Enhancement patterns of the normal facial nerve on three-dimensional T1W fast spin echo MRI

Objectives: With increasing neuroimaging applications of contemporary three-dimensional T1W fast spin echo (3D T1W FSE) sequences, it was aimed to reappraise the normal patterns of skull base facial nerve gadolinium enhancement. Methods: Pre- and post-gadolinium 3D T1W fast spin echo imaging studies (n = 64) were retrospectively analysed in patients without suspected facial nerve pathology. Two independent observers scored the signal at each of six skull base facial nerve segments. Wilcoxon signed-rank test was used to compare changes in signal between pre- and post-gadolinium sequences at each location, and how this differed between proprietary sequences or between the pairs of facial nerves. Results: There was significant enhancement at the fundal canalicular (16%), geniculate ganglion (96%), tympanic (45%) and mastoid (38%) facial nerve segments (p < 0.05). Two different proprietary sequences demonstrated similar patterns of enhancement and there was symmetry between the two sides. Conclusions: There is a differing pattern of normal facial nerve enhancement on contemporary 3D T1W FSE sequences compared to previous studies of 2D T1W SE imaging and fundal canalicular enhancement may be physiological. Advances in knowledge: This is the first study to evaluate patterns of normal facial nerve enhancement using contemporary 3D T1W FSE MRI sequences.

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Comparison of Single-Echo T2-weighted Fast Spin-Echo and Conventional Spin-Echo MR Sequences

Rivista di Neuroradiologia ◽

10.1177/197140099801100406 ◽

1998 ◽

Vol 11 (4) ◽

pp. 471-476

Author(s):

G. Sparacia ◽

T. Angileri ◽

A. Banco ◽

R. Miraglia ◽

N. Nicastro ◽

...

Keyword(s):

Spin Echo ◽

Fast Spin Echo ◽

Rank Test ◽

Significant Difference ◽

Signed Rank Test ◽

The Difference ◽

Student’S T ◽

Periventricular Lesions ◽

Conventional Spin Echo ◽

Fast Spin

We compared single-echo T2-weighted fast spin-echo (FSE) magnetic resonance imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 16 patients with clinically definite MS underwent brain imaging at 0.5 T with T2-weighted single-echo fast spin-echo (FSE) and conventional spin-echo (CSE) sequences. Image analysis was performed by three of the investigators who worked together to reduce interobserver variability. Statistical analysis was performed using Student's t test to assess the difference in the contrast-to-noise (C/N) ratio of MS lesions between CSE and FSE sequences. The Wilcoxon signed rank test was used to evaluate the difference in the number of lesions between the two sequences. There was no significant difference in the overall total number of lesions detected on FSE vs CSE (964 vs 1009, P >.05). However significantly (P = .02) more posterior fossa lesions were detected using FSE than CSE, whereas significantly (P = .002) more periventricular lesions were detected using CSE than FSE. The difference in the number of lesions in the other sites was not significant (P > .05). There was no significant difference in the overall total C/N ratio of MS lesions between FSE and CSE sequences (11.7 ± 3.9 vs 12.6 ± 4). Considerable time savings can be made when substituting FSE for CSE sequences in T2-weighted imaging, and this is a compelling reason to employ such sequences in clinical practice. Our results suggest that for single-echo T2-weighted imaging, FSE can replace CSE in long term monitoring especially when patient movement prevents a useful investigation and when optional scanning planes are required.

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