Journal of Ultrasound in Medicine, Vol 16, Issue 11 725-730, Copyright © 1997 by American Institute of Ultrasound in Medicine
Human dural thickness measured by ultrasonographic method: reflection of intracranial pressure
H. Kuchiwaki, S. Inao, N. Ishii, Y. Ogura and S. P. Gu
Department of Neurosurgery, Nagoya University School of Medicine, Japan.
We measured changes in dural thickness to estimate intracranial pressure.
The dural thickness on magnetic resonance imaging with contrast enhancement
was compared in a hydrocephalic patient before and after shunt operation.
Dural thickness also was measured directly using a micrometer at craniotomy
for aneurysmal clipping in 11 patients. A small ultrasound probe (5 MHz)
was held against the temporal scalp of 10 volunteers to extract convoluted
interference echoes from the dura mater using a computer--based system for
fast Fourier transform-Cepstrum analysis and maximum entropy analysis. The
degree of intracranial pressure in the supine position was varied in the
volunteers with transient neck compression. The enhanced dural thickness of
the patient with hydrocephalus, barely visualized before shunt operation,
increased after surgery. Dural thickness measurements obtained
ultrasonographically in the supine position were similar to direct
measurements of thickness. Changes in dural thickness on ultrasonography
reflect changes in intracranial pressure.
