Usefulness of Delayed Postcontrast Magnetic Resonance Imaging in the Detection of Residual Cholesteatoma after Canal Wall-Up Tympanoplasty

Abstract

When postoperative CT is not conclusive because of complete opacity of the tympanomastoid cavities, MRI with delayed postcontrast T1-weighted images is a reliable additional technique for the detection of a residual cholesteatoma when its diameter is at least 3 mm.

HASTE diffusion-weighted mri: reliability for detection of cholesteatoma

“…The known disadvantages of MRI include poor spatial resolution, long duration, and the necessary injection of contrast media, making this technique relatively difficult for routine use. Although it remains controversial whether the bright signal of cholesteatoma observed in MRI images is a result of restricted diffusion or a T2 shine-through effect, DWI has been increasingly used in the evaluation of postoperative residual cholesteatomas over the past decade (7). Several recent reports have focused mainly on two DWI techniques for detecting cholesteatoma: EPI DWI and non-EPI (single-shot turbo spin echo [SSTSE] DWI, also called HASTE) DWI (7, 9, 13−16).…”

“…Diffusion-weighted imaging (DWI) and delayed postcontrast T1-weighted (T1W) sequences have both been suggested. Delayed postcontrast T1 spin-echo sequences improve the diagnosis of recurrent cholesteatoma and allow differentiation between scar tissue, which shows delayed enhancement, and cholesteatoma, which does not show delayed enhancement; conversely, inflammatory tissue displays early enhancement (7). However, these sequences do not provide the diagnostic performance necessary to eliminate the need for second-look surgery (7)(8)(9)(10)(11).…”

“…Delayed postcontrast T1 spin-echo sequences improve the diagnosis of recurrent cholesteatoma and allow differentiation between scar tissue, which shows delayed enhancement, and cholesteatoma, which does not show delayed enhancement; conversely, inflammatory tissue displays early enhancement (7). However, these sequences do not provide the diagnostic performance necessary to eliminate the need for second-look surgery (7)(8)(9)(10)(11). Growing data suggest that DWI, particularly Half-Fourier acquisition single-shot turbo spin-echo (HASTE) DWI, yields better diagnostic performance for the detection of cholesteatomas (8,11).…”

Aplicação da ressonância magnética no acompanhamento da cirurgia do colesteatoma

“…Studies by Williams et al 8 and Ayache et al 9 reported improved specificity and sensitivity in this differential diagnosis by using delayed (30 minutes) T1-weighed imaging after intravenous contrast injection, as granulation tissue is poorly vascularized and contrast uptake takes longer to occur. Cholesteatomas are not vascularized and do not take contrast up.…”

“…Other studies reported improved specificity when using T1-weighed sequences with delayed post-contrast enhancement, as granulation tissue is poorly vascularized and contrast uptake occurs in a delayed fashion 8,9 . Cholesteatomas are not vascularized and cannot be enhanced by contrast.…”