Thomas Magee

Post-operative shoulder patients are often difficult to image due to scar tissue, metallic artifact, and residual irregularity of anatomic structures. The purpose of this study was to assess MR versus MR arthrography versus CT arthrography in the post-operative shoulder. Also, we assessed whether injecting CT contrast in addition to MR contrast during arthrography improved patient care.

Purpose:MR arthrogram imaging of the shoulder is considered more accurate in assessing shoulder pathology than conventional MR imaging. Arthrography is a minimally invasive procedure. However most patients prefer to have conventional MR imaging rather than MR arthrogram imaging. We report the benefit of assessing pre arthrogram conventional MR imaging to determine whether an MR arthrogram is needed for further evaluation.Methods and materials:One hundred consecutive conventional shoulder MR and MR arthrography exams performed on the same patients were reviewed retrospectively by independent reading of two musculoskeletal radiologists. Both conventional MR and MR arthrogram exams were performed on each patient on the same day. Conventional MR and MR arthrogram exams were assessed for labral tears and supraspinatus tendon tears. All patients went on to arthroscopy.Results:Of these one hundred patients, forty-three had SLAP (superior labral anterior to posterior) tears , twenty-eight had posterior labral tea...

OBJECTIVE. Shoulder surgeons commonly intervene to repair unstable labral tears (tears that displace with patient movement). Surgeons can detect unstable tears at surgery. It is difficult to be certain if a tear is unstable from a static MR image. This study reports the comparative benefits of using unenhanced MRI and MR arthrography together to detect unstable labral tears. MATERIALS AND METHODS. One hundred fifty consecutive unenhanced shoulder MRI and MR arthrography examinations performed on the same patients were reviewed retrospectively by consensus reading of two musculoskeletal radiologists. Both unenhanced MRI and MR arthrography were performed on each patient on the same day. Labral tears were assessed. It was also determined if there was any difference in position of the labral tear between unenhanced MR images and MR arthrograms. A change in position of 4 mm or more between unenhanced MR images and MR arthrograms was considered indicative of an unstable tear. All patients proceeded to arthrosc...

We report our experience in diagnostic sensitivity of 3.0-T conventional MR vs 3.0-T MR arthrography of the hip for detection of acetabular labral tears and chondral defects in the same patient population. 43 consecutive patients had both conventional hip MR and MR arthrography examinations performed. These examinations were reviewed retrospectively by independent reading of two musculoskeletal radiologists who read the MR and MR arthrogram examinations in a randomized fashion (i.e. MR and MR arthrogram examinations were read at separate sittings and in a randomized fashion so as not to bias reviewers). Scans were assessed for acetabular labral tears and chondral defects. All patients went on to arthroscopy. Of these 43 patients, 40 had acetabular labral tears read by Reader 1 and 39 had acetabular labral tears read by Reader 2 on MR arthrogram, 39 had acetabular labral tears read by Reader 1 and 38 had acetabular labral tears read by Reader 2 on conventional MR examination. There were 42 labral tears in 43 patients at arthroscopy. There were four false-negative labral tears compared with arthroscopy on MR and three false negatives on MR arthrography for Reader 1 and five false negatives on MR and four false negatives on MR arthrography for Reader 2. Each reader had one false-positive labral tear compared with arthroscopy on both MR and MR arthrography. There were 32 acetabular chondral defects at arthroscopy. Reader 1 saw 21 acetabular chondral defects on conventional MR and 27 chondral defects at MR arthrography. Reader 2 saw 19 acetabular chondral defects at conventional MR and 25 acetabular chondral defects on MR arthrography. There were no false-positive readings of chondral defects compared with arthroscopy on MR and one false positive for Reader 1 and two false positives for Reader 2 on MR arthrography as compared with arthroscopy. On conventional MR examination, sensitivities and specificities as compared with arthroscopy were as follows: Reader 1 acetabular labral tear (90% sensitivity, 0% specificity) and Reader 2 acetabular labral tear (88% sensitivity, 0% sensitivity). On MR arthrogram, sensitivities and specificities as compared with arthroscopy for Reader 1 were 93%, 0% and for Reader 2 were 90%, 0%, respectively. Sensitivities and specificities for detection of acetabular chondral defects as compared with arthroscopy were Reader 1 conventional MR (65% sensitivity, 100% specificity), Reader 1 MR arthrography (81% sensitivity, 91% specificity), Reader 2 conventional MR (59% sensitivity, 100% specificity) and Reader 2 MR arthrography (71% sensitivity, 82% specificity). In this series, 3.0-T MR demonstrated sensitivity for detection of acetabular labral tears that rivals the sensitivity of 3.0-T MR arthrography of the hip. In this series, 3.0-T MR arthrography was more sensitive than conventional 3.0-T MR for detection of acetabular chondral defects. 3.0-T MR and MR arthrography are near equivalent in the diagnosis of acetabular labral tears. This information is useful for pre-operative planning.

We report the prevalence of surgical intervention on shoulder labral lesions detected at MR examinations and how surgeons describe labral tears seen at MR examinations in their arthroscopy reports. A retrospective review of 100 consecutive patients aged 50 years or younger who had shoulder labral tears on MR and went on to have surgery performed. It was determined whether surgical intervention was performed on the MR lesions. Of these 100 patients, 72 had superior labral anterior to posterior (SLAP) tears, 38 had posterior labral tears and 28 had anterior labral tears on MR examination. All 100 patients went on to arthroscopy. All lesions described on MRI were described on arthroscopy. Of the 72 SLAP tears, 64 were described as fraying on arthroscopy with 51 debrided. The remaining eight SLAP tears were tacked surgically. Of the 38 posterior labral tears, 36 were described as fraying on arthroscopy with 29 debrided and 2 had surgical tacking performed. Of the 28 anterior labral tears described on MR examination, 26 had surgical tacking performed and 2 were debrided. There were four SLAP tears, two anterior labral tears and three posterior labral tears seen on arthroscopy but not seen on MR examination. In this series, a high percentage of SLAP tears and posterior labral tears described on MR examination did not have surgical tacking. Most anterior labral tears had surgical tacking. Based on the above, our surgeons request we describe superior and posterior labral lesions as fraying and/or tearing, unless we can see a displaced tear. Most anterior labral lesions are treated with surgical tacking. MRI allows for sensitive detection of labral tears. The tears often are not clinically significant.

This study assesses the accuracy of 3-Tesla (3-T) conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography in the diagnosis of meniscal retears as compared with arthroscopy. The study also assess whether there are false-negative cases in which injected contrast does not extend into the meniscus despite a meniscal retear being seen on arthroscopy. One hundred consecutive knee MR arthrograms performed on patients with previous knee surgery were reviewed retrospectively. 3-T conventional MR imaging, 3-T MR arthrography, and the combined use of conventional MR and MR arthrography were assessed for meniscal retears as compared with arthroscopy. The criterion used to diagnose a meniscal retear on MR arthrogram was injected contrast tracking into the meniscus. All patients underwent second-look arthroscopy. Seventy-four patients had conventional MR findings consistent with a meniscal retear. In 83 of the 100 patients, intraarticular contrast helped in demonstrating a retear. In ten patients, there were MR findings consistent with a meniscal retear despite intra-articular contrast not tracking into the meniscus. Ninety-four of the 100 patients had meniscal retears on second-look arthroscopy. Three-Tesla conventional MR examination was 78 % sensitive and 75 % specific, MR arthrogram examination was 88 % sensitive and 100 % specific, and the combined use of MR and MR arthrogram imaging was 98 % sensitive and 75 % specific in the diagnosis of a meniscal retear. The combined use of 3-T MR and MR arthrography allows for high sensitivity and specificity in meniscal retear detection. In some patients, intraarticular contrast will not track into a meniscal retear. When MR findings are consistent with a meniscal retear but contrast does not extend into the meniscus, a meniscal retear is likely.

Objective Humeral avulsion of the glenohumeral ligament (HAGL) is an uncommon shoulder injury. We report the prevalence of HAGL lesions and other associated shoulder injuries in a large series of shoulder MR examinations. All results were correlated with surgery. Materials and methods MR reports of 1,000 consecutive conventional shoulder MR exams performed on patients with shoulder pain were reviewed in our information system for the word HAGL. A total of 743 patients went on to surgery. There were 23 HAGL lesions reported at surgery. Those 23 examinations were reviewed retrospectively in consensus by two musculoskeletal radiologists. Scans were assessed for HAGL lesions, full or partial thickness supraspinatus, infraspinatus or subscapularis tendon tears, superior labral anterior posterior (SLAP) tears, anterior or posterior labral tears, and Hill–Sachs lesions. Results All 23 patients had HAGL lesions at surgery. Sixteen HAGL lesions were seen on prospective MR reading and 17 HAGL lesions were seen on retrospective MR consensus reading. Six HAGL lesions were not seen on retrospective consensus reading. Sixteen patients had Hill–Sachs deformities, ten had subscapularis tendon tears, five had supraspinatus tendon tears, six had superior labral tearing, and six had anterior labral tears. The above findings were confirmed on arthroscopy. Conclusions In this series, there was a 1.6 % prevalence on all MR examinations, and prevalence of 2.1 % seen on MR examination for those who went to surgery. Common injuries associated with HAGL lesions are Hill–Sachs deformities and subscapularis tendon tears. Anterior labral tears were seen in only six cases despite Hill–Sachs deformities in 16 patients. In patients with Hill–Sachs deformities without anterior labral tears, one must carefully assess for the presence of a HAGL lesion.

OBJECTIVE. The purpose of this study is to report the diagnostic sensitivity of 3-T conventional MRI versus MR arthrography of the shoulder in the same patient population.MATERIALS AND METHODS. One hundred fifty consecutive conventional shoulder MRI and MR arthrography examinations performed on patients 50 years or younger who subsequently underwent arthroscopy were reviewed retrospectively by consensus reading by two musculoskeletal radiologists. All patients selected for arthroscopy had abnormal findings on clinical examination and MRI or MR arthrography. All 150 patients were referred from one orthopedic group. All patients consented to undergo both MRI and MR arthrography. None had undergone prior shoulder surgery. Full- or partial-thickness supraspinatus tendon tears, superior labral anterior-to-posterior (SLAP) tears, and anterior or posterior labral tears were assessed.RESULTS. Three full-thickness and nine partial-thickness supraspinatus tendon tears, seven SLAP tears, six anterior labral tears, a...

OBJECTIVE. This study assesses the sensitivity and specificity of MRI at 3 T compared with arthroscopy for detection of intrinsic wrist ligament and triangular fibrocartilage complex (TFCC) tears.MATERIALS AND METHODS. MR wrist images in 300 consecutive patients underwent consensus review by two radiologists without knowledge of arthroscopy findings. Forty-nine of 300 patients underwent arthroscopy. Thirty-five of these 49 patients also underwent MR arthrography. Scans were assessed for full-thickness scapholunate, lunatotriquetral, or TFCC tears. After consensus review of MR images, arthroscopy results were compared with MR interpretations.RESULTS. Of the 49 patients who underwent arthroscopy, 22 had TFCC tears, 18 had scapholunate tears, and 11 had lunatotriquetral tears (51 total tears at arthroscopy). Nineteen of 22 TFCC tears, 16 of 18 scapholunate tears, and nine of 11 lunatotriquetral tears seen at arthroscopy were seen on MRI. Four patients had both a TFCC tear and a lunatotriquetral ligament tear...