Marc Muehlmann, Presenter: Nothing to Disclose

Inga Koerte MD, Abstract Co-Author: Nothing to Disclose

Denise Steffinger RT, Abstract Co-Author: Nothing to Disclose

Maximilian F. Reiser MD, Abstract Co-Author: Nothing to Disclose

Noam Alperin PhD, Abstract Co-Author: Stockholder, Alperin Noninvasive Diagnostics, Inc

Birgit Betina Ertl-Wagner MD, Abstract Co-Author: Scientific Advisory Board, Koninklijke Philips Electronics NV Consultant, Bracco Group Travel support, Siemens AG

Markus Lehner, Abstract Co-Author: Nothing to Disclose

Aurelia Peraud MD, Abstract Co-Author: Nothing to Disclose

1) To investigate the correlation between the pressure setting of the ventriculo-peritoneal shunt (VP-shunt) valve and an MR-based estimate of the intracranial pressure (MRICP) in patients with hydrocephalus. 2) To analyze the effect of the ventricle volume on the MRICP.

Sixteen consecutive patients (median age 9.5 years; range 2.2 to 29.0 years; 7 female) with shunt-treated hydrocephalus were examined on a 3T MR scanner with cardiac-gated cine-phase contrast sequences of the craniocervical region and 3D MP-RAGE sequences covering the whole brain. MRICP was derived from intracranial volume change (ICVC) and pulse pressure gradient and then compared to the setting of the shunt-valve. Pearson’s correlation coefficient was used to test for association of setting of the shunt valve and MRICP and to analyze the association between the size of the lateral ventricles, the 3rd and 4th ventricle and MRICP. Differences between the two measures were calculated using the Wilcoxon-test.

Median MRICP was 8.7 mmHg (IQR 1.6 mmHg) and median setting of the VP-shunt valve was 6.6 mmHg (IQR 1.5 mmHg). MRICP and shunt valve pressure settings were positively correlated (rho = 0.76, p < 0.01). The median MRICP was 1.7 mmHg (IQR 1.3 mmHg) higher than the setting of the shunt valve (p<0.01). The median ventricular volumes were 8.5 ml (IQR 10.85 ml) for the right lateral ventricle, 10.1 ml (IQR 7.8 ml) for the left lateral ventricle, 1.3 ml (IQR 0.79 ml) for the 3rd ventricle and 1.0 ml (IQR 1.25 ml) for the 4th ventricle. No significant relationship was found between MRICP and ventricular volumes.

1) The MRICP reflects the VP-valve setting and appears to be a feasible method for follow-up examinations of patients with hydrocephalus and VP-shunt. The systematic difference between MRICP and valve pressure settings may be due to additive factors e.g., intraperitoneal pressure. 2) Volumes of the lateral, 3rd or 4th ventricle did not predict MRICP in this study cohort.

"MRICP can serve as non-invasive tool in the clinical routine setting in patients with shunt treated hydrocephalus and thereby may reduce the need for invasive explorations."

Muehlmann, M, Koerte, I, Steffinger, D, Reiser, M, Alperin, N, Ertl-Wagner, B, Lehner, M, Peraud, A, MR-based Intracranial Pressure Quantitation is Related to VP-Shunt Valve Setting in Patients with Hydrocephalus.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043577.html