did not show articular cartilage damage different from those with extra-articular fractures. Greater articular cartilage degradation was observed after distal radius fracture compared with controls.

CONCLUSIONS

Posttraumatic radiocarpal articular cartilage damage did not differ between fractures with intra-articular and extra-articular extension, but patients with fractures had notably higher articular cartilage degradation compared with healthy controls. Magnetic resonance imaging using advanced multiparametric sequences may facilitate accurate, noninvasive assessment of articular cartilage changes after distal radius fracture without the need for a contrast agent.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Differences of radiocarpal cartilage alterations in arthritis and osteoarthritis using morphological and biochemical magnetic resonance imaging without gadolinium-based contrast agent administration

OBJECTIVES

To identify differences of radiocarpal cartilage alterations in osteoarthritis and arthritis using multiparametrical magnetic resonance imaging (MRI) comprising morphological and biochemical sequences without gadolinium-based contrast agent administration.

METHODS

In this prospective study, multiparametrical MRI of the radiocarpal cartilage was performed in 47 participants (mean age, 46.6 ± 17.6 years; min., 20 years; max., 79 years) on a 3 Tesla MRI. The cohort consisted of 11 patients suffering from arthritis, 10 patients with osteoarthritis, 14 patients after distal radius fracture, and 12 healthy volunteers. The radiocarpal cartilage was assessed using morphological (DESS, TrueFISP) and biochemical (T2*) MRI sequences without the application of intravenous contrast agent. The modified Outerbridge classification system for morphological and region-of-interest analyses for biochemical analysis was applied to assess the degree of cartilage damage in each patient before data were statistically tested for significant difference between the groups using a post hoc Tukey test.

RESULTS

In morphological imaging, cartilage damage was significantly more frequent in arthritis and osteoarthritis than in healthy volunteers (DESS: p = 0.01, p = 0.0004; TrueFISP: p = 0.02, p = 0.0001). In T2* imaging, patients with osteoarthritis showed higher cartilage damage compared to patients with arthritis (p = 0.01).

CONCLUSION

With multiparametrical MRI, it is possible to identify differences of radiocarpal cartilage alterations of patients with arthritis and osteoarthritis using the combination of morphological and biochemical MR imaging of the radiocarpal cartilage without the application of contrast agent. Multiparametrical MRI without the usage of contrast agent may be a potential tool helping to distinguish both entities.

KEY POINTS

• Multiparametrical MRI with morphological and biochemical sequences allows the differentiation of patients with arthritis and osteoarthritis. • High-resolution MRI of radiocarpal cartilage is possible without administration of contrast agent.

Influence of the thickness of the transverse carpal ligament in carpal tunnel syndrome

OBJECTIVE

To determine if the thickness of the transverse carpal ligament measured by T2 axial magnetic resonance imaging actually influences the onset of carpal tunnel syndrome.

MATERIAL AND METHOD

94 patients between January 2015 and June 2016, of whom 28 had carpal tunnel syndrome, underwent magnetic resonance imaging, 37 with discomfort in different carpus regions without symptoms of carpal tunnel and 29 healthy subjects. Two observers performed 3 measurements in 3 different levels, and in the 3 groups of patients.

RESULTS

No statistically significant differences in transverse carpal ligament thickness measurements between the carpal tunnel syndrome group and the group without carpal tunnel involvement became apparent, but statistical differences between the control group and the carpal tunnel syndrome group, and between the control group and the group without involvement of the carpal tunnel were observed. In both these groups, the thickness of the transverse ligament was higher than in the control group.

DISCUSSION

An increase in the thickness of the transverse ligament in was found in this study in subjects with involvement of carpal tunnel syndrome as evidenced by numerous studies in the literature. There is no certain causative factor, but rather a set of facts that make onset of the syndrome possible in a specific group of patients.

CONCLUSION

Carpal tunnel syndrome is multifactorial. The thickness of the transverse ligament does not directly affect the onset of symptoms.

MR imaging of the traumatic triangular fibrocartilaginous complex tear

Triangular fibrocartilage complex is a major stabilizer of the distal radioulnar joint (DRUJ). However, triangular fibrocartilage complex (TFCC) tear is difficult to be diagnosed on MRI for its intrinsic small and thin structure with complex anatomy. The purpose of this article is to review the anatomy of TFCC, state of art MRI imaging technique, normal appearance and features of tear on MRI according to the Palmar's classification. Atypical tear and limitations of MRI in diagnosis of TFCC tear are also discussed.

Diagnostic modalities for distal radioulnar joint

The first imaging modality in patients suspected of distal radioulnar joint pathology should be conventional radiography to exclude or diagnose wrist pathology including osteoarthritis, rheumatoid arthritis, calcium pyrophosphate deposition disease, (healed) fractures, or impaction syndromes. When conventional radiography is inconclusive, high resolution 3 Tesla magnetic resonance imaging is advised. We provide a broad overview of the literature regarding the use of intra-articular contrast both with computed tomography (CTA) or magnetic resonance imaging (MRA). Conventional arthrography and unenhanced computed tomography are not indicated. This article discusses the most useful imaging techniques in terms of clinical indications, patient positioning, technical imaging requirements, and diagnostic performance in patients with suspected distal radioulnar joint pathology. Furthermore, the most prevalent pathologies are discussed, with the focus on imaging characteristics in both stable and unstable distal radioulnar joints.

Effect of traction on wrist joint space and cartilage visibility with and without MR arthrography

OBJECTIVE

To compare the effect of traction during non-arthrographic and arthrographic MR examination of the wrist with regard to joint space width, joint fluid dispersion and cartilage surface visibility.

METHODS

Prospective 3-T MRI study of 100 wrists in 96 patients. The first 50 wrists underwent MR arthrography first without traction and then with traction. The following 50 wrists underwent standard MR first without traction and then with traction. On these examinations, two radiologists independently measured (i) joint space width, semi-quantitatively graded (ii) joint fluid dispersion between opposing cartilage surfaces and (iii) articular cartilage surface visibility. The three parameters were compared between the two groups.

RESULTS

Traction led to an increase in joint space width at nearly all joints in all patients (p < 0.05), although more so in the arthrography (∆ = 0.08-0.79 mm, all p < 0.05) than in the non-arthrography (∆ = 0.001-0.61 mm, all p < 0.05) group. Joint fluid dispersion and cartilage surface visibility improved after traction in nearly all joints (p < 0.05) in all patients and more so in the arthographic than in the non-arthrography group.

CONCLUSION

Traction did significantly improve cartilage surface visibility for standard MRI of the wrist although the effect was not as great as that seen with MR arthography or MR arthrography with traction. Advances in knowledge: This is the first study to show the beneficial effect of traction during standard non-arthrography MRI of the wrist and compare the effect of traction between non-arthrographic and arthrographic MRI of the wrist.

Safety of dorsal wrist arthroscopy portals: A magnetic resonance study

In wrist arthroscopy, the standard dorsal portals are the most commonly used. However, their placement can be associated with injuries to the neurovascular structures of the radiocarpal joint. The present study assessed and compared the distance of commonly used dorsal portals to radial and ulnar neurovascular structures. Forty patients (20 males, 20 females) were evaluated with T1-weighted spin-echo (SE) magnetic resonance (MR) sequences. We measured the distance between 1-2 and 3-4 portals and radial vascular bundle and the nearest branch of the superficial branch of radial nerve (SBRN). We also measured the distance between 4 and 5, 6/U and 6/R and ulnar vascular bundle and the nearest branch of the dorsal ulnar nerve (DUN). The median age of patients was 39 years (95% IC 36.97-43.32 years). The 3-4 portal was farther away from the vascular structure than the 1-2 portal (P < 0.0001), 4-5 portal (P = 0.008), 6/R (P < 0.0001), and 6/U portals (P < 0.0001). Moreover, the 3-4 portal was farther away from the nerve branch than the 1-2 portal (P < 0.0001), 4-5 portal (P < 0.0001), 6/R (P < 0.0001), and 6/U portals (P < 0.0001). No statistical significant differences were found between the two genders. The 3-4 and 4-5 portals are the farthest away from the neurovascular structures, and likely reduce the risk to damage these structures. On the other hand, the 1-2 and 6/U portals likely increase the risk of neurovascular damage, because of their proximity to neurovascular structures.

LEVEL OF EVIDENCE

Diagnostic study; Level III.

Magnetic Resonance Arthrography of the Wrist and Elbow

Magnetic resonance (MR) arthrography of the wrist and elbow is useful for detecting a variety of intra-articular pathologies. MR dictations should address whether intrinsic ligament tears of the wrist are partial-thickness or full-thickness, and involve the dorsal, membranous, and/or volar components of the ligaments. With regard to elbow soft tissue pathology, partial-thickness tears of the anterior band of the ulnar collateral ligament in overhead-throwing athletes are well evaluated with MR arthrography. MR arthrography also is helpful in staging osteochondritis dissecans of the capitellum, caused by repetitive valgus impaction injury in adolescent or young adult baseball pitchers.

Scapholunate kinematics of asymptomatic wrists in comparison with symptomatic contralateral wrists using four-dimensional CT examinations: initial clinical experience

OBJECTIVES

Using four-dimensional CT scan (4DCT), we aimed at showing the kinematics of scapholunate (SL) interval in asymptomatic wrists in comparison with symptomatic contralateral wrists with inconclusive radiographic findings.

METHODS

This is an IRB approved, HIPPA compliant, retrospective study. Patients suspected of SL interosseous ligament (SLIL) injuries were referred for further evaluation of chronic wrist pain (>3 months). Twelve wrists (11 subjects) with chronic symptoms and inconclusive plain radiographs and 10 asymptomatic wrists (in 10 different subjects) were scanned using 4DCT. The minimum SL interval was measured during three wrist motions: relaxed-to-clenched fist, flexion-to-extension, and radial-to-ulnar-deviation. Changes were recorded using double-oblique multiplanar reformation technique.

RESULTS

We extracted the normal limits of the SL interval as measured by dynamic CT scanning during active motion in asymptomatic wrists. In asymptomatic wrists, the average SL interval was observed to be smaller than 1 mm during all motions. In symptomatic wrists, during exams performed with clenched fist (SL interval (mean ± SD) = 2.53 ± 1.19 mm), extension (2.54 ± 1.48 mm) or ulnar deviation (2.06 ± 1.12 mm), the average SL interval was more than 2 mm. In contrast to symptomatic wrists, no significant change in SL interval measurements was detected during wrist motions in asymptomatic wrists. There was a mild to moderate correlation between SL interval change and presence/absence of symptoms (point-biserial correlation coefficients: 0.29-0.55).

CONCLUSION

In patients with wrist pain suspicious for SLIL injury and inconclusive radiographs, SL interval increase can be detected with 4DCT in the symptomatic wrist compared to the asymptomatic wrist.

Advanced imaging of the scapholunate ligamentous complex

The scapholunate joint is one of the most involved in wrist injuries. Its stability depends on primary and secondary stabilisers forming together the scapholunate complex. This ligamentous complex is often evaluated by wrist arthroscopy. To avoid surgery as diagnostic procedure, optimization of MR imaging parameters as use of three-dimensional (3D) sequences with very thin slices and high spatial resolution, is needed to detect lesions of the intrinsic and extrinsic ligaments of the scapholunate complex. The paper reviews the literature on imaging of radial-sided carpal ligaments with advanced computed tomographic arthrography (CTA) and magnetic resonance arthrography (MRA) to evaluate the scapholunate complex. Anatomy and pathology of the ligamentous complex are described and illustrated with CTA, MRA and corresponding arthroscopy. Sprains, mid-substance tears, avulsions and fibrous infiltrations of carpal ligaments could be identified on CTA and MRA images using 3D fat-saturated PD and 3D DESS (dual echo with steady-state precession) sequences with 0.5-mm-thick slices. Imaging signs of scapholunate complex pathology include: discontinuity, nonvisualization, changes in signal intensity, contrast extravasation (MRA), contour irregularity and waviness and periligamentous infiltration by edema, granulation tissue or fibrosis. Based on this preliminary experience, we believe that 3 T MRA using 3D sequences with 0.5-mm-thick slices and multiplanar reconstructions is capable to evaluate the scapholunate complex and could help to reduce the number of diagnostic arthroscopies.

[Morphological and functional cartilage imaging]

Excellent morphological imaging of cartilage is now possible and allows the detection of subtle cartilage pathologies. Besides the standard 2D sequences, a multitude of 3D sequences are available for high-resolution cartilage imaging. The first part therefore deals with modern possibilities of morphological imaging. The second part deals with functional cartilage imaging with which it is possible to detect changes in cartilage composition and thus early osteoarthritis as well as to monitor biochemical changes after therapeutic interventions. Validated techniques such as delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping as well the latest techniques, such as the glycosaminoglycan chemical exchange-dependent saturation transfer (gagCEST) technique will be discussed.

Osteoarthritis of the carpometacarpal joint of the thumb: a new MR imaging technique for the standardized detection of relevant ligamental lesions

OBJECTIVE

To assess ligament lesions and subluxations of the carpometacarpal joints of the thumbs (CMC I) of asymptomatic volunteers and of patients with CMC I osteoarthritis using advanced magnetic resonance imaging (MRI).

MATERIALS AND METHODS

A total of 20 CMC I joints of 14 asymptomatic volunteers (6× both sides) and 28 CMC I joints of 22 patients (6× both sides) with symptomatic and X-ray-diagnosed osteoarthritis of CMC I joints were studied. During extension, flexion, abduction and adduction of the thumb, the anterior oblique (AOL), intermetacarpal (IML), posterior oblique (POL) and dorsal radial (DRL) ligaments were evaluated using 3-T MRI on two standard planes, and translation of metacarpal I (MC I) was assessed.

RESULTS

The MRI demonstrated that ligament lesions of the AOL and IML are frequent. Isolated rupture of the AOL was found in 6 of 28 (21%), combined rupture of the AOL + IML in 5 of 28 (18%) and isolated IML rupture in 4 of 28 (14%) joints. The patients had a significantly increased dorsal translation of MC I during extension with a median of 6.4 mm vs. 5.4 mm in asymptomatic volunteers (p < 0.05).

CONCLUSION

MRIs of CMC I in two standardized planes frequently show combined ligament ruptures. The dorsal subluxation of MC I, which is increased in patients, correlates with OA severity based on X-ray and can be quantified by MRI. For joint-preserving surgical procedures and for prosthesis implantation of the CMC I, we recommend performing an MRI in two planes of the thumb-extension and abduction-to evaluate the ligaments and dorsal subluxation of MC I.

The role of imaging in diagnosing diseases of the distal radioulnar joint, triangular fibrocartilage complex, and distal ulna

OBJECTIVE

The purpose of this article is to review the anatomy, biomechanics, and multimodality imaging findings of common and uncommon distal radioulnar joint (DRUJ), triangular fibrocartilage complex, and distal ulna abnormalities.

CONCLUSION

The DRUJ is a common site for acute and chronic injuries and is frequently imaged to evaluate chronic wrist pain, forearm dysfunction, and traumatic forearm injury. Given the complex anatomy of the wrist, the radiologist plays a vital role in the diagnosis of wrist pain and dysfunction.