Three-dimensional Fast Imaging Employing Steady-state Acquisition Magnetic Resonance Imaging for Stereotactic Radiosurgery of Trigeminal Neuralgia

Neurosurgery ◽  
2005 ◽  
Vol 56 (3) ◽  
pp. E628-E628 ◽  
Author(s):  
Gabriela-del-Rocío Chávez Chávez ◽  
Antonio A.F. De Salles ◽  
Timothy D. Solberg ◽  
Alessandra Pedroso ◽  
Dulce Espinoza ◽  
...  

Abstract OBJECTIVE: The aim of this study was to demonstrate the use and applications of the three-dimensional fast imaging employing steady-state acquisition (3-D-FIESTA) magnetic resonance imaging sequence in targeting and planning for stereotactic radiosurgery of trigeminal neuralgia. METHODS: A 3-D-FIESTA sequence for visualization of cranial nerves in the cranial base was added to the routine magnetic resonance imaging scan to enhance the treatment planning for trigeminal neuralgia. T1-weighted images, 1 mm thick, were directly compared with the FIESTA sequence for the exact visualization of the trigeminal entry zone and surrounding vasculature. The target accuracy was evaluated by image fusion of computed tomographic and magnetic resonance imaging scans. The anatomy visualized with the FIESTA sequence was validated by direct inspection of the gross anatomic specimens of the trigeminal complex. RESULTS: A total of 15 consecutive patients, 10 women and 5 men, underwent radiosurgery for essential trigeminal neuralgia between April and July, 2003. The mean age of the patients was 65.2 years (range, 24–83 yr). Nine patients had right-sided symptoms. Four patients had had previous surgery (two microvascular decompression, one percutaneous rhizotomy, and one radiofrequency thermocoagulation). The 3-D-FIESTA sequence successfully demonstrated the trigeminal complex (root entry zone, trigeminal ganglion, rootlets, and vasculature) in 14 patients (93.33%). The 3-D-FIESTA sequence also allowed visualization of the branches of the trigeminal nerve inside Meckel's cavity. This exact visualization correlated precisely with the anatomic specimens. In one patient (6.66%), it was not possible to demonstrate the related vasculature. However, the other structures were clearly visualized. CONCLUSION: The 3-D-FIESTA sequence is used in this study for demonstration of the exact anatomy of the trigeminal complex for the purpose of radiosurgical planning and treatment of trigeminal neuralgia. With such imaging techniques, radiosurgical targeting of specific trigeminal nerve branches may be feasible. It has not been possible previously to target individual branches of the trigeminal nerve.

Reproduction ◽  
2000 ◽  
pp. 69-75 ◽  
Author(s):  
GE Sarty ◽  
GP Adams ◽  
RA Pierson

Three-dimensional magnetic resonance imaging coupled with maximum intensity projection display, a technique usually reserved for magnetic resonance imaging angiography, is useful for the study of ovarian follicular growth. The ovaries of 19 cows were examined each day by transrectal ultrasonography. From these data, the precise phase of the ovarian cycle was determined and cows were ovariectomized on day 3 of wave one (n = 5), on day 6 of wave one (n = 4), on day 1 of wave two (n = 4), >/= 17 days after ovulation (n = 5), and on the day of ovulation (n = 1). The excised ovaries were examined by magnetic resonance imaging using a fast imaging with steady state precession imaging sequence with maximum intensity projection reconstruction, displayed as a cine-loop of the ovaries rotating in space. This provided the clearest view among the three principal three-dimensional steady state data acquisition approaches tried; the follicles and other ovarian structures could be distinguished unambiguously. Results from the bovine model indicate that the acuity of the three-dimensional fast imaging with steady state precession technique has potential application in in vivo intravaginal imaging in women for studying normal and pathological ovarian function.


Neurosurgery ◽  
2008 ◽  
Vol 62 (4) ◽  
pp. E974-E975 ◽  
Author(s):  
Jonathan P. Miller ◽  
Feridun Acar ◽  
Kim J. Burchiel

Abstract OBJECTIVE Trigeminal neuralgia (TN) is often associated with neurovascular compression. However, intracranial tumors are occasionally observed, particularly when symptoms are atypical. We describe three patients with Type-1 TN and trigeminal schwannoma diagnosed by magnetic resonance imaging, with concomitant arterial compression of the trigeminal nerve. CLINICAL PRESENTATION All three patients had Type-1 TN with spontaneous onset, paroxysm-triggered pain, and response to antiepileptic medication. Contrast-enhanced T1-weighted magnetic resonance imaging scans demonstrated an ipsilateral enhancing perineural mass consistent with a schwannoma. Two of the three patients had previously undergone gamma knife radiosurgery without improvement. Subsequent high-resolution magnetic resonance imaging in all three patients revealed obvious compression of the trigeminal nerve by an arterial structure. INTERVENTION Two patients underwent retrosigmoid craniectomy followed by microvascular decompression and remain pain-free. One patient elected not to pursue surgical intervention. CONCLUSION Although intracranial tumors are occasionally observed in patients with TN, neurovascular compression must still be considered as an etiology, especially if typical TN symptoms are reported.


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