Virtual Endoscopic Images by 3D FASE Cisternography for Neurovascular Compression

Abstract

Three-dimensional fast asymmetric spin echo (3D FASE) cisternography provides high spatial resolution and excellent contrast as a water image acquisition technique. It is also useful for the evaluation of various anatomical regions. This study investigated the usefulness and limitations of virtual endoscopic images obtained by 3D FASE MR cisternography in the preoperative evaluation of patients with neurovascular compression. The study included 12 patients with neurovascular compression: 10 with hemifacial spasm and two with trigeminal neuralgia. The diagnosis was surgically conˆrmed in all patients. The virtual endoscopic images obtained were judged to be of acceptable quality for interpretation in all cases. The areas of compression identiˆed in preoperative diagnosis with virtual endoscopic images showed good agreement with those observed from surgery, except in one case in which the common trunk of the anterior inferior cerebellar artery and posterior inferior cerebellar artery (AICA-PICA) bifurcated near the root exit zone of the facial nerve. The veins are displayed in some cases but not in others. The main advantage of generating virtual endoscopic images is that such images can be used for surgical simulation, allowing the neurosurgeon to perform surgical procedures with greater conˆdence.

Pathology of the Trigeminal Nerve

“…Using high-resolution MR angiography and 3D gradient echo SSFP sequences, the areas of compression and the conflicting vessels can be identified preoperatively. 6,8 Recently, it has been shown that neurovascular conflicts can be identified at MR imaging in 88% of the typical TN cases and in 56% of the atypical TN cases. Although arterial compression is much more common than venous compression (90% of cases with typical TN and 52% of cases with atypical TN), pure venous compression is seen more often in patients who have atypical TN (24%) than in patients who have typical TN (1%).…”

“…Multiplanar reconstructions and 3D and virtual endoscopic views generated from these 3D data sets are extremely useful in assessing neurovascular conflicts in conjunction with 3D time of flight (TOF) MR angiography and contrast-enhanced MR angiography. [4][5][6][7][8] Recently, diffusion tensor imaging has been used to assess the tissue integrity of the trigeminal nerve, with diffusion tensor imaging-derived fractional anisotropy (FA) being calculated for the cisternal portion of the trigeminal nerve. 9 Meckel's cave, cavernous sinus, skull base, and extracranial portions of the trigeminal nerve are imaged using high-resolution 2 to 3-mm thin spin echo (SE) or fast spin echo T1-w images in the axial and coronal plane pre-and postcontrast, and 3D T1-w sequences with 1-mm thin slices, such as 3D spoiled gradient echo, Magnetized Prepared Rapid Gradient Echo (Ultrafast Gradient Echo 3D sequence with magnetization transfer), or 3D Volume Interpolation Breath hold Enhancement, which allow multiplanar reconstructions in any chosen plane.…”

MR Virtual Endoscopy for Biliary Tract and Pancreatic Duct

“…MRVE is a useful method to visualize the anatomy of the lumina of the gallbladder, bile duct, and pancreatic duct and can also be applied to other clinical procedures, such as visualization of vascular compression of the cranial nerve and navigation for laparoscopic surgery. 10,11 However, the threshold setting on the workstation is critical to obtain useful MRVE images. Because the appearance of the lumen on the MRVE images depends on the threshold setting, optimized threshold is essential.…”

Классическая Невралгия Тройничного Нерва

“…Однако количество рецидивов заболевания, по данным многих авторов, остается относительно высоким и колеблется от 4,5 до 31% [242,282,434]. Одной из причин рецидивов болей является исполь-зование неадекватных протекторов: жировая или мышечная ткань, тефлоновый фетр, полиуретановая губка, дакрон и пр.…”