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Biomedical subjects

R M Freedy

Publications and source records attributed to R M Freedy.

7 recordsLinked to original sources

MR myelography: imaging findings.

MR myelography, heavily T2-weighted fast spin-echo imaging with fat suppression, enhances the signal intensity of CSF with subtraction of the surrounding background signal. Krudy [1], who first described the technique, used multiple projections per examination. We illustrate the findings in 80 patients who were examined with a modified MR imaging technique that provides increased spatial resolution and uses a single coronal sequence after the conventional MR study. This report illustrates the usefulness of MR myelography in cases of spinal stenosis or spinal block, in both the lumbar and thoracic regions.

Adolescent↗

Metastatic pigmented neuroectodermal tumor with cranial CT-pathology correlation.

Pigmented neuroectodermal tumors are a relatively rare clinicopathologic entity, presenting in a variety of locations. Their histogenesis suggests a transformation from common pleuripotential neural crest cells with varying degrees of differentiation to neural elements and melanocytes. We present a case of just such a tumor, which presented initially in the mandible of a leukemic patient who received irradiation to the skull base, as well as systemic chemotherapy, for suspected cranial leukemic involvement. Subsequent development of intracranial spread was documented both by imaging and pathology. Extracranial spread was also found at autopsy. This unusual presentation and widespread dissemination of the neuroectodermal tumor in our case confirms its aggressiveness and potential for multifocality.

Acute Disease↗

Infections of the musculoskeletal system: high-field-strength MR imaging.

Twenty-two patients with clinical findings consistent with osteomyelitis, soft-tissue infection, or both were studied with magnetic resonance (MR) imaging at 1.5 T. Another 15 patients with joint effusion but no clinical or laboratory signs of infection served as controls. Soft-tissue abscesses, osteomyelitis, joint and tendon sheath effusion, and cellulitis were well depicted on MR imaging, allowing the correct diagnosis of presence and extent of infection in all but two cases. MR imaging was as sensitive as technetium-99m methylene diphosphonate bone scintigraphy in demonstrating osteomyelitis and was more specific and more sensitive than other scintigraphic techniques in demonstrating soft-tissue infections, primarily because of its superior spatial resolution. Computed tomography, performed in seven cases, was as accurate as MR imaging in demonstrating bone and soft-tissue infections. Infected and noninfected synovial effusions had the same signal intensity, but associated findings such as soft-tissue fluid collections or osteomyelitis made the distinction possible.

Abscess↗

Traumatic lumbosacral nerve root avulsion: evaluation by MR imaging.

Magnetic resonance (MR) imaging of traumatic lumbosacral nerve root avulsion and pseudomeningocele formation at multiple nerve root levels is presented. We report a case of this rare clinicopathologic entity identified by MR imaging in conjunction with more traditional lumbar myelography.

Adult↗