Does the technique of fusing MRI images with high-resolution CT images improve the efficiency of detecting recurrent cholesteatoma in children, in particular for small cholesteatomas?
Explore this issue:February 2011
Background: Radiographic documentation of small recurrent cholesteatoma following pediatric middle ear/mastoid surgery or primary diagnosis of a small congenital cholesteatoma could provide benefit in the management decisions for these entities. Diffusion-weighted MRI techniques do not require IV gadolinium and have good ability to detect cholesteatoma as small as 3-5 mm, but with poor anatomic resolution. High-resolution CT scanning provides good anatomic localization, but the distinction between cholesteatoma and non-cholesteatoma soft tissue is often difficult. Fusing diffusion-weighted MRI scans with high-resolution CT may combine the benefits of both techniques, with fewer drawbacks.
Study design: Retrospective cohort study.
Setting: Tertiary care university hospital.
Synopsis: Ten patients, aged two to 17 years, with a suspicion of recurrent cholesteatoma, or congenital cholesteatoma underwent high-resolution CT scanning and MRI scanning. Neither anesthesia nor IV contrast media were given. The CT images and the diffusion-weighted MRI images were fused by coregistration using commercially available computer software. CT images alone were considered positive in four patients and confirmed at surgery in three of the four patients. Diffusion-weighted MRI images alone were considered positive in nine patients and confirmed positive in all nine patients. The one patient with a negative MRI was confirmed negative at surgery. Fusing the CT and MRI data led to the same degree of diagnostic accuracy as MRI alone, with the advantage of accurate anatomic location data confirmed at the time of surgery.
Bottom line: Fusion of high-resolution CT images and diffusion-weighted MRI images holds great promise for accurate diagnosis and localization of recurrent cholesteatoma or congenital cholesteatoma as small as 3 mm. The techniques do not require anesthesia, and IV contrast may be avoided. Additional data should be collected to confirm the diagnostic accuracy of this combination of radiographic studies.
Citation: Plouin-Gaudon I, Bossard D, Ayari-Khalfallah S, et al. Fusion of MRIs and CT scans for surgical treatment of cholesteatoma of the middle ear in children. Arch Otolaryngol Head Neck Surg. 2010;136(9):878-883.
—Reviewed by George T. Hashisaki, MD