Radiological and radionuclide investigation of malignant otitis externa.

This study looks at case series of malignant otitis externa, outlines detailed structural (radiological) and functional (radionuclide) investigations, and discusses their utility in the initial diagnosis, patient management and follow up of this condition. Patients were investigated by computerized tomography (CT), magnetic resonance imaging (MRI), two-phase planar and single-photon emission tomography (SPECT), technetium-99m methylenediphosphonate bone scans, gallium-67 planar and SPECT scans, and indium-111 or technetium-99m labelled WBC planar and SPECT scintigraphy. We discuss example case reports with the various radiological and scintigraphic findings and outline a protocol for rational investigation. It is concluded that CT and/or MRI should be supported by routine SPECT bone imaging for initial diagnosis of malignant otitis externa. Routine SPECT bone imaging further supplemented by gallium scintigraphy should be the investigation of choice in the follow up of these cases for assessing response to treatment and disease recurrence.