@phdthesis{ElRefaei2013,
  author    = {Ehab Ahmed Mohamed El Refaei},
  title     = {Value of 3-D High Resolution Magnetic Resonance Imaging in Detecting the Offending Vessel in Hemifacial Spasm: Comparison with Intraoperative High Definition Endoscopic Visualization},
  journal    = {Beurteilung der Wertigkeit der 3-D MRT (Steady state free precession imaging SSFP und TOF MRA) zur Erkennung der vaskul{\"a}ren Kompression des Nervus facialis im Vergleich zur intraoperativen endoskopischen Visualisierung bei Patienten mit Hemispasmus},
  url       = {https://nbn-resolving.org/urn:nbn:de:gbv:9-001619-7},
  year      = {2013},
  abstract  = {Background: High resolution three-dimensional (3-D) magnetic resonance imaging (MRI) is widely used to predict the neurovascular anatomy within the cerebellopontine angle. Objective: To assess value of 3-D three-dimensional Steady-state free precession imaging (SSFP) and Time-of-flight magnetic resonance angiography (TOF MRA) and in detecting the offending vessels in hemifacial spasm by comparison to intraoperative endoscopic visualization. Methods: 42 patients underwent endoscope-assisted microvascular decompression (MVD). All available preoperative 3-D SSFP and TOF MRA images were checked. Intraoperative videos were captured by a high definition endoscopic camera attached to endoscopes while exploring the area of facial nerve root exit zone (REZ). Evaluation of the 3-D images was performed by two independent groups of observers and compared with the operative findings. Results: 3-D MRI had an average positive predictive value (PPV) of 89.1\% in differentiating between simple and complex compression. Mean accuracy of the before mentioned images in detection of the offending vessels was 83.3\% and 77\% according to the first and second group of observers respectively. Averaged inter-observer agreement between the two groups of observers was substantial with an averaged Kappa coefficient (K) of 0.56. In simple compression group, mean accuracy was 97\% and 89.4\% according to the first and second group of observers respectively. Averaged K for agreement was substantial (K=0.65). Conclusion: According to endoscopic visualisation, 3-D SSFP and TOF MRA images are accurate in detecting the offending vessels in simple compression of the facial nerve, and in predicting presence of a complex compression with variable sensitivity in identifying all offending vessels.},
  language  = {en}
}