Magnetic Resonance Imaging Arthrography Research Articles

Anterior Ankle Impingement and Talar Bony Outgrowths: Osteophyte or Enthesophyte? Paleopathologic and Cadaveric Study With Imaging Correlation

Bony "spurs" are a major component of anterior ankle impingement syndrome. The two major accepted hypotheses on the origin of these bony spurs are osteophyte formation due to repetitive microtrauma and enthesophyte development because of recurrent capsular or ligamentous traction. The purpose of this study was to provide a detailed evaluation of the bony outgrowths that arise on the anterior aspect of the talus and correlate them with the sites of capsular attachment. Twenty-eight well-preserved talus bones from the San Diego Museum of Man were assessed regarding the presence of outgrowths on the anterior aspect of the talus. The distance of the outgrowths from the talar head was measured. The results were correlated with measurements of capsular attachment on the anterior aspect of the talus derived from MR arthrographic images in 13 cadaveric ankles. The average distance of capsular attachment from the talar head in the medial aspect of the bone was 10.63 mm and in the lateral part was 12.04 mm. The mean distance of bony spurs from the talar head in the medial and lateral parts of the talus was 17.2 and 12.5 mm, respectively. Medially, the talar spurs developed more proximally on the neck compared to the capsular attachment (p < 0.01). Laterally, this difference was not significant (p = 0.26). On the medial part of the anterior talus, bone development appears to occur in an intraarticular location (i.e., osteophytes). Laterally, the outgrowths develop extraarticularly and appear to result from capsular and ligamentous traction (i.e., enthesophytes).

Transverse Thickening Along the Articular Surface of the Rotator Cuff Consistent With the Rotator Cable: Identification With MR Arthrography and Relevance in Rotator Cuff Evaluation

The purposes of this study were to describe the imaging appearance of transverse thickening along the articular surface of the supraspinatus and infraspinatus tendons presumed to represent the rotator cable on MR arthrographic images obtained with the shoulder in abduction and external rotation (ABER) and in the non-ABER position and to assess the role of the rotator cable in the diagnosis of rotator cuff tears. The study group comprised 54 patients who underwent arthroscopy of the shoulder and preoperative MR arthrography in which ABER images were obtained. Two blinded reviewers independently examined the ABER and non-ABER images for the presence of the rotator cable and rotator cuff tears. In intact rotator cuffs, the presumed rotator cable was not well visualized on non-ABER images. In one case of prominent rotator cable, MR arthrography showed no tear on non-ABER images, but at arthroscopy, a partial-thickness undersurface tear was found. On non-ABER images, both readers readily visualized the rotator cable in eight and 10 of 18 cases (44% and 56%) of partial-thickness undersurface tear and four of five cases (80%) of full-thickness tear. On ABER images, both readers readily visualized the rotator cable in 15 and 17 of 31 cases (48% and 55%) of intact cuff, 14 and 15 of 18 cases (78% and 83%) of undersurface tear, and four and five cases (80% and 100%) of full-thickness tear. Interobserver agreement on cable visualization was almost perfect (kappa = 0.86). On non-ABER MR arthrographic images, thickening along the articular side of the supraspinatus and infraspinatus tendons presumed to represent the rotator cable suggests the presence of a partial-thickness rotator cuff tear. On ABER images, the cable is well defined in intact and torn rotator cuffs.

Extension Loss Secondary to Femoral-Sided Inverted Cyclops Lesion After Anterior Cruciate Ligament Reconstruction

Loss of terminal knee extension after anterior cruciate ligament (ACL) reconstruction is problematic. Formation of a fibrous nodule, known as a cyclops lesion, at the site of the ACL graft exiting from the tibial tunnel can impinge at the roof of the intercondylar notch and block terminal knee extension. This article presents a case of an inverted cyclops lesion originating from the femoral tunnel site of the ACL graft, representing a variant of the traditional cyclops lesion. The lesion was identified by clinical examination including prone heel-height difference assessment in combination with magnetic resonance imaging arthrography. The lesion was treated successfully by arthroscopic resection, with rapid resolution of the patient's painful, symptomatic extension loss.

Virtual MR arthroscopy of the shoulder: image gallery with arthroscopic correlation of major pathologies in shoulder instability

BackgroundThe purpose of this study was to compare virtual MR arthroscopic reconstructions with arthroscopic images in patients affected by shoulder joint instability. MR arthrography (MR-AR) of the shoulder is now a well-assessed technique, based on the injection of a contrast medium solution, which fills the articular space and finds its way between the rotator cuff (RC) and the glenohumeral ligaments. In patients with glenolabral pathology, we used an additional sequence that provided virtual arthroscopy (VA) post-processed views, which completed the MR evaluation of shoulder pathology.Materials and methodsWe enrolled 36 patients, from whom MR arthrographic sequence data (SE T1w and GRE T1 FAT SAT) were obtained using a GE 0.5 T Signa—before any surgical or arthroscopic planned treatment; the protocol included a supplemental 3D, spoiled GE T1w positioned in the coronal plane. Dedicated software loaded on a work-station was used to elaborate VAs. Two radiologists evaluated, on a semiquantitative scale, the visibility of the principal anatomic structures, and then, in consensus, the pathology emerging from the VA images.ResultsThese images were reconstructed in all patients, except one. The visualization of all anatomical structures was acceptable. VA and MR arthrographic images were fairly concordant with intraoperative findings.ConclusionsAlthough in our pilot study the VA findings did not change the surgical planning, the results showed concordance with the surgical or arthroscopic images.

The Outcome and Structural Integrity of Arthroscopic Rotator Cuff Repair with Use of the Double-Row Suture Anchor Technique

The reported rate of failure after arthroscopic rotator cuff repair has varied widely. The influence of the repair technique on the failure rates and functional outcomes after open or arthroscopic rotator cuff repair remains controversial. The purpose of the present study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repairs performed with the double-row suture anchor technique on the basis of computed tomography or magnetic resonance imaging arthrography in order to determine the postoperative integrity of the repairs. A prospective series of 105 consecutive shoulders undergoing arthroscopic double-row rotator cuff repair of the supraspinatus or a combination of the supraspinatus and infraspinatus were evaluated at a minimum of two years after surgery. The evaluation included a routine history and physical examination as well as determination of the preoperative and postoperative strength, pain, range of motion, and Constant scores. All shoulders had a preoperative and postoperative computed tomography arthrogram (103 shoulders) or magnetic resonance imaging arthrogram (two shoulders). There were thirty-six small rotator cuff tears, forty-seven large isolated supraspinatus or combined supraspinatus and infraspinatus tendon tears, and twenty-two massive rotator cuff tears. The mean Constant score (and standard deviation) was 43.2 +/- 15.1 points (range, 8 to 83 points) preoperatively and 80.1 +/- 11.1 points (range, 46 to 100 points) postoperatively. Twelve of the 105 repairs failed. Intact rotator cuff repairs were associated with significantly increased strength and active range of motion. Arthroscopic repair of a rotator cuff tear with use of the double-row suture anchor technique results in a much lower rate of failure than has previously been reported in association with either open or arthroscopic repair methods. Patients with an intact rotator cuff repair have better pain relief than those with a failed repair. After repair, large and massive rotator cuff tears result in more postoperative weakness than small tears do.

MR-guided direct arthrography of the glenohumeral joint

To evaluate the feasibility of magnetic resonance (MR)-guided direct arthrography of the glenohumeral joint with a 1.5 T MR system, performing the entire procedure in a single MR examination. MR-guided direct arthrography was performed on 11 patients. MR imaging guidance and interactive MR fluoroscopy, with in-room control and display system, were used for needle placement and contrast medium injection. The outcome measures were success or failure of joint puncture, the time taken for introduction of contrast medium, and the diagnostic quality of the subsequent MR arthrography images. Contrast medium was successfully instilled into the joint and diagnostic quality MR arthrography images were obtained in all cases. The median time from initial placement of the skin marker to introduction of the contrast medium was 17 min (range 11-29 min). There were no immediate post-procedure complications. Accurate needle placement is feasible in a single MR examination on a commercial 1.5 T closed-bore MR system, using an in-room control and display system together with interactive fluoroscopic imaging, and this was used to provide direct MR arthrography in this study.

Evaluation of postoperative menisci with MR arthrography and routine conventional MRI

The diagnosis of a recurrent tear can be more difficult in the postoperative meniscus. The purpose of our study was to determine the accuracy of conventional magnetic resonance imaging (MRI) and MRI with intraarticular contrast material [magnetic resonance (MR) arthrography] for detecting recurrent meniscal tears after surgery. Seventy-two patients who had arthroscopic surgery for meniscal tear and still got complaints were selected prospectively for MR arthrography and conventional MRI. Routine knee protocols with appropriate surface coil were used on 0.5 T MRI system. A 1:100 gadolinium-saline solution 30-40 ml was injected intraarticulary for MR arthrography. Of 72 patients, 45 had repeated arthroscopy for comparison of the results. The morphology of the meniscus as seen on MR images was characterized according to meniscal repair an the degree of meniscal resection into three groups. (1) less than 25% of the meniscal resection, (2) more than 25% meniscal resection, (3) meniscal repair. With routine conventional MR images, we grouped patients according to the signal intensity of menisci as Grade 1, Grade 2, Grade 3, and tear. The prevalence of recurrent meniscal tears in our study group was [68% (37/72 tears)]. In the diagnosis of recurrent meniscal tear, conventional MRI and MR arthrography had sensitivities of 54.0% and 94.5%, respectively; specificities of 75.0% and 87.5%, respectively; and accuracy of 57.7% and 93.4%, respectively. The accuracy of the conventional MRI studies was significantly less than that of the MR arthrography group (P<.05). Our study results indicate high overall accuracy for MR arthrography in the diagnosis of recurrent or residual meniscal tears. When meniscal resection is minimal, the right diagnosis could be obtained with conventional MRI. MR arthrography is necessary for patients with meniscal resection of more than 25% and who do not have sufficient joint effusion.

Popliteomeniscal Fascicles: Anatomic Considerations Using MR Arthrography in Cadavers

This study was performed to examine the normal MR arthrographic anatomy of the popliteomeniscal fascicles with specific reference to the number of popliteomeniscal fascicles, thickness and course of the fascicles, and presence of other posterior attachments from the medial aponeurosis of the popliteus musculotendinous region. Multiplanar 1.5-T MR arthrography of 10 cadaveric knees was performed using a quadrature knee coil. Specimens were frozen and sectioned in the sagittal (n = 4), axial (n = 3), and coronal (n = 3) planes. MR images and anatomic specimens were correlated by two musculoskeletal radiologists. Three popliteomeniscal fascicles were identified on MR arthrography: anteroinferior and posterosuperior fascicles in all 10 knees and posteroinferior fascicles in four of the knees. The posterosuperior popliteomeniscal fascicle was uniform in thickness, and the anteroinferior popliteomeniscal fascicle was variable in thickness. The anteroinferior popliteomeniscal fascicle formed a conjoined fibular attachment with the popliteofibular ligament. A medial aponeurotic extension from the popliteus musculotendinous region gave rise to the posteroinferior popliteomeniscal fascicle, which extended upward and attached to the inferomedial aspect of the posterior horn of the lateral meniscus. Additional attachments from the medial aponeurosis of the popliteus musculotendinous region to the posterior cruciate ligament, posterior capsule, oblique popliteal ligament, and posterior meniscofemoral ligament of Wrisberg were seen. Three popliteomeniscal fascicles were identified on MR arthrographic images. The popliteus muscle-tendon unit forms robust attachments in the superior, inferior, medial, and lateral oblique aspects, highlighting its importance in posterolateral stability of the knee.

The Outcome and Structural Integrity of Arthroscopic Rotator Cuff Repair with Use of the Double-Row Suture Anchor Technique

Background: The reported rate of failure after arthroscopic rotator cuff repair has varied widely. The influence of the repair technique on the failure rates and functional outcomes after open or arthroscopic rotator cuff repair remains controversial. The purpose of the present study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repairs performed with the double-row suture anchor technique on the basis of computed tomography or magnetic resonance imaging arthrography in order to determine the postoperative integrity of the repairs. Methods: A prospective series of 105 consecutive shoulders undergoing arthroscopic double-row rotator cuff repair of the supraspinatus or a combination of the supraspinatus and infraspinatus were evaluated at a minimum of two years after surgery. The evaluation included a routine history and physical examination as well as determination of the preoperative and postoperative strength, pain, range of motion, and Constant scores. All shoulders had a preoperative and postoperative computed tomography arthrogram (103 shoulders) or magnetic resonance imaging arthrogram (two shoulders). Results: There were thirty-six small rotator cuff tears, forty-seven large isolated supraspinatus or combined supraspinatus and infraspinatus tendon tears, and twenty-two massive rotator cuff tears. The mean Constant score (and standard deviation) was 43.2 ± 15.1 points (range, 8 to 83 points) preoperatively and 80.1 ± 11.1 points (range, 46 to 100 points) postoperatively. Twelve of the 105 repairs failed. Intact rotator cuff repairs were associated with significantly increased strength and active range of motion. Conclusions: Arthroscopic repair of a rotator cuff tear with use of the double-row suture anchor technique results in a much lower rate of failure than has previously been reported in association with either open or arthroscopic repair methods. Patients with an intact rotator cuff repair have better pain relief than those with a failed repair. After repair, large and massive rotator cuff tears result in more postoperative weakness than small tears do. Level of Evidence: Therapeutic Level IV. See Instructions to Authors for a complete description of levels of evidence.

The Outcome and Structural Integrity of Arthroscopic Rotator Cuff Repair with Use of the Double-Row Suture Anchor Technique

The reported rate of failure after arthroscopic rotator cuff repair has varied widely. The influence of the repair technique on the failure rates and functional outcomes after open or arthroscopic rotator cuff repair remains controversial. The purpose of the present study was to evaluate the functional and anatomic results of arthroscopic rotator cuff repairs performed with the double-row suture anchor technique on the basis of computed tomography or magnetic resonance imaging arthrography in order to determine the postoperative integrity of the repairs. A prospective series of 105 consecutive shoulders undergoing arthroscopic double-row rotator cuff repair of the supraspinatus or a combination of the supraspinatus and infraspinatus were evaluated at a minimum of two years after surgery. The evaluation included a routine history and physical examination as well as determination of the preoperative and postoperative strength, pain, range of motion, and Constant scores. All shoulders had a preoperative and postoperative computed tomography arthrogram (103 shoulders) or magnetic resonance imaging arthrogram (two shoulders). There were thirty-six small rotator cuff tears, forty-seven large isolated supraspinatus or combined supraspinatus and infraspinatus tendon tears, and twenty-two massive rotator cuff tears. The mean Constant score (and standard deviation) was 43.2+/-15.1 points (range, 8 to 83 points) preoperatively and 80.1+/-11.1 points (range, 46 to 100 points) postoperatively. Twelve of the 105 repairs failed. Intact rotator cuff repairs were associated with significantly increased strength and active range of motion. Arthroscopic repair of a rotator cuff tear with use of the double-row suture anchor technique results in a much lower rate of failure than has previously been reported in association with either open or arthroscopic repair methods. Patients with an intact rotator cuff repair have better pain relief than those with a failed repair. After repair, large and massive rotator cuff tears result in more postoperative weakness than small tears do.

Wrist Ligament Tears: Evaluation of MRI and Combined MDCT and MR Arthrography

The purpose of this study was to evaluate the performance of MRI and a combination of MDCT arthrography and MR arthrography in the diagnosis of tears and cartilage abnormalities of the wrist ligaments. The feasibility of combining MDCT arthrography and MR arthrography and performing them with an optimized contrast solution was evaluated in vitro and in vivo. Forty-five consecutively enrolled subjects with suspected wrist ligament tears underwent MRI and a combined MDCT and MR arthrographic procedure. Two observers reviewed the images for evidence of tears and cartilage abnormalities of the scapholunate and lunotriquetral ligaments and triangular fibrocartilaginous complex. Interobserver agreement was determined with kappa statistics, and the diagnostic accuracy of each technique was calculated. A 1:1 solution of 2.5 mmol/L tetraazacyclododecanetetraacetic acid (DOTA)-gadolinium and 300 mg I/mL iopamidol provided adequate contrast enhancement for both in vitro and in vivo MDCT arthrographic and MR arthrographic images. Interobserver agreement was substantial for MRI (kappa = 0.61) and MR arthrography (kappa = 0.71) and almost perfect for MDCT arthrography (kappa = 0.93). The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for tears of the scapholunate ligament were 59% and 70%, 95% and 96%, and 68% and 87% for the first observer and 77% and 83%, 95% and 100%, and 77% and 87% for the second observer. For tears of the lunotriquetral ligament, these values were 30% and 94%, 100% and 94%, and 60% and 97% for the first observer and 50% and 97%, 90% and 100%, and 50% and 94% for the second observer. The three techniques appeared equivalent for complete tears of the scapholunate and lunotriquetral ligaments, but partial tears were significantly better visualized with MDCT arthrography. The sensitivity and specificity of MRI, MDCT arthrography, and MR arthrography for triangular fibrocartilaginous complex tears were 27% and 100%, 100% and 100%, and 82% and 100% for the first observer and 45% and 100%, 100% and 100%, and 82% and 100% for the second observer. For cartilage abnormalities, these values were 30% and 100%, 100% and 100%, and 30% and 100% for the first observer and 10% and 100%, 100% and 100%, and 40% and 100% for the second observer. MDCT arthrography appears more accurate than MRI and MR arthrography, particularly for discerning partial tears of the scapholunate and lunotriquetral ligaments that do not necessitate surgical therapy.

Minor Shoulder Instability

The wide spectrum of shoulder instability is difficult to include in 1 classification. The distinction between traumatic, unidirectional, and atraumatic multidirectional instability is still widely used, even though this classification is not sufficiently precise to include all the different pathological findings of shoulder instability. We present “minor instability,” which is a pathological condition causing a dysfunction of the glenohumeral articulation, especially in combination with microtrauma, repetitive or not, or after a period of immobilization or inactivity. When “minor shoulder instability” is suspected, the patient’s history and detailed clinical examination represent the most important factors when establishing the diagnosis. In particular, the apprehension test stressing the middle glenohumeral ligament (MGHL)/labral complex in the position of midabduction and external rotation may be painful and may even reveal anterior instability or subluxation. Conventional radiographs are negative in most cases, as is magnetic resonance imaging arthrography. It is only after an accurate arthroscopic assessment that the pathological lesion can be found. The major pathological process can be identified at the level of the anterior superior labrum, in particular the MGHL complex, and appears as hyperemia, fraying, stretching, loosening, thinning, hypoplasia, or even absence. It may, however, be difficult to distinguish between a normal variant and a pathological lesion. Clinical symptoms and examination should always be correlated with arthroscopic findings. Recommended treatment is to restore shoulder stability and thereby prevent shoulder pain secondary to the increase in laxity. A reduction in range of motion should be expected during the postoperative phase, at least up to six to nine months. External rotation is usually permanently reduced by a few degrees.

Prognostic Value of Magnetic Resonance Arthrography for Czerny Stage II and III Acetabular Labral Tears

To assess the intraobserver reliability and prognostic value of magnetic resonance arthrography (MRA) on the basis of postoperative outcome measures following arthroscopic acetabular labral debridement (partial limbectomy). Between January 1999 and November 2000, 24 patients (13 females, 11 males) with an average age of 37.1 years (range, 21 to 56 years) underwent hip arthroscopy for the treatment of presumed acetabular labral tears. All patients underwent preoperative MRA and/or magnetic resonance imaging (MRI); images were evaluated by a single musculoskeletal radiologist on 2 independent occasions. Hip arthroscopy was performed on all patients. Outcomes were assessed by means of the Modified Harris Hip Score (MHHS) and the Short Form-36 (SF-36) questionnaires, which were completed by patients an average of 24.1 months (range, 12 to 55 months) postoperatively. The accuracy of the initial read, as well as the prognostic value of the Czerny MRA classification system for stage II (intrasubstance tears) and stage III (complete avulsions) acetabular labral tears, was assessed. Twenty-two of 23 tears (96%) were detected on the initial read. On the basis of intraoperative findings, 1 false-positive MRA, 1 false-negative MRA, and 1 incident of MRA overstaging were reported. On repeat interpretation, 23 of 23 (100%) tears were identified, and intraobserver reliability for recording the presence of a tear was excellent (kappa coefficient = 0.96). No difference was noted in outcomes between patients with or without arthroscopic evidence of chondromalacia (all P > .29), or between patients older or younger than 30 years (all P > .34). Likewise, no difference in outcome was seen between 15 patients with Czerny stage II tears revealed on MRA versus 9 patients with Czerny stage III tears (all P > .79). MRA is sensitive and accurate for the detection of acetabular labral tears, with excellent intraobserver reliability. Arthroscopic partial limbectomy is successful in two thirds of patients. Patients with Czerny stage II and III tears do not appear to have significantly different outcomes following arthroscopic labral debridement. Level IV, prognostic case series.

Superior Labrum Anterior to Posterior Lesion Type II with Accompanied Findings: Assessment of Shoulder MR Arthrographic Findings

Purpose: To describe the pattern of various shoulder abnormalities with an associated superior labrum anterior to posterior (SLAP) lesion type II using magnetic resonance (MR) arthrography, and to assess the clinical significance of the associated abnormalities. Materials and Methods: A retrospective review of the MR arthrographic findings of 92 cases of a shoulder with an arthroscopically confirmed SLAP lesion type II was performed. The MR arthrography images were reviewed and analyzed. MR arthrographic analysis noted the presence of a rotator cuff abnormality, acromioclavicular arthritis, adhesive capsulitis, glenohumeral arthritis, a labral abnormality besides the SLAP lesion, and a paralabral cyst. The patients with SLAP lesions were divided into two age groups: those over 40 years of age and those forty years old or younger. Statistical analysis was performed to evaluate the influence of age on the various shoulder abnormalities with associated SLAP lesion. Results: Of the 92 SLAP lesions type II, there were 7 cases (8%) of isolated SLAP lesions without any associated any shoulder abnormality. Eighty-five (92%) SLAP lesions were associated with various shoulder abnormalities including rotator cuff tendinosis (30/92, 33%), partial-thickness tear (36/92, 39%), full-thickness tear (2/92, 2%), acromioclavicular arthritis (46/92, 50%), adhesive capsulitis (7/92, 8%), glenohumeral arthritis (15/92, 16%), labral abnormality (26/92, 28 %) and paralabral cyst (7/92, 8%). The SLAP lesions (60/92, 65%) in patients over forty years of age were accompanied by a significantly high number of rotator cuff abnormalities (p

Comparison of Plain MRI and MR Arthrography in the Evaluation of Lateral Ligamentous Injury of the Ankle Joint

The purpose of this study was to determine the efficacy of plain magnetic resonance imaging (MRI) and magnetic resonance (MR) arthrography for detecting collateral ligamentous injury of the ankle joint. Fifty patients (October 2001 to November 2003) suffering from ankle disability who underwent plain MRI and MR arthrographic studies were enrolled in this study. The diagnostic criteria for ligament disruption on plain MRI included nonvisualization, disruption, waviness of the ligament, or coexistent avulsion fracture. The MR arthrographic findings of ligament disruption were based on leakage of gadolinium contrast medium anterior to the anterior talofibular (ATaF) ligament following ATaF ligament disruption, and the contrast medium filling into the common peroneal tendon sheath after calcaneofibular (CF) ligament disruption. The 2 modalities were interpreted respectively and blindly. Seventeen patients received surgical intervention. There were 14 patients who had a torn ATaF ligament and 6 patients who suffered from CF ligament disruption proved by surgery. Limited detection of preoperative plain MRI survey, which showed 12 patients had torn ATaF and 2 patients had torn CF ligament, was noted. However, most patients with ligamentous injury were correctly diagnosed by MR arthrography preoperatively (only 1 case of CF injury was missed). The plain MRI alone had a higher incidence of false negative and false positive detection. MR arthrography was also valuable for evaluating the coexisting intra-articular pathologies of the ankle joint. For evaluating ankle disability, using plain MRI alone is not adequate for correctly detecting lateral collateral ligamentous injury of the ankle joint. MR arthrography improves the sensitivity and the accuracy for ATaF and CF ligament injuries. It also helps in assessing coexisting pathologic lesions of ankle joints, especially impingement syndromes and osteochondral lesions, and provides more information for therapeutic decision making.

Magnetresonanztomographie und -arthrographie des Hüftgelenks

Plain film radiographs represent the imaging of choice for the initial evaluation of pathologies of the hip. However, many lesions of the joint itself and surrounding soft tissues are often not visualized by conventional radiographs. Magnetic resonance imaging (MRI) demonstrates most of these pathologies with high sensitivity and specificity. For further assessment of intra-articular lesions such as labral tears, hyaline cartilage lesions, rupture of the ligamentum teres, and loose bodies, direct MR arthrography after intra-articular administration of contrast medium may be indicated. This article summarizes the technical aspects and the most important indications for MRI and MR arthrography of the hip in correlation with typical imaging findings of the most frequent pathologies.

Adhesive capsulitis of the shoulder: evaluation with MR arthrography

The purpose of this study was to determine the usefulness of magnetic resonance (MR) arthrography for diagnosing adhesive capsulitis. Shoulder MR images of 28 patients with (n=14) and without (n=14) adhesive capsulitis were retrospectively analyzed. MR images were assessed for capsule and synovium thickness as well as the width of the axillary recess on oblique coronal fat-suppressed T1-weighted images and T2-weighted images, respectively. On oblique sagittal fat-suppressed T1-weighted images, the width of the rotator interval and the presence of abnormal tissue in the interval were evaluated. Significant differences were found between the two groups in capsule and synovium thickness on both sides of the recess on oblique coronal T2-weighted images (P=0.000), whereas thickness on the humeral aspect showed no significant difference on oblique coronal fat-suppressed T1-weighted images (P=0.109). On oblique coronal T2-weighted images, a cut-off value of 3-mm thickness gave the highest diagnostic accuracy for adhesive capsulitis with sensitivity, specificity, and accuracy of 79% (11/14), 100% (14/14), and 89% (25/28) at the humeral side and 93% (13/14), 86% (12/14), and 89% (25/28) at the glenoid side, respectively. There were significant differences in rotator interval width, presence of abnormal tissue in the rotator interval, and axillary recess width between the two groups (P<0.05). Thickness of capsule and synovium of the axillary recess greater than 3 mm is a practical MR criterion for diagnosing adhesive capsulitis when measured on oblique coronal T2-weighted MR arthrography images without fat suppression. The presence of abnormal tissue in the rotator interval showed high sensitivity but rather low specificity.

Accuracy of anterior intra-articular injection of the glenohumeral joint

Intra-articular glenohumeral injections are an important part of orthopaedic practices, and the therapeutic benefit and diagnostic information of certain injections is based on the premise of the injection reaching its desired target. This study assessed the accuracy of an anterior intra-articular injection in awake subjects without radiologic assistance. Case control study. Forty-one patients scheduled for magnetic resonance imaging arthrography underwent anterior placement of a spinal needle using a location just lateral to the coracoid as the anterior landmark for injection, without radiographic assistance. After the needle was placed and clinically estimated to be intra-articular, 1 mL of gadolinium was injected into the joint to determine accuracy of position. The presence of intra-articular contrast was judged as an accurate injection. Only 26.8% (11 of 41) of injections placed anteriorly were actually intra-articular. The remaining were extra-articular, the most common location of error being either too medial or too superficial in the deltoid muscle. Based on our cadaveric study, we believed that an unassisted anterior injection to the glenohumeral joint would be accurately placed. However, this study shows that without some form of radiologic guidance, it is unlikely that an anteriorly placed intra-articular glenohumeral injection will be accurately placed in awake patients, and we do not recommend this technique. Level IV.

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.

Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography

Objective: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. Materials and methods: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. Results: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year ( P<0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. Conclusion: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process.