Magnetic resonance imaging of bone marrow and osteochondral injury.

Posttraumatic occult subcortical fractures represent a heterogeneous group of lesions, with different subgroups associated with a high incidence of osteochondral sequelae. The role of MR imaging must be to determine the significance of the different subgroups of occult fractures in the pathogenesis of posttraumatic osteoarthritis. The ultimate goal is to minimize the eventual effects of impactive forces on the osteochondral complex at the time of detection. Modifications in immediate and rehabilitative management of such patients will ensure maintenance of the best possible chondral integrity.

Osteoid osteoma of the neck of the talus: percutaneous, computed tomography-guided technique for complete excision.

CT-guided core drill excision of talar neck osteoid osteomas, in addition to other locations, appears to be a promising alternative to standard surgical treatment. As in this report, the technique is minimally invasive, which allows for complete, accurate excision and early return to activity.

MR imaging of chest wall lesions.

To assess the magnetic resonance (MR) imaging findings of chest wall lesions, images from 45 patients were reviewed by two experienced chest radiologists. The study included 14 benign and 31 malignant lesions. Images were obtained on 1.5-T imagers with use of conventional T1-, proton-density, and T2-weighted sequences in transverse, coronal, and sagittal imaging planes. Where appropriate, motion artifact was minimized with respiratory compensation, spatial presaturation, flow compensation, and cardiac gating. Twelve of 14 benign lesions showed well-defined, smooth margins compared with 10 of 31 malignant lesions (P < .05). The remaining 21 malignant lesions had irregular or ill-defined margins and evidence of muscle, bone, or vascular invasion. A capsule or pedicle was seen only in benign lesions. Characteristic MR signal intensity was seen in all four lipomas and in the only arteriovenous malformation. The remaining benign and malignant lesions showed nonspecific signal intensity characteristics. MR imaging allows the detection of muscle, bone, or vascular invasion by chest wall tumors. However, as in other musculoskeletal regions, MR imaging does not allow confident distinction of benign from malignant chest wall lesions.

Biliary-jejunal drainage for failed biliary-duodenal drainage.

Percutaneous biliary drainage, as palliation for malignant biliary obstruction, is subject to complications, particularly blockage of the drainage tube. Blockage may occur because of duodenal tumour involvement. In nine patients with blockage of the biliary-duodenal drainage tube, conversion to biliary-jejunal drainage allowed continued internal drainage of bile.

Portobiliary fistula: occurrence and treatment.

Portobiliary fistula is a rare complication of percutaneous biliary drainage. The authors report its occurrence in four patients who had multiple percutaneous biliary procedures. One patient was treated by simple tamponade over several days, the other three by temporary balloon tamponade and permanent coil occlusion.

Plasma leukotriene C4 and reactions to contrast media.

Forty-five patients were randomly divided into three groups of 15 and within each group patients were given iothalamate, iopamidol or ioxaglate intravenously during radiological investigations. The plasma leukotriene C4 level was measured before and 30 s and 3 min after the administration of the respective contrast media. In patients demonstrating non-idiosyncratic contrast reactions, a consistent decrease in plasma leukotriene concentration was noted at both 30 s and 3 min following the administration of all three contrast media. A statistically significant decrease in plasma leukotriene occurred at 30 s with ioxaglate, but not with the other two agents. In the limited number of patients who experienced idiosyncratic reactions, the decrease in plasma leukotriene concentration was less apparent. This decrease in plasma leukotriene concentration has been attributed to changes in plasma volume following administration of hyperosmolar contrast media. The inability to demonstrate an increase in plasma leukotriene levels following the administration of both conventional and new, low-osmolar radiographic contrast media supports the cumulative evidence against an allergic mechanism in the majority of non-idiosyncratic and some idiosyncratic contrast reactions.

Fine needle aspiration cytology of mucinous cystadenocarcinoma of the pancreas. Further observations.

Mucinous cystadenocarcinoma of the pancreas is among the few potentially curable malignancies of this organ; recognition of the differences between this and other pancreatic tumors is thus of paramount importance. A second example of mucinous cystadenocarcinoma of the pancreas diagnosed by fine needle aspiration, performed under ultrasonographic guidance, is presented, emphasizing both the radiographic distinction from other cystic lesions plus cytologic features not previously stressed. In essence, the cytodiagnosis relies less on cell morphology, which is characteristically bland and relatively monomorphic, than on the presence of extracellular mucin, which must be distinguished from amorphous background material and necrotic debris. The possibility of diagnosing benign mucinous and serous cystadenomas by imaging and cytology is addressed.

The clinical value of scintigraphic brain scanning. Experience at the Hillbrow Hospital, Johannesburg, South Africa.

Patients were referred to the Department of Nuclear Medicine for brain scintigraphy to be screened for possible intracranial pathology. These referrals were made in order to reduce the heavy load on the transmission computerized tomography (TCT) facilities. Great clinical importance, therefore, has been attached to scintigraphic findings; this emphasizes the need for an accurate assessment of the predictive value of this procedure.

Adult tethered cord syndrome. A case report.

A patient with adult onset of the tethered cord syndrome is described. The significance of the clinical presentation and the myelographic and computed tomographic findings are discussed.