The efficiency of PC-MRI in diagnosis of normal pressure hydrocephalus and prediction of shunt response

Abstract

Rationale and Objectives: In this prospective study, we aimed to reveal the efficiency of phase-contrast magnetic resonance imaging (PC-MRI) in the diagnosis of idiopathic normal pressure hydrocephalus (INPH) and prediction of shunt response.

Materials and Methods: The study group consisted of 43 patients with INPH diagnosis and 15 asymptomatic age-matched controls. PC-MRI studies were applied on cerebral aqueduct and superior sagittal sinus (SSS) in all the cases.

Results: The maximum and mean cerebrospinal fluid (CSF) flow velocities were significantly higher in the INPH patients compared with the controls (P < .05). CSF stroke volume (43.2 +/- 63.8 mu L) and output/min (3921 +/- 5668 mu L) were remarkably higher in the NPH group compared with the control group (3.9 +/- 3.9 mu L, 439 +/- 487 mu L, respectively) (P < .05). Maximum and mean venous velocity values of the INPH patients (maximum, 19.2 +/- 4.3 cm/s; mean, 16 +/- 3.7 cm/s), were lower than those of the control group (maximum, 21.8 +/- 4.6 cm/s; mean, 18.9 +/- 3.9 cm/s) (P < .05). Stroke volume and venous output/min values of INPH patients in SSS, were significantly lower than those of the control group (P <.001, P = .007, respectively). The response of INPH patients against shunt treatment showed no statistical correlation with any of the PC-M RI parameters (P > .05).

Conclusion: The measurement of CSF venous flow velocities with PC-MRI is a noninvasive test that benefits INPH diagnosis, but remains inadequate in prediction of response against shunt treatment.