Idrocefalo normoteso: Valutazione comparativa tra studi di dinamica liquorale mediante TC e RM

Aim of this study was to evaluate the sensitivity of MR dynamic Bolus Tracking technique versus CT-cysterno graphy in Normal Pressure Hydrocephalus (NPH). Seven patients (age 64–76 yrs), clinically suspected of NPH, were retrospectively evaluated. They had been submitted to CT-cysternography, MR dynamic Bolus Tracking technique in the acqueduct (cardiac-gated flow direction evaluation by means of 12–16 FFE T2*-w acquisitions per cardiac cycle, on sagittal plane along the acqueduct, with presaturation perpendicular to the acqueduct) and finally to surgical evaluation and subsequent ventriculo-peritoneal shunt. MR showed in all cases altered cerebrospinal fluid (CSF) dynamics: 5 patients showed CSF reflux in the third ventricle during all cardiac cycle, in 2 patients an increased ejection rate through the acqueduct and into the cisterna magna was found. CT-cysternography showed CSF dynamics alterations only in 4 cases. MR dynamic Bolus Tracking technique has proven to be more sensitive than CT-cysternography in the evaluation of NPH. Even though this study has to be considered preliminary, we believe that this simple and noninvasive technique should be recommended when NPH is suspected.