Ultrasound of the shoulder.

Ultrasound has been widely used for the evaluation of the shoulder, mainly for rotator cuff pathology. Developments in technology, as well as better knowledge of the pathology and the anatomy make this examination one of the most useful in the exploration of the shoulder, especially in the hands of the experienced radiologist. Ultrasound is low-cost, readily available and should be considered with plain films as the first step examination of the shoulder. Ultrasound is not only useful for the evaluation of the rotator cuff pathology and impingement syndrome, but is also performing in the evaluation of non rotator cuff pathology such as biceps tendon pathology, shoulder instability, mass evaluation, infection, degenerative and inflammatory arthropathies and nerve entrapment syndromes. Making a complete evaluation of the shoulder helps to differentiate between rotator cuff pathology and others that can mimic rotator cuff disorders. This article will review shoulder anatomy and examination technique and the different pathologies that can be assessed by ultrasound.

Whole-body magnetic resonance imaging: technical aspects, indications and preliminary experience.

This article reviews the interest and potential applications of whole body MR and presents a new technical concept of the technique. Preliminary experience with this new technology is presented.

Imaging overuse injury of the elbow in professional team handball players: a bilateral comparison using plain films, stress radiography, ultrasound, and magnetic resonance imaging.

The purpose of this study was to compare the manifestations of elbow stress due to repetitive valgus forces between the dominant and the non-dominant elbow in 40 uninjured elite team handball players using plain films, stress radiographs, ultrasound, and MRI examination. On comparative plain films generalized bony hypertrophy manifested by increased humeral diameter, and cortical hypertrophy of the humeral shaft of the dominant extremity was observed in all players. A significantly greater difference in medial joint space opening between stressed and unstressed elbows was measured in the dominant elbow compared with the non-dominant elbow (0.41 +/- 0.59 mm). The ultrasonographic findings showed statistically significant bilateral differences in the thickness of the flexor-pronator tendon (0.90 +/- 0.56 mm), extensor tendon (0.96 +/- 0.50 mm), triceps tendon (0.69 +/- 0.27 mm), and medial collateral ligament (0.47 +/- 0.24 mm): the values were systematically higher on the dominant side. US examination showed intra-articular effusions in 67% and small loose bodies in 33.3% of the players, exclusively in dominant elbows. MRI showed joint effusion in the same subjects as US, but loose bodies were only detected in half of the cases found by ultrasound. This study demonstrates that repetitive stress on the dominant extremities of handball players is responsible for physiologic and pathologic changes in the dominant elbow.

Comparison of spin echo, gradient echo and fat saturation magnetic resonance imaging sequences for imaging the canine elbow.

Two comparison studies were performed. In the first conventional spin-echo (T1- and T2-weighted) sequences and a three-dimensional (3-D Fourier transform [3DFT]) echo gradient fast-imaging sequence were compared for imaging the canine normal elbow joint. In all three sequences, there was an isointense signal of the articular cartilage and a hyposignal of the subchondral bone, as compared with the muscles. The medial coronoid process of the ulna was clearly seen on the dorsal plane images, it appeared with a homogenous low-intensity signal. Its articulation with the radius was clearly outlined. In a second study, the 3DFT echo gradient fast-imaging sequence was compared to a fat saturation sequence on normal shoulder and elbow joints. Elbows were imaged with and without injection of saline, in an attempt to show the opposing cartilaginous articular surfaces. This distinction was possible in the shoulder joint but not in the elbow because of insufficient spatial resolution. On the three MRI sequences compared, gradient echo fast imaging with steady-state precession (GE FISP) sequence was found to be the most suitable for imaging the canine elbow joint.

Evaluation of patellar cartilage surface lesions: comparison of CT arthrography and fat-suppressed FLASH 3D MR imaging.

The aim of this study was to evaluate the sensitivity and specificity of fat-suppressed fast low-angle shot (FLASH) 3D MR imaging in the detection of patellar cartilage surface lesions in comparison with CT arthrography. Fifty patients, with or without symptoms of chondromalacia, were prospectively examined by CT arthrography and fat-suppressed 3D gradient-echo MR imaging. All MR examinations were evaluated by three observers, two of them reaching a consensus interpretation. The lesions were graded according to their morphology and their extent. The CT arthrography was considered as the reference examination. For both sets of observers, the final diagnosis of chondromalacia was obtained in 92.5 %. The specificity was 60 % on a patient-by-patient basis. Fissures were missed in 83 and 60 %, respectively, but were isolated findings only in 2.5 % of the cases. Considering ulcers involving more than 50 % of the cartilage thickness, 65 and 88 %, respectively, were recognized. Fat-suppressed FLASH 3D is an adequate pulse sequence for the detection of patellar cartilage ulcers. It can be applied on a routine clinical basis, but it does not show as many fissures as CT arthrography and is less precise for grading of lesions.

Measurements of cortical thickness in experimentally created endosteal bone lesions: a comparison of radiography, CT, MR imaging, and anatomic sections.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of cortical measurements of experimentally created endosteal cortical lesions and to assess the sensitivity of radiography, CT, and MR imaging in the detection and measurement of such lesions. MATERIALS AND METHODS: Thirty-six cortical lesions were created in three fresh cadaveric femurs. After performing radiography, CT, and MR imaging, we sectioned the specimens in the axial plane. We then measured the remaining cortex at the lesions and the normal cortex adjacent to the lesions on all images and corresponding anatomic sections. The measurements of thickness of the cortex as seen with the different imaging methods and the anatomic sections were compared. Measurements were repeated to evaluate the influence of different window settings on the MR imaging measurements. RESULTS: When measured on radiographs, cortical thickness was overestimated in 58% of lesions. With CT, cortical thickness was overestimated by 0-15% in 94% of all lesions. With MR imaging, cortical thickness was uniformly underestimated by 3-17%. Measurements made on MR images varied according to different window settings. The proton density-weighted sequence yielded the highest sensitivity in the detection of shallow cortical lesions; the T1-weighted spin-echo sequence was the least sensitive of the MR sequences. CONCLUSION: In our cadaveric study, cortical thickness in the presence of endosteal lesions was overestimated on radiographs and CT scans and underestimated on MR images. Measurements derived from MR imaging are strongly influenced by the window setting. MR imaging with the proton density-weighted sequence is the most sensitive for detection of shallow cortical lesions and is more sensitive than CT.

Symptomatic herniation pits of the femoral neck: anatomic and clinical study.

OBJECTIVE: The purpose of this study was to investigate the pathogenesis of herniation pits of the femoral neck, which are frequently considered a normal variant, and to describe the imaging abnormalities of such pits in three symptomatic patients. CONCLUSION: The changing relationship between the joint capsule and the iliopsoas muscle appears to be important in the pathogenesis of the herniation pit, especially in athletic persons. In some cases, these pits may enlarge, the overlying cortex may fracture, and significant clinical manifestations may be apparent.

MR imaging of the tarsometatarsal joint: analysis of injuries in 11 patients.

OBJECTIVE: We evaluated how well MR imaging revealed ligamentous and bony abnormalities in patients with injuries of Lisfranc's joint. SUBJECTS AND METHODS: We evaluated the studies of 11 patients with plantar hyperflexion injuries of the foot who underwent MR imaging in all three planes using spinecho T1-weighted, fast spin-echo T2-weighted, and short inversion time inversion recovery sequences. In four of the 11 patients, a three-dimensional spoiled gradient-recalled acquisition in the steady-state volume sequence was performed in the coronal plane. For five of the 11 patients, radiographs were available for evaluation. RESULTS: Radiographs revealed tarsometatarsal joint malalignment in all five patients for whom plain films were available, metatarsal fractures in four of these patients, and tarsal fractures in the same four patients. MR imaging showed joint malalignment in all 11 patients and disruption of the Lisfranc's ligament in eight of the 11 patients. In the remaining three patients, normal Lisfranc's ligaments were associated with avulsion fractures of the second metatarsal bases or the medial cuneiform bones. On MR imaging, fractures of the metatarsal bases were evident in 10 of 11 patients. Fractures of the tarsal bones were seen in the same 10 patients. CONCLUSION: MR imaging allows the detection of disruption of the Lisfranc's ligament as well as tarsal and metatarsal fractures and therefore may be a valuable technique in assessing patients after trauma to the tarsometatarsal joints when results of routine radiographs are not conclusive.

Imaging of osseous and cartilaginous intraarticular bodies in the knee: comparison of MR imaging and MR arthrography with CT and CT arthrography in cadavers.

PURPOSE: To compare magnetic resonance (MR) imaging and MR arthrography with computed tomography (CT) and CT arthrography in the detection of intraarticular bodies in the knee. MATERIALS AND METHODS: Cuboid (3- or 6-mm-long sides) osseous and cartilaginous bodies were implanted in 16 cadaveric knee specimens. MR imaging was performed with T1-weighted spin-echo (SE), T2-weighted SE, proton-density-weighted SE, gradient recalled acquisition in the steady state (GRASS), and spoiled GRASS sequences. MR arthrography was performed in two phases with saline and 2 mmol/L gadopentetate dimeglumine. CT and CT arthrography were performed in the transaxial plane. RESULTS: MR arthrography yielded the highest accuracy for the detection of osseous and cartilaginous bodies combined (92%) and was significantly (P < .01) better than MR imaging (57%-70%), CT arthrography (80%), and CT (74%). Accuracy of CT arthrography was significantly better than that of MR imaging and that of CT. Accuracy of saline-enhanced MR arthrography was significantly inferior (P < .001) to that of gadolinium-enhanced MR arthrography. CONCLUSION: MR arthrography is the best imaging technique for detection of individual intraarticular bodies. CT arthrography is the second most accurate method. Spoiled GRASS and T2-weighted SE sequences are the most accurate at MR imaging. The presence of intraarticular fluid and performance of saline-enhanced MR arthrography improve detectability of intraarticular bodies.

Tarsometatarsal joint: anatomic details on MR images.

PURPOSE: To evaluate the diagnostic capabilities of magnetic resonance (MR) imaging in the tarsometatarsal ([TMT] Lisfranc) joint with close anatomic correlation. MATERIALS AND METHODS: Six normal cadaveric feet were imaged by using T1-weighted spin-echo (oblique axial) and three-dimensional spoiled gradient-recalled acquisition in the steady state ([SPGR] coronal, sagittal) sequences. Subsequently, gadolinium-enhanced arthrography was performed in three specimens followed by T1-weighted spin-echo and SPGR MR imaging. Specimens were sectioned in all three planes followed by correlation of the MR imaging results with gross anatomic findings. RESULTS: In all specimens, the oblique axial and, less effectively, the coronal and sagittal planes allowed visualization of the Lisfranc ligament. Intermetatarsal ligaments were seen almost exclusively on the coronal images, and TMT ligaments on the sagittal images. Bone alignment could be assessed on the oblique axial images. CONCLUSION: MR imaging reliably depicts the anatomy of the TMT joint including ligamentous and osseous structures.

[MRI of the knee. Value of delayed sequences after intravenous injection of gadolinium]. / IRM du genou. Intérêt de séquences retardées après injection intraveineuse de gadolinium.

A prospective study of delayed sequences after intravenous injection of gadolinium for knee MRI shows the similar results as from the literature: enhancement of synovial fluid after 30 minutes. Sixteen patients were studied mainly with gradient echo. This phenomenon improves the visualisation of the intraarticular structures like meniscus, cruciate ligaments, or cartilage. This study leads to use this technique in case of difficulties like postoperative intraarticular lesions.