Comparison of multislice CT arthrography and MR arthrography for the detection of articular cartilage lesions of the elbow

The objective of this study was to compare the value of multislice CT arthrography and MR arthrography in the assessment of cartilage lesions of the elbow joint. Twenty-six cadaveric elbow specimens were examined with the use of CT arthrography and MR arthrography prior to joint exploration and macroscopic inspection of articular cartilage. Findings at CT and MR arthrography were compared with macroscopic assessments in 104 cartilage areas. At macroscopic inspection, 45 cartilage lesions (six grade 2 lesions, 25 grade 3 lesions, 14 grade 4 lesions) and 59 areas of normal articular cartilage were observed. With macroscopic assessment as the gold standard CT and MR arthrography showed an overall sensitivity/specificity of 80/93% and 78/95% for the detection of cartilage lesions, respectively. Only two of six grade 2 lesions were detected by CT and MR arthrography. For the diagnosis of grade 3 and 4 lesions, the sensitivity/specificity was 87/94% with CT arthrography, and 85/95% with MR arthrography. In an experimental setting multislice CT arthrography and MR arthrography showed a similar performance in the detection of cartilage lesions. Both methods indicated limited value in the diagnosis of grade 2 articular cartilage lesions.     

MR and CT arthrography of the knee

MR and CT arthrography are important imaging modalities for the assessment of the knee in certain situations. Indications for MR arthrography of the knee include assessment of the postoperative meniscus, the presence of chondral and osteochondral lesions, and the presence of intra-articular bodies. The major indication for CT arthrography is evaluating suspected internal derangement in patients who are unable to undergo MRI. In addition to reviewing the established clinical indications for MR and CT arthrography of the knee, the commonly used techniques, normal variants that can simulate disease, and the most commonly found pathologies that can be diagnosed with these modalities are discussed. Potential indications that are not currently well established in the literature including the evaluation of anterior cruciate ligament injury and autologous chondrocyte implants are examined. Where appropriate, the literature on controversial topics or diagnoses is reviewed. The use of conventional imaging versus CT and MR arthrography is also compared.     

MR and CT arthrography of the shoulder

The combined use of shoulder arthrography with MR and CT imaging offers distinct advantages over conventional nonarthrographic imaging techniques. The improved contrast and joint distension afforded by direct arthrography optimize evaluation of various intra-articular structures and help to define subtle abnormalities and distinguish normal variants from true shoulder pathology. In this article, we review the rationale and basic approaches to shoulder arthrography as well as the imaging appearance of the normal shoulder, anatomical variants, and pathology highlighted by this technique.     

MR and CT arthrography of the hip

CT arthrography (CTa) and MR arthrography (MRa) are useful tools for the investigation of intra-articular hip disease. They are minimally invasive techniques with a very low rate of complications and can be performed safely. CTa or MRa can be performed after an intra-articular injection of diluted contrast, but both techniques can also be performed after a single injection. As radiologists we should be able to address the surgeon's questions and work together to standardize terminology and classifications systems for accurate reporting. This update emphasizes radiological findings with a clinical perspective. CTa and MRa allow the precise diagnosis of labral tears, loose bodies, and intra-articular ligaments (capsular and ligamentum teres). The use of careful technique and a tailored protocol has improved our ability to detect and describe cartilage lesions. This is essential because knowledge of the status of the cartilage may dictate a specific surgical approach, and when cartilage lesions are extensive, they are a negative prognostic indicator for arthroscopic treatment.     

MR arthrography of elbow: evaluation of the ulnar collateral ligament of elbow

 Objective. The purpose of this study was to evaluate ulnar collateral ligament (UCL) injury of the elbow in throwing athletes by MRI and MR arthrography. Design. Ten elbows of throwing athletes were examined on both plain MRI and MR saline arthrography and the injuries subsequently surgically proven. Spin-echo (SE) T1-weighted and fast SE T2-weighted coronal images were obtained. Results. The UCL was unclear in all ten cases on T1-weighted MRI. In five cases an avulsion fracture was also found on T1-weighted MRI. On T2-weighted MRI, abnormal high-intensity areas were identified in or around the UCL. On T2-weighted MR arthrography images, extracapsular high-intensity areas, which represent extracapsular leakage, were found in four of five cases with avulsion fracture. At surgery, all these four cases showed avulsion fractures with instability; the other case had a fracture but it was stable and adherent to the humerus. On T2-weighted MR arthrography images, an extracapsular high-intensity area was found in one of the five cases without avulsion fracture. At surgery this patient had a complete tear of the UCL itself. Conclusion. MR arthrography provided additional information for evaluating the degree of UCL injury.     

Cartilage lesions in the ankle joint: comparison of MR arthrography and CT arthrography

OBJECTIVE: To compare MR arthrography and CT arthrography for the evaluation of cartilage lesions in the ankle joint. DESIGN AND PATIENTS: Thirty-six consecutive patients with clinically suspected cartilage lesions were prospectively included in the study. A 1:1 mixture of diluted gadoteridol (4 mmol/l) and iopamidol (300 mg iodine/ml) was injected. The articular cartilages of the talus, tibia, and fibula were analyzed separately by two musculoskeletal radiologists. A review panel consisting of two musculoskeletal radiologists and an orthopedic surgeon represented the standard of reference. RESULTS: For reader 1 accuracy of MR arthrography in the talus/tibia/fibula (88%/88%/94%) was slightly inferior to CT arthrography (90%/94%/92%). For reader 2, the accuracy was 76%/78%/83% for MR arthrography, and 92%/93%/92% for CT arthrography, respectively. Interobserver agreement for MR arthrography was 79%/74%/89% (kappa 0.47/0.34/0.27), while interobserver agreement for CT arthrography was 89%/90%/89% (kappa 0.69/0.54/0.54). CONCLUSION: CT arthrography appears to be more reliable than MR arthrography for the detection of cartilage lesions in the ankle joint.     

MR arthrography

Review article on MR arthrography: technique and main indications. Intra-articular injection of diluted Gadolinium provides good distension and better appreciation of intra-articular structures than standard MRI. It is useful for partial tears of the rotator cuff, in cases of gleno-humeral instability, lesions of the acetabular labrum and hyaline articular cartilage and also for elbow, wrist and ankle ligamentous ruptures.     

Comparison study of indirect MR arthrography and direct MR arthrography of the shoulder

Objective  To compare the diagnostic value of indirect magnetic resonance arthrography (I-MRA) with that of direct MR arthrography (D-MRA) for labral tears, rotator cuff tears, and long head of biceps tendon (LHBT) tears using a 3-T MR unit. Materials and methods  Institutional review board approval was given; written informed consent was obtained from all patients. From November 2005 to June 2006, 19 patients (eight men and 11 women; mean age, 51 years) who had undergone both I-MRA and D-MRA underwent arthroscopic surgery. Both methods were performed in fat-saturated axial, coronal oblique, and sagittal oblique T1-weighted sequences, as well as axial and coronal oblique T2-weighted sequences. Two radiologists independently and retrospectively evaluated two sets of MRA for the diagnosis of superior and anterior labral tears, subscapularis tendon (SSC), and supraspinatus–infraspinatus tendon (SSP–ISP) tears, and LHBT tears. With the arthroscopic finding as a gold standard, we analyzed statistical differences of sensitivities and specificities between two sets of MRA and inter-observer agreement was evaluated using the kappa value. Results  The sensitivity and specificity of I-MRA and D-MRA for reader 1 were 79/80% and 71/80%, respectively, for superior labral tears; 100/100% and 100/100%, respectively, for anterior labral tears; 64/75% and 64/100%, respectively, for SSC tears; 100/86% and 100/100%, respectively, for SSP–ISP tears; and 67/100% and 78/100%, respectively, for LHBT tears. Those of I-MRA and D-MRA for reader 2 were 86/80% and 71/100%, respectively, for superior labral tears; 100/83% and 100/100%, respectively, for anterior labral tears; 64/88% and 82/100%, respectively, for SSC tears; 92/86% and 100/100%, respectively, for SSP–ISP tears; and 78/90% and 89/100%, respectively, for LHBT tears. No significant differences were found between the methods. Inter-observer agreements were higher than moderate (κ > 0.41) with both methods. Conclusions  Based on a relatively small number of patients, no significant difference was detected between I-MRI and D-MRI with regard rotator cuff, labral, and LHBT tears.     

Multidetector spiral CT arthrography of the shoulder. Clinical applications and limits, with MR arthrography and arthroscopic correlations

Although MR imaging and MR arthrography are the first choice modalities for shoulder imaging, CT arthrography (CTA) may be used successfully to address many clinical questions. The advent of submillimeter multiple detector CT technology and subsequent excellent three-plane resolution has considerably increased the quality of CTA examinations and has propelled this technique to the forefront in a growing number of indications. The combined use of iodinated contrast material for fluoroscopic confirmation of the articular position of the needle before injection of gadolinium chelates for MR arthrography offers the unique opportunity to compare CTA and MRA findings in carefully selected cases. This paper illustrates capabilities and limits of CTA for the study of rotator cuff tears, shoulder instability, cartilage lesions, anatomical variants and abnormalities of the glenoid labrum, with correlations to MR arthrography and surgical findings.     

评价肩袖肌腱撕裂:多层螺旋CT关节成像与1.5TMR关节成像的比较

摘要目的比较多层螺旋CT关节成像与1.5T MR关节成像对于肩袖损伤的诊断价值。材料与方法本研究已获得伦理委员会批准,且所有受试者均签署知情同意书。对56例病人分别行CT及MR关节成像,并由2名放射科医师独立评估     

C-arm flat-panel CT arthrography of the wrist and elbow: first experiences in human cadavers

Objective

To determine the optimal intra-articular iodine concentration for C-arm flat-panel computed tomography (FPCT) arthrography using advanced joint phantoms and to evaluate its application in human cadaveric wrists and elbows. Multi-detector (MD) CT served as the standard of reference.

Materials and methods

Joint phantoms and 10 human cadaveric wrist and elbow joints were scanned with C-arm FPCT (5-s, 8-s, and 20-s runs) and standard MDCT using different and optimal concentrations of iodinated contrast material. CT numbers of contrast material, tissue, and noise were measured and contrast-to-noise ratios (CNR) calculated for quantitative analysis. Image and depiction of cartilage, bone, and soft tissues were rated. Radiation doses were compared.

Results

In FPCT, iodine concentrations positively correlated with CT numbers and noise of contrast material and with radiation dose (r?=?0.713–0.996, p?<?0.05 each). At an iodine concentration of 45 mg/ml, CNR of cartilage and soft tissues were highest for all FPCT acquisitions and higher than in MDCT. The 20-s FPCT run performed best for image quality and depiction of anatomical structures and was rated overall equal to MDCT (p?=?0.857).

Conclusion

The optimal iodine concentration for C-arm FPCT arthrography in this study is 45 mg/ml, leading to superior CNR and image quality for an optimal FPCT protocol compared with standard MDCT arthrography in human cadaveric joints.     

The search for joint loose bodies in the elbow joint--conventional or CT arthrography?

Assessment of intraarticular loose bodies in the elbow joint with CT arthrography is more successful than with conventional arthrography. Calcification in the capsule is better delineated by CT. The diagnosis of osteochondrosis dissecans can mostly be established by plane ray and conventional tomography.     

Analysis of patellar cartilage. Comparison of conventional MR imaging and MR and CT arthrography in cadavers

Objective: To compare the sensitivity of conventional MR sequences, MR arthrography, and CT arthrography for the detection of cartilage lesions of the patella in cadavers.Material and Methods: Cartilage lesions in 10 cadaveric specimens were evaluated by MR imaging, including T1-weighted, proton density-weighted and T2-weighted sequences, and fat-suppressed spoiled gradient recalled acquisition in the steady state (SPGR), MR arthrography including T1-weighted and SPGR sequences, and double-contrast CT arthrography including conventional and subtracted images. The sensitivities with regard to detection of lesions were compared to results from morphologic and histologic investigations of sectioned specimens.Results: Twenty-one lesions were detected morphologically. For the detection of these lesions, sensitivities were as follows: T1-weighted images 33.3%; proton density-weighted images 85.7%; T2-weighted images 85.7%; SPGR images 80.9%; MR arthrography with T1-SE sequences 57.1%; MR arthrography with SPGR sequence 90.5%; and CT arthrography, both regular and subtracted images 85.7%.Conclusion: For noninvasive techniques, T2-weighted images revealed the highest sensitivity for the detection of patellar cartilage lesions, which was surpassed only by MR arthrography using the SPGR sequence. CT arthrography delineated surface irregularities but failed to demonstrate intrachondral lesions.     

Imaging findings in the dominant shoulder of throwing athletes: comparison of radiography, arthrography, CT arthrography, and MR arthrography with arthroscopic correlation

OBJECTIVE: Conventional radiography, arthrography, CT arthrography, and MR arthrography--including use of the abduction and external rotation position--were compared, with arthroscopic correlation, to determine the spectrum of abnormalities encountered and the relative benefits of each imaging method in the evaluation of shoulder lesions occurring in 17 throwing athletes. SUBJECTS AND METHODS: Each of 36 athletes with shoulder pain aggravated by abduction and external rotation was examined in a single visit during which conventional radiography, arthrography, CT arthrography, and MR arthrography were performed. In 17 of these athletes, imaging findings were compared with those at arthroscopy. All images were independently evaluated by two groups of musculoskeletal radiologists. RESULTS: Structures found to be affected were, in decreasing order of frequency, the following: the posterosuperior labrum, supraspinatus tendon, infraspinatus tendon, humeral head, glenoid cavity and rim, acromioclavicular joint, anteroinferior capsulolabral complex, biceps tendon, and subscapularis tendon. MR arthrography without and with abduction and external rotation yielded the highest sensitivity and specificity for all lesions with the exceptions of bone sclerosis and enthesophytes (which were best seen with CT arthrography). MR arthrography with abduction and external rotation was most accurate for diagnosis of rotator cuff and anteroinferior capsulolabral complex tears. CONCLUSION: On the basis of these preliminary results, we believe that MR arthrography with abduction and external rotation should be part of the imaging evaluation of shoulder pain in throwing athletes, owing to the high sensitivity of this imaging technique.