Does High-Resolution MR Imaging Have Better Accuracy than Standard MR Imaging for Evaluation of the Triangular Fibrocartilage Complex?

No evidence for the superiority of 3 T MRI over 1.5 T MRI for diagnosing wrist ligamentous lesions: a systematic review and meta-analysis

PURPOSES

Our aim was to determine the diagnostic accuracy of native MRI regarding different ligamentous lesions of the wrist and to analyze the influence of technical characteristics, such as field strength, application of fat saturation, 3D sequences, and wrist coils.

METHODS

The systematic search was performed using MEDLINE, Embase, and CENTRAL databases. Studies that were published before the 12th of February 2024 were included. All studies comparing the diagnostic accuracy of native wrist MRI to that of wrist arthroscopy for suspected ligamentous lesions were included. Results were analyzed by anatomic localization and technical aspects of the MRI. To assess the quality of included studies, we used the revised QUADAS-2 tool.

RESULTS

The systematic search revealed 5,181 articles. Thirty-seven studies, reporting 3893 ligamentous lesions, were eligible for inclusion. The studies displayed heterogeneity in terms of technical conditions, such as field strength, the use of wrist coils, the application of 3D sequences and fat saturation. Research methods also varied. Overall sensitivity and specificity were 0.78 (0.66 - 0.86) and 0.81 (0.70 - 0.89) for 1.5T MRI, while sensitivity was 0.73 (0.68 - 0.78) and specificity was 0.90 (0.59 - 0.98) for 3T MRI. There was no significant difference between the two subgroups (p=0,3807 and p=0,4248). Sensitivity was 0.82 (0.75 - 0.87) for triangular fibrocartilage complex (TFCC) lesions, 0.63 (0.50 - 0.74) for scapholunate ligament (SL) tears, and 0.41 (0.25 - 0.60) for lunotriquetral ligament (LT) lesions. Specificity for TFCC lesions was 0.82 (0.73 - 0.89), for SL tears 0.86 (0.73 - 0.93), and for LT lesions 0.93 (0.81 - 0.98).

CONCLUSION

The sensitivity and specificity of MRI is influenced by the anatomic location of the lesion and technical conditions. In terms of diagnostic accuracy, no significant difference was found between 1.5T and 3T MRI.

LEVEL OF EVIDENCE

III. Systematic review of Level II. - III.

STUDIES

Comparison between MRI and Arthroscopy of the Wrist for the Assessment of Posttraumatic Lesions of Intrinsic Ligaments and the Triangular Fibrocartilage Complex

Background  Magnetic resonance imaging (MRI) has been considered the most appropriate examination for wrist ligament injuries diagnosis, but it frequently fails to assess the intrinsic ligament lesion. Therefore, wrist arthroscopy is required to enhance and define the diagnosis. Purpose  We compare the MRI imaging with wrist arthroscopy for intrinsic wrist ligaments (scapholunate [SL] and lunotriquetral [LT]) and triangular fibrocartilage complex (TFCC) injuries detection. Patients and Methods  From 2007 to 2014, 532 patients affected by suspected SL, LT, and TFCC posttraumatic ligament injury have been investigated by 1.5-Tesla MRI and wrist arthroscopy. Inclusion and exclusion criteria were adopted. Only for SL ligament injury, the arthroscopic findings of complete (stage IV) and partial (stages I-III) SL ligament injury were compared with MRI findings. Statistical analysis, including sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios, and the diagnostic odds ratio, was used to compare MRI with arthroscopic findings. Results  A total of 146 patients were accepted in the study. In 68 cases of arthroscopic SL ligament lesion, MRI confirmed the diagnosis only in 50% of the cases. In partial SL lesions, MRI was positive in 24.3% and in complete SL lesions, MRI was positive in 80.6% of the cases. In 10 cases of arthroscopic LT ligament lesion, MRI was positive in 30.0% of the cases. In 33 patients with arthroscopic TFCC lesion, MRI was positive in 66.7% of the cases. Conclusion  1.5-T MRI demonstrated to fail in confirming the lesion of SL, LP, and TFCC ligaments respectively in 50, 70, and 33.3% of the cases positive at arthroscopy. In complete SL ligament lesion, MRI reaches a higher sensitivity than in partial lesion. Arthroscopy remains the best method to demonstrate the ligament lesion and obtain more information regarding the extent and quality of the ligament damage. Level of Evidence  This is a Level II, retrospective comparative study.

The Prevalence of Triangular Fibrocartilage Complex Signal Abnormalities on Magnetic Resonance Imaging Relative to Clinical Suspicion of Pathology

PURPOSE

To determine the prevalence of triangular fibrocartilage complex (TFCC) signal changes in patients undergoing magnetic resonance imaging (MRI) of the wrist and its relationship to a clinical suspicion of TFCC pathology. The secondary purpose was to study factors that are associated with TFCC signal changes.

METHODS

In this retrospective study, we looked for any TFCC signal changes in the reports of MRI findings performed during a 3-year period in 1,134 patients. Demographic characteristics, the categorized indications for MRI, and symptoms at the time of the MRI were also retrieved from the medical records. Patients were divided into 6 groups, based on age, to calculate the proportions of TFCC signal changes in the entire cohort and as an incidental finding among patients without a clinical suspicion of TFCC pathology within each age group.

RESULTS

A total of 321 patients (28%) had incidental TFCC signal changes. The prevalence among 18- to 30 year-olds was 19%, and increased to 64% in patients older than 70 years. Multivariable logistic regression analysis demonstrated that an increase in age is significantly associated with having TFCC signal changes on MRI in patients who have a low clinical suspicion of TFCC pathology. The rate of incidental TFCC signal changes steadily increases with age.

CONCLUSIONS

The TFCC signal abnormalities on MRI are more common with increasing age in patients with low clinical suspicion of TFCC pathology. At age 70, more than half of all patients will have TFCC signal changes, and more than 90% are present in patients with a low clinical suspicion of TFCC pathology.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

High-resolution MRI (3T-MRI) in diagnosis of wrist pain: is diagnostic arthroscopy still necessary?

INTRODUCTION

3T MRI has become increasingly available for better imaging of interosseous ligaments, TFCC, and avascular necrosis compared with 1.5T MRI. This study assesses the sensitivity and specificity of 3T MRI compared with arthroscopy as the gold standard.

PATIENTS AND METHODS

Eighteen patients were examined with 3T MRI using coronal T1-TSE; PD-FS; and coronal, sagittal, and axial contrast-enhanced T1-FFE-FS sequences. Two musculoskeletal radiologists evaluated the images independently. Patients underwent diagnostic arthroscopy.

RESULTS

The classifications of the cartilage lesions showed good correlations with the arthroscopy findings (κ = 0.8-0.9). In contrast to the arthroscopy, cartilage of the distal carpal row was very good and could be evaluated in all patients on MRI. The sensitivity for the TFCC lesion was 83%, and the specificity was 42% (radiologist 1) and 63% (radiologist 2). For the ligament lesions, the sensitivity and specificity were 75 and 100%, respectively, with a high interobserver agreement (κ = 0.8-0.9).

DISCUSSION

3T MRI proved to be of good value in diagnosing cartilage lesions, especially in the distal carpal row, whereas wrist arthroscopy provided therapeutic options. When evaluating the surgical therapeutical options, 3T MRI is a good diagnostic tool for pre-operatively evaluating the cartilage of the distal carpal row.

Efficacy of Magnetic Resonance Imaging and Clinical Tests in Diagnostics of Wrist Ligament Injuries: A Systematic Review

PURPOSE

To investigate the diagnostic performance of magnetic resonance imaging (MRI) and clinical provocative tests on injuries to the triangular fibrocartilage complex (TFCC), the scapholunate (SL) ligament, and the lunotriquetral (LT) ligament.

METHODS

An electronic literature search of articles published between January 1, 2000, and February 28, 2014, in PubMed, Embase, and the Cochrane Library was carried out in April 2014. Only studies of the diagnostic performance of MRI and clinical provocation tests using wrist arthroscopy as the gold standard were eligible for inclusion. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist guided the extraction and reporting of data. The methodologic quality of the included articles was assessed with the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The primary outcome measure was the negative predictive value (NPV) of wrist MRI and provocative wrist tests, which was defined as the probability of an intact wrist ligament given a negative investigation. The question was whether negative results of MRI or provocative tests were enough to safely discontinue further investigation with arthroscopy. A minimum NPV of 95% was considered a clinically relevant cutoff value. The secondary outcome measures were the positive predictive value (PPV), sensitivity, and specificity.

RESULTS

A total of 7 articles (327 patients with MRI and 105 patients with clinical tests) were included in this systematic review. The included articles displayed heterogeneity regarding participants, diagnostic methods, and study design. Seven articles investigated the diagnostic performance of MRI, whereas 1 article investigated clinical testing. The NPVs of MRI were as follows: TFCC, 37% to 90%; SL ligament, 72% to 94%; and LT ligament, 74% to 95%. The NPVs of clinical tests were 55%, 74%, and 94% for the TFCC, SL ligament, and LT ligament, respectively. Only 1 study reached the predetermined cutoff value for the primary outcome measure (NPV ≥95%) but only for MRI of the LT ligament; this study also reached a borderline-cutoff NPV of 94% for MRI of the SL ligament. Another study reached borderline-cutoff NPVs of 94% both for MRI and for clinical tests of the LT ligament.

CONCLUSIONS

A negative result from MRI is unable to rule out the possibility of a clinically relevant injury to the TFCC, SL ligament, or LT ligament of the wrist. Clinical provocation wrist tests were of limited diagnostic value. The current gold standard--wrist arthroscopy--remains the preferred diagnostic technique with sufficient conclusive properties when it comes to wrist ligament injuries.

LEVEL OF EVIDENCE

Level II, systematic review of Level II diagnostic studies.

Distal radioulnar joint stress radiography for detecting radioulnar ligament injury

PURPOSE

To determine the reliability and efficacy of clenched-fist stress radiographs in patients with radioulnar ligament injury.

METHODS

We examined 30 patients with chronic radioulnar ligament injury. These patients underwent stress radiography, which included clenched-fist posteroanterior (PA) views in forearm pronation and computed tomography in pronation. We measured distal radioulnar joint (DRUJ) gap distance and ulnar variance using clenched-fist PA views. We measured the radioulnar ratio with pronated computed tomography to quantify dorsal translation of the ulnar head. We analyzed these radiographic data and compared them between the injured and contralateral sides. We examined test-retest reliability and interobserver and intraobserver reliability using intraclass correlation coefficients as a measurement of the DRUJ gap distance in clenched-fist PA views.

RESULTS

The DRUJ gap distance observed with clenched-fist PA views in injured wrists was significantly greater than in the contralateral side. The DRUJ gap distance observed with stress radiography significantly correlated with the magnitude of the radioulnar ratio in forearm pronation. We found a significant test-retest reliability for measuring DRUJ gap distance using clenched-fist PA views, as well as a significant level of intraobserver and interobserver reliability.

CONCLUSIONS

The DRUJ gap distance observed with clenched-fist PA radiography in forearm pronation was a reliable parameter and may be useful for evaluating DRUJ instability.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Prevalence of triangular fibrocartilage complex abnormalities on MRI scans of asymptomatic wrists

PURPOSE

Magnetic resonance imaging (MRI) of the wrist is increasingly used in the diagnosis of ulnar-sided wrist pain; however, its efficacy in this setting still needs clarification. The purposes of this study were to investigate the prevalence of abnormal MRI findings in the triangular fibrocartilage complex (TFCC) in asymptomatic volunteers and to provide the clinician with comparative data when interpreting MRI results.

METHODS

A total of 103 asymptomatic volunteers underwent imaging of the wrist using a 1.9-T MR scanner and a send-receive birdcage quadrature coil. The images were evaluated by 3 independent interpreters, 2 musculoskeletal radiologists, and 1 orthopedic hand surgeon. We noted details regarding the TFCC morphology and the presence, characteristics, and location of any TFCC abnormality.

RESULTS

The TFCC was considered abnormal in 39 wrists. The scans were abnormal in 31 subjects younger than 50 years of age, in 5 subjects 50 to 59 years of age, and in all subjects older than 60 years of age (3 subjects). We diagnosed a complete tear of the TFCC in 23 wrists. An increase in age was correlated with an abnormal TFCC (r(pb) = 0.23; P = .016).

CONCLUSIONS

The prevalence of incidental TFCC findings in MRI scans of asymptomatic subjects is high. The presence of an abnormal TFCC on MRI may be of questionable clinical meaning, because there is a high incidence of TFCC abnormalities in asymptomatic subjects, particularly those over the age of 50. Imaging results must be viewed in the context of the clinical history and physical examination.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

The relationship between stress positions and pain intensity in triangular fibrocartilage lesions

We investigated the relationship between stress applied in several positions of the wrist and pain intensity in triangular fibrocartilage lesions in sixty-one patients who were diagnosed as having triangular fibrocartilage lesions and had a wrist arthroscopy. Before arthroscopy, we stressed the wrist with an axial load applied in four different wrist positions, and the evoked pain was graded into four levels. The patients who had a triangular fibrocartilage lesion on arthroscopy were divided into those with a traumatic tear and those with degenerative changes. While hypersupination and extension of wrist position evoked the most severe pain in patients with a traumatic tear, the intensity of pain did not relate to wrist rotation in patients with degenerative changes.

Ulnar-sided wrist pain. II. Clinical imaging and treatment

Pain at the ulnar aspect of the wrist is a diagnostic challenge for hand surgeons and radiologists due to the small and complex anatomical structures involved. In this article, imaging modalities including radiography, arthrography, ultrasound (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography are compared with regard to differential diagnosis. Clinical imaging findings are reviewed for a more comprehensive understanding of this disorder. Treatments for the common diseases that cause the ulnar-sided wrist pain including extensor carpi ulnaris (ECU) tendonitis, flexor carpi ulnaris (FCU) tendonitis, pisotriquetral arthritis, triangular fibrocartilage complex (TFCC) lesions, ulnar impaction, lunotriquetral (LT) instability, and distal radioulnar joint (DRUJ) instability are reviewed.

High-resolution magnetic resonance imaging of triangular fibrocartilage complex lesions in acute wrist trauma: image quality at different field strengths

PURPOSE

The purposes of this study were to assess the diagnostic capacity of a new high-resolution imaging protocol for the wrist and triangular fibrocartilage complex (TFCC) lesions at 3.0 T and to compare it with our established 1.5-T protocol.

MATERIALS AND METHODS

Twenty-one patients with an acute wrist trauma were examined at a 3.0-T imaging system and agreed to undergo an additional examination at 1.5 T. Magnetic resonance imaging was performed with 1.5-T (standard wrist coil) and 3.0-T (purpose-build phased-array coil) imaging system, using coronal T1-weighted turbo-spin-echo, proton density-weighted fat-saturated, and coronal and axial contrast-enhanced T1-weighted gradient-echo fat-saturated sequences, with reduced voxel size from 0.50 x 0.50 x 3.0 mm (1.5 T) to 0.20 x 0.20 x 1.5 mm (3.0 T). For qualitative analysis, 2 observers assessed in consensus delineation, image quality, and artifacts in anatomical landmarks (cartilage, TFCC, and TFCC lesion) and ranked them on a 5-point scale from 1 (nondiagnostic) to 5 (optimal). For quantitative analysis, measurements of the contrast-to-noise ratio were obtained between disk and surrounding tissue.

RESULTS

All parts of the TFCC and TFCC lesions (n = 14) were seen significantly better at 3.0 T (mean [SD], 4.6 [0.5] vs 2.6 [1.2], P < 0.0001), with higher ranked overall image quality. In 3 cases, TFCC lesions were seen only at 3.0 T. Proton density-weighted fat-saturated sequence had significantly more artifacts at 3.0 T (2.5 [0.6] vs 1.9 [0.5], P < 0.001) in contrast to T1 sequences. Quantitative evaluation showed significantly higher contrast-to-noise ratio for 3.0 T (5.0 [1.1] vs 3.9 [0.9], P < 0.0001).

CONCLUSION

Depiction of anatomy and pathology of the TFCC benefits significantly from 3.0-T imaging when higher signal-to-noise ratio is invested into improved spatial resolution. Especially small lesions of the disk were detected only or better at 3.0 T.

Management of acute triangular fibrocartilage complex injury of the wrist

Acute trauma to the triangular fibrocartilage complex includes tears of the fibrocartilage articular disk substance and meniscal homolog as well as radioulnar ligament avulsions, with or without an associated fracture. Patient evaluation includes clinical examination, imaging studies, and wrist arthroscopy (diagnostic). The Palmer classification is typically used to define injuries to the triangular fibrocartilage complex. The critical distinction is in differentiating injuries that produce instability of the distal radioulnar joint from those that do not. Also important is the recognition of acute injuries in the context of an ongoing degenerative pattern (ie, Palmer class 2 lesions). Nonsurgical management includes temporary splint immobilization of the wrist and forearm, oral nonsteroidal anti-inflammatory medication, corticosteroid joint injection, and physical therapy. Surgical strategies include débridement, acute repair, and subacute repair. Most surgical procedures can be performed arthroscopically. However, open ligament repair may be needed in the setting of distal radioulnar joint instability.

[Bulge of the scapholunate ligament: an arthro-CT sign of traumatic scapholunate instability]

Tears of the scapholunate ligament are usually diagnosed during an arthro-CT or arthro-MRI examination. Typically, the contrast agent passes from one joint to the other. In certain cases, fibrous scar tissue devoid of any mechanical effect may block the passage and lead to an erroneous interpretation of the images. We reviewed retrospectively patients who underwent arthroscopic treatment for scapholunate tears and who had normal arthro-CT images. We searched for specific aspects suggestive of ligament injury. Analysis of the arthro-CT images demonstrated that a bulge of the scapholunate ligament could be noted in patients whose diagnosis of scapholunate ligament injury was established arthroscopically. We propose that appropriate lecture of wrist images can identify scapholunate ligament injury in patients wrongly considered to be free of wrist injury, but who actually have an occult injury to the scapholunate ligament.

The diagnostic utility of midcarpal anesthetic injection in the evaluation of chronic wrist pain

The evaluation of chronic wrist pain can be a diagnostic dilemma. Lidocaine injections combined with corticosteroids are often used for both diagnosis and therapy. The purpose of this study was to determine if a midcarpal injection of lidocaine could serve as a diagnostic tool in patients with chronic wrist pain. Specifically, the relationship of pain relief from the injection and improvement of grip strength were compared to the presence of intracarpal pathology as confirmed by wrist arthroscopy. Forty-five patients with chronic wrist pain underwent a midcarpal injection of lidocaine with or without corticosteroids. Forty of the 45 underwent comcomitant steroid injections; a majority of the 40 patients reported relief of pain for two or more weeks. Improvement of pain and improvement of grip strength were determined. Each of these patients subsequently underwent a radiocarpal and midcarpal arthroscopy, and the pathologic findings of arthroscopy were compared to the improvement of pain and grip strength. These data were compared to a cohort of six volunteers without history of wrist pain or trauma that underwent midcarpal injection of lidocaine. Statistical analysis was performed using Receiver-Operator-Characteristic analysis. The average age of patients with chronic pain was 30.3 years, with an average of 9.8 months of wrist pain. The ultimate diagnoses included 35 patients with carpal instability dissociative, two with nondissociative instability, seven with complex instability of the carpus, three with extensor carpi ulnaris tendonitis and one with deQuervain's tenosynovitis. After lidocaine injection, the normal cohort had a mean loss of 2 kg (-5.3%) (p = 0.02) in grip strength, whereas the experimental cohort had a mean improvement in grip strength of 5.73 kg (34.4%). Improvement of pain after injection did not correlate with pathologic arthroscopic findings (p = 0.92). Improvement in grip strength after midcarpal lidocaine injection of 6 kg or 28% had a 73% sensitivity and a 70% specificity (p = 0.02) of having intracarpal pathology at the time of arthroscopy. Of the chronic wrist pain patients, only four had a normal arthroscopy, and the remainder had at least one area of significant pathology attributing to their pain. We conclude that a midcarpal injection of lidocaine can serve as an effective diagnostic tool in the evaluation of the patient with chronic wrist pain. Improvement of grip of 28% with or without relief of pain is highly correlated with intracarpal pathology.

Comparison between high-resolution MRI with a microscopy coil and arthroscopy in triangular fibrocartilage complex injury

PURPOSE

To determine whether high-resolution magnetic resonance imaging (MRI) could detect injuries to the triangular fibrocartilage complex (TFCC).

METHODS

Eleven patients who showed both a positive sign during the ulnocarpal stress test and tenderness at the distal end of the ulna had a high-resolution MRI using a 47-mm diameter microscopy coil. Six regions of the TFCC were investigated for injury: the radial attachment, disc, ulnar attachment of the triangular fibrocartilage (TFC), ulnotriquetral ligament, palmar radioulnar ligament (PRUL), and dorsal radioulnar ligament (DRUL). Arthroscopy was performed subsequently on each patient.

RESULTS

For injuries to the radial attachment or the disc of the TFC, a high-resolution MRI showed 100% sensitivity and 100% specificity compared with arthroscopy. In 3 cases in which injury to the ulnar attachment of the TFC was detected with MRI and examination showed a positive piano-key sign and distal radioulnar joint instability, only 1 injury was confirmed with arthrotomy. For MRI diagnosis of an ulnotriquetral ulnolunate attachment injury, the sensitivity was 100% and the specificity was 70%; however, 3 cases had false-positive results. Finally MRI had 100% sensitivity for detecting DRUL and PRUL injuries, although specificities were 75% and 83%, respectively. With MRI there were 2 false-positive DRUL injury diagnoses and 1 false-positive PRUL injury diagnosis.

CONCLUSIONS

High-resolution MRI using a microscopy surface coil allowed assessment of each TFCC component and showed a higher accuracy for diagnosing injuries to the radial attachment and the disc of the TFC compared with previous studies. High-resolution MRI, however, was not able to diagnose DRUL, PRUL, or ulnolunate ligament injuries accurately.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Pediatric distal radius fractures and triangular fibrocartilage complex injuries

Management of distal radius fractures is guided by the pattern and location of injury, degree of deformity, and expectations of bony remodeling based on the amount of remaining skeletal growth.Indications for surgical treatment include unstable or irreducible fractures, open fractures, floating elbow injuries, and neurovascular or soft-tissue compromise precluding cast immobilization. Patients and families should be counseled regarding the potential for post-traumatic distal radial growth arrest following physeal fractures. In these cases, epiphysiodeses, ulnar shortening osteotomies, or corrective radial osteotomies may be performed, depending on the pattern of arrest,degree of deformity, and remaining skeletal growth.TFCC tears may be the source of ulnar-sided wrist pain in children and adolescents, though symptoms and physical examination findings maybe subtle. Patients who have persistent pain and functional limitations despite activity modification and therapy are candidates for surgical treatment. Appropriate repair of peripheral TFCC tears with correction of concomitant wrist pathology restores normal wrist anatomy, alleviates pain, and allows for return to functional activities.

3T MR Imaging of the Musculoskeletal System (Part II): Clinical Applications

The gain in SNR that is afforded by 3T MR imaging systems has tremendous clinical applications in the musculoskeletal system. The potential for demonstrating and enhancing the visibility of normal osseous, tendinous, cartilaginous, and ligamentous structures is exciting. Furthermore, harnessing this added signal to increase spatial resolution may improve our diagnostic abilities in various joints dramatically. Radiologists have enjoyed great success in assessing joint disease with current MR imaging field strengths; however, many intrinsic joint structures remain poorly evaluated, which leads to a golden opportunity for 3T MR imaging. The articular cartilage of the knee, the glenoid labrum of the shoulder, the intrinsic ligaments and TFC of the wrist, the collateral ligaments of the elbow, the labrum and articular cartilage of the hip, and the collateral ligaments of the ankle have been evaluated suboptimally on 1 .5T systems using routine nonarthrographic MR images. Because of the enhanced SNR, the higher spatial resolution, and the greater CNR of intrinsic joint structures at higher field strengths, 3T MR imaging has the potential to improve diagnostic abilities in the musculoskeletal system vastly, which translates into better patient care and management. The author's 2 years of clinical experience with musculoskeletal MR imaging on 3T systems has met and exceeded his expectations, and has bolstered the confidence of his orthopedic surgeons in his diagnoses. As coil technology advances and as the use of parallel imaging becomes more available in the extremities, the author expects to see even more dramatic improvements in image quality.

Acute Wrist Trauma: Value of a Short Dedicated Extremity MR Imaging Examination in Prediction of Need for Treatment

PURPOSE

To assess predictive value of a short magnetic resonance (MR) imaging examination in addition to or instead of radiography in patients with acute wrist trauma to identify patients who require additional treatment versus those who do not and can be discharged without further follow-up.

MATERIALS AND METHODS

Informed consent was obtained from all participating patients; the institutional review board approved the randomized controlled trial and use of data to create prediction models. Of 90 patients (37 female, 53 male; mean age, 40.0 years), 87 with acute wrist trauma were randomized to undergo radiography (n = 43) or radiography and a short MR imaging examination with low-field-strength dedicated extremity MR system (n = 44). Age, sex, trauma mechanism, presence of tenderness of the anatomic snuffbox, radiographic results, MR imaging results, and treatment data were collected. Univariable and multivariable logistic regression analysis was used to create four models for prediction of treatment need.

RESULTS

Thirty-six patients had one or more fractures; one patient had a marked soft-tissue lesion. In univariable analysis, age (odds ratio, 1.02; 95% confidence interval: 1.00, 1.05), anatomic snuffbox tenderness (odds ratio, 2.31; 95% confidence interval: 0.90, 5.96), radiographic results (odds ratio, 31.2; 95% confidence interval: 8.90, 109), and positive MR imaging results versus MR imaging not performed (odds ratio, 1.86; 95% confidence interval: 0.57, 6.06) were significantly predictive of treatment need. In multivariable analysis, radiographic results (odds ratio, 24.7; 95% confidence interval: 6.59, 93.1) and positive MR imaging results (odds ratio, 6.28; 95% confidence interval: 1.27, 31.0) were significantly predictive of treatment need. Negative MR imaging results were not significantly predictive (odds ratio, 0.87; 95% confidence interval: 0.20, 3.82).

CONCLUSION

A short MR imaging examination with a low-field-strength MR imaging system following radiography in initial evaluation of patients with acute wrist trauma has additional value in prediction of treatment need; it does not have value in identification of patients who can be discharged without further follow-up.

Protocols in sports magnetic resonance imaging

Magnetic resonance imaging, with its multiplanar imaging capability and superior soft-tissue contrast, has become the preferred method for imaging sports-related injuries. Advances in gradient technology, receiver coils, and imaging software have allowed the imaging of the injured athlete to take place quickly and at high resolution. Understanding the tissues being imaged, the underlying anatomy, and the capabilities of today's scanners is crucial to the design of intelligent and efficient protocols.