Agreement between intraoperative and magnetic resonance imaging assessments of rotator cuff pathology and 2 magnetic resonance imaging-based assessments of supraspinatus muscle atrophy.

Background: Magnetic resonance imaging (MRI)-based rotator cuff assessment is often qualitative and subjective; few studies have tried to validate such preoperative assessments. This study investigates relationships of preoperative MRI assessments made by conventional approaches to intraoperative findings of tear type, location, and size or MRI-assessed muscle occupation ratio.

Methods: Intraoperatively, surgeons assessed tear type, location, anterior-posterior (AP) width, and medial-lateral length in 102 rotator cuff repair patients.

Inter-rater agreement of rotator cuff tendon and muscle magnetic resonance imaging parameters evaluated preoperatively and during the first postoperative year following rotator cuff repair.

Background: Magnetic resonance imaging (MRI) is standard of care for rotator cuff evaluation, with clinical interpretation usually limited to qualitative judgments. The reliability of MRI-based measurements and scoring systems has been evaluated only preoperatively or ≥6 months following rotator cuff repair, when repairs are in the later stages of healing. This study describes the MRI assessments and inter-rater agreement of various rotator cuff tendon and muscle parameters evaluated preoperatively and 4 times during the first postoperative year.

Comparison of Clinical and Semiquantitative Cartilage Grading Systems in Predicting Outcomes After Arthroscopic Partial Meniscectomy.

Cartilage loss on preoperative knee MRI is a predictor of poor outcomes after arthroscopic partial meniscectomy. The purpose of this study was to compare the ability to predict outcomes after arthroscopic partial meniscectomy with a clinically used modified Outerbridge system versus a semiquantitative MRI Osteoarthritis Knee Score system for grading cartilage loss. Patients who underwent preoperative knee MRI within 6 months of arthroscopic partial meniscectomy and who had outcomes available from the time of surgery and 1 year later were eligible for inclusion.

Thrower's Shoulder: An Approach to MR Imaging Interpretation.

In this article, the authors aim to focus on the challenges of interpreting shoulder MR imaging in the throwing athlete with an approach formed by evidence-based literature and clinical experience, with a particular focus on superior labrum tears.

Ultrasound evaluation of infrapatellar fat pad impingement: An exploratory prospective study.

Background: We sought to determine whether there are ultrasound parameters that differ between knees with symptomatic fat pad synovial impingement and asymptomatic knees.

Methods: A prospective study was performed in patients with clinical signs and symptoms of fat pad synovial impingement and asymptomatic controls. Eleven symptomatic knees and 10 asymptomatic controls were evaluated.

Dose Reduction With Dedicated CT Metal Artifact Reduction Algorithm: CT Phantom Study.

Objective: The objective of this study was to compare reader accuracy detecting lesions near hardware in a CT phantom model at different radiation exposures using an advanced metal artifact reduction (MAR) algorithm and standard filtered back projection (FBP) techniques and to determine if radiation exposure could be decreased using MAR without compromising lesion detectability.

Materials And Methods: A CT phantom manufactured with spherical lesions of various sizes (10-20 mm) and attenuations (20-50 HU) embedded around cobalt-chromium spheres attached to titanium rods, simulating an arthroplasty, was scanned on a single CT scanner (FLASH, Siemens Healthcare) at 140 kVp and 0.6-mm collimation using clinical-dose (300 Quality Reference mAs [Siemens Healthcare]), low-dose (150 Quality Reference mAs), and high-dose (600 Quality Reference mAs) protocols.

Comparison of a fast 5-min knee MRI protocol with a standard knee MRI protocol: a multi-institutional multi-reader study.

Purpose: To compare diagnostic performance of a 5-min knee MRI protocol to that of a standard knee MRI.

Materials And Methods: One hundred 3 T (100 patients, mean 38.8 years) and 50 1.

Comparison of a Fast 5-Minute Shoulder MRI Protocol With a Standard Shoulder MRI Protocol: A Multiinstitutional Multireader Study.

Objective: The purpose of this study was to compare the diagnostic performance of a 5-minute shoulder MRI protocol consisting of multiplanar 2D fast spin-echo (FSE) sequences with parallel imaging to that of a standard shoulder MRI protocol.

Materials And Methods: A retrospective review of 151 3-T MRI examinations of shoulders of 147 patients (mean age, 46.95 years) and 50 1.

Pathomechanics and Magnetic Resonance Imaging of the Thrower's Shoulder.

Repetitive, high-velocity overhead throwing can lead to several adaptive changes in the throwing shoulder, which over time lead to structural microtrauma and eventually overt injury. MR imaging is a useful imaging modality to evaluate these changes and to characterize their acuity and severity. Understanding the throwing motion and the effects of this motion on the structures of the shoulder can help radiologists to recognize these findings and provide useful information to referring physicians, which may affect the treatment of these athletes.

Imaging of Arthroplasties: Improved Image Quality and Lesion Detection With Iterative Metal Artifact Reduction, a New CT Metal Artifact Reduction Technique.

Objective: The purpose of this study was to compare iterative metal artifact reduction (iMAR), a new single-energy metal artifact reduction technique, with filtered back projection (FBP) in terms of attenuation values, qualitative image quality, and streak artifacts near shoulder and hip arthroplasties and observer ability with these techniques to detect pathologic lesions near an arthroplasty in a phantom model.

Materials And Methods: Preoperative and postoperative CT scans of 40 shoulder and 21 hip arthroplasties were reviewed. All postoperative scans were obtained using the same technique (140 kVp, 300 quality reference mAs, 128 × 0.

Throwing-related injuries of the subscapularis in professional baseball players.

Objective: To describe the MR appearance of a series of throwing-related injuries to the subscapularis muscle-tendon complex among baseball players.

Materials And Methods: A retrospective review of MR scans of the shoulder in players from 1 professional baseball organization over the course of 5 years was performed to identify cases with findings suggestive of subscapularis injury. These findings were graded and the medical record was reviewed to assess clinical findings, treatment, and follow-up.

Iterative metal artifact reduction: evaluation and optimization of technique.

Objective: Iterative metal artifact reduction (IMAR) is a sinogram inpainting technique that incorporates high-frequency data from standard weighted filtered back projection (WFBP) reconstructions to reduce metal artifact on computed tomography (CT). This study was designed to compare the image quality of IMAR and WFBP in total shoulder arthroplasties (TSA); determine the optimal amount of WFBP high-frequency data needed for IMAR; and compare image quality of the standard 3D technique with that of a faster 2D technique.

Materials And Methods: Eight patients with nine TSA underwent CT with standardized parameters: 140 kVp, 300 mAs, 0.

Relationship between humeral torsion and injury in professional baseball pitchers.

Background: High levels of humeral torsion allow baseball pitchers to achieve maximum external rotation in the late cocking phase of pitching with lower twisting and shear forces on the long head of the biceps tendon and rotator cuff tendons.

Hypothesis: Humeral torsion is inversely related to the incidence and severity of shoulder injuries and other upper extremity injuries in professional baseball pitchers.

Study Design: Case-control study; Level of evidence, 3.

Failure with continuity in rotator cuff repair "healing".

Background: Ten to seventy percent of rotator cuff repairs form a recurrent defect after surgery. The relationship between retraction of the repaired tendon and formation of a recurrent defect is not well defined. PURPOSE/ HYPOTHESES: To measure the prevalence, timing, and magnitude of tendon retraction after rotator cuff repair and correlate these outcomes with formation of a full-thickness recurrent tendon defect on magnetic resonance imaging, as well as clinical outcomes.

Accuracy of MRI in the diagnosis of meniscal tears in older patients.

Objective: The objective of our study was to determine the accuracy of MRI in diagnosing meniscal tears in older patients and the frequency with which abnormal MRI findings correlate with degeneration, fraying, and tears at arthroscopy.

Materials And Methods: Ninety-two patients 50 years old or older who had undergone knee MRI followed by knee arthroscopy within 6 months were selected. Menisci were graded on a 5-point scale: 1, definitely no tear; 2, probably no tear; 3, indeterminate or equivocal; 4, probably a tear; and 5, definitely a tear.

MRI of the knee ligaments and menisci: comparison of isotropic-resolution 3D and conventional 2D fast spin-echo sequences at 3 T.

Objective: The purpose of this study was to evaluate the diagnostic performance of sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) 3D fast spin-echo acquisition relative to conventional 2D fast spin-echo acquisition in the 3-T MRI evaluation of the menisci and ligaments of the knee.

Materials And Methods: Images from all MRI knee examinations performed with a single 3-T system from September 2008 to January 2009 were reviewed. Seventy-one examinations of patients who subsequently underwent knee arthroscopy and an additional 29 examinations of patients who did not undergo surgery were selected for a total of 100 examinations.

Vacuum phenomenon: prevalence and appearance in the knee with 3 T magnetic resonance imaging.

Objectives: To determine the prevalence of vacuum phenomenon (VP) in the knee on magnetic resonance (MR) images, describe the imaging features that characterize VP, and assess how often VP mimics pathological knee lesions.

Materials And Methods: Consecutive knee MR studies performed on a 3 T MR system over a 9-month period were retrospectively reviewed by one radiologist who then selected studies with findings potentially indicating VP. Three experienced musculoskeletal radiologists reviewed these cases in consensus to confirm the presence of VP and to assess the shape, size, and signal of VP; the presence of magnetic susceptibility artifacts; and the ability of MR sequences to show VP.

Shoulder MRI: what do we miss?

Objective: Our aim is to review several shoulder abnormalities that are difficult to detect accurately on shoulder MRI, describe the technical reasons that limit their detection, and suggest imaging protocol modifications that may improve radiologists' accuracy.

Conclusion: Although MRI is an excellent tool for detecting some abormalities, there are a number of subtler abnormalities of clinical significance that give radiologists greater difficulty. By understanding the reasons for limited detection and modifying protocols accordingly, radiologists may be able to improve identification, allowing more accurate clinical decision making.

Postoperative single-fraction radiation for prevention of heterotopic ossification of the elbow.

Purpose: Heterotopic ossification (HO) about the elbow has been described after surgery, trauma, and burns. Even limited deposits can lead to significant functional deficits. Little data exist regarding outcomes of patients treated with radiation therapy (RT) after elbow surgery.

CT arthrography: in vitro evaluation of single and dual energy for optimization of technique.

The purpose of this study was to optimize CT arthrography technique and determine if dual energy CT (DECT) can provide any benefit over single energy CT (SECT). Iodinated contrast attenuation at different concentrations was measured using DECT and SECT at different beam energies (140, 120, and 80 kVp). Dose and noise were measured on phantoms at different tube currents.

Three-dimensional volume-rendering computed tomography for measuring humeral version.

Hypothesis: Humeral version is highly variable in human beings. Accurate assessment of humeral version may allow for more anatomic reconstruction at shoulder arthroplasty. Two-dimensional (2D) computed tomography (CT) has been used to measure humeral version but has limitations of poor interobserver reproducibility and strict dependence on arm positioning during image acquisition.

Rheumatoid arthritis: evaluation with contrast-enhanced CT with digital bone masking.

The purpose of this HIPAA-compliant study was to prospectively evaluate the feasibility of contrast material-enhanced computed tomography (CT) with digital bone masking for the evaluation of synovitis and tenosynovitis in patients with rheumatoid arthritis. Four patients with rheumatoid arthritis and findings at magnetic resonance (MR) imaging were evaluated after informed consent for this institutional review board-approved study was obtained. To improve the conspicuity of synovial enhancement, postcontrast CT was performed with a relatively low kilovoltage and high iodine concentration and precontrast images were used as a subtraction mask to eliminate high-attenuation cortical bone contours.

MRI and gross anatomy of the iliopsoas tendon complex.

Objective: The objective was to explain the anatomic basis of a longitudinal cleft of increased signal in the iliopsoas tendon seen on hip MR arthrograms.

Materials And Methods: A prospective review of 20 MR hip arthrograms was performed using standard and fat-suppressed T1-weighted images to establish whether or not the cleft was composed of fatty tissue and to define the anatomy of the iliopsoas tendon complex. Three cadaver dissections of the hip region were then performed for anatomic correlation.

Comparison of MR arthrography with arthroscopy of the hip for the assessment of intra-articular loose bodies.

Objective: To assess the specificity and sensitivity of MR arthrography of the hip in comparison with arthroscopy for the evaluation of intra-articular loose bodies.

Design: Over a 3-year period, 81 consecutive patients underwent a total of 82 hip arthroscopies by a single orthopedic surgeon for intractable hip pain. Of the 82 arthroscopies, 70 had pre-operative MR arthrograms.