Readout-Segmented Echo-Planar DWI for the Detection of Cholesteatomas: Correlation with Surgical Validation

Congenital cholesteatoma: what radiologists need to know

Congenital cholesteatoma is a rare, non-neoplastic lesion that causes conductive hearing loss in children. It is underrecognized and often diagnosed only when there is an established hearing deficit. In the pediatric population, hearing deficiency is particularly detrimental because it can impede speech and language development and, in turn, the social and academic well-being of affected children. Delayed diagnosis leads to advanced disease that requires more extensive surgery and a greater chance of recurrence. A need to promote awareness and recognition of this condition has been advocated by clinicians and surgeons, but no comprehensive imaging review dedicated to this entity has been performed. This review aims to discuss the diagnostic utility of high-resolution computed tomography and magnetic resonance imaging in preoperative and postoperative settings in congenital cholesteatoma. Detailed emphasis is placed on the essential preoperative computed tomography findings that facilitate individualized surgical management and prognosis in the pediatric population.

Readout-Segmented Echoplanar (RESOLVE) Diffusion-Weighted Imaging on 3T MRI in Detection of Cholesteatoma-Our Experience

Background  Several research studies have demonstrated the utility of diffusion-weighted imaging (DWI) in detecting middle ear cholesteatomas, especially with the non-echoplanar imaging (non-EPI) DWI technique. REadout Segmentation Of Long Variable Echo trains (RESOLVE), a multishot-EPI DWI, has better spatial resolution at a thinner section acquisition with reduced image distortion compared to the single-shot-EPI DWI technique. Purpose  In this study, we evaluated the diagnostic ability of RESOLVE -DWI in middle ear cholesteatomas with surgical and histopathological support. Patients and Methods  Fifty patients with clinical suspicion of primary cholesteatoma or postoperative recurrence were subjected to routine sequences and RESOLVE-DWI on magnetic resonance imaging (MRI). Thirty-eight patients had unilateral disease, while 12 patients had bilateral disease. The bilateral temporal bones of 50 patients were evaluated on MRI. The results attained by RESOLVE-DWI were correlated with intraoperative and histopathological findings. Results  RESOLVE-DWI truly detected 55 of the 58 surgically proven cholesteatomas. RESOLVE-DWI could not detect three cholesteatoma lesions due to their small size and falsely diagnosed one case each of impacted wax and non-cholesteatomatous otitis media as cholesteatoma. With a 95% confidence interval, RESOLVE-DWI showed 94.8% sensitivity, 95.2% specificity, 96% positive predictive value, 93% negative predictive value, and 95% diagnostic accuracy in cholesteatoma detection. Conclusion  RESOLVE-DWI is a sensitive and specific DWI technique for detecting middle ear cholesteatoma. However, RESOLVE-DWI has limitations in the diagnosis of small (<3 mm) cholesteatomas.

The diagnostic utility of diffusion-weighted magnetic resonance imaging and high-resolution computed tomography for cholesteatoma: A meta-analysis

Objective

The purpose of this meta-analysis was to compare the efficiency of high-resolution computed tomography (HRCT) and diffusion-weighted magnetic resonance imaging (DWI) in guiding the diagnosis of middle ear cholesteatoma in clinical practice.

Materials and methods

Cochrane Library, Medline, Embase, PubMed, and Web of Science were searched for studies that evaluated the sensitivity and specificity of HRCT or DWI in detecting middle ear cholesteatoma. A random-effects model was used to calculate and summarize the pooled estimates of sensitivity, specificity, and diagnostic odds ratios. Postoperative pathological results were considered as the diagnostic gold standard for middle ear cholesteatoma.

Results

Fourteen published articles (860 patients) met the inclusion criteria. The sensitivity and specificity of DWI when diagnosing cholesteatoma (regardless of type) were 0.88 (95% confidence interval [CI], 0.80-0.93) and 0.93 (95% CI, 0.86-0.97), respectively, while those of HRCT were 0.68 (95% CI, 0.57-0.77) and 0.78 (95% CI, 0.60-0.90), respectively. Notably, the sensitivity and specificity levels of DWI were similar to those of HRCT (p = .1178 for sensitivity, p = .2144 for specificity; pair-sampled t tests). The sensitivity and specificity of DWI or HRCT for the diagnosis of primary cholesteatoma were 0.78 (95% CI, 0.65-0.88) and 0.84 (95% CI, 0.69-0.93), respectively, while that for recurrent cholesteatoma were 0.93 (95% CI, 0.61-0.99) and 0.94 (95% CI, 0.82-0.98), respectively.

Conclusion

DWI and HRCT have similar levels of high sensitivity and specificity in detecting various cholesteatomas. Also, the diagnostic efficiency of HRCT or DWI for recurrent cholesteatoma is identical to that of primary cholesteatoma. Therefore, HRCT may be used in clinical settings to reduce the use of DWI and save clinical resources.

Lay summary

Data on the use of diffusion-weighted magnetic resonance imaging and high-resolution computed tomography in the diagnosis of cholesteatoma were obtained through a literature search. They were analyzed to guide the clinical diagnosis and treatment of cholesteatoma.

Level of evidence

NA.

Detection of cholesteatoma: 2D BLADE turbo gradient- and spin-echo imaging versus readout-segmented echo-planar diffusion-weighted imaging

PURPOSE

This study is to compare the accuracy of 2D BLADE turbo gradient- and spin-echo imaging (TGSE BLADE) diffusion-weighted imaging (DWI) with that of readout-segmented echo-planar (RESOLVE) DWI in the detection of primary and residual/recurrent temporal bone cholesteatoma.

METHODS

The prospective study population consisted of 58 patients who were underwent magnetic resonance (MR) imaging for the evaluation of suspected temporal bone cholesteatoma. Two radiologists independently evaluated the two sequences. Kappa (k) statistics, the intra-class correlation coefficient (ICC), and a paired t test were used for statistical analysis.

RESULTS

Of the 58 patients included, all had histo-pathologically confirmed cholesteatomas. In ≤ 3 mm group (n = 13), TGSE BLADE sequence correctly identified all cases except one that was recorded as equivocal on both sequences because of high signal intensity on T1WI; while on RESOLVE sequences, 6 were positive, 4 were equivocal, and 3 were false negative. For > 3 mm group (n = 45), detection performance was similar between the two sequences. The mean ADC of cholesteatoma on TGSE BLADE DWI was 0.923 × 10^-3 mm²/s, and the mean ADC of cholesteatoma on RESOLVE DWI was 0.949 × 10^-3 mm²/s, with no significant difference in the mean ADC values of cholesteatoma measured on the two sequences (p = 0.9216).

CONCLUSION

TGSE BLADE outperforms RESOLVE in the detection of small temporal bone cholesteatoma ≤ 3 mm.

Pearls of Temporal Bone Imaging in Children with Hearing Loss

Hearing loss is one of the most common indications for temporal bone imaging in children. Hearing loss may be congenital or acquired, and it may be conductive, sensorineural, or mixed audiologically. Temporal bone imaging plays an important role in the assessment and management of this condition. An understanding of the embryology of ear structures better enables the radiologist to interpret abnormalities on imaging of the temporal bone. Here, we provide a general review of ear development and a description of known genetic defects that contribute to congenital ear anomalies associated with hearing loss. We provide appropriate imaging techniques for the temporal bone depending on the clinical presentation and a systematic approach to imaging for children with hearing loss. Diagnostic imaging for developmental anomalies of the ear and cholesteatoma will be discussed.

MRI of middle ear cholesteatoma: The importance of observer reliance from diffusion sequences

BACKGROUND AND PURPOSE

Diffusion-weighted imaging(DWI) in MRI has been developed as an important tool for the detection of cholesteatoma. Various DWI sequences are available. This study aims to evaluate the importance of the observer's reliance level for the detection of cholesteatoma.

METHODS

Forty patients meeting the following criteria were included in the study: (1) chronic otitis media, (2) preoperative MRI including various DWI sequences, and (3) middle-ear surgery. The MRI protocol contained the following sequences: (1) axial and (2) coronal echoplanar imaging (EPI) readout-segmented (RESOLVE) DWI with Trace acquisition and (3) coronal non-EPI half-Fourier acquired single-shot turbo spin-echo (HASTE) DWI. Cholesteatoma diagnosis was based on standard diagnostic criteria for cholesteatoma with DWI. Additionally, the radiologists were asked to grade personal reliance on their diagnosis using a Likert-type scale from 1 = very insecure to 5 = very secure.

RESULTS

Axial and coronal RESOLVE DWI showed a sensitivity of 77.3% and a specificity of 72.2%, respectively. The mean reliance was 3.9 for axial and 3.8 for coronal images. HASTE DWI had a sensitivity/specificity of 81.8%/66.7% with the highest reliance of all evaluated sequences (4.4). Cases with a reliance level of 5 showed a sensitivity/specificity of 100% in all sequences. A reliance level of 5 was given in the axial and coronal RESOLVE DWI in 32.5% of cases and in the HASTE DWI in 57.5%.

CONCLUSION

The evaluated DWI sequences showed comparable results. The reliance level significantly improved the predictor of cholesteatoma disease with MRI techniques.

Comparison of Readout-Segmented Echo-Planar Imaging and Single-Shot TSE DWI for Cholesteatoma Diagnostics

BACKGROUND AND PURPOSE

The high diagnostic value of DWI for cholesteatoma diagnostics is undisputed. This study compares the diagnostic value of readout-segmented echo-planar DWI and single-shot TSE DWI for cholesteatoma diagnostics.

MATERIALS AND METHODS

Thirty patients with newly suspected cholesteatoma were examined with a dedicated protocol, including readout-segmented echo-planar DWI and single-shot TSE DWI at 1.5T. Acquisition parameters of both diffusion-weighted sequences were as follows: b=1000 s/mm,² axial and coronal section orientations, and section thickness of 3 mm. Image quality was evaluated by 2 readers on a 5-point Likert scale with respect to lesion conspicuity, the presence of susceptibility artifacts mimicking cholesteatomas, and overall subjective image quality. Sensitivity and specificity were calculated using histology results as the gold standard.

RESULTS

Twenty-five cases of histologically confirmed cholesteatomas were included in the study group. Lesion conspicuity was higher and fewer artifacts were found when using TSE DWI (both P < .001). The overall subjective image quality, however, was better with readout-segmented DWI. For TSE DWI, the sensitivity for readers 1 and 2 was 92% (95% CI, 74%-99%) and 88% (95% CI, 69%-97%), respectively, while the specificity for both readers was 80% (95% CI, 28%-99%). For readout-segmented DWI, the sensitivity for readers 1 and 2 was 76% (95% CI, 55%-91%) and 68% (95% CI, 46%-85%), while the specificity for both readers was 60% (95% CI, 15%-95%).

CONCLUSIONS

The use of TSE DWI is advisable for cholesteatoma diagnostics and preferable over readout-segmented DWI.

Cholesteatoma Localization Using Fused Diffusion-Weighted Images and Thin-Slice T2 Weighted Images

BACKGROUND

Fusion of diffusion-weighted imaging (DWI) to computed tomography (CT) has been touted as a possible technique to improve cholesteatomas localization. This study set out to assess the ability of DWI images fused with thin-slice heavily T2-weighted images to similarly localize surgically-confirmed cholesteatomas.

MATERIALS AND METHODS

A retrospective review was completed of consecutive patients that underwent MR temporal bone imaging (9/2011-3/2020) with both DWI and thin-slice T2-weighted imaging. Included patients underwent surgical resection of primary or recidivistic cholesteatoma after preoperative MR imaging. A neuroradiologist, who was blinded to operative and clinical notes, localized each lesion on both DWI and fused DWI-T2 images in 11 anatomic subdivisions of the temporal bone. Surgical confirmation of cholesteatoma location was used as the gold standard for comparison.

RESULTS

Of 24 included examinations, the average age at time of MR was 48.2 ± 24.7 years; 12/24 (50.0%) were female. Five of 24 had primary cholesteatoma, while the remainder had recidivistic disease. Sensitivity, specificity, and accuracy of unfused DWI images were 52.1%, 88.9%, and 75.8%, respectively. Sensitivity, specificity, and accuracy of fused DWI-T2 images were 57.1%, 94.8%, and 81.8%, respectively.

CONCLUSION

Fused DWI-T2 images outperformed unfused DWI images in the anatomic localization of temporal bone cholesteatomas. This method represents a potential alternative to MR-CT fusion for pre-operative cholesteatoma evaluation, and warrants future investigations. Opposed to MR-CT fusion, this method only necessitates MR sequences and removes the need for additional CT acquisition.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:E1662-E1667, 2021.

Novel Radiologic Approaches for Cholesteatoma Detection: Implications for Endoscopic Ear Surgery

Technological advancement in computed tomography (CT) and MRI has improved cholesteatoma detection rates considerably in the past decade. Accurately predicting disease location and extension is essential for staging, planning, and preoperative counseling, in particular in the newer approach of endoscopic ear surgery. Improved sensitivity and specificity of these radiological methods may allow the surgeon to confidently monitor patients, therefore avoiding unnecessary surgery. This article outlines recent advances in CT and MRI technology and advantages and disadvantages of the newer techniques. Emphasis on improving the feedback loop between the radiologist and surgeon will increase the accuracy of these new technologies.

Diffusion MR Imaging in the Head and Neck: Principles and Applications

Diffusion imaging is a functional MR imaging tool that creates tissue contrast representative of the random, microscopic translational motion of water molecules within human body tissues. Long considered a cornerstone MR imaging sequence for brain imaging, diffusion-weighted imaging (DWI) increasingly is used for head and neck imaging. This review reports the current state of diffusion techniques for head and neck imaging, including conventional DWI, DWI trace with apparent diffusion coefficient map, diffusion tensor imaging, intravoxel incoherent motion, and diffusion kurtosis imaging. This article describes background physics, reports supportive evidence and potential pitfalls, highlights technical advances, and details practical clinical applications.

Panel 6: Otitis media and associated hearing loss among disadvantaged populations and low to middle-income countries

OBJECTIVE:

Summarise the published evidence on otitis media and associated hearing loss in low to middle-income countries (LMIC) and disadvantaged populations.

DATA SOURCES:

PubMed and other databases.

REVIEW METHODS:

Firstly, sensitive search strategy using ‘otitis media’, combined with specific key words for each topic of the review, from January 2015 to June 2019. Then, restriction to LMIC and disadvantaged populations. Topics covered included prevention, epidemiology, risk factors, microbiology, prognosis, diagnosis, and treatment.

CONCLUSIONS:

There was a high degree of methodological heterogeneity and high risk of bias. The majority of studies were school-based. In Africa, Asia and Oceania (e.g., Australian Aboriginal populations) the prevalence of OM was respectively 8% (range 3–16%), 14% (range 7–22%) and 50% (4–95%). Prevalence of any hearing loss in these regions was 12% (range 8–17%), 12% (range 3–24%), and 26% (range 25–28%) respectively. Risk factors in LMIC and disadvantaged populations included age, gender, exposure to smoke and pollution. Microbiology was reported for otitis media with effusion at time of surgery or ear discharge (acute otitis media with perforation or chronic suppurative otitis media). Specimen handling and processing in hospital laboratories was associated with low detection of S. pneumoniae and H. influenzae. Case series described complicated cases of OM due to M. tuberculosis, multidrug resistance and HIV. QOL studies identified discrimination of persons with OM and hearing loss. Diagnostic methods varied greatly, from naked eye to tympanometry. Treatment interventions were reported from four RCTs. Non-RCTs included evaluations of guidelines, surgery outcomes, access to ENTs.

IMPLICATIONS FOR CLINICAL PRACTICE:

Chronic suppurative otitis media, otitis media with effusion and conductive hearing loss are common in LMIC and disadvantaged populations. Paucity of research, poor regional representation, non-standardised methods and low-quality reporting preclude accurate assessment of disease burden in LMIC and disadvantaged populations. Awareness and adherence to reporting Guidelines should be promoted.