Diffusion weighted imaging for the detection and evaluation of cholesteatoma

Characteristics and diagnostic performance of nonechoplanar diffusion-weighted imaging in detecting canine tympanokeratoma (cholesteatoma)

Tympanokeratomas (cholesteatomas) are destructive keratinic masses of the middle ear that are often treated surgically. In humans, nonechoplanar (non-EP) diffusion-weighted (DW) MRI is efficient in diagnosing tympanokeratomas and differentiating recurrent tympanokeratomas from granulation or fibrous tissue after surgery. The objectives of this study were to (1) determine the characteristics of non-EP DWI of histologically or cytologically confirmed canine tympanokeratomas, (2) determine the performance of non-EP DW images, apparent diffusion coefficient (ADC) map and ADC values in discriminating between tympanokeratomas and other causes of otitis media in dogs, and (3) find an optimal ADC cut-off value. Medical records of dogs diagnosed on MRI with otitis media in two veterinary hospitals were retrospectively reviewed. Sixty-two ears with a cytological or pathological diagnosis of either tympanokeratoma (36/62) or nontympanokeratoma otitis media (26/62) were selected. Diffusion-weighted images had an accuracy of 77.4%, a sensitivity of 94.4%, and a specificity of 53.8% for the detection of tympanokeratoma. The ADC value of middle ear content ranged from 517 to 1355.10-6 mm2/s in tympanokeratoma and from 454 to 2447 × 10-6 mm2/s in nontympanokeratoma otitis media. An ADC value below 916 × 10-6 mm2/s interpreted as a tympanokeratoma yielded an accuracy of 78.7%, a sensitivity of 92.6%, and a specificity of 60%. In the study population, combined qualitative analysis of DW images and ADC maps was the most effective method for diagnosing tympanokeratomas with an accuracy of 80.9%, a sensitivity of 92.6%, and a specificity of 65%.

Recent advances in Otology: Current landscape and future direction

Hearing is an essential sensation, and its deterioration leads to a significant decrease in the quality of life. Thus, great efforts have been made by otologists to preserve and recover hearing. Our knowledge regarding the field of otology has progressed with advances in technology, and otologists have sought to develop novel approaches in the field of otologic surgery to achieve higher hearing recovery or preservation rates. This requires knowledge regarding the anatomy of the temporal bone and the physiology of hearing. Basic research in the field of otology has progressed with advances in molecular biology and genetics. This review summarizes the current views and recent advances in the field of otology and otologic surgery, especially from the viewpoint of young Japanese clinician-scientists, and presents the perspectives and future directions for several topics in the field of otology. This review will aid next-generation researchers in understanding the recent advances and future challenges in the field of otology.

Improved reconstruction for highly accelerated propeller diffusion 1.5 T clinical MRI

PURPOSE

Propeller fast-spin-echo diffusion magnetic resonance imaging (FSE-dMRI) is essential for the diagnosis of Cholesteatoma. However, at clinical 1.5 T MRI, its signal-to-noise ratio (SNR) remains relatively low. To gain sufficient SNR, signal averaging (number of excitations, NEX) is usually used with the cost of prolonged scan time. In this work, we leveraged the benefits of Locally Low Rank (LLR) constrained reconstruction to enhance the SNR. Furthermore, we enhanced both the speed and SNR by employing Convolutional Neural Networks (CNNs) for the accelerated PROPELLER FSE-dMRI on a 1.5 T clinical scanner.

METHODS

Residual U-Net (RU-Net) was found to be efficient for propeller FSE-dMRI data. It was trained to predict 2-NEX images obtained by Locally Low Rank (LLR) constrained reconstruction and used 1-NEX images obtained via simplified reconstruction as the inputs. The brain scans from healthy volunteers and patients with cholesteatoma were performed for model training and testing. The performance of trained networks was evaluated with normalized root-mean-square-error (NRMSE), structural similarity index measure (SSIM), and peak SNR (PSNR).

RESULTS

For 4 × under-sampled with 7 blades data, online reconstruction appears to provide suboptimal images-some small details are missing due to high noise interferences. Offline LLR enables suppression of noises and discovering some small structures. RU-Net demonstrated further improvement compared to LLR by increasing 18.87% of PSNR, 2.11% of SSIM, and reducing 53.84% of NRMSE. Moreover, RU-Net is about 1500 × faster than LLR (0.03 vs. 47.59 s/slice).

CONCLUSION

The LLR remarkably enhances the SNR compared to online reconstruction. Moreover, RU-Net improves propeller FSE-dMRI as reflected in PSNR, SSIM, and NRMSE. It requires only 1-NEX data, which allows a 2 × scan time reduction. In addition, its speed is approximately 1500 times faster than that of LLR-constrained reconstruction.

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.

Comparison Between EPI DWI and PROPELLER DWI in Brain MR Imaging

OBJECTIVE

EPI DWI is a routinely used sequence in brain imaging but it has limitations when it comes to SNR and artifact reduction. PROPELLER DWI has the benefit of improving image quality compared to EPI DWI. The aim of this study is to compare the EPI DWI sequence in brain MR imaging with the PROPELLER DWI sequence. The objective is to identify which sequence is more beneficial in brain imaging by evaluating image quality and the depiction of pathologies.

MATERIALS AND METHODS

A total of 101 patients (55 females and 46 males, mean age 56 years) underwent brain MRI examination on a 1.5 T scanner. EPI DWI and PROPELLER DWI sequences were acquired in every exam and were reviewed by 2 radiologists. The images were evaluated by performing a quantitative analysis based on Relative Contrast and a qualitative analysis (overall image quality, conspicuousness of lesions, artifact reduction, etc.).

RESULTS

In both the qualitative and quantitative analysis PROPELLER DWI achieved better results than EPI DWI. PROPELLER DWI showed statistical significance in the overall image quality (P < 0.001), the elimination of susceptibility (P < 0.001) and flow pulsation artifacts (P < 0.001), as well as in the contrast between CSF with white (P < 0.001) and grey matter (P < 0.001). Also, PROPELLER DWI presented better delineation of pathologies like ischemic strokes, metastasis, tumors and vasogenic edemas than conventional EPI DWI.

CONCLUSION

PROPELLER DWI was the preferred sequence during the image evaluation. Compared to EPI DWI, PROPELLER DWI managed to reduce susceptibility and flow pulsation whilst achieving higher image quality and lesion delineation and earlier depiction of ischemic strokes than the conventional EPI DWI. PROPELLER DWI may be incorporated in brain MR imaging replacing EPI DWI.

Imaging of Pathologies of the Temporal Bone and Middle Ear: Inflammatory Diseases, Their Mimics and Potential Complications-Pictorial Review

Imaging of the temporal bone and middle ear is challenging for radiologists due to the abundance of distinct anatomical structures and the plethora of possible pathologies. The basis for a precise diagnosis is knowledge of the underlying anatomy as well as the clinical presentation and the individual patient's otological status. In this article, we aimed to summarize the most common inflammatory lesions of the temporal bone and middle ear, describe their specific imaging characteristics, and highlight their differential diagnoses. First, we introduce anatomical and imaging fundamentals. Additionally, a point-to-point comparison of the radiological and histological features of the wide spectrum of inflammatory diseases of the temporal bone and middle ear in context with a review of the current literature and current trends is given.

Early Magnetic Resonance Imaging to Diagnose Residual Cholesteatoma in Children and Benefit of Radiological Rereview

OBJECTIVE

Non-echo-planar diffusion-weighted (DW) magnetic resonance imaging (non-EPI MRI) is the appropriate sequence to detect residual cholesteatoma. In the child, MRI may be clinically useful to determine the timing of the second-look procedure. The aim of this paper was to retrospectively evaluate the performance of early MRI (before the 18th postoperative month) in detecting residual cholesteatoma in children after review by experienced specialized neuroradiologists.

STUDY DESIGN

Retrospective study.

SETTING

One university center comparative cohort.

METHODS

All patients who had a 2-staged procedure for cholesteatoma with an MRI before the second stage from 2010 to 2020 were included and analyzed. Three pediatric neuroradiologists reviewed all the images blinded to the surgical result.

RESULTS

N = 141 cholesteatoma events (140 children) were included with a mean age at MRI of 10 (±4) years old. Non-EPI MRIs were performed 10.7 (±3.8) months after the first-stage surgery and 2.2 (±2.6) months before the second-stage procedure. Non-EPI MRI had a 0.57 sensitivity (SE) and 0.83 specificity (SP). MRI was reviewed in 112 cases. The diagnosis was corrected in 17 cases (15.1%) (3 true positives, 7 false negatives, and 7 false positives). SE = 0.63 (p = 0.1) and SP = 0.92 (p = 0.08) after rereading.

CONCLUSION

Early MRI's SE is poor but SP is excellent after rereading. Evidence does not support the use of early non-EPI MRI to modify the surgical strategy or to postpone the second look. If performed, early non-EPI MRI should be read by specialized experienced radiologists with all 3 sequences (T1, T2, and non-EPI DW) and apparent diffusion coefficient calculation, especially in cases of otitis media with effusion.

PROPELLER diffusion weighted imaging for diagnosis of cholesteatoma in comparison with surgical and histopathological results: emphasis on false positivity and false negativity

PURPOSE

To investigate the role of non-echo planar diffusion weighted imaging (DWI) using "periodically rotated overlapping parallel lines with enhanced reconstruction" (PROPELLER) sequence for the diagnosis of cholesteatoma compared to surgical and histopathological results in an attempt to determine the factors causing false negative and false positive diagnoses.

METHODS

Patients who had PROPELLER DWI before ear surgery were retrospectively reviewed. The presence of a lesion with diffusion restriction on PROPELLER DWI was accepted as positive for cholesteatoma, and the results were compared to the intraoperative and histopathological findings.

RESULTS

A total of 112 ears in 109 patients were reviewed. On PROPELLER DWI, a lesion with diffusion restriction was found in 101 (90.2%) ears, while in 11 (9.8%) of the patients, no diffusion restriction was found. Surgery and histopathological analysis revealed a cholesteatoma in 100 (89.3%) ears, while in 12 (10.7%) ears, no cholesteatoma was found surgically. There were 96 (85.7%) true positives, 7 (6.2%) true negatives, 5 (4.5%) false positives and 4 (3.6%) false negatives. The accuracy, sensitivity, specificity, positive predictive and negative predictive values of non-echo planar DWI were calculated to be 91.96%, 96%, 58.33%, 95.05%, and 63.64%, respectively.

CONCLUSION

Non-echo planar DWI using PROPELLER sequence has high accuracy, sensitivity and positive predictive value and can be used for the detection of cholesteatoma. The external auditory canal, postoperative ears and small lesions should be evaluated with caution to avoid false results.

Comparison of Diagnostic Performance and Image Quality between Topup-Corrected and Standard Readout-Segmented Echo-Planar Diffusion-Weighted Imaging for Cholesteatoma Diagnostics

This study compares the diagnostic performance and image quality of single-shot turbo spin-echo DWI (tseDWI), standard readout-segmented DWI (rsDWI), and a modified rsDWI version (topupDWI) for cholesteatoma diagnostics. Thirty-four patients with newly suspected unilateral cholesteatoma were examined on a 1.5 Tesla MRI scanner. Diagnostic performance was evaluated by calculating and comparing the sensitivity and specificity using histopathological results as the standard of reference. Image quality was independently reviewed by two readers using a 5-point Likert scale evaluating image distortions, susceptibility artifacts, image resolution, lesion conspicuity, and diagnostic confidence. Twenty-five cholesteatomas were histologically confirmed after surgery and originated in the study group. TseDWI showed the highest sensitivity with 96% (95% confidence interval (CI): 88–100%), followed by topupDWI with 92% (95% CI: 81–100%) for both readers. The sensitivity for rsDWI was 76% (95% CI: 59–93%) for reader 1 and 84% (95% CI: 70–98%) for reader 2, respectively. Both tseDWI and topupDWI revealed a specificity of 100% (95% CI: 66–100%) and rsDWI of 89% (95% CI: 52–100%). Both tseDWI and topupDWI showed fewer image distortions and susceptibility artifacts compared to rsDWI. Image resolution was consistently rated best for topupDWI, followed by rsDWI, which both outperformed tseDWI. TopupDWI and tseDWI showed comparable results for lesions’ conspicuity and diagnostic confidence, both outperforming rsDWI. Modified readout-segmented DWI using the topup-correction method is preferable to standard rsDWI and may be regarded as an accurate alternative to single-shot turbo spin-echo DWI in cholesteatoma diagnostics.

Mastoid obliteration versus canal wall down or canal wall up mastoidectomy for cholesteatoma: Systematic review and meta-analysis

BACKGROUND

There is ongoing debate over the optimal surgical approach for cholesteatoma treatment^1-5. The aim of this review was to determine whether canal-wall down with mastoid obliteration is associated with favourable outcomes compared to either canal-wall down without obliteration or canal-wall up. The primary outcome was cholesteatoma reoccurrence with secondary outcomes including otorrhoea, reoperation and patient-reported outcome measures.

METHODS

Medline, Embase, Cochrane databases and clinicaltrials.gov were searched for studies reporting outcomes of patients undergoing primary CWD-MO for cholesteatoma and directly compared with CWD and CWU mastoidectomies. Data were collated and meta-analysis performed.

RESULTS

2379 patients were included from 12 studies that met the inclusion criteria. CWD-MO was found to be associated with significantly less risk of recurrence when compared to CWU (OR = 0.330 (95 % CI 0.191-0.570, p < 0.001). When compared to CWD, CWD-MO was associate with significantly lower incidence of persistent otorrhoea (OR 0.405 (95 % CI 0.232-0.706, p < 0.001) while the rates of recurrence were comparable (OR: 1.231 [95 % CI: 0.550-2.757] p = 0.613). Otorrhoea rates between CWD-MO and CWU were equivalent as was reoperation. Quality of life and hearing outcomes were variably reported.

CONCLUSIONS

This systematic review demonstrates that CWD-MO technique achieves lower recurrence rates comparable to CWD approaches and superior to CWU, while offering improved long-term control of otorrhoea. The final procedural choice should be decided based on surgeon experience, skill set and individual patient factors. To address the risk of selection bias, a randomised controlled trial is needed to answer this important research question.

Role of Diffusion-Weighted Magnetic Resonance Imaging in the Evaluation of Clinically Suspected Cholesteatoma Cases

To analyze the apparent diffusion coefficient (ADC) values of middle ear and mastoid lesions in Diffusion weighted Magnetic Resonance Imaging (DW-MRI) to arrive at a probable demarcating value to differentiate cholesteatoma from non-cholesteatomatous lesions. Accurate anatomic localization of the lesion was also done using High Resolution Computed Tomography (HRCT) temporal bone. The study cohort consisted of 30 patients who had undergone HRCT, DW-MRI and surgical intervention in clinically suspected cholesteatomatous lesions during the period August 2018 to August 2020.Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy values of HRCT and MRI in relation to intraoperative findings and histopathological findings (gold standard) were calculated and compared using the 2-sided McNemar's Chi Square test. Receiver operating characteristic (ROC) curve was used to predict the cut off value of ADC to differentiate between cholesteatoma and non cholesteatomatous lesions. Total patients were 30 out of which 15 were histopathologically proven cholesteatoma. MR DWI showed 100% sensitivity, 80% specificity, and 90% accuracy in diagnosing cholesteatoma compared to HPE. The probable cut off value of ADC in differentiating cholesteatoma from non-cholesteatomatous lesions was found to be < 1.226 × 10^-3 mm²/s, statistically using ROC curve. HRCT showed 96.6% accuracy in identifying the location of the lesion. MR-DWI is a useful tool both individually and in combination with HRCT in the diagnosis of cholesteatomas with high accuracy. An ADC cut-off value could also significantly help increase the accuracy of diagnosis.

Performance of 2D BLADE turbo gradient- and spin-echo diffusion-weighted imaging in the quantitative diagnosis of recurrent temporal bone cholesteatoma

BACKGROUND

Diffusion-weighted imaging (DWI) has become an important tool for the detection of cholesteatoma. The purpose of this study was to explore the value of 2D BLADE turbo gradient- and spin-echo imaging (TGSE BLADE) DWI in the quantitative diagnosis of recurrent temporal bone cholesteatoma (CS).

METHODS

From March 2018 to October 2021, 67 patients with suspected recurrence of temporal bone CS after assessment by clinical otorhinolaryngologists who had undergone previous ear surgery for CS were prospectively evaluated by magnetic resonance imaging (MRI). Two radiologist assessed images independently. Quantitative parameters such as signal intensity ratio (SIR) calculated using, as a reference, the inferior temporal cortex (SIRT) and the background noise (SIRN), apparent diffusion coefficient (ADC) value, and ADC ratio (with pons as reference) measured on TGSE BLADE sequences were assessed. Using receiver operating characteristic (ROC) curve analysis, the optimal threshold and diagnostic performance for diagnosing recurrent CS were determined. Pair-wise comparison of the ROC curves was performed using the area under the ROC curve (AUC).

RESULTS

Finally, 44 patients were included in this study, including 25 CS and 19 non-cholesteatoma (NCS). Mean SIRT and mean SIRN on TGSE BLADE DWI were significantly higher for CS than NCS lesions (p < 0.001). Meanwhile, mean ADC values and mean ADC ratios on ADC maps were significantly lower in the CS group than in the NCS group (p < 0.001). According to ROC analysis, the diagnostic efficacy of quantitative parameters such as SIRT (AUC = 0.967), SIRN (AUC = 0.979), ADC value (AUC = 1.0), and ADC ratio (AUC = 0.983) was significantly better than that of qualitative DWI (AUC = 0.867; p = 0.007, 0.009, 0.011 and 0.037, respectively).

CONCLUSIONS

Residual/recurrent temporal bone CS can be accurately detected using quantitative evaluation of TGSE BLADE DWI.

Proposal of a magnetic resonance imaging follow-up protocol after cholesteatoma surgery: a prospective study

BACKGROUND

Non-echo planar (EPI) diffusion-weighted (DW) MRI has become an effective tool for the follow-up after cholesteatoma surgery and decreased the rate of second-look surgeries.

OBJECTIVES

To shed light on the optimal imaging follow-up protocol to detect postoperative residual or recurrent cholesteatoma.

MATERIALS AND METHODS

64 patients were included in this prospective study. Three different surgical procedures were considered: canal-wall-up (26 patients), canal-wall-down (20 patients), and obliterative (18 patients). The imaging follow-up protocol included non-EPI DW MRI during the following postoperative periods: 1 month, 6 months, and 1, 3, 5, and 7 years after the primary surgery.

RESULTS

MRI-positive lesions were present in 18.75% of patients. 50% of the MRI-positive findings occurred at the 1-month follow-up. The other peak of MRI positivity occurred at the 3-year follow-up. The last MRI-positive finding appeared at the 5-year follow-up.

CONCLUSIONS

The timing for the imaging protocol proposed by this prospective study to detect recidivism after cholesteatoma surgery stressed the importance of performing non-EPI DW MRI for detecting residual, though rare, disease. Likewise, extending the follow-up to a least 5 years after primary surgery was also recommended to detect any recurrent cholesteatoma that would appear unlikely to be present beyond this time set.

Epidemiologic, Imaging, and Clinical Issues in Bezold’s Abscess: A Systematic Review

Bezold’s abscess is a deep neck abscess related to otomastoiditis. Due to the insidious clinical presentation, diagnosis can be extremely challenging, leading to delays in treatment and possible life-threatening complications. The literature currently provides a fragmented picture, presenting only single or small number of cases. The present study aims at examining our experience and the literature findings (based on PRISMA criteria) of 97 patients with Bezold’s abscess, summarizing their epidemiology, pathogenesis, clinical presentation, imaging findings, and treatments. Bezold’s abscess is found at any age, with overt male prevalence among adults. The clinical presentation, as well as the causative pathogens, are strikingly heterogeneous. Otomastoiditis and cholesteatoma are major risk factors. A clinical history of otitis is commonly reported (43%). CT and MRI are the main diagnostic tools, proving the erosion of the mastoid tip in 53% of patients and the presence of a concomitant cholesteatoma in 40%. Intracranial vascular (24%) or infectious (9%) complications have also been reported. Diagnosis might be easily achieved when imaging (CT) is properly applied. MRI has a limited diagnostic role, but it might be crucial whenever intracranial complications or the coexistence of cholesteatoma are suspected, helping to develop proper treatment (prompt antibiotic therapy and surgery).

Comparative evaluation of temporal subtraction computed tomography and non-echoplanar diffusion-weighted imaging for the mastoid extension of middle ear cholesteatoma

OBJECTIVE

Preoperative imaging assessment influences the decision to perform mastoidectomy for the mastoid extension of middle ear cholesteatoma. This study compared the performance of temporal subtraction CT (TSCT) and non-echoplanar diffusion-weighted imaging (non-EP DWI) in evaluating such mastoid extensions.

METHODS

We retrospectively evaluated 239 consecutive patients with surgically proven middle ear cholesteatoma between April 2016 and April 2021. The diagnostic performance of TSCT, wherein the presence of black color indicated progressive bone erosion, and non-EP DWI, wherein high signal intensity in the mastoid region suggested mastoid extension, was compared using Fisher's exact test.

RESULTS

In 34 patients with evaluable TSCT images, black color was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of TSCT were 1.00, 0.95, 0.94, 1.00, and 0.97, respectively. In 90 patients with evaluable non-EP DWI, high signal intensity was significantly more common in patients with mastoid extension than in those without; the sensitivity, specificity, PPV, NPV, and accuracy of non-EP DWI were 0.88, 0.85, 0.91, 0.81, and 0.87, respectively. In 16 patients with both evaluable TSCT and non-EP DWI, the diagnostic performance of the TSCT was slightly superior to that of the non-EP DWI for predicting mastoid extension, although the difference was not significant.

CONCLUSIONS

TSCT images generated using consecutively acquired preoperative high-resolution CT images are useful for predicting mastoid extension of middle ear cholesteatoma, and the diagnostic performance of TSCT is non-inferior to that of non-EP DWI.

Pediatric Petrous Apex Lesions: A Radiological Classification and Diagnostic Algorithm

The petrous apex (PA) is involved in a myriad of pathological conditions, some of which are exclusive in children. Diagnosis may be difficult due to vague clinical presentation, and local examination is challenging owing to its inaccessible location. This is further complicated by multiple unfused sutures and ongoing PA pneumatization in children. Cross-sectional imaging is vital for the evaluation of the PA lesions, due to their precarious location and proximity to the major neurovascular structures. Several classification systems have been proposed for these lesions based on their site of origin, solid or cystic appearance, surgical or non-surgical (no touch lesions) management, and benign or malignant nature. In this article, we emphasize the distinctive role of different cross-sectional imaging modalities in the diagnosis of pediatric PA lesions, with special attention to normal variants that should not be mistaken for pathology. We also propose a radiological classification and algorithmic approach to aid in the precise diagnosis and facilitate appropriate management of the various PA lesions in children.

Preoperative prediction for mastoid extension of middle ear cholesteatoma using temporal subtraction serial HRCT studies

OBJECTIVES

This study investigated the utility of temporal subtraction computed tomography (TSCT) obtained with temporal bone high-resolution computed tomography (HRCT) for the preoperative prediction of mastoid extension of middle ear cholesteatomas.

METHODS

Twenty-eight consecutive patients with surgically proven middle ear cholesteatomas were retrospectively evaluated. The presence of black color in the mastoid region on TSCT suggested progressive changes caused by bone erosion. Enlarged width of the anterior part of mastoid on HRCT was interpreted as suggestive of mastoid extension. Fisher's exact test was used to compare the widths and black color on TSCT for cases with and without mastoid extension. The diagnostic accuracy of TSCT and HRCT for detecting mastoid extension and interobserver agreement during the evaluation of black color on TSCT were calculated.

RESULTS

There were 15 cases of surgically proven mastoid extension and 13 cases without mastoid extension. Patients with black color on TSCT were significantly more likely to have a mastoid extension (p < 0.001). The sensitivity and specificity of TSCT were 0.93 and 1.00, respectively. Patients in whom the width of the anterior part of the mastoid was enlarged were significantly more likely to have a mastoid extension (p = 0.007). The sensitivity and specificity of HRCT to detect the width of the anterior part of the mastoid were 0.80 and 0.77, respectively. Interobserver agreement during the evaluation of TSCT findings was good (k = 0.71).

CONCLUSIONS

This novel TSCT technique and preoperative evaluations are useful for assessing mastoid extension of middle ear cholesteatomas and making treatment decisions.

KEY POINTS

•TSCT shows a clear black color in the mastoid region when the middle ear cholesteatoma is accompanied by mastoid extension. •TSCT obtained with preoperative serial HRCT of the temporal bone is useful for assessing mastoid extension of middle ear cholesteatomas.

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.

Diffusion-Weighted Imaging of the Head and Neck (Including Temporal Bone)

Diffusion techniques provide valuable information when performing head and neck imaging. This information can be used to detect the presence or absence of pathology, refine differential diagnosis, determine the location for biopsy, assess response to treatment, and prognosticate outcomes. For example, when certain technical factors are taken into consideration, diffusion techniques prove indispensable in assessing for residual cholesteatoma following middle ear surgery. In other scenarios, pretreatment apparent diffusion coefficient values may assist in prognosticating outcomes in laryngeal cancer and likelihood of response to radiation therapy. As diffusion techniques continue to advance, so too will its clinical utility.

Non-EPI versus Multishot EPI DWI in Cholesteatoma Detection: Correlation with Operative Findings

BACKGROUND AND PURPOSE

Although multishot EPI (readout-segmented EPI) has been touted as a robust DWI sequence for cholesteatoma evaluation, its efficacy in disease detection compared with a non-EPI (eg, HASTE) technique is unknown. This study sought to compare the accuracy of readout-segmented EPI with that of HASTE DWI in cholesteatoma detection.

MATERIALS AND METHODS

A retrospective review was completed of consecutive patients who underwent MR imaging for the evaluation of suspected primary or recurrent/residual cholesteatomas. Included patients had MR imaging examinations that included both HASTE and readout-segmented EPI sequences and confirmed cholesteatomas on a subsequent operation. Two neuroradiologist reviewers assessed all images, with discrepancies resolved by consensus. The ratio of signal intensity between the cerebellum and any observed lesion was noted.

RESULTS

Of 23 included patients, 12 (52.2%) were women (average age, 47.8 [SD, 25.2] years). All patients had surgically confirmed cholesteatomas: Six (26.1%) were primary and 17 (73.9%) were recidivistic. HASTE images correctly identified cholesteatomas in 100.0% of patients. On readout-segmented EPI sequences, 16 (69.6%) were positive, 5 (21.7%) were equivocal, and 2 (8.7%) were falsely negative. Excellent interobserver agreement was noted between reviews on both HASTE (κ = 1.0) and readout-segmented EPI (κ = 0.9) sequences. The average signal intensity ratio was significantly higher on HASTE than in readout-segmented EPI, facilitating enhanced detection (mean difference 0.5; 95% CI, 0.3-0.8; P = .003).

CONCLUSIONS

HASTE outperforms readout-segmented EPI in the detection of primary cholesteatoma and disease recidivism.

Microtia and cholesteatoma: Implications for the reconstructive surgeon

Infection after reconstructive surgery for microtia is a technical challenge. This can be a sign of cholesteatoma formation by entrapment of epithelium in the middle or outer ear, specifically when the patient does not respond to first choice antibiotic therapy and debridement.

Two patients with microtia presented themselves with severe infections after ear reconstruction. In both cases cholesteatoma was diagnosed as the cause of the infection. After cholesteatoma management an additional surgical procedure was necessary to improve the esthetic outcome. The plastic surgeon should identify possible signs of cholesteatoma after reconstruction of the auricle.

Non-echoplanar diffusion weighed imaging and T1-weighted imaging for cholesteatoma mastoid extension

OBJECTIVES

A broad mastoid extension limits cholesteatoma resection via a transmeatal approach including endoscopic ear surgery. Therefore, a preoperative diagnosis of mastoid extension is a the most critical factor to determine whether to perform mastoidectomy. The purpose of this study was to assess the efficacy of non-echoplanar diffusion-weighted imaging (non-EPI DWI) and T1-weighted imaging in the evaluation of mastoid extension in cholesteatomas of the middle ear.

METHODS

Patients who underwent magnetic resonance imaging (MRI) for pretreatment evaluation before primary surgery for pars flaccida or tensa cholesteatoma, which revealed a high-signal intensity in the mastoid on T2-weighed imaging were retrospectively evaluated. Two board-certified radiologists retrospectively evaluated the extent of cholesteatomas on MRI with non-EPI DWI, non-EPI DWI- and T1-weighted axial imaging. The presence of a high signal intensity on non-EPI DWI or low or high signal intensity on T1-weighted imaging in the mastoid was evaluated. All cases were subclassified as M+ (surgically mastoid extension-positive) or M- (surgically mastoid extension-negative).

RESULTS

A total of 59 patients with middle ear cholesteatoma were evaluated. There were 37 M+ cases and 22 M- cases. High-signal intensity on non-EPI DWI exhibited a sensitivity of 0.89 and specificity of 0.82, whereas partial low-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.84 and specificity of 0.91 for detecting mastoid involvement. Complete high-signal intensity on T1-weighted imaging exhibited a sensitivity of 0.73 and specificity of 0.89 for detecting non-involvement of the mastoid. The sensitivity (0.92) and specificity (0.96) of combined non-EPI DWI and T1-weighted imaging evaluation were higher than those of with non-EPI DWI or T1-weighted imaging alone. The interobserver agreement for the presence of high-signal intensity in the mastoid cavity on non-EPI DWI was very good at 0.82, that of a partial low-signal intensity area in the mastoid cavity lesions on T1-weighted imaging was good, at 0.76 and that of complete high-signal intensity in the mastoid cavity lesions on T1-weighted imaging was good, at 0.67.

CONCLUSIONS

The signal intensity on non-EPI DWI and T1-weighted imaging of the mastoid could be used to accurately assess the extent of middle ear cholesteatoma, which could facilitate surgical treatment planning.

Distribution of different morphological types of anterior epitympanic plate “cog” and Köerner’s septum in CT images of cholesteatomatous and non-cholesteatomatous CSOM: is it really significant?

Background

The anterior epitympanic plate (cog) and Köerner’s septum are gaining more importance since the introduction of transcanal mastoidectomy as these anatomical structures are serving landmarks for the attic. Moreover, different morphological types of cog and Köerner’s septum revealed embryological relation to the development of the isthmic membrane; the latter is linked to aeration of the attic and thus affects the pathological development of the cholesteatoma.

Results

A retrospective review of CT images of 86 patients proved by surgical biopsies revealed: 49 cholesteatomas and 37 non-cholesteatomatous CSOM. The type-I “cog” had a higher incidence (n = 40) and was statistically more prevalent in non-cholesteatomatous CSOM (n = 30, 81.1%). Type-II was the second commonest and was statistically more prevalent in cholesteatomatous CSOM (n = 22, 44.9%). Type-III was the third commonest, seen in (n = 18, 20.9%) and was statistically more prevalent in cholesteatomatous CSOM (n = 17, 34.7%). Köerner’s septum was more prevalent in non-cholesteatomatous CSOM (70.3%) with statistical significance (p value = 0.002).

Conclusions

The difference in the distribution of different morphological types of anterior epitympanic plate “cog,” as well as the difference in Köerner’s septum existence amongst cholesteatomatous and non-cholesteatomatous CSOM are suggested as risk factors for the development of cholesteatoma and may predict a cholesteatoma on CT images.

Positive predictive value for diffusion-weighted magnetic resonance imaging in pediatric cholesteatoma: A retrospective study

OBJECTIVES

The aims of this study were first to calculate the Positive Predictive Value (PPV) of DW-MRI to detect cholesteatoma and then to analyze false positives.

METHODS

All temporal bone MRI with DWI sequences performed in our pediatric university hospital between 2005 and 2015 were included retrospectively. 46 patients with a cholesteatoma diagnosis on the MRI report and who underwent surgery were studied.

RESULTS

The number of DW-MRI for identification of cholesteatoma has grown in ten years. We calculated an 89% Positive Predictive Value. DW-MRI sensitivities were 100.0% and 70.7% for respectively keratin and squamous epithelium.

CONCLUSION

DW-MRI hypersignal is not synonymous of cholesteatoma diagnosis. Indeed, this diagnosis relies on the importance of a proper otoscopic examination, a suggestive medical history, CT scan data and analysis of other MRI sequences, including T1-weighted sequence, to rule out other etiologies of middle ear DW-MRI hypersignal.

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.

Cross-Sectional Imaging Evaluation of Congenital Temporal Bone Anomalies: What Each Radiologist Should Know

Hearing loss in pediatric age group is associated with many congenital temporal bone disorders. Aberrant development of various ear structures leads into either conductive or sensorineural hearing loss. Knowledge of the embryology and anatomical details of various compartments of the ear help better understanding of such disorders. In general, abnormalities of external and middle ears result in conductive hearing loss. Whereas abnormalities of inner ear structures lead into sensorineural hearing loss. These abnormalities could occur as isolated or part of syndromes. Temporal bone disorders are a significant cause of morbidity and developmental delays in children. Imaging evaluation of children presented with hearing loss is paramount in early diagnosis and proper management planning. Our aim is to briefly discuss embryology and anatomy of the pediatric petrous temporal bones. The characteristic imaging features of commonly encountered congenital temporal bone disorders and their associated syndromes will be discussed.

Temporal bone meningiomas: emphasizing radiologic signs to improve preoperative diagnosis

PURPOSE

Temporal bone meningioma is an extremely rare disease. Lack of clinical attention due to its rarity might lead to delayed diagnosis. This short communication aims to emphasize radiologic signs of temporal bone meningiomas to improve preoperative diagnosis.

METHODS

Radiological characteristics of temporal bone meningiomas are discussed.

RESULTS

Temporal bone meningioma is characterized by diffuse "hairy" trabecular hyperostosis without the destruction of trabecular structures, bone thickening, and irregular surface margins of the temporal bone on computed tomography. The dural tail sign is a unique feature of temporal bone meningioma on magnetic resonance imaging.

CONCLUSION

Otolaryngologists certainly should be aware of characteristic radiologic signs of temporal bone meningiomas. Using modern computed tomography and magnetic resonance imaging protocols enables with a high degree of accuracy to distinguish temporal bone meningiomas from other more common entities in this location.

Rapid diffusion-weighted MRI for the investigation of recurrent temporal bone cholesteatoma

BACKGROUND

Suspected cholesteatoma recurrence is commonly investigated with magnetic resonance imaging (MRI) of the temporal bone. Non-echo planar diffusion-weighted imaging (non-EP DWI) has become the sequence of choice.

PURPOSE

To assess the agreement between an MRI protocol incorporating both non-EP DWI and contrast-enhanced sequences, and a shortened protocol without contrast-enhanced sequences in the assessment of suspected cholesteatoma recurrence.

MATERIALS AND METHODS

One hundred consecutive MRIs, consisting of T2-weighted, non-EP DWI and pre- and post-contrast T1-weighted sequences, were reviewed by two radiologists at a tertiary referral centre. Agreement between the two protocols was assessment by means of a weighted Cohen kappa coefficient.

RESULTS

We found a near perfect agreement between the two protocols (kappa coefficient with linear weighting 0.98; 95% confidence interval 0.95-1.00). There were two cases in which the two protocols were discordant. In both cases, the lesion measured <3 mm and images were degraded by artefact at the bone-air interface. The shortened protocol without post-contrast sequences yielded a 32% reduction in acquisition time.

CONCLUSION

When non-EP DWI is available, contrast-enhanced sequences can be omitted in the vast majority of cases without compromising diagnostic accuracy. Contrast-enhanced sequences may provide additional value in equivocal cases with small (<3 mm) lesions or in cases where images are degraded by artefact.

Performance of TGSE BLADE DWI compared with RESOLVE DWI in the diagnosis of cholesteatoma

Background

Based on its high resolution in soft tissue, MRI, especially diffusion-weighted imaging (DWI), is increasingly important in the evaluation of cholesteatoma. The purpose of this study was to evaluate the role of the 2D turbo gradient- and spin-echo (TGSE) diffusion-weighted (DW) pulse sequence with the BLADE trajectory technique in the diagnosis of cholesteatoma at 3 T and to qualitatively and quantitatively compare image quality between the TGSE BLADE and RESOLVE methods.

Method

A total of 42 patients (23 males, 19 females; age range, 7–65 years; mean, 40.1 years) with surgically confirmed cholesteatoma in the middle ear were enrolled in this study. All patients underwent DWI (both a prototype TGSE BLADE DWI sequence and the RESOLVE DWI sequence) using a 3-T scanner with a 64-channel brain coil.

Qualitative imaging parameters (imaging sharpness, geometric distortion, ghosting artifacts, and overall imaging quality) and quantitative imaging parameters (apparent diffusion coefficient [ADC], signal-to-noise ratio [SNR], contrast, and contrast-to-noise ratio [CNR]) were assessed for the two diffusion acquisition techniques by two independent radiologists.

Result

A comparison of qualitative scores indicated that TGSE BLADE DWI produced less geometric distortion, fewer ghosting artifacts (P < 0.001) and higher image quality (P < 0.001) than were observed for RESOLVE DWI. A comparison of the evaluated quantitative image parameters between TGSE and RESOLVE showed that TGSE BLADE DWI produced a significantly lower SNR (P < 0.001) and higher parameter values (both contrast and CNR (P < 0.001)) than were found for RESOLVE DWI.

The ADC (P < 0.001) was significantly lower for TGSE BLADE DWI (0.763 × 10^− 3 mm²/s) than RESOLVE DWI (0.928 × 10^− 3 mm²/s).

Conclusion

Compared with RESOLVE DWI, TGSE BLADE DWI significantly improved the image quality of cholesteatoma by reducing magnetic sensitive artifacts, distortion, and blurring. TGSE BLADE DWI is more valuable than RESOLVE DWI for the diagnosis of small-sized (2 mm) cholesteatoma lesions. However, TGSE BLADE DWI also has some disadvantages: the whole image intensity is slightly low, so that the anatomical details of the air-bone interface are not shown well, and this shortcoming should be improved in the future.

Diagnosis and management of spontaneous cerebrospinal fluid fistula and encephaloceles

PURPOSE OF REVIEW

To describe the current state in the diagnosis and management of spontaneous cerebrospinal fluid (sCSF) fistula and encephaloceles.

RECENT FINDINGS

The increased incidence of obesity has resulted in more cases of sCSF fistula and encephaloceles. Obesity results in increased intracranial pressure and a greater chance of developing a sCSF fistula or encephalocele. Obstructive sleep apnea can also result in transient increase in intracranial pressure and has been shown to be common in patients with sCSF fistula. Treatment of CSF fistula is usually necessary because of the increased risk of meningitis. The use of hydroxyapatite bone cements to repair the temporal bone defects has been described with a high success rate of closing the fistula and a low complication rate. Concurrent superior semicircular canal dehiscent can be seen in up to 15% of cases and should be suspected during the surgical approach to avoid potential sensorineural hearing loss and chronic imbalance.

SUMMARY

sCSF fistula and encephaloceles are an uncommon cause of hearing loss, middle ear effusion, and otorrhea, but should be recognized and repaired because of the risk of meningitis.

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

BACKGROUND AND PURPOSE

MR imaging has become an important tool for the detection of cholesteatomas of the middle ear. Various diffusion-weighted imaging sequences are available and have shown promising results. This study aimed to evaluate readout-segmented echo-planar DWI for the detection of cholesteatoma and compare the results with surgical validation.

MATERIALS AND METHODS

Fifty patients with chronic otitis media (24 females and 26 males; range, 12-76 years of age; mean age, 41 years) who underwent MR imaging before an operation of the middle ear (1-169 days) were included. The MR imaging protocol consisted of axial and coronal readout-segmented echo-planar DWI with b-values of 0 and 1000 s/mm² and 3-mm slice thickness. The readout-segmented echo-planar diffusion-weighted images were fused with standard T2-weighted sequences for better anatomic assignment. The results of the MR imaging evaluation were correlated with the results from the operation.

RESULTS

Readout-segmented echo-planar DWI detected 22 of the 25 cases of surgically proved cholesteatoma. It has an accuracy of 92% (95% confidence interval, 80.8%-97.8%), a sensitivity of 88%, a specificity of 96%, a positive predictive value of 96%, and a negative predictive value of 89%. In 1 case, a positive finding for cholesteatoma with readout-segmented echo-planar DWI could not be proved by histology, and in 3 cases, histology yielded a cholesteatoma that was not detected with MR imaging.

CONCLUSIONS

Readout-segmented echo-planar DWI is a promising and reliable MR imaging sequence for the detection and exclusion of cholesteatoma.

The diagnostic accuracy of 1.5 T versus 3 T non-echo-planar diffusion-weighted imaging in the detection of residual or recurrent cholesteatoma in the middle ear and mastoid

PURPOSE AND BACKGROUND

This study retrospectively compares diagnostic performance of 1.5 T versus 3 T non-echo planar diffusion weighted imaging with or without additional T1 and T2 sequences in the detection of residual and/or recurrent cholesteatoma.

METHODS

Patients with clinically suspected recurrent cholesteatoma or postoperative routine survey MR who subsequently underwent surgical procedure were retrospectively included (135 patients, 164 operated ears) from a large database. Patients underwent 1.5 T (128 ears) or 3 T MRI (36 ears), with non-echo planar DWI, T1 and T2 acquisitions. Two radiologists independently reassessed the images. Definitive surgical diagnosis was used as gold standard. Sensitivity, specificity and diagnostic odds ratio were evaluated.

RESULTS

According to surgical diagnosis a cholesteatoma was present in 124 of 164 ears, corresponding with a prevalence of 75%. Sensitivity and specificity were lower for 3 T compared to 1.5 T, irrespective of whether additional T1 and T2-weighted sequences were used or not. Diagnostic odds ratios were higher for 1.5 T (34 and 12 for reader 1 and 2, respectively) compared to 3 T (3 and 4 for reader 1 and 2, respectively). Adding T1 and T2 sequences lowers sensitivity but increases specificity.

CONCLUSION

Non-epi DWI for the detection of residual/recurrent cholesteatoma is preferably performed on 1.5 T scanners over 3 T. The use of additional sequences regarding detection of cholesteatoma is debatable as it lowers sensitivity but increases specificity. However, these sequences may also be of use in diagnosing complications and planning surgical procedures in some hospitals.

Diffusion-weighted magnetic resonance imaging in the detection of residual and recurrent cholesteatoma in children: A systematic review and meta-analysis

OBJECTIVE

To examine the performance of diffusion-weighted magnetic resonance imaging (DW-MRI) in the detection of residual and recurrent cholesteatoma in children.

METHODS

A systematic review and meta-analysis was conducted as per PRISMA guidelines using the following databases from their date of inception: MEDLINE, PubMed, Embase, Cochrane Library, Web of Science. Bivariate meta-analysis using a random effects model was used to calculate summarized pooled estimates of sensitivity, specificity, and diagnostic odds ratios, using second-look surgery as the gold standard comparison.

RESULTS

A total of ten articles (141 cases) were included for qualitative and quantitative analysis. Pooled sensitivity and specificity of non-echo planar imaging (non-EPI) DW-MRI were 89.4% (95%CI 51.9%-98.5%) and 92.9% (95%CI 81.4%-97.5%) respectively. DW-MRI appears limited in its ability to detect lesions less than 3 mm in size.

CONCLUSION

Non-EPI DW-MRI is highly specific but carries uncertain sensitivity in the detection of residual and recurrent cholesteatoma in children. Further research is warranted to determine the specific role of DW-MRI in this patient group, namely when and how often children should be referred for imaging and in which cases the method can be used to completely replace second-look surgery.

Cholesteatoma Pearls: Practical Points and Update

The European Academy of Otology and Neurotology in collaboration with the Japanese Otological Society (EAONO/JOS) recently produced a joint consensus document outlining the definitions, classification and staging of middle ear cholesteatoma. The goals were to provide terminologies in the description of cholesteatoma, classify cholesteatoma into distinct categories to facilitate the comparison of surgical outcomes and to provide a staging system that reflects the severity, difficulty of complete removal and restoration of normal function. Cholesteatoma is considered a benign, expanding and destructive epithelial lesion of the temporal bone that is the result of a multifactorial process. If undetected and left treated, cholesteatoma may lead to significant complications including hearing loss, temporal bone destruction and cranial invasion. Recent advances in imaging modalities have allowed for high sensitivity and specificity in identifying the presence of cholesteatoma. Despite these advances, deficiencies exist around the world with access to health care facilities meaning cholesteatoma remains a serious and challenging entity to manage whether found within the pediatric or adult population. Proper diagnosis and management of each form of cholesteatoma is achieved by a thorough understanding of the etiology, classification, clinical presentation and histology, thereby facilitating prevention, early detection and appropriate treatment.