RT Journal Article SR Electronic T1 Primary mucocele of the petrous apex: MR appearance. JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 203 OP 204 VO 13 IS 1 A1 Larson, T L A1 Wong, M L YR 1992 UL http://www.ajnr.org/content/13/1/203.abstract AB Mucoceles of the petrous apex are rare. Their MR appearance varies depending on the degree of hydration or inspissation of the contents. Concise preoperative diagnosis is helpful, since mucoceles are better drained to the mastoids via an infralabyrinthine approach rather than the more risky middle cranial fossa approach used for cholesteatomas.