ADC Benchmark Range for Correct Diagnosis of Primary and Recurrent Middle Ear Cholesteatoma

Abstract

Objectives Magnetic resonance imaging (MRI) and in particular diffusion-weighted imaging (DWI) have been broadly proven to be the reference imaging method to discriminate between cholesteatoma and noncholesteatomatous middle ear lesions, especially when high tissue specificity is required. The aim of this study is to define a range of apparent diffusion coefficient (ADC) values within which the diagnosis of cholesteatoma is almost certain. Methods The study was retrospectively conducted on a cohort of 124 patients. All patients underwent first- or second-look surgery because primary or secondary acquired cholesteatoma was clinically suspected; they all had preoperative MRI examination 15 days before surgery, including DWI from which the ADC maps were calculated. Results Average ADC value for cholesteatomas was 859,4 × 10−6 mm2/s (range 1545 × 10−6 mm2/s; IQR = 362 × 10−6 mm2/s; σ = 276,3 × 10−6 mm2/s), while for noncholesteatomatous inflammatory lesions, it was 2216,3 × 10−6 mm2/s (range 1015 × 10−6 mm2/s; IQR = 372,75 × 10−6 mm2/s; σ = 225,6 × 10−6 mm2/s). Interobserver agreement with Fleiss' Kappa statistics was 0,96. No overlap between two groups' range of values was found and the difference was statistically significant for p < 0.0001. Conclusions We propose an interval of ADC values that should represent an appropriate benchmark range for a correct differentiation between cholesteatoma and granulation tissue or fibrosis of noncholesteatomatous inflammatory lesions.

Computed-Tomography-Structured Reporting in Middle Ear Opacification: Surgical Results and Clinical Considerations From a Large Retrospective Analysis

“…The literature data on the CT sensitivity and specificity in determining lesion nature and origin differ among studies, with results ranging between 50 and 60% ( 11 , 13 ) and 80 and 95% ( 12 , 21 , 22 ). However, this limitation has been largely overcome thanks to the inclusion of DW-MRI in the diagnostic flow chart to assess the presence of admixed cholesteatomatous tissue ( 2 – 5 ). Nowadays, the presence of cholesteatoma > 3 mm can be easily revealed by low values on apparent diffusion coefficient (ADC) maps derived from DW-MRI sequences, both for primary diagnosis and in cases of residual/recurrent disease ( 2 – 5 , 23 ).…”

“…COM suspicion is raised at clinical examination (otoscopy, oto-endoscopy and micro-otoscopy), then supported by imaging techniques, such as computed tomography (CT) and magnetic resonance imaging (MRI) ( 2 – 5 ). Although CT is unable to define a proper assessment of lesion nature [so it is useful to integrate imaging detection with MRI diffusion weighted imaging (DWI)], it still remains the golden standard for evaluating the site of origin, the extent of disease and the possible involvement of crucial ear landmarks (e.g., facial canal, labyrinth, dural plate, tegmen tympani, scutum, ossicular chain) ( 3 , 6 – 8 ).…”

A case report of rare intraperitoneal cholesteatoma diagnosed and treated through multidisciplinary collaboration

“…Studies by Schwartz et al found that cholesteatoma showed high intensity in DWI because of limited water fusion and partly because its keratin content produced high signal intensity in the T2 penetrating effect area of the diseased tissue and that the high signal intensity of cholesteatoma in DWI images had a higher diagnostic accuracy. 15,16 In the diagnosis of primary, residual, or recurrent cholesteatoma, the assessment of DWI is objective and reliable. In recent years, studies by Atsushi Fukuda and other scholars found that a high concentration of protein, 17,18 not cholesterol and triglyceride content, is the cause of high signal intensity in T1-weighted images of cholesteatoma.…”

“…A study by Williams et al found that cholesteatoma is avascular and cannot be enhanced with contrast agent in MRI, 14 whereas granulation tissue is poorly vascularized and is enhanced on delayed imaging. Studies by Schwartz et al found that cholesteatoma showed high intensity in DWI because of limited water fusion and partly because its keratin content produced high signal intensity in the T2 penetrating effect area of the diseased tissue and that the high signal intensity of cholesteatoma in DWI images had a higher diagnostic accuracy 15,16 . In the diagnosis of primary, residual, or recurrent cholesteatoma, the assessment of DWI is objective and reliable.…”

Combining Thin-Section Coronal and Axial Diffusion Weighted Imaging: Good Practice in Middle Ear Cholesteatoma Neuroimaging

“…Indeed, although computed tomography (CT) better defines localization and extent of the inflammatory tissue as well as the possible presence of bone erosions, only MR-DWI is able to define the nature of middle ear cavity opacification (cholesteatoma vs. granulation tissue) ( 3 ). Moreover, in recent times the extrapolation of quantitative values on apparent diffusion coefficient (ADC) maps generated from DWI has been proposed as a tool for distinguishing cholesteatoma from other types of middle ear inflammatory disorders (i.e., non-cholesteatomatous granulation tissue and abscesses), as well as to assess the risk of recurrence after surgical removal ( 4 – 7 ).…”