Muscle denervation patterns in upper limb nerve injuries: MR imaging findings and anatomic basis.
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Adult↗
Biomedical subjects
P F Tirman
Publications and source records attributed to P F Tirman.
A practical approach to imaging of the shoulder with emphasis on MR imaging.
Our understanding of shoulder disorders has changed considerably as a result of improved diagnostic tools, such as arthroscopy and multiplanar imaging modalities. The diagnosis of the cause of shoulder pain can be difficult because a spectrum of disorders, including cervical spine disease, acromioclavicular arthritis, and shoulder instability. Impingement and denervation syndromes can present with similar clinical findings. Accurate depiction of anatomic abnormalities is important for treatment planning. The purpose of this article is to report on the application of available imaging modalities, with emphasis on MR imaging. A strategy for the appropriate use of these studies and their variations of technique is also provided.
Adolescent↗
Magnetic resonance imaging of the elbow.
Magnetic resonance imaging (MRI) provides useful information regarding the elbow joint. Many abnormalities seen in the elbow are a result of trauma, often from sports such as baseball and tennis. Elbow problems are frequently related to the medial tension-lateral compression phenomenon where repeated valgus stress produces flexor-pronator strain, ulnar collateral ligament sprain, ulnar traction spurring, and ulnar neuropathy. The lateral compression causes osteochondritis dissecans of the capitellum and radial head, degenerative arthritis, and loose bodies. Other elbow abnormalities seen on MRI include radial collateral ligament injuries, biceps and triceps tendon injuries, other nerve entrapment syndromes, loose bodies, osseous and soft tissue trauma, arthritis, and masses, including bursae.
Arm Injuries↗
Using abduction and external rotation of the shoulder to increase the sensitivity of MR arthrography in revealing tears of the anterior glenoid labrum.
OBJECTIVE: The purpose of this study was to compare oblique axial MR arthrograms obtained with the patient's shoulder in abduction and external rotation (ABER) position with conventional axial MR arthrograms obtained with the patient's arm in neutral position and the shoulder not rotated in revealing tears of the anterior glenoid labrum (AGL). SUBJECTS AND METHODS: MR arthrography of the shoulder that included an additional oblique axial imaging sequence with the patient in the ABER position was performed in 256 patients. Assessment of AGL integrity with patients in both conventional axial and ABER positions was made before surgery. These assessments were compared with the surgical findings. RESULTS: Of the 92 patients who underwent surgery, AGL tears were found in 27. Conventional axial MR arthrograms revealed 13 tears (sensitivity, 48%; specificity, 91%). A separate review of MR arthrograms obtained with patients in the ABER position revealed 24 tears (sensitivity, 89%; specificity, 95%). Reviewed together, axial MR arthrograms and MR arthrograms obtained with patients in the ABER position revealed 26 tears (sensitivity, 96%; specificity, 97%). CONCLUSION: Oblique axial MR arthrograms obtained with the patient's shoulder in the ABER position were significantly more sensitive in revealing AGL tears (p = .005) than were conventional axial MR arthrograms obtained with the patient's aim in a neutral position and the shoulder not rotated.
Adolescent↗
MR imaging of the elbow. An update.
MR imaging provides clinically useful information in assessing the elbow joint. Superior depiction of muscles, ligaments, and tendons as well as the ability to visualize nerves, bone marrow, and hyaline cartilage directly are advantages of MR imaging relative to conventional imaging techniques. These features of MR imaging may help to establish the cause of elbow pain by accurately depicting the presence and extent of bone and soft-tissue pathology. Ongoing improvements in surface coil design and newer pulse sequences have resulted in higher quality MR images of the elbow that can be obtained more rapidly. Recent clinical experience has shown the utility of MR imaging in detecting and characterizing disorders of the elbow in a noninvasive fashion.
Collateral Ligaments↗
MR arthrography of the shoulder.
Although conventional MR imaging allows direct visualization of major anatomic structures, smaller intraarticular structures, including the glenoid labrum, glenohumeral ligaments, and articular surface of the rotator cuff tendon can be difficult to evaluate in the absence of a joint effusion. The authors review the techniques employed in performing MR arthrography, imaging characteristics of MR arthrography, and diagnostic utilization of the technique. Suggested indications are provided.
Adult↗
Magnetic resonance imaging of labral cysts of the hip.
OBJECTIVE: To present the magnetic resonance (MR) imaging findings in patients with labral cysts adjacent to the acetabulum and to examine their association with hip pathology. DESIGN: MR images and conventional radiographs of seven patients with paralabral cysts were retrospectively reviewed by three musculoskeletal radiologists. PATIENTS: The patients included three men and four women with hip pain, ranging in age from 29 to 82 years. Two patients had developmental dysplasia of the hip and six had a history of remote trauma/dislocation. Clinical history and follow-up were obtained in all patients. Surgery was performed on one patient. RESULTS AND CONCLUSIONS: Paralabral cysts were located in the posterosuperior aspect of the hip joint in five patients and in the anterior aspect in two patients. A tear of the adjacent acetabular labrum was confirmed surgically in one patient, and in all patients the MR features suggested the presence of an abnormal labrum. Osteoarthritis was observed in three patients and there was associated subchondral cyst formation in the acetabulum adjacent to the cyst in three patients. The paralabral cyst of the hip is well visualized on MR imaging and is seen in patients with a predisposition to labral pathology.
Acetabulum↗
Humeral avulsion of the anterior shoulder stabilizing structures after anterior shoulder dislocation: demonstration by MRI and MR arthrography.
OBJECTIVE: To demonstrate the MRI findings of an anterior shoulder capsular avulsion from the humerus, with or without subscapularis rupture, after anterior dislocation or severe abduction external rotation injury. DESIGN AND PATIENTS: We retrospectively reviewed the MRI and MR arthrographic examinations of seven patients who were identified at surgery with avulsion of the anterior shoulder stabilizers from the humerus. MRI was correlated with clinical history and surgical results. RESULTS: MRI findings included: inhomogeneity or frank disruption of the anterior capsule at the humeral insertion (all), fluid intensity anterior to the shoulder (six patients), tear of the subscapularis tendon (six patients), dislocation of the biceps tendon (four patients), and a Hill-Sachs deformity (four patients). MR arthrography additionally found extravasation of contrast through the capsular defect (two patients). CONCLUSIONS: Our findings suggest that MRI is helpful for diagnosing humeral avulsion of the anterior glenohumeral capsule, especially when a tear of the subscapularis tendon insertion is present. MR arthrography may be of benefit for diagnosing capsular avulsion without associated subscapularis tendon abnormality.
Adult↗
The Buford complex--a variation of normal shoulder anatomy: MR arthrographic imaging features.
OBJECTIVE: The purpose of this study was to show the MR arthrographic imaging features of a normal anatomic variation of the shoulder: the absence of the anterior superior labrum and the presence of a "cordlike" middle glenohumeral ligament,which together are known as the Buford complex. MATERIALS AND METHODS: We retrospectively analyzed the MR arthrographic examinations of 10 patients with arthroscopically proven Buford complexes. RESULTS: MR arthrographic examinations showed an absent anterior superior labrum and an associated cordlike middle glenohumeral ligament in all patients. No contiguous tear of the superior labrum or anterior inferior labrum was evident. Originally, this variation was mistakenly diagnosed as a labral avulsion in two of the 10 patients. Also, a differential diagnosis of a superior labral tear was mistakenly offered for four patients. CONCLUSION: An absent anterior superior labrum and an associated cordlike middle glenohumeral ligament represent the normal variation that is known as the Buford complex rather than an avulsed labrum. This normal variation may be mistaken for a detached labrum.
Adolescent↗
Semimembranosus-tibial collateral ligament bursitis: MR imaging findings.
PURPOSE: The purpose of this paper is to describe the MR imaging characteristics of semimembranosus-tibial collateral ligament (SMTCL) bursitis. MATERIALS AND METHODS: Fifteen patients (37-68 years old) with medial joint pain and presumed internal derangements of the knee underwent MR imaging. Fluid collections around the SMTCL were found prospectively in five patients. Our retrospective evaluation of recent MR imaging cases that had been previously diagnosed as pes anserinus bursitis revealed 10 additional cases with similar findings. RESULTS: We believe that SMTCL bursitis clinically explained the patients' medial pain in all cases diagnosed prospectively. We gave the additional cases the same diagnosis presumptively. CONCLUSIONS: SMTCL bursitis has a characteristic MR imaging appearance of fluid draped over the semimembranosus tendon in the shape of an inverted U. This entity can clinically mimic internal derangement of the knee, typically causing pain more superior and posterior to that of pes anserinus bursitis. MR imaging is useful in diagnosing SMTCL bursitis and avoiding unnecessary knee arthroscopy.
Adult↗
Ganglia and cysts around joints.
Para-articular cysts frequently are seen on routine imaging examinations. They may be clinically asymptomatic or may cause pain, swelling, or impaired joint function. They often are associated with underlying joint disorders, such as trauma, degeneration, or inflammation. This article discusses the cause, symptoms, and appearance of para-articular cysts on various imaging examinations including arthrography, ultrasound, CT scan, and MR imaging. Specific attention is focused on those cystic masses appearing around the hip, knee, ankle and foot, shoulder, elbow, wrist and hand, spine, temporomandibular joints, and periosteum.
Arthrography↗
Lead "bursogram" and focal synovitis secondary to a retained intraarticular bullet fragment.
We present an unusual case in which retained lead bullet in the wrist joint dissolved and migrated into a synovial recess, producing reactive focal synovitis. The clinical presentation suggested a soft tissue mass or ganglion cyst. The radiologic findings of dense metallic fragments within a recess of the wrist joint established the correct diagnosis and excluded other causes of soft tissue masses. Radiologic recognition of retained intra-articular lead fragments is important, as the clinical features of systemic lead intoxication, lead arthopathy, or reactive focal synovitis may be subtle or misleading.
Adult↗
Magnetic resonance imaging of the shoulder: review.
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Humans↗
Meniscal ossicle: radiographic and MR imaging findings.
PURPOSE: To determine the magnetic resonance (MR) imaging appearance of meniscal ossicles and correlate that with the radiographic and clinical features. MATERIALS AND METHODS: Radiographs and MR images were studied retrospectively in six patients with meniscal ossicles; all patients had intermittent discomfort in the knee, and five patients had experienced knee trauma. Imaging findings were correlated with the clinical history. Four patients underwent arthroscopy. RESULTS: All patients had a visible ossicle on conventional radiographs initially interpreted as a loose joint body. MR imaging features included a corticated marrow-containing structure within the substance of the medial meniscus near the tibial attachment that appeared as a rounded focus of increased signal intensity on T1-weighted images that decreased in signal intensity on T2-weighted images. CONCLUSION: Meniscal ossicles have a characteristic MR appearance that may help distinguish them from loose bodies. They should be considered diagnostically when a circumscribed ossification is identified near the posterior horn of the medial meniscus on radiographs.
Adolescent↗
Quantification of the volume of articular cartilage in the metacarpophalangeal joints of the hand: accuracy and precision of three-dimensional MR imaging.
OBJECTIVE: Cartilage loss is central to the development of joint failure in arthritis. However, radiographic assessment of cartilage loss is highly unreliable. This study examined the accuracy and reproducibility of a noninvasive technique for quantifying the volume of articular cartilage in the metacarpophalangeal joints of the hand by use of three-dimensional (3D) MR imaging. SUBJECTS AND METHODS: Eight metacarpophalangeal joints (four normal, one rheumatoid arthritic, and three normal cadaveric) each were imaged three times with a 1.5-T clinical MR imaging scanner with a small partial volume coil and a fat-saturated 3D spoiled gradient-echo sequence optimized for delineating articular cartilage. The volumes of cartilage over the metacarpal and phalangeal surfaces were quantified by summing the voxels within segmented 3D reconstructions of the images. Cartilage volumes in the three cadaver joints also were estimated by scraping cartilage off the articular surfaces and measuring water displacement in graduated cylinders. These values were used as the gold standard for assessing the accuracy of cartilage volume quantification by MR imaging. RESULTS: The fat-saturated sequence discriminated the articular cartilage from adjacent joint structures with high contrast and high spatial resolution. Cartilage volumes determined by MR imaging for the different subjects ranged from 115 microliters to 222 microliters for metacarpal cartilage and from 34 microliters to 86 microliters for proximal phalangeal cartilage. Accuracy errors for quantifying cartilage volume by MR imaging were -1.8% (95% confidence interval, -3.5% to -0.7%) for metacarpal cartilage and 9.1% (4.3% to 14.7%) for proximal phalangeal cartilage. Reproducibility errors were 5.2% (95% confidence interval, 2.9% to 7.6%) and 9.9% (5.4% to 15.1%), respectively. CONCLUSION: Fat-suppressed T1-weighted 3D MR imaging provides sufficient contrast and spatial resolution to allow accurate and reproducible quantification of articular cartilage volume in the metacarpophalangeal joints of the hand. This technique may be useful for monitoring cartilage loss in patients with arthritis.
Adult↗
Lipoma arborescens of the shoulder: magnetic resonance imaging findings.
Lipoma arborescens is a rare intra-articular lesion that typically affects the knee. This condition represents villous lipomatous proliferation of the synovial membrane. The magnetic resonance imaging findings are diagnostic and include a frond-like, fatty synovial mass and associated joint effusion. The authors describe a 90-year-old woman with lipoma arborescens of the shoulder. To the authors' knowledge, lipoma arborescens has not previously been reported in this joint.
Aged↗
Association of glenoid labral cysts with labral tears and glenohumeral instability: radiologic findings and clinical significance.
PURPOSE: To determine the relationship between labral cysts and labral tears and glenohumeral instability. MATERIALS AND METHODS: Magnetic resonance (MR), clinical, and arthroscopic examinations of the shoulder and the surgical findings of 20 patients were correlated and retrospectively analyzed. A cystic-appearing mass adjacent to the labrum was the selection criterion for inclusion. RESULTS: MR imaging showed labral tear intimately associated with cystic-appearing mass in these 20 patients. The tear and cyst complex was located anteriorly in two patients, posteriorly in nine, and superiorly in nine. The mass extended into the spinoglenoid notch in six patients, the suprascapular notch in three, and both notches in four. Physical examination showed glenohumeral instability in the direction of the labral tear and cystic-appearing mass in 11 patients (55%). Findings at intraarticular surgery, performed in eight patients, confirmed a labral tear with communication between the joint space and the cyst. CONCLUSION: Glenoid labral cysts are associated with glenoid labral tears and shoulder instability.
Adult↗
MR arthrographic depiction of tears of the rotator cuff: benefit of abduction and external rotation of the arm.
PURPOSE: To show the effectiveness of positioning the arm in abduction and external rotation (ABER) during magnetic resonance (MR) arthrography for depiction of tears of the rotator cuff. MATERIALS AND METHODS: Five throwing athletes with shoulder pain were prospectively imaged with standard MR imaging, MR arthrography, and ABER MR arthrography. The status of the rotator cuff was recorded; arthroscopic correlation was obtained. RESULTS: One partial tear of the distal infraspinatus tendon was detected with ABER MR arthrography only. One full-thickness tear was detected with both MR arthrography and ABER MR arthrography, but the component of the tear that extended into the infraspinatus tendon was depicted with ABER MR arthrography only. One partial tear was detected with both MR arthrography and ABER MR arthrography; no additional information was provided by either technique alone. CONCLUSION: The ABER position may be useful in detection and characterization of tears of the rotator cuff, especially partial tears of the undersurface. This information would be useful in selection of patients for conservative therapy, arthroscopy, or arthrotomy.
Adult↗