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

Table 16 The use of miscellaneous radiological markers 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
McGirt et al. [34]	n = 132	•Corpus callosum distention	•N/A	•CT/MRI	•N/A	•30 (28%) of patients had distention of the corpus callosum. Univariate analysis showed a significant likelihood of shunt response in those with distention, RR:1.64 (95% CI: 1.05–2.58). However, this was no shown in multivariate analysis: RR: 1.38 (95% CI: 0.85–2.20)
Agerskov et al. [2]	n = 168	•Widening of anterior part of Interhemispheric fissure. Graded for 0–2	•N/A	•MRI 1.5 T. trans-axial T1-weighted images	•Axial slice	•There was no difference, in each grade, between SR and SNR. There was also no significant correlation between grade and composite score. (-0.20, -0.04, -0.04 for total, gait, and cognition respectively.)

Studies included assessing the use of any miscellaneous radiological markers on MRI or CT as predictors of shunt responsiveness. MRI studies are above the double solid lines, CT studies are below. SR, shunt response; S-NR, shunt non-response; RR, risk ratio; CI, confidence interval