Evaluation of magnetic resonance imaging features of spontaneous third ventriculostomy in triventricular hydrocephalus

BackgroundSpontaneous third ventriculostomy (STV) is considered rare in obstructive hydrocephalus cases.PurposeTo investigate the efficacy of phase-contrast magnetic resonance imaging (PC-MRI) and three-dimensional constructive interference in steady-state (3D-CISS) for the diagnosis of STV and the potential changes of various radiological parameters measured in hydrocephalus in cases with STV.Material and MethodsPatients with triventricular hydrocephalus who underwent at least one MRI examination, including PC-MRI and 3D-CISS, between 2010 and 2021 were included. The presence of STV was scored separately on PC-MRI and 3D-CISS as follows: 0 = no evidence of STV; 1 = suspicious findings; and 2 = strong evidence of STV. The total STV score was also created by summing the scores determined on both sequences. Evans' index, third ventricle diameter (TVD), third ventricle height and floor bowing, and height of the interpeduncular cistern were compared between cases with and without STV.ResultsSTV diagnosis was confirmed in 10/187 (5.3%) cases. The first observer detected suspicious findings in four and two patients without a confirmed diagnosis on PC-MRI and 3D-CISS, respectively, while the second detected suspicious findings in three and two patients, respectively. There was a strong correlation between PC-MRI, 3D-CISS, total scoring results, and consensus results (<i>P</i> < 0.001). No significant difference was found in measurements except TVD between the two groups.ConclusionSTV may not be a very rare phenomenon and the combined use of PC-MRI and 3D-CISS for diagnosis may aid in overcoming diagnostic challenges. No significant change can be observed in ventriculomegaly-related parameters in patients with STV.