Posteroinferior labral cleft at direct CT arthrography of the shoulder by using multidetector CT: is this a normal variant?
ABSTRACT To describe a posterior labral cleft at direct computed tomographic (CT) arthrography of the shoulder by using multidetector CT and to compare this finding with a true posterior labral tear.
Institutional ethics review board approval was obtained, and informed consent was waived. One hundred twenty-seven shoulders in 126 patients were examined with direct CT arthrography by using 16- or 64-section multidetector CT and arthroscopy. Two musculoskeletal radiologists retrospectively reviewed CT arthrographic images for the presence, location, and size of a posterior labral tear, defined as a detectable contrast material-filled focal discontinuity of the labrum on an axial image, proved by using arthroscopy. A posterior labral cleft was defined as a false-positive lesion at CT arthrography that was proved to be a normal finding arthroscopically. Sensitivity, specificity, accuracy, positive and negative predictive values of tears and clefts were determined; incidence according to the patient's age and sex and the laterality (right or left shoulder), location, and size of the lesion were compared.
In 127 shoulders, radiologists 1 and 2 found 12 and 11 posterior labral tears, respectively, seen exclusively in male patients with posterior instability. Radiologist 1 observed 24 (18.9%) clefts, and radiologist 2 observed 20 (15.7%) clefts, seen more commonly in female patients (P = .037 for radiologist 1, P = .026 for radiologist 2) and in the inferior quadrant of the posterior labrum (along 7- to 8-o'clock positions, P < .05 for both radiologists); these clefts were shallower than labral tears (P = .005 for radiologist 1, P = .025 for radiologist 2).
At direct CT arthrography, a labral cleft may be a normal variation of the posterior labrum.
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ABSTRACT: Imaging the shoulder in the position of flexion, adduction, and internal rotation (FADIR) may be useful in characterizing lesions of the posteroinferior labrum. The purpose of this preliminary study is to illustrate the diagnostic utility of FADIR positioning in the assessment and characterization of posteroinferior labral tears. In the FADIR position, the arm is placed across the chest, with the hand on the contralateral shoulder and palm facing outwards. FADIR positioning was performed if there was a subtle or equivocal abnormality of the posteroinferior labrum on conventional MR arthrography sequences. A retrospective review of the charts of 9 people who were imaged using FADIR positioning in addition to routine MR arthrographic sequences of the shoulder was performed. The review included the indication for the study, documentation of presence of clinical posterior instability, and surgical correlation, where available. In all 9 patients, FADIR positioning helped confirm, exclude, or better characterize a posteroinferior labral abnormality by increasing the diagnostic confidence. Flexion, adduction, and internal rotation positioning appears to be a useful adjunct in evaluating patients with equivocal or subtle posteroinferior labral abnormalities on conventional MR arthrography sequences.Skeletal Radiology 02/2010; 39(5):481-8. DOI:10.1007/s00256-010-0907-3 · 1.74 Impact Factor
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ABSTRACT: To evaluate the accuracy and interobserver reliability of multidetector computed tomographic (CT) arthrography for the diagnosis and classification of superior labral anteroposterior (SLAP) lesions. Institutional review board approval and informed consent were obtained. Retrospective review of images from 161 multidetector CT arthrographic examinations was performed by two radiologists independently for detection and classification of SLAP lesions (type I-X), and sensitivity, specificity, accuracy, and interobserver agreement were evaluated. The SLAP group included 94 patients, and the no-SLAP group included 67 patients with normal labrum. At arthroscopy, a total of 88 SLAP lesions (excluding type I) were found. For detection of SLAP lesions excluding SLAP type I lesions, sensitivity, specificity, and accuracy were 94.3%, 76.7%, and 86.3% for reader 1 and 97%, 72.6%, and 86.3% for reader 2, respectively, and the interobserver agreement was very good (κ = 0.87). The distribution of SLAP lesions was as follows: six type I, 58 type II, one type III, one type IV, 16 type V, one type VI, five type VII, three type VIII, one type IX, one type V and VI, and one type V and VII. Percentages of correct classification of SLAP lesions were variable according to the types, but the overall percentage was noted to be 69.2% for reader 1 and 68.1% for reader 2. The interobserver agreement of classification of SLAP lesions was good (κ = 0.72). Multidetector CT arthrography shows high accuracy and good interobserver reliability for diagnosis of SLAP lesions in spite of its limitations in specific classification.Radiology 07/2011; 260(1):207-15. DOI:10.1148/radiol.11101176 · 6.21 Impact Factor
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ABSTRACT: PURPOSE: To determine the prevalence of a normal variant cleft/recess at the labral-chondral junction in the anterior, inferior, and posterior portions of the shoulder joint. MATERIALS AND METHODS: One hundred and three consecutive patients (106 shoulders) who had a direct MR arthrogram followed by arthroscopic surgery were enrolled in this IRB-approved study. Scans were carried out on a 1.5-T scanner with an eight-channel shoulder coil. The glenoid rim was divided into eight segments and the labrum in all but the superior and anterosuperior segments was evaluated by two radiologists for the presence of contrast between the labrum and articular cartilage. We measured the depth of any cleft/recess and correlated the MR findings with surgical results. Generalized estimating equation models were used to correlate patient age and gender with the presence and depth of a cleft/recess, and Cohen's kappa values were calculated for interobserver variability. RESULTS: For segments that were normal at surgery, a cleft/recess was present within a segment on MR arthrogram images in as few as 7 % of patients (within the posteroinferior segment by observer 1), and in up to 61 % of patients (within the posterosuperior segment by observer 1). 55-83 % of these were only 1 mm deep. A 2- to 3-mm recess was seen within 0-37 % of the labral segments, most commonly in the anterior, anteroinferior, and posterosuperior segments. Age and gender did not correlate with the presence of a cleft/recess, although there was an association between males and a 2- to 3-mm deep recess (p = 0.03). The interobserver variability for each segment ranged between 0.15 and 0.49, indicating slight to moderate agreement. CONCLUSION: One-mm labral-chondral clefts are not uncommon throughout the labrum. A 2- to 3-mm deep smooth, medially curved recess in the anterior, anteroinferior or posterosuperior labrum can rarely be seen, typically as a continuation of a superior recess or anterosuperior labral variant.Skeletal Radiology 08/2012; 42(3). DOI:10.1007/s00256-012-1496-0 · 1.74 Impact Factor