CT scanning of middle ear cholesteatoma: what does the surgeon want to know?

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

Purpose: The aim of the study is to compare the accuracy of unstructured preoperative Computed Tomography (CT) reports from non-tertiary diagnostic centers with intraoperative findings in a large cohort of patients with Chronic Otitis Media (COM) undergone surgery.

Methods: From 2012 to 2019, a total number of 301 patients were considered for our purposes. All patients with clinical evidence of COM had preoperative non-contrast high resolution CT scan of the temporal bone in non-tertiary diagnostic centers, performed within 3 months before surgery.

Results: The accuracy of CT reports was analyzed in terms of nature, anatomical site, disease extension, bony erosion, vascular structures abnormalities relevant to surgical planning, and Eustachian tube patency. Compared to post-surgical findings, CT reporting critical analysis revealed a tendency to overestimation of bony erosion, coupled to underestimated description of facial canal/lateral semi-circular canal, vascular structures, and Eustachian tube.

Conclusion: Discrepancies between CT reports and surgical findings in middle ear opacification can be at least in part due to limited expertise of general radiologists in ENT neuroimaging. To limit this lack of information and the limited accuracy of middle ear structures depiction, here we propose a structured checklist to adopt in the case of a temporal bone CT scan for COM, in order to optimize the communication with surgeons and provide all the crucial information for an accurate surgical planning.

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.

The Role of Preoperative Computed Tomography of Temporal Bone in Atticotomy as a New Tool for Determining the Approach

The temporal bone is a complex anatomical structure and so preoperatively computed tomography (CT) of the temporal bone is important for choice of the surgical procedure. In this study, evaluation of the surgical difficulty to conduct transmastoid atticotomy with the coronary cut of CT temporal bone. Additional, attic pathology intraoperative is evaluated. The current research is a retrospective study of 79 patients with chronic suppurative otitis media (safe type) with the preoperative opacity of the attic in CT temporal bone. The researcher correlates difficulty to do transmastoid attictomy with the distance in mm between the roof of external audiatory canal (EAC) and tegmen with ruler directly in the coronary cut of CT temporal bone at the the level of internal auditory canal (IAC). The researcher also compares attic pathology intraoperative with preoperative CT attic opacity. In group of surgically difficulty average distance between the superior wall of EAC and tegmen on preoperative CT at the level of IAC is 2-5 mm while distance in easily surgical approach is from 6 to 10 mm. 68.4%(54/79) of cases had pathology in attic in the form of granulation tissue in 50 cases and glue in 4 cases. Preoperative CT temporal bone is very important to detect atticotomy approach either transmastoid or transcanal, through measuring the distance in mm between the roof of EAC and tegmen with ruler directly in the coronal cut of CT temporal bone at the level of internal auditory canal. The opacity of the attic in Preoperative CT does not mean that there is a pathology in the attic.

Chronic Draining Ear and Cholesteatoma Recidivism: A Retrospection from Clinical, Imaging, and Surgical Perspectives

Objective

To evaluate the reasons for persistent draining ear and cholesteatoma recidivism following canal wall down (CWD) tympanomastoidectomy by studying the sensitivity of high-resolution computed tomography (HRCT) scanning in different potential etiologies, corroborating through appropriate surgical intervention, and thereby, to suggest proper preventive measures.

Methods

In this observational study, 32 chronic, refractory draining ears were subjected to revision surgery following a radical or a modified radical mastoidectomy. Besides disease (cholesteatoma/granulations) eradication, pitfalls of the primary surgeries were addressed. Data were interpreted for studying the epidemiologic profile, the clinical presentation at recurrence, the type of primary surgery, the sites of recidivism, the probable causes, and the best possible management at revision.

Results

Of the 32 patients/ears, 23 had residual/recurrent cholesteatoma. Major reasons were inadequate disease clearance, contracted/inadequate conchomeatoplasty, no cavity obliteration, and inappropriate bone work. HRCT predicted persistent bridge and lateral semicircular canal dehiscence with 100%, and ossicular integrity and bony overhang with >80% sensitivity. Sinus tympani and oval window niche were the commonest sites of recurrence. At revision, radical/modified radical mastoidectomies were associated with cavity obliteration and appropriate revision of conchomeatoplasty in 28 patients.

Conclusion

Recurrence of cholesteatoma/granulations is an important cause for chronic drainage from post-CWD cavities. Revision surgery explores the surgical pitfalls, and ensures clearance of disease from hidden areas, adequate bone work, and optimum conchomeatoplasty following cavity obliteration to provide a safe, dry ear with hearing improvement whenever feasible.

Interpreting pre-operative mastoid computed tomography images: comparison between operating surgeon, radiologist and operative findings

Objectives:

This study aimed to compare the interpretations of temporal bone computed tomography scans by an otologist and a radiologist with a special interest in temporal bone imaging. It also aimed to determine the usefulness of this imaging modality.

Methods:

A head and neck radiologist and an otologist separately reported pre-operative computed tomography images using a structured proforma. The reports were then compared with operative findings to determine their accuracy and differences in interpretations.

Results:

Forty-eight patients who underwent pre-operative computed tomography scans in a 30-month period were identified. Six patients were excluded because complete operative findings had not been recorded. Positive and negative predictive values and accuracy of the anatomical and pathological findings were calculated for 42 patients by both reporters. The accuracy was found to be less than 80 per cent, except for identification of the tegmen and lateral semicircular canal erosion. Overall, there was no significant difference in interpretations of computed tomography scans between reporters. There was a slight difference in interpretation for tympanic membrane retraction, facial canal erosion and lateral semicircular canal fistula and/or erosion.

Conclusion:

Pre-operative computed tomography scanning of the temporal bone is useful for predicting anatomy for surgical planning in patients with chronic otitis media, but its reliability remains questionable.

Role of High Resolution Computed Tomography in Evaluation of Pathologies of Temporal Bone

BACKGROUND

High Resolution Computed Tomography (HRCT), a modification of routine CT, provides a direct visual window in the temporal bone providing minute structural details. Purpose of the present study was to evaluate the normal variations, pathological processes (infections and congenital anomalies) and their extent involving the temporal bone along with their complications on HRCT and to correlate these imaging findings surgically, wherever available.

MATERIALS AND METHODS

The prospective study included 50 patients who were referred to the radiology department with clinically suspected temporal bone or ear pathologies. After detailed clinical examination, the patients were subjected to high resolution computed tomography (HRCT) examination. The imaging findings were correlated with the surgical findings wherever available. The surgical findings were considered as final.

RESULTS

From a total of 50 cases, 83.33% had cholesteatoma. The surgical and radiological findings showed a high level of sensitivity (89.29%) in the identification of cholesteatoma. HRCT provides a good sensitivity of 80.65% in the identification of changes to the ossicular chain despite the presence of surrounding soft tissue. HRCT was highly informative in identification of erosion of lateral semicircular canal. In diagnosis of facial canal dehiscence HRCT had a low sensitivity of 33.33%. In the evaluation of any congenital abnormality of the ear HRCT proved to be beneficial in depicting the anatomical details.

CONCLUSION

The clinical and radiological findings showed a high level sensitivity with intraoperative findings as regards to the presence of cholesteatoma, changes of the ossicular chain and erosion of the lateral semicircular canal. HRCT findings, in the treatment of any congenital abnormality of the ear were a good guide to the surgeon for planning and management.

Role of High Resolution Computed Tomography of Mastoids in Planning Surgery for Chronic Suppurative Otitis Media

Chronic suppurative otitis media (CSOM) presents with a typical history of recurrent otorrhoea with tympanic membrane perforation. The diagnosis of cholesteatoma is usually made on otologic examination. High resolution computed tomography (HRCT) is indicated to evaluate the extension and the complications of cholesteatoma. The aim of the work was to study the role of HRCT in detecting, evaluating diagnosing and managing CSOM. All patients presenting with CSOM who were planned for mastoid exploration surgery in department of ENT, Gauhati Medical College and Hospital within a period of 2 years-from 1st January, 2013 to 31th December, 2014, were taken up for the study. HRCT mastoids done routinely before cholesteatoma surgery, but with improved resolution, to characterize all middle ear structures and complications of the disease prior to surgery, might guide as road map during mastoid explorations for unsafe CSOM. The important role of HRCT lies on the early detection of cholesteatoma, and more conservative surgical procedures can be used to eradicate the disease.

Evaluation of temporal bone cholesteatoma and the correlation between high resolution computed tomography and surgical finding

BACKGROUND

Acquired cholesteatomas are commonly seen in patients less than 30 years. There is a typical history of recurrent middle ear infections with tympanic membrane perforation. The diagnosis of cholesteatoma is usually made on otologic examination.

OBJECTIVE

The aim of the work was to study the role of high resolution computed tomography (HRCT) in detecting, evaluating, and diagnosing middle ear cholesteatoma.

PATIENTS AND METHODS

This was a prospective study that included 56 consecutive patients with chronic suppurative otitis media, unsafe type cholesteatomas. Each patient was subjected to full clinical evaluation, and HRCT examination. Intravenous contrast media was used in some patients with suspected intracranial complication. Preoperative radiological data were correlated with data related to surgical findings.

RESULTS

The study showed that a high incidence of cholesteatoma in the third decade of life. The scutum and lateral attic wall were the most common bony erosions in the middle ear bony wall (64.3%), and the incus was the most eroded ossicle in the middle ear (88.2%). Sclerosing of mastoid air cells were encountered in 60.7% of patients and the lateral semicircular canal was affected in 9%, while facial canal erosion was found in 21.4%. Temporal bone complications are more common than intracranial complications. HRCT findings were compared with operative features; the comparative study included the accuracy and sensitivity of HRCT in detecting cholesteatoma (92.8%), its location and extension (96.4%), ossicular chain erosion (98%), labyrinthine fistula and intracranial complications (100%).

CONCLUSION

The important role of HRCT scannig lies on the early detection of cholesteatoma, and more conservative surgical procedures can be used to eradicate the disease.

Soft tissue attenuation in middle ear on HRCT: Pictorial review

Middle ear disease is a common clinical entity; imaging, especially High resolution Computed Tomography (HRCT), plays a crucial role in diagnosis and assessing the disease extent, helping to decide appropriate management. Temporal bone imaging is challenging and involves thorough understanding of the anatomy, especially in relation to HRCT imaging. Most of the middle ear pathologies appear as “soft tissue” on imaging. Careful analysis of the soft tissue on the HRCT is crucial in achieving the right diagnosis; clinical information is essential and the imaging findings need correlation with clinical presentation and otoscopic findings. The purpose of this pictorial essay is to enlist the pathologies that present as soft tissue in middle ear and to provide a structured and practical imaging approach that will serve as a guide for confident reporting in daily practice.

A preliminary investigation of four-dimensional ultrasound for evaluation of middle ear ossicles: an in vitro study

OBJECTIVE

Temporal bone imaging in children has several inherent limitations. Computed tomography has the disadvantage of ionizing radiation, possible sedation, cost and accessibility. Magnetic resonance imaging has most of these disadvantages, with the exception of radiation, and provides bone images of limited resolution. Recent advances in ultrasound have led to its increased application in numerous medical fields. The purpose of this study was to investigate the ability of four-dimensional ultrasound (4DUS) to image middle ear ossicles in vitro and determine if this technology should be adapted for future clinical use.

METHODS

Thirty cadaveric ossicles (10 malleus, 10 incus, and 10 stapes) were randomized and measured by two evaluators under a microscope. The ossicles were then immersed in a cold water bath and imaged, randomized, and measured using four-dimensional ultrasound by the same two evaluators. A separate cadaveric temporal bone, modified to allow the ultrasound probe to rest on the tympanic membrane, was imaged to visualize the ossicles in situ and evaluate whether or not the tympanic membrane and malleus would impede visualization of more medial structures.

RESULTS

Microscopic measurements were: malleus (h=8.0 mm+/-0.32, w=2.7 mm+/-0.20), incus (h=6.8 mm+/-0.41, w=5.3 mm+/-0.46), stapes (h=3.5 mm+/-0.34, w=2.4 mm+/-0.17). Inter-rater reliability was 0.8. Measurements were in agreement with previously published values. Ultrasound measurements were: malleus (h=8.0 mm+/-0.51, w=2.9 mm+/-0.27), incus (h=6.8 mm+/-0.49, w=5.5 mm+/-0.42), stapes (h=3.6 mm+/-0.41, w=2.5 mm+/-0.19). Inter-rater reliability was 0.7. Mean intra-class correlation coefficient for microscopic and ultrasound measurements was 0.7. Images of the ossicular chain in continuity in the temporal bone specimen were not as clear as images of individual ossicles that were disarticulated and imaged under water.

CONCLUSIONS

4DUS provides reasonable images of ossicles disarticulated and mounted in underwater medium. However, images of the intact ossicular chain in a modified cadaveric temporal bone were not as clear, making interpretation difficult. Further investigation into the development of a thinner ultrasound probe that can pass through the external auditory canal and into overcoming limitations of air in the middle ear cleft are warranted. This could allow for a clinically relevant, faster, lower cost and lower risk alternative to current imaging techniques.

The role of preoperative CT scan in patients with chronic otitis media

Chronic otitis media may be due to chronic mucosal disease or cholesteatoma. Differentiating the two is usually achieved by clinical examination. The computed tomography (CT) scan is the standard imaging technique for the temporal bone, but its exact role in the preoperative assessment of patients with chronic otitis media is controversial. In this retrospective study we compared preoperative CT results with operative findings in 50 patients who had scan between January 2003 and December 2007. We analyzed the clinical presentation and checked if CT scan confirmed or excluded the presence of cholesteatoma and if this was affected by previous surgery. We concluded that CT scan could not be relied on to differentiate cholesteatoma from chronic mucosal disease. It should be used selectively in the preoperative preparation only if complications of the disease suspected.