Improved Depiction of Pterygopalatine Fossa Anatomy Using Ultrahigh-Resolution Magnetic Resonance Imaging at 7 Tesla

R. L. A. W. Bleys,G. J. Hordijk,J. J. M. Zwanenburg,F. A. Pameijer,K. P. Q. Oomen,J. A. De Ru

doi:10.1100/2012/691095

Abstract

Purpose. To study the anatomy of the pterygopalatine fossa (PPF) using ultrahigh-resolution magnetic resonance imaging. Methods. A human cadaveric tissue block containing the pterygopalatine fossa was examined on a clinical 7-Tesla magnetic resonance imaging system. Subsequently, cryosections of the tissue block were created in a coronal plane. The cryosections were photographed and collected on adhesive tape. The on-tape sections were stained for Mallory-Cason, in order to detail the anatomic structures within the fossa. Magnetic resonance images were compared with surface photos of the tissue block and on-tape sections. Results. High-resolution magnetic resonance images demonstrated the common macroscopic structures in the PPF. Smaller structures, best viewed at the level of the operation microscope, which have previously been obscured on magnetic resonance imaging, could be depicted. Some of the orbital pterygopalatine ganglion branches and the pharyngeal nerve were clearly viewed. Conclusions. In our experience with one human cadaver specimen, magnetic resonance imaging at 7 Tesla seems effective in depicting pterygopalatine fossa anatomy and provides previously unseen details through its demonstration of the pharyngeal nerve and the orbital pterygopalatine ganglion branches. The true viability of depicting the pterygopalatine fossa with ultrahigh-resolution MR will depend on confirmation of our results in larger studies.

Highlights

The pterygopalatine fossa (PPF) is an inverted pyramidal space located inferior to the orbital apex, which contains the pterygopalatine ganglion (PPG) and various arteries, veins, lymphatics, and nerves
Our study demonstrates that ex vivo MR imaging of the PPF at 7 T provides excellent depiction of PPF content, the PPG and some of its branches
The few MR studies that are available focus on perineural tumor spread in the PPF, which excludes a detailed search for structures such as the PPG and its communications [5, 14,15,16]

Summary

Introduction

The pterygopalatine fossa (PPF) is an inverted pyramidal space located inferior to the orbital apex, which contains the pterygopalatine ganglion (PPG) and various arteries, veins, lymphatics, and nerves. The PPF communicates with the orbit, nasal cavity, and oral cavity, and through the orbit with the maxillary sinus and upper teeth, which makes it an important cranial neurovascular crossroad as well as a common site for invasion and perineural spread of malignant disease [1]. The neural content of the PPF plays an important role in the pathophysiology of pain syndromes with cranial autonomic features such as cluster headache and Sluder’s neuralgia [2, 3]. These syndromes are invalidating and may require invasive treatment, such as PPG blockage, for refractory cases [4]. Studying the PPF in head and neck imaging is of importance, for both diagnostic and preoperative purposes

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