Differential diagnosis of intra-cranial lesions with high signal on T1 or low signal on T2-weighted MRI

Abstract

Sir—I would like to make some comments about the paper by Warakaulle et al. 1. Warakaulle D.R Anslow P Differential diagnosis of intra-cranial lesions with high signal on T1 or low signal on T2-weighted MRI. Clin Radiol. 2003; 58: 922-933 Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar Fig. 5 shows axial computed tomography (CT), T1 and T2-weighted magnetic resonance imaging (MRI) images of a “cholesterol granuloma” of the left petrous apex. The appearances are, however, typical of a petrous apex pseudo lesion secondary to asymmetric pneumatization of the right petrous apex with a non-pneumatized marrow space in the left petrous apex. There is no evidence of an expansile lesion in the left petrous apex. Asymmetrical pneumatization of the petrous apex is seen in 5% of the population and is the commonest “leave-me-alone” lesion occurring at this site. The nature of the pseudo lesion could be proven by a T1-weighted fat-saturation sequence. Failure to make the distinction can lead to unnecessary surgery and morbidity. 2. Moore K.R Harnsberger H.R Shelton C Davidson: “Leave me alone” lesions of the petrous apex. AJNR Am J Neuroradiol. 1998; 19: 733-738 PubMed Google Scholar