Magnetic resonance cisternography for trigeminal neuralgia: comparison between gradient-echo and spin-echo 3D sequences.

Objective: To quantitatively and qualitatively compare directly two types of cisternography images for diagnosing trigeminal neuralgia (TN) using 3-T magnetic resonance imaging.

Methods: This prospective study recruited 64 patients with a clinical diagnosis or suspicion of TN. Patients were examined through the three-dimensional (3D) Constructive Interference in Steady State (CISS) and Sampling Perfection with Application-optimized Contrasts using different flip angle Evolutions (SPACE) sequences. Three radiologists quantitatively measured the signal intensity of the trigeminal nerve (cranial nerve V, CN5) (SICN5), cerebrospinal fluid (CSF) (SICSF), and contrast between CN5 and CSF (Cont.). Additionally, two radiologists qualitatively evaluated the basilar artery (BA), CN5, CSF, image artefacts, and overall image quality. Statistical analyses included paired-sample t-tests, non-parametric McNemar tests, and the Friedman test (significance set at p < 0.05).

Results: Mean SICN5 (p < 0.001), SICSF (p = 0.679), and Cont. (p < 0.001) were as follows: 203.08 ± 26.68, 936.03 ± 91, and 3.68 ± 0.74 in CISS; 46.80 ± 16.88, 940.61 ± 71.39, and 23.19 ± 14.52 in SPACE. Low-to-moderate CN5 and BA visibility was observed in all cases in CISS, while it was noted in one case for CN5 and in none for BA in SPACE (p < 0.001). Homogenous CSF and minor artefacts were observed in 14 cases in CISS, while it was seen in 52 cases for CN5 and 59 for BA in SPACE (p < 0.001). The overall image quality was scored as four in 57 cases in SPACE, while no cases received this score in CISS (p < 0.001).

Conclusions: SPACE provided better images than CISS for evaluating CN5 and prepontine cistern vascularity, indicating a valuable sequence for TN diagnosis.

Advances in knowledge: This study indicates that SPACE should be selected for TN diagnosis instead of CISS sequence.