Accuracy Of Magnetic Resonance Arthrography Research Articles

Diagnostic Accuracy of Magnetic Resonance Arthrography and its Correlation with Arthroscopy in the Detection of Lesions Triangular Fibrocartilaginous Complex and Intrinsic Ligaments in the Wrist

Objectives: To assess the diagnostic validity and reliability of magnetic resonance arthrography in identifying the lesion of triangular intrinsic wrist ligaments and fibrocartilaginous complex based on arthroscopy as reference standard and preferred modality of imaging. Methodology: This was a retrospective validation study that was carried out at the Radiology department of PESSI (Punjab Employees Social Security) Hospital, Islamabad, between April 2019 and September 2022. A total of 11 patients with an age range 21-58 years, lesions of the triangular fibrocartilaginous complex (TFCC), and MR arthrography were included. MR arthrography images of the wrist were evaluated to assess the integrity of the intrinsic wrist ligaments, including those of the TFCC, scapholunate, and lunotriquetral ligament. MR arthrography injection was performed into the wrist joint, likely to help visualize the ligaments and other structures within the joint. The injection was performed under fluoroscopic guidance, and the size of the needle used for the injection was 20-24G. The data collected from the MR arthrograms and arthroscopy was analyzed using SPSS v 23. Results: The patient’s mean age was 40.0±12.31 years. Out of 11 patients, there were 6 (55.5%) males and 5 (45.5%) females. Sensitivity of MR arthrography is 71.4% and specificity that of 75% for detecting TFCC defects, and a 100% sensitivity and 85.7% specificity for diagnosing intrinsic ligament defects. MR arthrography had an overall accuracy of 73% for detecting TFCC, while the overall accuracy for detecting intrinsic ligament defects was 90.9%. Conclusion: MR arthrography was an adequate diagnostic tool for detecting defects of the intrinsic ligaments and the TFCC of the wrist when compared to diagnostic arthroscopy.

Accuracy of Magnetic Resonance Arthrography in the Detection and Classification of Chronic Anteroinferior Labrum Lesions

INTRODUCTION: Bankart, and Bankart variant labrum lesions such as Perthes lesion and anterior labrum periosteal sleeve avulsion are different types of surgically treatable anterioinferior labral lesions contributing to shoulder instability. Successful outcome following arthroscopic surgery requires accurate lesion diagnosis, pre operative planning and deployment of accordant surgical technique. The purpose of our study was to retrospectively evaluate the accuracy of Magnetic Resonance Arthrography not only in the detection but also the classification of chronic antero-inferior labrum injuries by using arthroscopy as the reference standard. STUDY DESIGN & METHODS: This study included 80 consecutive patients, 12 female with mean age of 28 year (range 17-46) presenting with recurrent shoulder instability who underwent Magnetic Resonance Arthrography in neutral and abduction external rotation positions prior to arthroscopic stabilisation. The findings of a single dedicated musculoskeletal radiologist were compared with the arthroscopic findings of a single experienced shoulder surgeon. RESULTS: Arthroscopic findings revealed 40 Bankart, 18 anterior labrum periosteal sleeve avulsion and 15 Perthes anteroinferior labrum lesions. Magnetic Resonance Arthrography detected 95.8% of overall labrum lesions with a sensitivity of 94% (0.86 to 0.98 ) and specificity 85.7% (0.46 to 0.99 ) and correctly classified 90% of labrum lesions with an accuracy of 93.8% (0.86-0.97) for Bankart lesions, 95% (0.88-0.98) for anterior labrum periosteal sleeve avulsion lesions and 95.5% (0.91-0.99) for Perthes lesions. CONCLUSION: Our study demonstrates that Magnetic Resonance Arthrography in neutral and abduction and external rotation position can achieve high levels of accuracy in detecting and correctly classifying chronic anteroinferior labrum lesions. It emphasises its value in alerting the surgeon to the presence and the type of labrum lesion. This allows forward-planning the surgical technique to be employed for intra-operative detection, correct dissection and optimal fixation.

Accuracy of Magnetic Resonance Arthrography in the Detection and Classification of Chronic Anteroinferior Labrum Lesions

Accuracy of Magnetic Resonance Arthrography in the Detection and Classification of Chronic Anteroinferior Labrum Lesions

Diagnostic Accuracy of Magnetic Resonance Arthrography in Detecting Intra-articular Pathology Associated with Femoroacetabular Impingement.

Purpose The aim of this study was to assess the diagnostic accuracy of magnetic resonance arthrography (MRA) in the detection of intra-articular lesions of the hip in patients affected by femoroacetabular impingement (FAI) by using arthroscopy as reference standard. Methods Twenty-nine consecutive hip arthroscopies performed in 24 patients were considered for the study. Patients had a mean age of 38.3 years. Ultrasound-guided 1.5-T MRA was performed with precontrast short tau inversion recovery, T1-weighted and PD coronal, T1-weighted, and T2-weighted axial with 3-mm-thick slice sequences, and postcontrast T1-weighted fat saturation MRA (Fat-SAT) axial, coronal and oblique sagittal, and T1-weighted Vibe 3D coronal sequences with MPR sagittal, axial, and radial reconstructions with 2-mm-thick slice and coronal density protonil (DP) Fat-SAT. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRA were evaluated by comparison arthroscopy for the following intra-articular findings: acetabular and femoral chondral lesions, labral degeneration, labral tears, synovitis, ligamentum teres (LT) tears, CAM lesions, pincer lesions, loose bodies, and osteophytes. Results An absolute per cent agreement (100%) was observed for all the variables in the assessment of CAM lesions. Sensitivity, specificity, PPV, and NPV of MRA were 100, 68.4, 72.7, and 100%, respectively, for acetabular chondral lesions; 100, 50, 47.3, and 100%, respectively, for femoral chondral lesions; 33, 85, 20, and 91.6%, respectively, for labral tears; 95, 71, 91.3, and 83.3%, respectively, for labral degeneration; 100, 88, 57.1, and 100%, respectively, for LT tears; 33.3, 85, 50, and 73.9%, respectively, for pincer lesions; 50, 96, 66.6, and 92.3%, respectively, for intra-articular loose bodies; and 100, 73.9, 50, and 100%, respectively, for osteophytes. Conclusion MRA may play an important role in detecting intra-articular lesions associated with FAI. This might be helpful for the preoperative planning before hip arthroscopy. Level of Evidence This is a Level 2, diagnostic accuracy study compared with gold standard.

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Diagnostic accuracy of single-compartment magnetic resonance arthrography in detecting common causes of chronic wrist pain.

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RETRACTED: Abduction external rotation position in magnetic resonance arthrography for the diagnosis of rotator cuff tears.

This article aims at evaluating the effectiveness of abduction and external rotation (ABER) position used in magnetic resonance (MR) arthrography for diagnosing rotator cuff tears. A retrospective analysis was performed using 183 MR arthrography images of shoulder joint. Each patient was either examined in a neutral position or ABER position. Then the imaging results were compared with those diagnostic results obtained from shoulder arthroscopy. Also the specificity, sensitivity, negative predictive value, positive predictive value, and accuracy of MR arthrography in the two positions described above were evaluated. A total of 64 patients were diagnosed with rotator cuff tears using arthroscopy and the diagnostic results include 16 complete rotator cuff tears and 48 partial tears; 47 supraspinatus tendon tears and 17 posterosuperior cuff tears; 22 delamination tears and 26 tears complicated with anteroinferior labrum-ligament complex injuries. The differences in specificity, sensitivity, negative predictive value, positive predictive value and accuracy between neutral position and ABER position using MR arthrography were not statistically significant (all P>0.05). For diagnosing posterosuperior cuff tears, the sensitivity of ABER position was significantly higher than that of the neutral position (94.12% vs. 64.71%, P=0.034). For diagnosing delamination tears, the sensitivity and negative predictive value of ABER position were significantly higher than those of the neutral position (P=0.009 and P=0.036 respectively). For diagnosing rotator cuff tears complicated with anteroinferior labrum-ligament complex injuries, the sensitivity of ABER position was statistically higher than that of the neutral position (96.15% vs. 73.08%, P=0.021). This study suggests that MR arthrography in ABER position is a superior tool for diagnosing certain types of rotator cuff tears. Apart from that, MR arthrography in ABER position improved the detection rate of posterosuperior cuff tears, delamination tears and rotator cuff tears complicated with anteroinferior labrum-ligament complex injuries.

The Accuracy of Magnetic Resonance Arthrography in Hip Arthroscopic Labral Revision Surgery

The interpretation of a magnetic resonance arthrogram (MRA) after a labral tear has been surgically treated can be challenging and there is no published evidence on its accuracy. The aim of this study was to evaluate the MRA accuracy in identifying labral pathology after hip arthroscopy. We reviewed 60 patients who had undergone a revision hip arthroscopy. Patients were divided into two groups. First, a study group (n = 40), which included patients who had undergone arthroscopic labral surgery at index operation. Secondly, there was a control group (n = 20), for patients who had not undergone labral surgery at index procedure. Findings regarding labral pathologies at MRA and at revision surgery were recorded. Sensitivity for MRA after hip arthroscopy was 53% and 71% in the study and control groups, respectively; specificity was 50% and 92%, positive predictive value was 81% and 83%, negative predictive value was 21% and 86% and accuracy was 53% and 85%. We conclude that the MRA is not reliable after hip arthroscopy where a labral tear has been addressed. When a labral tear has been repaired or partial labral excision has been performed, a postoperative MRA may inaccurately diagnose the presence of a persistent, recurrent, or unhealed tear.

Reliability and Validity of Diagnosing Acetabular Labral Lesions with Magnetic Resonance Arthrography

Arthroscopic surgery of the hip is being increasingly used to diagnose and treat various abnormalities, including acetabular labral tears. Magnetic resonance arthrography has been suggested as the imaging test of choice for the evaluation of the acetabular labrum. There is substantial variability in the previously reported accuracy of magnetic resonance arthrography for diagnosing labral lesions. Interobserver reliability has not been established previously. The purpose of this study was to establish the interobserver reliability and the validity of magnetic resonance arthrography for detecting lesions of the acetabular labrum in a retrospective case series. Two radiologists independently assessed the acetabular labrum on magnetic resonance arthrograms of ninety-five hips in ninety-three patients who underwent hip arthroscopy for a suspected acetabular labral lesion. Magnetic resonance arthrography findings were compared with the gold standard, which was defined as the assessment of the labrum during the hip arthroscopy. At arthroscopy, ninety-one labral lesions were identified in the ninety-five hips. The interobserver reliability of detecting labral lesions with magnetic resonance arthrography was fair (kappa=0.268). Magnetic resonance arthrography, as interpreted by observers A and B, showed a sensitivity of 86% and 86%, specificity of 75% and 50%, negative predictive value of 19% and 13%, and positive predictive value of 99% and 98%, respectively. Because of its limited reliability and the high prevalence of labral lesions, magnetic resonance arthrography provides a limited complementary benefit in the detection of labral lesions in patients with a high clinical suspicion of labral pathology. When there is a high clinical suspicion of a labral lesion, magnetic resonance arthrography has a poor negative predictive value and cannot be used to rule out a labral lesion. Physicians should critically consider whether the findings on a magnetic resonance arthrogram will alter the treatment strategy for an individual patient with a clinical suspicion of labral pathology.

Correlation of Preoperative MRI and MRA With Arthroscopically Proven Articular Cartilage Lesions of the Elbow

The purpose of this study was to evaluate the usefulness of magnetic resonance imaging (MRI) in detecting elbow articular cartilage injuries through comparison of preoperative MRI and magnetic resonance arthrography (MRA) with arthroscopic findings. Retrospective case analysis. Tertiary care orthopedic private practice. Consecutive series of 31 patients presenting with elbow pain and diagnosed at arthroscopy with articular cartilage defects of the elbow. All patients had a preoperative MRI or MRA using a 1.5 T magnet. Each patient had a systematic elbow arthroscopy, with careful inspection and recording of chondral injuries in 4 anatomical regions: capitellum, radius, trochlea, and ulna. Each MRI/MRA was then independently reviewed by 2 radiologists blinded to the arthroscopic findings. The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were calculated for MRI and MRI compared with arthroscopy as the gold standard, for each of the anatomical regions. The accuracy of MRI was 45% for chondral injuries of the radius, 65% for the capitellum, 20% for the ulna, and 30% for the trochlea. The accuracy of MRA was 45% for chondral injuries of the radius, 64% for the capitellum, 18% for the ulna, and 27% for the trochlea. We conclude that the ability of MRI and MRA using a 1.5 T magnet to detect articular cartilage lesions is limited. Neither MRI nor MRA demonstrates the intraarticular surface as accurately as direct visualization with the arthroscopy. This may be improved with the use of 3 T MRI. This study demonstrates that MRI and MRA with a 1.5 T magnet, as used in community practice, have limited ability to detect cartilage lesions of the elbow.

The diagnostic accuracy of X-ray arthrography for triangular fibrocartilaginous complex injury: a systematic review and meta-analysis

The purpose of this study was to evaluate the diagnostic test accuracy of X-ray arthrography in the detection of TFCC tear. Both published and unpublished databases were searched from their inception to August 2010. All studies comparing the diagnostic accuracy of X-ray arthrography (index test) to arthroscopy (reference standard) for patients with suspected TFCC tears were included in this review. Twelve studies assessing 430 patients (430 wrists) satisfied the eligibility criteria and were included. X-ray arthrography presented with a pooled sensitivity of 76.2% and specificity of 92.5% for the detection of complete TFCC tear. The triple-compartment injection X-ray arthrography was superior to the single-compartment injection technique. To conclude, the diagnostic test accuracy of X-ray arthrography is limited. Neither the single- nor the triple-compartment injection arthrography method is acceptable, given their reported low sensitivities. Further evaluation of the diagnostic test accuracy of Magnetic Resonance Arthrography and Magnetic Resonance Imaging is therefore warranted.

Magnetic resonance arthrography including aber view in diagnosing partial-thickness tears of the rotator cuff: Accuracy, and inter- and intra-observer agreements

Partial-thickness tear of the rotator cuff is a common cause of shoulder pain. Magnetic resonance (MR) arthrography has been described as a useful measure to diagnose rotator cuff abnormalities. To determine the reliability and accuracy of MR arthrography with abduction and external rotation (ABER) view for the diagnosis of partial-thickness tears of the rotator cuff. Among patients who underwent MR arthrographies, 22 patients (12 men, 10 women; mean age 45 years) who had either partial-thickness tear or normal tendon on arthroscopy were included. MR images were independently scored by two observers for partial-thickness tears of the rotator cuff. Interobserver and intraobserver agreements for detection of partial-thickness tears of the rotator cuff were calculated by using kappa coefficients. The differences in areas under the receiver operating characteristic (ROC) curves were assessed with a univariate Z-score test. Differences in sensitivity and specificity for interpretations based on different imaging series were tested for significance using the McNemar statistic. Sensitivity, specificity, and accuracy of each reader on MR imaging without ABER view were 83%, 90%, and 86%, and 83%, 80%, and 82%, respectively, whereas on overall interpretation including ABER view, the sensitivity, specificity, and accuracy of each reader were 92%, 70%, and 82%, and 92%, 80%, and 86%, respectively. Including ABER view, interobserver agreement for partial-thickness tear increased from kappa=0.55 to kappa=0.68. Likewise, intraobserver agreements increased from kappa=0.79 and 0.53 to kappa=0.81 and 0.70 for each reader, respectively. The areas under the ROC curves for each reader were 0.96 and 0.90, which were not significantly different. Including ABER view in routine sequences of MR arthrography increases the sensitivity, and inter- and intraobserver agreements for detecting partial-thickness tear of rotator cuff tendon.

Acetabular Cartilage Delamination in Femoroacetabular Impingement

Delamination of acetabular articular cartilage is a common abnormality in hips with femoroacetabular impingement. The purpose of the present study was to identify clinical and radiographic factors predisposing to delamination and to assess the diagnostic accuracy of magnetic resonance arthrography for the detection of these lesions. Following a retrospective review of records, we determined that acetabular cartilage delamination had been present in twenty-eight of sixty-four hips that had undergone a surgical dislocation procedure for the treatment of femoroacetabular impingement. Multivariable logistic regression was performed to assess the correlation of radiographic findings (i.e., magnetic resonance imaging and computerized tomography findings) with the status of delamination. The preoperative interpretations of the magnetic resonance arthrograms for twenty-seven hips that underwent surgical dislocation were reviewed to assess the accuracy of detecting delamination. At the time of surgery, nine of these twenty-seven hips were found to have delamination. Magnetic resonance arthrography interpretations that did not correlate with operative findings were subjected to conspicuity assessment and error analysis. The rate of delamination of the acetabular cartilage as noted at the time of surgical dislocation was 44% (twenty-eight of sixty-four). Delamination was strongly associated with male sex and femoral sided signs of impingement; however, it was not associated with acetabular overcoverage (center-edge angle, >40 degrees) (odds ratio = 0.16; p < 0.05). While there was no significant difference in the prevalence of labral lesions between groups, whenever labral and delamination lesions were found in the same hip, they were directly adjacent to one another. Preoperative magnetic resonance arthrography had a low sensitivity for delamination (22%) but had a high specificity (100%). Two-thirds of the delamination lesions were visible on retrospective review of these images when the reader was unblinded to the surgical findings. Delamination could most often be identified on the sagittal T1-weighted image and on the proton-density sequences with fat saturation. There should be a high level of suspicion for articular cartilage delamination in men and in patients with primarily cam-type femoroacetabular impingement. Acetabular overcoverage may be protective against delamination. Preoperative high-quality magnetic resonance arthrograms should be carefully analyzed for evidence of delamination in this patient population.

Accuracy of direct magnetic resonance arthrography in the diagnosis of triangular fibrocartilage complex tears of the wrist

The aim of this study was to assess the value of direct magnetic resonance (MR) arthrography of the wrist for detecting full-thickness tears of the triangular fibrocartilage complex (TFCC). Twenty-four consecutive patients who had ulnar-sided wrist pain and clinical suspicion of TFCC tear were included in the study. All patients underwent direct MR arthrography and then wrist arthroscopy, and the results of MR arthrography were compared with the arthroscopic findings. The positive predictive value of MR arthrography in detecting TFCC full-thickness tear was 0.95, and the negative predictive value was 0.50. The sensitivity of MR arthrography in detecting a TFCC full-thickness tear was 74% (15/19), and specificity was 80% (4/5). The overall accuracy of MR arthrography in detecting a full-thickness tear of the TFCC in our study was 79% (19/24). We believe that diagnosis of tears in the TFCC by direct MR arthrography is not entirely satisfactory, although MR arthrography has a high positive predictive value for detecting TFCC tears. Negative results of MR arthrography in patients with clinical suspicion of TFCC tear should be interpreted with caution.

Accuracy of direct magnetic resonance arthrography in the diagnosis of triangular fibrocartilage complex tears of the wrist

The aim of this study was to assess the value of direct magnetic resonance (MR) arthrography of the wrist for detecting full-thickness tears of the triangular fibrocartilage complex (TFCC). Twenty-four consecutive patients who had ulnar-sided wrist pain and clinical suspicion of TFCC tear were included in the study. All patients underwent direct MR arthrography and then wrist arthroscopy, and the results of MR arthrography were compared with the arthroscopic findings. The positive predictive value of MR arthrography in detecting TFCC full-thickness tear was 0.95, and the negative predictive value was 0.50. The sensitivity of MR arthrography in detecting a TFCC full-thickness tear was 74% (15/19), and specificity was 80% (4/5). The overall accuracy of MR arthrography in detecting a full-thickness tear of the TFCC in our study was 79% (19/24). We believe that diagnosis of tears in the TFCC by direct MR arthrography is not entirely satisfactory, although MR arthrography has a high positive predictive value for detecting TFCC tears. Negative results of MR arthrography in patients with clinical suspicion of TFCC tear should be interpreted with caution.

Anterior Shoulder Instability: Accuracy of MR Arthrography in the Classification of Anteroinferior Labroligamentous Injuries

To retrospectively evaluate the accuracy of magnetic resonance (MR) arthrography in the classification of anteroinferior labroligamentous injuries by using arthroscopy as the reference standard. Ethical committee approval and informed consent were obtained. MR arthrograms obtained in 205 patients, including a study group of 104 patients (74 male and 30 female; mean age, 28.2 years) with arthroscopically proved labroligamentous injuries and a control group of 101 patients (65 male and 36 female; mean age, 31.4 years) with intact labroligamentous complex, were reviewed in random order. MR arthrograms were analyzed for the presence and type (Bankart, anterior labral periosteal sleeve avulsion [ALPSA], Perthes, glenolabral articular disruption [GLAD], or nonclassifiable lesion) of labroligamentous injuries by two radiologists in consensus. Results were compared with arthroscopic findings. Sensitivity, specificity, accuracy, and corresponding 95% confidence intervals for the detection and classification of anteroinferior labroligamentous lesions with MR arthrography were calculated. At arthroscopy, 104 anteroinferior labroligamentous lesions were diagnosed, including 44 Bankart lesions, 22 ALPSA lesions, 12 Perthes lesions, and three GLAD lesions. Twenty-three labral lesions were nonclassifiable at arthroscopy, all of which occurred after a history of chronic instability. Nineteen (83%) of these 23 lesions were also nonclassifiable at MR arthrography. With arthroscopy used as the reference standard, labroligamentous lesions were detected and correctly classified at MR arthrography with sensitivities of 88% and 77%, specificities of 91% and 91%, and accuracies of 89% and 84%, respectively. Bankart, ALPSA, and Perthes lesions were correctly classified in 80%, 77%, and 50% of cases, respectively. The three GLAD lesions were all correctly assessed. MR arthrography is accurate in enabling classification of acute and chronic anteroinferior labroligamentous injuries, although correct interpretation of Perthes lesions remains difficult.

Evaluating Hip Labral Tears Using Magnetic Resonance Arthrography: A Prospective Study Comparing Hip Arthroscopy and Magnetic Resonance Arthrography Diagnosis

To evaluate the sensitivity and accuracy of magnetic resonance arthrography (MRA) with true sagittal scout image mapped radial reformation in localizing hip labral tears. Case series. Thirty patients were examined with hip MRA because of suspected labral tears. Every patient underwent normal hip arthrography and MR examinations using a 1.5-T scanner with a 3D-FLASH pulse sequence. Multiplanar reformation using double oblique technique produced radial reformatted rotation images with 10 degrees increment on the acetabular rim. Labral tears were annotated as anterior-superior (AS), anterior-inferior (AI), posterior-superior (PS), and posterior-inferior (PI) quadrant based on the cranial-caudal axis in true sagittal reformatted scout localizing image. Patients with positive MRA findings were counseled to have the arthroscopic hip procedure. Five patients showed no MRA indication of labral tear. Of 25 patients who had MRA evidence of labral tear, 17 underwent arthroscopic hip surgery. One patient had only synovial process in the hip joint near the suspected MRA area. The remaining 16 operated patients had labral tears with a total of 21 quadrant lesions on arthroscopy (distributed as AS, 14; AI, 3; PS, 2; and PI, 2). Radial reformatted images revealed accurate mapping with arthroscopic findings in 21 of the 22 quadrant lesions. The sensitivity and accuracy of MRA for the diagnosis of hip labral tear were 100% and 94%, respectively, and the sensitivity and accuracy of radial reformatted MRA for mapping the tear location were 100% and 96%, respectively. MRA using radial reformatted images with a true sagittal localizer may achieve superior success rates in diagnosing hip labral lesions and in guiding the arthroscopist in portal selection, thus rendering location of hip labral tears simpler in surgery. It supplied detailed preoperative information to the surgeon, avoiding unnecessary surgery for patients if the diagnosis was unconfirmed. Level III.

Magnetic resonance arthrography applied to the diagnosis of intraarticular adhesions of the temporomandibular joint

The purpose of this study is to investigate the diagnostic accuracy of magnetic resonance arthrography (MRAr) on the diagnosis of intraarticular adhesions of the temporomandibular joint (TMJ). Twenty-four patients (31 joints) diagnosed as internal disorders of TMJ were examined to establish the presence, suspicion or absence of intraarticular adhesions through MRAr according to the MRAr radiographic criteria in a blind fashion, subsequent arthroscopy were performed on all 31 joints. The findings were compared to MRAr with those of arthroscopy. The comparison data were assessed by generating receiver operating characteristic curve (ROC curve) and analyzing the area (Az) under the curve with SPSS11.0 software. The area under the ROC curve was 0.91 (0.86, 0.95), P < 0.05. MRAr proves to be an excellent modality to diagnose intraarticular adhesions of TMJ.

Evaluating hip labral tears using magnetic resonance arthrography: a prospective study of comparison between hip arthroscopy and magnetic resonance arthrography diagnosis (SS-92)

To evaluate the usefulness and accuracy of magnetic resonance arthrography (MRAr) with true sagittal scout image mapped radial reformation in localizing hip labral tears. We demonstrate a prospective study to compare the clinical result between the preoperative MRAr diagnosis and hip arthroscopic finding. Materials and Methods: During April 2002 to Dec 2002, 30 patients were referred for hip MRAr due to suspected labral tears in the authors’ hospital. They included 17 male and 13 female patients, age ranged from 17 to 62 yr, mean age 41 yr. All patients received standard hip arthrography using 1:200 diluted Gd-DTPA as contrast medium. MR examinations were performed at a 1.5-T scanner (Vision; Siemens, Er LANGen, Germany) using 3D-FLASH pulse sequence (TR/TE/flip angle = 48ms/11ms/40°, FOV 15 cm, matrix 256∗256, effective thickness 1.5 mm for 44 partitions, and 1 acquisition). Multi-planar reformation (MPR) using double oblique technique was performed to produce the radial reformatted rotation images with 10° increment on the acetabular rim. For ease of localizing the lesion during arthroscopic surgery, we adopt the true sagittal reformatted image on the hip joint as scout localizer to map the radial reformatted images. Labral tears were annotated as anterior-superior (AS), anterior-inferior (AI), posterior-superior (PS), and posterior-inferior (PI) quadrant based on the cranial-caudal axis in true sagittal reformatted scout localizing image. MRAr images were interpreted by one M.S. radiologist (L.C. Lien). Patients who had positive MRAr findings were advised to have the hip arthroscopic operation. By supine position, two or three portals (anterior, anterolateral or posterolateral portals) were placed after application of traction to the involved leg. These lesions were debrided and excised by the aid of flexible and curved electrothermal probes or shaver. All the surgery was performed by the same surgeon (Y.S.C.). Results: Five patients had no MRAr evidence of labral tear. Two of them showed MR evidence of avascular necrosis of the femoral head. Of the 25 patients who had MRAr evidence of labral tear, 17 patients (M:F = 10:8, RT: LT = 13:5, age 22–64 yr, mean age 43 yr) received operation. The duration between MRAr examination and the operation ranged from 5 to 44 days (mean 23 days). One patient had only synovial process in the hip joint near the MRAr suspected region. All the remaining 16 operated patients had labral tears with totally 21 quadrant lesions in arthroscope (distributed as AS: AI: PS: PI = 14: 3: 2: 2). Radial reformatted images showed correct mapping with arthroscope findings in 20 of the 21 quadrant lesions. Conclusions: MRAr using radial reformatted images with true sagittal localizer may have high accurate rate in diagnosis for hip labral lesions and guide the arthroscopist in portal selection, making localization of hip labral tears easier during surgery. However, the accuracy of MRAr diagnosis for hip labral tears also depends on the experienced MRAr technique and imaging reading.

Sonographic versus magnetic resonance arthrographic evaluation of full-thickness rotator cuff tears in millimeters

Preoperative knowledge of full-thickness rotator cuff tear size is important in counseling patients because tear size affects the choice of surgical techniques and the functional outcome of surgery. Twenty-six shoulders of twenty-five consecutive patients were included in a prospective study that compared the preoperative accuracy of magnetic resonance arthrography and ultrasonography for tear size in millimeters with intraoperative findings. No significant differences were found between intraoperative, ultrasonographic, and magnetic resonance arthrographic data for the width of tears. Adoption of a “curved line measurement” for ultrasonographic evaluation of large tears eliminated the tendency of ultrasonography to underestimate tears greater than or equal to 35 mm in width. No significant differences were found between intraoperative, ultrasonographic, and magnetic resonancearthrographic data for retraction of tears. However, a limitation of ultrasonography to evaluate retractions of more than 30 mm was found. Therefore, ultrasound is of equal value for tears less than 30 mm, but magnetic resonance arthrography is more accurate for tears greater than 30 mm. (J Shoulder Elbow Surg 2003;12:110-16)