title: Signal intensity patterns in intraspinal dermoids and epidermoids on MR imaging.
abstract: Retrospective evaluation of MR images of nine intraspinal dermoid (n = 4) and epidermoid (n = 5) tumours was undertaken. T1-weighted images were available in all the patients while proton density (PD) and T2-weighted images were available in seven patients. Except for one lesion (only T1-weighted images were available in this case), all the lesions were clearly delineated on MR images. Most (5 out of 7) were better appreciated on T1- and PD-weighted images than on T2-weighted images. On T1-weighted images, the epidermoids were either iso- to mildly hypointense to the cord (n = 3), isointense to CSF (n = 1) or markedly hyperintense (n = 1). On the PD images, the epidermoids were either isointense to cord (n = 3) or markedly hyperintense (n = 1). All the lesions were iso- to hyperintense to CSF on T2-weighted images. Of the four dermoids three showed a mixed intensity pattern on all sequences; the dominant component gave short T1 and short T2 values, consistent with fat. The fourth lesion showed homogenous material with a signal intensity intermediate between that of CSF and cord on T1-weighted images. Dermal sinus tracts were present in four of the nine patients; three patients had an intraspinal component. This study shows that although MR imaging is excellent for their detection, it cannot differentiate the two tumour types.
authors.affiliation: Department of Radiodiagnosis, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India.
authors.forename: S
authors.initials: S
authors.lastname: Gupta
authors.forename: R K
authors.initials: RK
authors.lastname: Gupta
authors.forename: R B
authors.initials: RB
authors.lastname: Gujral
authors.forename: P
authors.initials: P
authors.lastname: Mittal
authors.forename: M
authors.initials: M
authors.lastname: Kuriyal
authors.forename: N
authors.initials: N
authors.lastname: Krishnani
mesh_terms: D002555:Cerebrospinal Fluid; D002648:Child; D002675:Child, Preschool; D003884:Dermoid Cyst / Q000175:diagnosis*; D004814:Epidermal Cyst / Q000175:diagnosis*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D016136:Spina Bifida Occulta / Q000175:diagnosis; D013120:Spinal Cord Neoplasms / Q000175:diagnosis*