Identification of the Normal Jugular Foramen and Lower Cranial Nerve Anatomy: Contrast-Enhanced 3D Fast Imaging Employing Steady-State Acquisition MR Imaging

I Davagnanam,S.V Chavda

doi:10.3174/ajnr.a0860

Abstract

Conventional imaging protocols are unable to visualize the intraforaminal/canalicular segments of the lower cranial nerves (IX-XII). On the basis of previous successful demonstration of individual cranial nerves within the cavernous sinus by constructive interference in steady-state MR imaging, we describe the use of contrast-enhanced 3D fast imaging employing steady-state acquisition MR imaging to demonstrate normal in vivo intraforaminal and canalicular segments of cranial nerves IX-XII in 10 patients by using a standardized imaging protocol.

Highlights

TECHNICAL NOTEIdentification of the Normal Jugular Foramen and Lower Cranial Nerve Anatomy: Contrast-Enhanced 3D Fast Imaging Employing Steady-State Acquisition MR Imaging
The detection of individual cranial nerves in the intraforaminal portion of the jugular foramen and hypoglossal canal is useful in diagnostic imaging[1]; visualization by using conventional MR imaging protocols does not provide adequate detail of individual nerves.[2,3] Recently, contrastenhanced 3D constructive interference in steady state (CISS) MR imaging has successfully demonstrated the trigeminal ganglion and its divisions and individual cranial nerves within the cavernous sinus.4,5 3D fast imaging employing steady-state acquisition (FIESTA) is a similar form of steady-state sequence MR imaging
The intraforaminal and canalicular segments of cranial nerves IX–XII were localized in all cases consistent with the known anatomic courses of cranial nerves IX–XII (Fig 3)

Summary

TECHNICAL NOTE

Identification of the Normal Jugular Foramen and Lower Cranial Nerve Anatomy: Contrast-Enhanced 3D Fast Imaging Employing Steady-State Acquisition MR Imaging. On the basis of previous successful demonstration of individual cranial nerves within the cavernous sinus by constructive interference in steady-state MR imaging, we describe the use of contrast-enhanced 3D fast imaging employing steady-state acquisition MR imaging to demonstrate normal in vivo intraforaminal and canalicular segments of cranial nerves IX–XII in 10 patients by using a standardized imaging protocol. Evidence has shown a proportional increase in contrast between the background structures and the cranial nerves within the cisterns as the concentration of gadolinium-based contrast agent increases with 3D steady-state imaging sequences.[4,6] This Technical Note describes the use of 3D-FIESTA imaging after intravenous administration of gadodiamide hydrate contrast to demonstrate the normal anatomy of the intraforaminal and canalicular portions of cranial nerves IX–XII. The images were evaluated by 2 neuroradiologists, making initial evaluations independently but resolving any inconsistencies by collaborative review and consensus agreement

Results

Discussion

Conclusion