The ultrasonographic diagnosis of bacterial ventriculitis in infancy: a technical note.

High resolution real-time ultrasound equipment used for clinical cerebral ultrasonography in neonates and infants can provide a measure of blood cell counts in varying dilutions. In the study described, the threshold of visualization of leukocytes was in the range of 500 cells/mm3 and for erythrocytes 10,000 cells/mm3. The size, configuration, and nucleus of the leukocyte, compared with the erythrocyte, may explain this difference. Bacteria alone were not visualized up to a count of 5 X 10(8) per mm3. Specimens of fluid-containing cells or bacteria show changes visible to the naked eye which can be confirmed ultrasonographically. However, the threshold for visualization is lower with the naked eye than with the ultrasonograph .