Radiological predictors of shunt response in the diagnosis and treatment of idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis

Table 12 The use of CSF flow dynamics on MRI and CT for prediction of shunt response in iNPH

Study	Sample size	Radiological methodology	Cutoff specification	Image specification	Image plane	Main reported outcomes
Stecco et al., 2020 [52]	n = 38	•Aqueductal stroke volume (ACSV)	•N/A	•FFE 3D T2 weighted sequence on phase contrast cine MRI	•Sagittal plane	•Mean ACSV value in SR was 271.85 (± 143.032) while in SNR was 79.83 (± 31.24), p < 0.01
Poca et al., 2002 [45]	n = 35	•CSF flow velocity	•Hyperdynamic: aqueductal CSF peak velocities are > 97.5 percentile of control group of heathy volunteers	•Phase-Contrast Velocity MRI with Retrospective Cardiac Gating	•Sagittal plane through the aqueduct	•29 (83%) NPH patients were considered hyperdynamic. Hyperdynamic CSF velocity had a sensitivity 90%, specificity 50%, PPV 95.6& and NPV 25%. TP28, TN1, FN3, FP1

Studies included assessing the use of any MRI or CT CSF flow dynamics analyses as predictor of shunt responsiveness. MRI studies are above the double solid lines, CT studies are below. SR, shunt response; S-NR, shunt non-response; ACSV, aqueductal stroke volume; NPV, negative predictive value; PPV, positive predictive value; TP, true positives; FP, false positives; TG, true negatives; FN, false negatives