John I. Lane
We first became interested in utilizing non-EPI DWI for the detection of recurrent cholesteatomas after reading the published works of our European colleagues.1,2 Clinical diagnosis of recurrence is quite limited in patients following canal wall-up mastoidectomy and tympanoplasty procedures (often performed with opaque cartilaginous grafts), precluding adequate otoscopic inspection of the middle ear. CT is often nondiagnostic unless evidence of bony erosion can be found to suggest recurrence. Surgical re-exploration (second-look surgery) to exclude recurrence at 9–12 months after the initial procedure has been the standard of care for decades. When we approached our neurotology colleagues, they were quite interested in investigating the possibility of replacing second-look surgeries with serial follow-up non-EPI DWI MR examinations to exclude recurrence.
Our initial results at 1.5T were promising and corroborated the results of previously reported studies, leading to a significant practice change in the follow-up of these patients and replacing an invasive surgical procedure with a noninvasive imaging study.3 We felt strongly that it would be useful to disseminate this information more widely by way of a review article for AJNR, and were delighted to respond to an invitation to submit the review.4
Unfortunately, despite reports in the literature to the contrary,5,6 our initial enthusiasm for employing these techniques at 3T have been tempered by the image degradation we observed secondary to increased susceptibility artifact at higher field strength. This is particularly problematic with the