The Utility of Diffusion-Weighted Imaging for Cholesteatoma Evaluation

Detection of recurrent cholesteatoma when physical examination is obscured and CT is indeterminate. A 53-year-old man with 3 prior left tympanomastoidectomies presented for routine follow-up with mildly progressive decreased hearing. Otologic examination was obscured by cartilage reconstruction and an opaque tympanic membrane. A and B, CT shows soft-tissue opacification of the Prussak space without definite bony erosion (arrow), considered indeterminate for recurrent disease versus postoperative scar or granulation tissue. C−E, MR imaging shows a corresponding area in the left middle ear (arrow) that is isointense on T2 (C) and T1 (D), without definite enhancement (E). BLADE DWI shows hyperintensity (arrow) in this same area, consistent with recurrent cholesteatoma. F, Cholesteatoma (arrow) was found in this location at surgery, confirmed by pathology. Fig 2A, C, and F reproduced with permission from Ear, Nose & Throat Journal (Schwartz KM, Lane JI, Neff BA, et al. Diffusion-weighted imaging for cholesteatoma evaluation. 2010;89:E14-19).³²

Detection of recurrent disease and intracranial extension when otologic evaluation is obscured and CT is nonspecific. A 14-year-old girl with a long history of recurrent cholesteatoma and multiple surgeries. The middle ear is obscured due to a stenotic external auditory canal (A and B). CT shows nonspecific diffuse opacification of the mastoidectomy and middle ear (arrow). C−F, MR imaging shows T2 hyperintense (arrow, C) and T1 hypointense (arrow, D) regions with hyperintensity on BLADE DWI (arrow, E and F) along the superior aspect of the right temporal bone, suspicious for recurrent cholesteatoma with intracranial extension. The patient declined contrast material. At surgery, intradural extension of disease was confirmed.

Evaluation of disease extent in a patient with lateral semicircular canal fistula. A 61-year-old man with multiple prior ear surgeries, including a right mastoidectomy for unknown reasons, presented with vertigo and imbalance. Visual inspection of the middle ear cavities was obscured by postoperative changes, but no cholesteatoma was seen. A and B, CT shows soft tissue (arrow) in the mastoid defect, external auditory canal, and epitympanum with bony erosion of the lateral semicircular canal. C and D, MR images show the extent of cholesteatoma and demonstrate a large area of hyperintensity on HASTE DWI in the mastoid defect and middle ear (B in Fig 1) with T2 hypointensity (arrow, C), and mild T1 hyperintensity but no definite enhancement (arrow, D). A portion of the right lateral semicircular canal is obscured by the soft-tissue mass (C), again consistent with the fistula shown on CT. Cholesteatoma and lateral semicircular canal fistula were confirmed at surgery. Fig 4A, B, and C reproduced with permission from Ear, Nose & Throat Journal (Schwartz KM, Lane JI, Neff BA, et al. Diffusion-weighted imaging for cholesteatoma evaluation. 2010;89:E14-19).³²

Detection of de novo cholesteatoma in a patient with indeterminate findings on physical examination and CT. A 20-year-old man presented with left-sided hearing loss and prior otorrhea following traumatic tympanic membrane perforation. Visual inspection showed slight retraction of the pars flaccida of the tympanic membrane on the left without a definite cholesteatoma seen. A, Temporal bone CT scan shows soft-tissue opacification (arrow) in the left Prussak space without definite bony erosion. B and C, MR images show corresponding mild T2 hyperintensity (arrow, B), peripheral enhancement (arrow, C), and subtle increased DWI signal intensity (arrow, D) in the left epitympanum. Cholesteatoma was confirmed in this location at surgery.