Value of Echo-Planar Diffusion-Weighted Magnetic Resonance Imaging for Detecting Tympanomastoid Cholesteatoma

Abstract

OBJECTIVE:The aim of this study was to evaluate the diagnostic accuracy of echo-planar diffusion-weighted magnetic resonance imaging (EP-DWI) and high-resolution computed tomography (HRCT) in the detection and localization of cholesteatoma. MATERIALS and METHODS:Fifty-four patients were prospectively included in this study. Patients with suspected primary or residual cholesteatoma were evaluated by EP-DWI and HRCT before tympanomastoid surgery. Radiological findings were correlated with intraoperative findings.RESULTS: EP-DWI and HRCT accurately predicted the presence or absence of cholesteatoma in 49 of 54 (90.7%) and 37 of 54 (68.5%) patients, respectively. The sensitivity, specificity, and positive and negative predictive values of EP-DWI were 88.4%, 92.8%, 92%, and 89.6%, respectively. However, sensitivity, specificity, and positive and negative predictive values of HRCT were 69%, 67.8%, 66.6%, and 73.07%, respectively. CONCLUSION:This study demonstrates that EP-DWI is more reliable in predicting the presence and localization of cholesteatoma compared with HRCT, before tympanomastoid surgery.

The value of different diffusion-weighted magnetic resonance techniques in the diagnosis of middle ear cholesteatoma. Is there still an indication for echo-planar diffusion-weighted imaging?

“…In our research the sensitivity and specificity of EPI DWI were estimated as 69.2% and 66.6-83.3% for both readers, respectively. In the literature it has been reported that the EPI DWI technique may show higher sensitivity, reaching as much as 80%, but only in cases of lesions larger than 5 mm, but its sensitivity tends to drop to as little as 12.5% in lesions smaller that 4 mm [6][7][8][9][10][11][12][13]. In our study even cholesteatomas larger than 5 mm were misdiagnosed by both readers using EPI DWI.…”

“…It must be stressed that in our study both techniques, EPI and non-EPI DWI, overdiagnosed 1 case of chronic otitis as otitis with cholesteatoma. False positive results may lead to unnecessary ear operations while false negative results may cause postponing of the surgery and further middle ear destruction by a cholesteatoma [6][7][8]14].…”

“…A meta-analysis by Lingam et al, based on 26 studies, found non-EPI DWI to reach a sensitivity and specificity of 91% and 92%, respectively [18]. The reason for such good results of non-EPI DWI sequences is that they use half-Fourier single-shot-turbo spin-echo acquisition (HASTE) or multi shot turbo spin-echo acquisition with central kspace oversampling (PROPELLER, BLADE), which minimize motion and susceptibility artifacts, and geometric distortions, and increase the signal-to-noise ratio and spatial resolution with slice thickness less than 4 mm [5][6][7][8][9][10][11][12][13][14][15]. Moreover, Lips et al retrospectively evaluated 135 patients with non-EPI DWI using 1.5 T and 3 T MR scanners and observed significantly lower sensitivity and specificity for 3 T in comparison to 1.5 T due to increased susceptibility artifacts at higher field strength.…”

“…It is characterized by low spatial resolution, geometric distortion, and low signal-to-noise ratio (SNR). It is also prone to susceptibility artifacts at air/bone interfaces, which may cause problems while imaging skull base structures such as the middle ear [5][6][7][8]. Non-EPI DWI techniques, such as half-Fourier acquisition single-shot turbo spin-echo (HASTE) DWI, PROPELLER (multishot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstruction) DWI, BLADE DWI, and multishot DWI turbo spin-echo (MS TSE), require longer scanning times compared to EPI DWI, but they are said to reduce susceptibility artifacts, geometric distortions, and section thickness as well as to increase spatial resolution [7][8][9][10][11][12][13][14][15].…”

Diffusion weighted imaging for the detection and evaluation of cholesteatoma

“…This second-look is conducted 6-18 mo after the initial operation because most recur within the first 2 postoperative years, with 60% occurring during the first year after surgery[2,3]. The second-look surgery is mainly to assess residual or recurrent disease because both cannot adequately be diagnosed solely by clinical examination[4]. …”