The rotator cuff tear: MR evaluation

Magnetic resonance imaging (MRI) is evolving as a particularly valuable diagnostic procedure in the evaluation of musculoskeletal pathology. To assess the role of MRI as applied to the shoulder, we examined eight normal volunteers, six patients with seven arthrographically proven rotator cuff tears and two patients with impingement symptomatology but with negative double contrast conventional and computed tomographic arthrography. The studies were performed on a 1-Tesla magnet operating at 0.5 Tesla. Coronal T1-weighted images were obtained in all cases and coronal spin density and T2-weighted pulse sequences were employed in two cases. In the normal individuals, the supraspinatus muscle and tendon could be consistently demonstrated. The proximal humeral marrow, the superior glenoid labrum, and the acromioclavicular joint could also be examined. Findings in patients with rotator cuff tears included: (1) hypointense gap within the supraspinatus muscle-tendon complex on T1-weighted sequences, (2) absence of a demonstrable supraspinatus tendon with narrowing of the subacromial space secondary to elevation of the humeral head, and (3) increased signal within the supraspinatus tendon on T2-weighted images. In the patients with impingement syndrome and negative arthrography, MR demonstrated elevation of the supraspinatus tendon with subacromial impingement in one case and a normal supraspinatus tendon in the other. Impingement on the coracoacroaminal arch causes progressive fibrosis, atrophy, and eventual tear of the rotator cuff. The potential applications of MRI relative to the shoulder include assessment of tendon retraction in patients with supraspinatus tears and noninvasive evaluation of patients with impingement syndrome, permitting etiologic determinations, hopefully before irreversible tendon injury has occurred.     

The diagnostic accuracy of MRI for the detection of partial- and full-thickness rotator cuff tears in adults

This study assessed the diagnostic test accuracy of magnetic resonance imaging (MRI) in the detection of partial- and full-thickness rotator cuff tears in the adult population. A systematic review was conducted of the following electronic databases: Cochrane Central Register of Controlled Trials, Medline, Embase, CINAHL, AMED, ISI Web of Science, Current Controlled Trials, National Technical Information Service, the National Institute for Health Research Portfolio, the UK National Research Register Archive and WHO International Clinical Trials Registry Platform database and reference lists of articles. All studies assessing the sensitivity and/or specificity of MRI for adult patients with suspected rotator cuff tear where surgical procedures were the reference standard were included in the study. A meta-analysis was performed to calculate pooled sensitivity, specificity, likelihood and diagnostic odds ratio values, and summary receiver operating characteristic plots were constructed. Forty-four studies were included. These included 2751 shoulders in 2710 patients. For partial-thickness rotator cuff tears, the pooled sensitivity and specificity values were 0.80 [95% confidence interval (CI): 0.79-0.84] and 0.95 (95% CI: 0.94-0.97), respectively. For full-thickness tears, the sensitivity and specificity values were 0.91 (95% CI: 0.86-0.94) and 0.97 (95% CI: 0.96-0.98), respectively. While there was no substantial difference in diagnostic test accuracy between MRIs reviewed by general radiologists and those reviewed by musculoskeletal radiologists, higher-field-strength (3.0 T) MRI systems provided the greatest diagnostic test accuracy.     

Bone marrow edema in the greater tuberosity of the humerus at MR imaging: association with rotator cuff tears and traumatic injury

The purpose of this study was to determine the prevalence of bone marrow edema in the greater tuberosity of the humerus on MR imaging, the association with other findings at MR imaging and the injury mechanism which can lead to this finding.Subjects and methods: MR reports from 863 patients referred for shoulder MRI over 74 months were reviewed to identify patients with marrow edema in the greater tuberosity. The MR images from patients with greater tuberosity marrow edema were reviewed by consensus of two radiologists for the extent of marrow edema and for associated injuries. Marrow edema in the greater tuberosity was seen in 11 of 863 patients (1.3%). Nine patients (82%) had associated rotator cuff tear by MR imaging (four full thickness and five partial thickness), one patient had avulsion of the greater tuberosity from the humerus, and one had no rotator cuff abnormality. History of trauma was reported by eight patients including fall without direct blow to the shoulder (6), car accident (1) and direct blow to the top of the shoulder (1). Marrow edema in the greater tuberosity is an infrequent finding. Marrow edema most often is associated with a history of trauma and with rotator cuff abnormalities including full thickness tears. The history of trauma without direct blow to the shoulder and the location of the edema indicates that marrow edema often results from avulsion injury by the supraspinatus tendon.     

Stiffness change of the supraspinatus muscle can be detected by magnetic resonance elastography

Magnetic resonance elastography (MRE) and ultrasound shear wave elastography (SWE) are imaging techniques to measure stiffness of the soft tissue using magnetic resonance imaging (MRI) and ultrasound images, respectively. The purpose of this study was to explore the feasibility of the MRE measurement to evaluate the change in supraspinatus (SSP) muscle stiffness before and after rotator cuff tear, and to compare the result with those of SWE. Six swine shoulders were used. The skin and subcutaneous fat were removed, and the stiffness value of the SSP muscle was measured by MRE and SWE. The MRE measurement was performed with 0.3 T open MRI and the vibration from a pneumatic driver system with active driver to a passive driver to create the shear wave in the tissue. The passive driver was placed on the center of the SSP muscle. The stiffness was estimated from the wave images using local frequency estimation methods. In the SWE measurement, the probe of the ultrasound was placed on the center of the SSP muscle. The shear wave propagation speed was measured at a depth of 1 cm from the surface, and the stiffness was calculated. After those measurements, the rotator cuff tendon was detached from the greater tuberosity, and MRE and SWE measurements were then performed in the same manner again. The differences in the stiffness values were compared between before and after the rotator cuff tendon tear on both the MRE and SWE measurements. The results indicated that stiffness values on MRE and SWE were 9.3 ± 1.8 and 10.0 ± 1.2 kPa respectively before the rotator cuff tear, and 7.3 ± 1.3 and 8.0 ± 0.8 kPa respectively after the tendon detachment. Stiffness values were significantly lower after the tendon detachment on both the MRE and SWE measurements (p < 0.05). Our results demonstrated that stiffness values of the SSP muscle on MRE and SWE were lower after rotator cuff detachment. From this result, MRE may be a feasible method for quantification of the change in rotator cuff muscle stiffness.     

Ultra-low-field magnetic resonance imaging of acute cruciate ligament tears

Ultra-low-field (0.04 T) magnetic resonance imaging (MRI) was evaluated in 15 patients with acute trauma to the knee and clinically suspected injuries of the cruciate ligaments. Subsequent arthroscopy was performed within 14 days (mean: 3 days) in 14 patients and after 3 mo in one patient. At arthroscopy/arthrotomy tears of the anterior cruciate ligament (ACL) were verified in 13 patients (11 complete, 2 partial tears). An additional tear of the posterior cruciate ligament (PCL) was found in one patient. All the tears could be demonstrated by MRI. There was one false positive MR diagnosis of ACL tear. It is possible with low-field MRI to diagnose injuries of the cruciate ligaments with good accuracy.     

MRI description of knee medial collateral ligament abnormalities in the absence of trauma: edema related to osteoarthritis and medial meniscal tears

A retrospective case series regarding the knees of 12 adult patients with MRI abnormalities of the medial collateral ligament (MCL), but without clinical history of trauma to the MCL, were collected and compared with six knee MR images from patients with clinical traumatic injuries to their MCLs. The MR images were studied for the extent of edema of the MCL, as well as other associated findings. Edema of the MCL on MRI could be found in three distinct categories of patients: (a) those with trauma to the MCL, which was an expected finding; (b) those without trauma but with medial compartment osteoarthritis; and (c) those without trauma but with degenerative medial meniscal tears. The clinical significance, if any, of the edema found in MCLs without trauma remains unclear. Atraumatic MCL edema may serve as a marker for medial knee compartment osteoarthritis or for a degenerative medial meniscal tear and should not be confused with traumatically induced MCL injuries, although this distinction can often be difficult to make based on MRI findings alone.     

Intrinsic ligament and triangular fibrocartilage complex (TFCC) tears of the wrist: comparison of isovolumetric 3D-THRIVE sequence MR arthrography and conventional MR image at 3 T

Purpose

The purpose of the study was to validate the diagnostic performance of high-resolution isovolumetric magnetic resonance arthrography (MRA) for intrinsic ligament and triangular fibrocartilage complex (TFCC) tears of the wrist as compared to conventional MR imaging (MRI).

Materials and methods

Forty-eight patients with traumatic TFCC tears at arthroscopy were enrolled. All patients had underwent proton-density- and T2-weighted MRI before arthrography and three-dimensional T1 high-resolution isovolumetric examination (3D-THRIVE) MRA on a 3-T MR. We assessed the presence of scapholunate interosseous ligament (SLIL)/lunotriquetral interosseous ligament (LTIL) or TFCC tears using the arthroscopy as a gold standard.

Results

Arthroscopy revealed 37 TFCC central tears, 15 TFCC peripheral tears, 20 SLIL tears and 13 LTIL tears. Sensitivities of MRI and MRA were 70.3% and 94.6% for detection of TFCC central tears, 60.0% and 93.3% for detection of TFCC peripheral tears, 65.0% and 85.0% for SLIL tears, and 61.5% and 84.6% for LTIL tears. The specificity of the MRI was 100% for the detection of ligaments and TFCC tears. The specificities of the MRA for detection of TFCC central tears, TFCC peripheral tears, SLIL tears and LTIL tears were 100%, 97%, 96.4% and 100%, respectively.

Conclusion

Isovolumetric 3D-THRIVE wrist MRA provided better results for depiction of intrinsic ligament and TFCC tears than wrist MRI.     

Sonographic evaluation of subacromial space

GOAL OF THE STUDY: The purpose of this study is to compare the accuracy of sonographic to radiographic measurements of subacromial space, and verify its variations in relation to acromial morphology, age, sex and rotator cuff pathologies. MATERIALS AND METHODS: As a result, we have compared a radiographic examination to sonographic examination, each measuring the subacromial space in 200 random shoulders, with a personal method. The sonographic examination was performed by using a HDI 5000 ultrasound scanner Sono-CT with 7.5 MHz linear array transducer. No stand-off pad was utilized. RESULTS: The statistical analysis of the data derived from the two measurements was not sufficient to conclude that the two techniques are different (p>0.8). They also correspond with the radiographic morphology of the acromion. The size of subacromial space was related to the acromial morphology, female gender, and rotator cuff pathology, however, it was not related to age. DISCUSSION AND CONCLUSIONS: Our results clearly show that sonographic measurements are very close to those obtained by X-ray (p>0.8). The Bland-Altman analysis showed that for all groups, the were small enough to give us confidence that the sonographic technique may be used in place of the radiographic one for clinical purposes. One-way ANOVA showed that sonographic measurements were statistically different among the four groups (p<0.05). The sonography demonstrated precision, accuracy and carefulness in the measurement of the subacromial space.     

Evaluation of cartilage defect at medial femoral condyle in early osteoarthritis of the knee

OBJECTIVE: The purpose of this study was to evaluate cartilage defect at medial femoral condyle on MRI in early osteoarthritis and to compare with early osteoarthritis with meniscal tear without clear cartilage defect. MATERIALS AND METHODS: Twelve patients with medial pain of the knee and cartilage defect without meniscal tear by MRI were studied for cartilage defect. There were two males and 10 females with cartilage defect, and they were between 42 and 61 years of age (average, 51.6). Fifteen patients with medial pain of the knee and meniscal tear and without clear cartilage defect had been studied as meniscal tear cases. There were five males and 10 females with meniscal tear, and they were between 45 and 61 years of age (average 54.5). In both groups, knee injuries by trauma and Kellgren radiographic grade III and IV osteoarthritis were excluded. We compared cartilage defect cases and meniscal tear cases by gender, age, medial meniscus displacement ratio from the edge of the tibial medial joint surface, femorotibial angle (FTA) and Mikulicz line. We measured medial meniscus displacement ratio by the proportion of medial meniscus lesion protruding from the edge of tibial medial joint surface to all the medial meniscus width on MRI. For the evaluation of Mikulicz line, we measured the score by the length from tibial medial joint surface to Mikulicz line to tibial plateau width. chi(2) Test was used for gender, and Mann-Whitney U test was used for age, medial meniscus displacement ratio, FTA and Mikulicz line. RESULTS: Statistically significant difference was not observed between cartilage defect cases and meniscal tear cases for age and gender. Medial meniscus displacement ratio was 13+/-12.3% in cartilage defect cases and 50.4+/-20.1% in meniscal tear cases. Medial meniscus displacement ratio in cartilage defect cases was significantly smaller than in meniscal tear cases (P=.0001). FTA was 174.9+/-2.2 degrees in cartilage defect cases and 178.3+/-4.8 degrees in meniscal tear cases. FTA in cartilage defect cases was significantly smaller than in meniscal tear cases (P=.00390). The score by the length from tibial medial joint surface to Mikulicz line to tibial plateau width was 35.8+/-11.8% in cartilage defect cases and 21.7+/-15.8% in meniscal tear cases. Mikulicz line in cartilage defect cases passes more laterally than in meniscal tear cases significantly (P=.0264). CONCLUSION: In this study, we reported cartilage defect cases at medial femoral condyle in the early osteoarthritis of the knee. We think that these cases were different from early osteoarthritis with meniscal tear in alignment of lower limb and onset mechanism. It is necessary to evaluate meniscus and cartilage in MRI when we diagnose middle-aged patients with medial pain of the knee and without remarkable changes of X-ray.     

Finite-distance singularities in the tearing of thin sheets

We investigate the interaction between two cracks propagating quasistatically in a thin sheet. Two different experimental geometries allow us to tear sheets by imposing an out-of-plane shear loading. A single tear propagates in a straight line independently of its position in the sheet. In contrast, we find that two tears converge along self-similar paths and annihilate each other. These finite-distance singularities display geometry-dependent similarity exponents, which we retrieve using scaling arguments based on a balance between the stretching and the bending of the sheet close to the tips of the cracks.     

Asymptomatic adult cystic lymphangioma of the spleen: case report and review of the literature

In the present report we describe a case of an asymptomatic splenic cystic lymphangioma in a 43 year-old female. Only a few cases of this benign tumor have been reported in adult patients so far. Clinical examination revealed a tender mass in the upper left quadrant of the abdomen. Abdominal ultrasound and CT-scan revealed a large well-defined splenic cystic mass surrounded by multiple peripheral cysts, all divided by thin septa. MRI confirmed these findings and excluded the possibility of malignant degeneration. Histologic examination permitted the accurate diagnosis to be made. Different imaging findings of this tumor have been described but only a few reports have focused on the value of MRI imaging.     

MRI of uterine leiomyosarcoma

We report a case of a patient with uterine leiomyosarcoma. At MR imaging, the patient was found to have a bilobed uterine mass with two components. While the caudal portion of the mass had the MRI appearance of a simple leiomyoma, the cephalad component showed atypical degeneration with an irregular contour. Malignant degeneration of a leiomyoma was confirmed by operative and histologic examination. We conclude that malignant degeneration should be considered on MR images of any degenerated leiomyoma showing an irregular contour.     

MR knee imaging: axial 3DFT GRASS pulse sequence versus spin-echo imaging for detecting meniscal tears.

The knees of 17 patients (34 menisci) referred for magnetic resonance (MR) imaging to evaluate knee pain were examined using thin axial three-dimensional Fourier transform (3DFT) gradient-refocused acquisition in a steady state (GRASS) images through the menisci, to determine if this method is sensitive and specific for detecting meniscal tears. Results were compared with spin-echo images with long TR and double-echo TE in both coronal and sagittal planes. Arthroscopy results, available in each case, were used as the "gold standard." Twelve meniscal tears were identified at arthroscopy. Axial 3DFT GRASS technique detected 10 of the 12 meniscal tears compared to 9 or 12 using spin-echo technique. With axial 3DFT GRASS technique one false-positive meniscal tear was reported, compared with two false-positive tears on spin-echo images. Axial 3DFT GRASS images were very useful in detecting peripheral tears, showing displaced meniscal fragments, and evaluating complex tears. In this small study, thin axial 3DFT GRASS images were comparable to spin-echo images for detecting meniscal tears, and were helpful in complicated cases in which they provided complementary information to that obtained from spin-echo images.     

Diagnostic performance of low field MRI in acute knee injuries

The diagnostic performance of low field (0.1 T) magnetic resonance imaging (MRI) was studied prospectively and double-blindly among 33 patients with acute knee injuries. The subsequent arthroscopy was the golden standard. For lesions of the medial meniscus low field MR had a sensitivity of 88% and a specificity of 80%; for lesions of the lateral meniscus the sensitivity was 25% and the specificity 97%. For anterior cruciate ligament tears, low field MRI had a sensitivity of 83% and a specificity of 85%. The specificity for posterior cruciate ligament tears was 97%. The performance of low field MRI equalled that reported earlier for high field MRI, the only exception being the sensitivity for lateral meniscus lesions.     

Magnetic resonance imaging: application in musculoskeletal infection

Forty-two patients with clinically suspected osteomyelitis were examined using magnetic resonance imaging (MRI). Twenty-seven patients (64%) had previous surgery or fracture, and 15 (36%) were referred for differentiation of acute osteomyelitis from bone tumors or other pathologic conditions. MRI was compared with computed tomography in 12 cases and with 111In-labeled leukocytes scans in 22. With MRI, 92% of proved infections were detected, and bone and soft-tissue changes were more evident than with routine radiographs, tomography, or computed tomography. In patients with negative cultures and no previous surgery or fracture, it was difficult for MRI to differentiate operative changes from infection. In these patients, 111In-labeled leukocyte images were more specific than MRI.     

Magnetic resonance imaging and computed tomography in Pelizaeus-Merzbacher disease

Six patients with the classical form of Pelizaeus-Merzbacher disease (PMD) were studied with computed tomography (CT) and magnetic resonance imaging (MRI) of the brain. While final diagnosis of PMD should be made on the basis of histopathologic findings in the brain, findings in this group support the fact that MRI can be used for tentative early diagnosis when computer tomographic examination is normal or nondiagnostic. All patients had MRI findings reflecting a pattern of diffuse white matter disease that can be considered characteristic in the appropriate clinical setting.     

A New Diagnostic Approach to Vascular Rings and Pulmonary Slings: The Role of MRI

The conventional diagnostic work-up of a patient suspected of having a vascular cause for stridor, or dysphagia, includes esophagography and bronchoscopy to delineate the abnormal structure without imaging the structure itself. Cine-angiography is regarded as the golden standard, but is not routinely performed. Magnetic resonance imaging (MRI) is non-invasive and has the important advantage over cine-angiography of depicting all structures in the field of view. Color Doppler echocardiography depicts the great vessels, but not the esophagus and trachea. In 14 patients with obstructive symptoms and in four patients without obstructive symptoms MRI successfully imaged the abnormal structure, as was the case in two symptomatic patients using computer tomography. In this series, the findings were confirmed at surgery or by cine-angiography. Conclusion: we suggest that in patients suspected of having a vascular cause for stridor or dysphagia, MRI should be performed. If there is need for a screening procedure, color Doppler echocardiography should be used and if that is equivocal or non-conclusive, esophagography and bronchoscopy should be used. If MRI is difficult to interpret, it should be augmented by magnetic resonance angiography before considering cine-angiography.     

Spin echo MRI in the evaluation of hearts with a double outlet right ventricle: usefulness and limitations

The surgical approach to a double outlet right ventricle (DORV) is dependent on the spatial relationship of the semilunar valves, outflow tracts and ventricular septal defect (VSD). The purpose of the study was to assess the value of MRI for the evaluation of cardiovascular anatomy in patients before and after surgery for DORV. Spin echo MRI was performed in 12 patients with DORV (eight preoperative and four postoperative patients). Thin-section MRI was performed in three orthogonal planes and selected angulated views were obtained. Conventional imaging by color Doppler echocardiography and cine-angiocardiography and surgical findings, when present, served as the reference standards. The results found that the spatial relationship between semilunar valves and VSD was accurately assessed by MRI in eight out of eight preoperative patients. In the four postoperative cases MRI depicted the morphology of both outflow tracts and provided adequate information on their patency. Of the eight preoperative patients, five have undergone corrective surgery and the MRI findings were confirmed. MRI provided additional information to conventional imaging preoperatively in three cases in which the VSD opened into the outlet portion of the DORV, without there being a direct relation to a semilunar valve. In two preoperative cases in which the VSD was directly committed to the aorta, conventional imaging was conclusive. MRI was unable to depict aberrant chordae tendineae in four out of four cases. We conclude that MRI provides accurate additional anatomic information in patients with DORV, which is helpful in presurgical planning as well as during follow-up. Spin echo MRI does not visualize aberrant chordae tendineae.     

Incidental abdominal aortic aneurysm on lumbosacral magneticresonance imaging — a case series

Magnetic resonance imaging (MRI) is commonly used as part of the assessment of patients presenting with leg/back pain to the orthopedic spinal outpatient clinic. Abdominal aortic aneurysm (AAA) can cause symptoms often similar to those of spinal stenosis. We report a case series of four patients who had incidental AAA detected on lumbosacral MRI. All patients were suffering from degenerative spinal disease and had been referred to the orthopedic spinal clinic. After history, examination and review of the imaging, all patients were referred to a vascular surgeon, and three were found to be completely asymptomatic from their aneurysm. One patient required open repair with an aortic graft due to the size of the aneurysm, although his symptoms were attributable to his spinal disease. All patients still required management of their degenerative spinal disease after their vascular review. We can find no other case reports of AAA as an incidental finding on lumbosacral MRI. This case series highlights the importance of looking at all aspects of our imaging and remembering the nonspinal causes of back and leg pains. Furthermore, in the presence of AAA when managing patients in the orthopedic outpatient setting, the authors recommend vascular review before offering orthopedic interventional management options to these patients.