Monday, June 6, 2011

Malignant external otitis - Diagnosis

Diagnosis of malignant external otitis is given by clinical examination and confirmation of the laboratory and imaging tests.
Laboratory studies:
Mandatory laboratory tests include:Erythrocyte-sedimentation rate, is high in this specific disease and is a good indicator of treatment rasunsului-CBC, glucose and creatinine-Cultivation of ear secretions, before systemic and topical antibiotic treatmentPathologie-examination of granulation tissue taken from the ear canal is essential to exclude malignant processes is presented as nonresponsive inflammatory disease.
Imaging Studies:
Imaging is necessary to prove the extension of infection to bone and to establish the diagnosis of malignant otitis externa. Imaging modalities including CT scan, bone scan and scintigraphy with Tc 99 Ga67.
Bone CT scan is used to locate and expand detrmina tissue.Temporal bone is affected first with compromised bone imminent Peter and mastoid apex. Extension extratemporala bone is rare since the introduction of powerful antibiotics. It is important to know that at least one third of bone mineral must be lost before radiographic changes are evident, and the remineralization of bone healing continues long after infection. This pathology appears later in CT and later disappears. These factors limit the usefulness of the scan.
Bone scan with Tc99: osteoclasts and osteblastele absorb technetium. Such a bone scan can locate Pathologie process in bone but not give information on the nature of the process: infectious or otherwise. Since Tc99 scan remains positive as long as it takes way to restore bone imaging is useful in monitoring patients.
Scintigraphy with gallium 67 as gallium is absorbed by macrophages and cells of the reticuloendothelial system with this radioisotope scanning is sensitive to the infectious process. If available with Ga67 scintigraphy should be used as a method for initial diagnosis and surveillance.

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