Current status of magnetic resonance imaging of the wrist

Conventional imaging of the wrist has relied heavily on plain radiography, tomography, fluoroscopy and arthrography. More recently, computed tomography and magnetic resonance imaging (MRI) have been added to this armamentarium. In this article the authors review the normal anatomy of the wrist and demonstrate a variety of pathologic conditions that can be assessed with MRI, including avascular necrosis and tears of the intrinsic and the extrinsic ligaments and the triangular fibrocartilage. MRI of the wrist is still evolving rapidly, and its place in the work-up of wrist disorders is only now being defined.

Current status of magnetic resonance imaging of the ankle and the hindfoot

With the increasing use of magnetic resonance imaging (MRI) for examining the musculoskeletal system, numerous applications have been found in the evaluation of ankle and hindfoot problems. For example, MRI is ideal for assessing tendon disorders, which are common in this region. In addition, the technique allows accurate staging of osteochondral fractures, as well as both soft-tissue and bony neoplasms. Tarsal coalition can be readily evaluated and the type determined. Increasingly, arthritis and synovial abnormalities are coming under scrutiny with MRI; this is currently an area of avid interest. In this article the authors review the current status of MRI of the ankle and the hindfoot and illustrate a variety of these disorders.

Real-time sonography in ocular trauma

Real-time sonography was evaluated retrospectively in 71 consecutive patients with ocular trauma. A total of 51 vitreous hemorrhages, 20 hemorrhages in the anterior chamber, 22 retinal detachments, seven choroidal detachments, five foreign bodies, and 12 dislocated lenses were identified sonographically. In 10 instances (three choroidal detachments, six retinal detachments, and one lens dislocation), these sonographic findings were not apparent on clinical examination. One hemorrhage of the anterior chamber was missed on sonography. Both sonography and clinical examination failed to visualize one retinal detachment. The results of this study show that real-time sonography is valuable in the assessment of ocular trauma and supplements clinical examination with valuable information.

Computed tomography of the knee

Although magnetic resonance imaging (MRI) has become the imaging technique of choice in Canada and elsewhere in the evaluation of knee disorders, magnetic resonance units are frequently unavailable, or access to them is greatly restricted. The authors have found that computed tomography (CT) can sometimes be successfully substituted for MRI as a noninvasive method for imaging a wide variety of knee disorders. This article reviews the CT appearance of normal knee anatomy and illustrates a wide variety of pathological conditions that can be successfully evaluated.

Sonography of the eye

Real-time sonography of the eye is a technique that is rapidly performed and readily available in most sonography departments. It is less expensive than CT and MR imaging and, if necessary, may be performed at the patient's bedside. This essay demonstrates a few of the large number of clinical entities that may be successfully examined with this technique.

Imaging techniques of the shoulder: present perspectives

Through its ability to evaluate the individual components of the rotator cuff, the labral-capsular complex, the subacromial and subdeltoid spaces, and the glenoid, humerus, clavicle, and acromion, MRI provides a means of comprehensively evaluating the shoulder. Further advances in the use of intra-articular MRI contrast agents will undoubtedly enhance the role of MRI in the evaluation of subtle labralcapsular pathology. Although they are experimental, kinematic studies of the shoulder may provide valuable insight into the pathogenesis of disorders such as impingement syndrome. The ability of MRI to provide detailed pathologic information about individual components of the shoulder, particularly the rotator cuff, presents a challenge to shoulder surgeons. Patient symptomatology should be correlated with MRI findings and the clinical significance attached to different pathologies reevaluated. Through rigorous confirmation of MRI findings, dedicated therapeutic algorithms can be established based on detailed clinicopathologic data. Present and future surgical and nonsurgical management of the shoulder will undoubtedly be shaped by MRI.

Characterization of pancreatic adenocarcinoma by magnetic resonance imaging

In the past, magnetic resonance imaging (MRI) of the pancreas has suffered from many technical obstacles that have precluded success, particularly in the evaluation of adenocarcinoma. However, with the improved quality of pancreatic MRI and the use of intravenous gadolinium as a contrast agent, MRI is now proving useful in the evaluation of pancreatic adenocarcinoma. MRI's main role is in accurate preoperative staging when computed tomography and ultrasonography provide equivocal results.

Characterization of intrahepatic space-occupying lesions by magnetic resonance imaging

Hepatic neoplasia can be accurately characterized with magnetic resonance imaging of architectural, signal and dynamic gradient-echo contrast-enhancing features. Architectural characteristics valuable in determining the nature of hepatic neoplasia include the outer and inner contours of the lesion; the presence of fibrous encapsulation; the presence, signal and enhancing characteristics of a central scar; the presence and distribution of hemorrhage or necrosis; the relation of the lesion to regional vasculature and bile ducts; and lesion multiplicity. The signal characteristics in spin-echo and gradient-echo pulse sequences of the adjacent hepatic parenchyma and the lesion itself provide further information. In certain instances hepatic neoplasia can be definitively characterized on dynamic gradient-echo pulse sequences obtained after administration of the contrast agent gadolinium.

Occult posttraumatic osteochondral lesions of the knee: prevalence, classification, and short-term sequelae evaluated with MR imaging

The prevalence, characterization, and classification of acute, post-traumatic, occult subcortical fractures of the knee, identified at magnetic resonance (MR) imaging, were evaluated prospectively in 120 consecutive patients first seen with acute posttraumatic hemarthrosis of the knee. Occult subcortical femoral and tibial fractures were identified in 72% of patients. A modified MR imaging classification is suggested based on a combination of the appearances of such lesions at MR imaging and their short-term osteochondral sequelae. Among 67% of a cohort of 21 patients first seen with what have been described as occult geographic subcortical fractures, osteochondral sequelae were seen at follow-up MR imaging 6-12 months later. The evidence from this study indicates that specific subcategories of occult subcortical knee fractures are associated with an inordinately high prevalence of osteochondral sequelae, especially significant cartilage damage.

Accuracy of nonorthogonal magnetic resonance imaging in acute disruption of the anterior cruciate ligament

A controlled, prospective study of 30 patients with suspected acute internal derangement of the knee was undertaken to evaluate the sensitivity, specificity, predictive value, and accuracy of nonorthogonal (oblique) sagittal magnetic resonance imaging (MRI) in the assessment of anterior cruciate ligament (ACL) injuries. Thirty patients with acute hemarthroses underwent MRI within 12 days of injury, followed by arthroscopy within 24 h of the MRI. A control population of 30 chondromalacia patients underwent similar evaluation. In the acute hemarthrosis patient population, the incidence at arthroscopy of acute complete ACL tears was 60% (18/30); of partial ACL tears, 13.3% (4/30); and of chronic tears, 10% (3/30). A normal ACL was found in 16.6% (5/30) of patients. In the MRI evaluation of patients with suspected ACL injury the following results were obtained for both acute and chronic complete disruption on orthogonal (sagittal) and nonorthogonal (oblique sagittal) imaging, respectively: sensitivity, 61 (16/26) versus 100%; specificity, 70 (21/34) versus 100%; positive predictive value, 61 (16/26) versus 100%; negative predictive value 70 (24/34) versus 100%; and accuracy, 66 (40/60) versus 100%. In the evaluation of partial ACL injury, four partial tears were correctly diagnosed on nonorthogonal MRI, with one false-positive diagnosis. Orthogonal imaging failed to correctly identify any of the partial ACL injuries. Two patients in the control population demonstrated evidence of chronic ACL tears. We believe that we have demonstrated the superiority of T2-weighted nonorthogonal sagittal over conventional orthogonal sagittal ACL MRI in the evaluation of ACL injury.

Exophytic renal angiomyolipoma. A case report

A case of a large exophytic renal angiomyolipoma is presented. Despite the features on excretory urography suggestive of an extrarenal mass, computed tomography provided information concerning the origin and pathological nature of the lesion.

Eye metastases in carcinoma of the cervix. A case report

Eye metastases in carcinoma of the cervix are very rare, although not an uncommon presentation of carcinomas in general. A patient with eye symptoms secondary to retro-ocular metastatic carcinoma of the cervix is presented.