Imaging of the postoperative middle ear

Comparison of dislocation rates of Teflon and Titanium stapes prostheses: a retrospective survival analysis on 855 patients

BACKGROUND

Stapes prosthesis dislocation is the first cause of revision stapes surgery. To our knowledge, there is no data about stability of the incus attachment of manual crimped prosthesis of different materials. This study aimed to compare the dislocation incidence between titanium and fluoroplastic stapes prostheses.

METHOD

A monocentric retrospective cohort study was conducted between January 2013 and June 2022 in a tertiary-care center. All patients that underwent a primary stapes surgery with manually crimped fluoroplastic or titanium prostheses were included. Prosthesis dislocation from the incus was identified intraoperatively or with CT scan. The incidence of stapedial prosthesis dislocation over time was estimated using the Kalbfleisch and Prentice survival analysis method. Other indications for revision surgery prior to prosthesis dislocation were considered as competing events. Differences in the cumulative incidence functions between the fluoroplastic group and the titanium group was assessed using the Gray's test.

RESULTS

Eight hundred and fifty-five patients underwent primary stapes surgery during the study period. Fluoroplastic prosthesis was used in 758 (88.7%) cases and titanium prosthesis in 97 (11.3%) cases. Median follow-up was 51.7 months (28.4-80.1). Dislocation was observed in 23 (3.0%) patients with fluoroplastic prosthesis and none (0.0%) in the titanium group. The probability of prosthesis dislocation at two years after surgery was 3.5% in the Teflon group and 0.0% in the Titanium group. No significant difference was found in the cumulative incidence of prosthesis dislocation between the fluoroplastic group and the titanium group (p = 0.12).

CONCLUSIONS

Despite lack of statistical power, our results suggest a trend in a more stable incus attachment of manually crimped titanium stapes prosthesis compared to fluoroplastic over time. Further prospective randomized studies could be valuable to assess our findings.

"Transcanal view" computed tomography reformat: Applications for transcanal endoscopic ear surgery

PURPOSE

Transcanal endoscopic ear surgery (TEES) is an increasingly used surgical approach for otologic surgeries, but no en face preoperative imaging format currently exists. We aim to assess the utility of a transcanal high resolution computed tomography (HRCT) reformat suitable for TEES preoperative planning.

MATERIALS AND METHODS

Preoperative HRCTs of patients with middle ear pathologies (cholesteatoma, otosclerosis, and glomus tympanicum) who underwent TEES were obtained. Axial image series were rotated and reformatted -90 or +90 degrees for left and right ear surgeries, respectively, where additional rotation along the left-right axis was performed to align the transcanal series with the plane of the external auditory canal. Quantitative measurements of middle ear structures were recorded. Consecutive transcanal reformatted sections were then reviewed to identify critical middle ear anatomy and pathology with corresponding TEES cases.

RESULTS

The aforementioned methodology was used to create three transcanal view HRCTs. The mean left-right axis degree of rotation was 4.0 ± 2.2 degrees. In the cholesteatoma transcanal HRCT, areas of cholesteatoma involvement in middle ear compartments (e.g. epitympanum) and eroded ossicles were successfully identified in the corresponding case. In the otosclerosis transcanal HRCT, areas for potential otosclerotic involvement were visualized such as the round window as well as a low-hanging facial nerve. In the glomus tympanicum transcanal HRCT, the span of the glomus tympanicum was successfully visualized in addition to a high riding jugular bulb.

CONCLUSION

A transcanal HRCT reformat may aid preoperative planning for middle ear pathologies. This novel reformat may help highlight patient-specific anatomy.

Radiological evaluation of the postsurgical middle ear

OBJECTIVE

The radiological evaluation of the postsurgical middle ear is complex due to the intricate anatomy of this region and the wide variety of procedures and materials used iin middle ear surgery. Knowledge of these factors will enable normal postsurgical changes to be differentiated from complications. This article describes the most common surgical procedures in the middle ear, their indications, and the normal radiological appearance after these procedures. It reviews the most common causes of failure in stapes surgery, in surgery for chronic otitis media, and in surgery for cholesteatoma, suggesting the best imaging method to assess the middle ear in each case.

CONCLUSION

Computed tomography enables the evaluation of prostheses and the aeration of the cavities, whereas magnetic resonance imaging makes it possible to characterize the possible occupation of the cavities and is the technique of choice for the follow-up of closed mastoidectomy for cholesteatomas.

Radiological evaluation of the postsurgical middle ear

OBJECTIVE

The radiological evaluation of the postsurgical middle ear is complex due to the intricate anatomy of this region and the wide variety of procedures and materials used iin middle ear surgery. Knowledge of these factors will enable normal postsurgical changes to be differentiated from complications. This article describes the most common surgical procedures in the middle ear, their indications, and the normal radiological appearance after these procedures. It reviews the most common causes of failure in stapes surgery, in surgery for chronic otitis media, and in surgery for cholesteatoma, suggesting the best imaging method to assess the middle ear in each case.

CONCLUSION

Computed tomography enables the evaluation of prostheses and the aeration of the cavities, whereas magnetic resonance imaging makes it possible to characterize the possible occupation of the cavities and is the technique of choice for the follow-up of closed mastoidectomy for cholesteatomas.

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.

Imaging Studies in Otosclerosis: An Up-to-date Comprehensive Review

Introduction  Otosclerosis is a primary osteodystrophy of the otic capsule, frequently responsible for acquired hearing loss in adults. Although the diagnostic value of imaging investigations in otosclerosis is debatable, they might still be employed with different goals within the context of the disease.

Objectives  The present paper aims to review the most recent literature on the use of imaging studies in otosclerosis for the most varied purposes, from routine application and differential diagnosis to prognostic prediction and investigation of surgical failure.

Data Synthesis  The diagnosis of otosclerosis is usually clinical, but computed tomography (CT) is paramount in particular cases for the differential diagnosis. The routine use, however, is not supported by strong evidence. Even so, there is growing evidence of the role of this method in surgical planning and prediction of postoperative prognosis. In specific scenarios, for example when superior semicircular canal dehiscence (SSCD) syndrome is suspected or in surgical failure, CT is crucial indeed. Magnetic resonance imaging (MRI), however, has limited – although important – indications in the management of individuals with otosclerosis, especially in the evaluation of postoperative complications and in the follow-up of medical treatment in active ostosclerosis.

Conclusion  Imaging studies have a broad range of well-established indications in otosclerosis. Besides, although the routine use of CT remains controversial, the most recent papers have shed light into new potential benefits of imaging prior to surgery.

Value of DW-MRI in the preoperative evaluation of congenital cholesteatoma

OBJECTIVE

This study evaluated the clinical value of diffusion-weighted magnetic resonance imaging (DW-MRI) in the diagnosis and staging of congenital cholesteatoma (CC).

PATIENTS AND METHODS

We retrospectively reviewed 24 patients with CC. All the patients underwent computed tomography (CT) and DW-MRI preoperatively; thereafter, surgery was performed. DW-MRI examination was performed with a 3 T MRI system using three-dimensional reversed fast imaging with steady-state precession and diffusion-weighted magnetic resonance sequence. The preoperative and operative CT and DW-MRI findings were compared.

RESULTS

Using DW-MRI, cholesteatoma was successfully detected in 17 (71%) of the 24 patients with CC. Among the seven patients with false-negative results, the cholesteatoma mass diameter was <5 mm in six patients and ≥5 mm in one patient. One of these patients had open type congenital cholesteatoma (OTCC). The detection rates for closed type cholesteatoma and OTCC were 85% (17/20) and 0% (0/4), respectively, using DW-MRI. Using CT and DW-MRI, the correct stage was identified in 88% (15/17) and 59% (10/17) of the patients with aeration around the CC and in 0% (0/7) and 100% (7/7) of those without aeration around the CC, respectively.

CONCLUSION

CT is the primary imaging tool for evaluating suspected CC in patients with aeration around the CC. However, CT is unreliable for the detection of the extension and staging of CC when the middle ear is filled with nonspecific imaging. DW-MRI is useful for the preoperative diagnosis and staging of CC > 5 mm in diameter with or without surrounding granulation tissue. Thus, we recommend using DW- MRI at least when CT fails to localize CC as a soft tissue mass because of non-specific tissue filling the middle ear and the mastoid.

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.

The Role of Non-Echoplanar Diffusion-Weighted Magnetic Resonance Imaging in Diagnosis of Primary Cholesteatoma and Cholesteatoma Recidivism as an Adjunct to Clinical Evaluation

Introduction:

The aim of this study was to analyze the sensitivity and specificity of non-echoplanar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) for the detection of cholesteatoma, with a focus on its value as an adjunct to clinical examination.

Methods:

In a prospective cohort study, 92 cases were divided into 2 groups: “clinically cholesteatoma” ( n = 79) and “clinically no cholesteatoma” ( n = 13). Non-EPI DW MRI was performed preoperatively in all cases. The presence of a cholesteatoma was assessed by clinicians otoscopically, by neuroradiologists on non-EPI DW MRI, by the surgeon intraoperatively, and finally by the pathologist postoperatively. Data analysis was performed for specificity, sensitivity, positive predictive value, negative predictive value, and interrater variability.

Results:

The sensitivity and specificity were 89.3% and 75%, respectively, in the “clinically cholesteatoma” group and 0% and 100% in the “clinically no cholesteatoma” group. Non-EPI DW MRI had a positive predictive value of 98.5% when cholesteatoma was suspected clinically and a negative predictive value of 84.6% when cholesteatoma was not suspected clinically.

Conclusion:

If cholesteatoma is suspected clinically, non-EPI DW MRI is not necessary. If there is no clinical suspicion of cholesteatoma in second-look situations, sensitivity is low and serial follow-up MRI with long intervals is advised.

MRI as an Alternative to Second Look Mastoid Surgery

The main goal of surgery of cholesteatoma is eradication of the disease and revision surgery is indicated when a dry and safe ear has not been achieved. Residual cholesteatoma usually occurs at the sites that are difficult to reach with an operating microscope, such as posterior tympanum and anterior epitympanic recess. Computed tomography can be performed to delineate the extent of disease. High-resolution computed tomography scanning is important for planning for surgery and is indicated for all revision mastoid operations. Magnetic resonance imaging is superior to computed tomography in tissue characterization for diagnosis of recurrent cholesteatoma. To evaluate the cases of recurrent cholesteatoma comparing the intraoperative surgical findings with the preoperative MRI radiological findings and if the preoperative MRI can replace the second look surgery for cholesteatoma. This study was applied on 60 patients that have a recurrent cholesteatoma after previous mastoid surgery. A preoperative radiological evaluation was done by Magnetic resonance, surgical management was done by canal wall up or canal wall down mastoidectomy to exclude residual disease. Then, radiological, and surgical findings correlation was done. Diffusion-weighted MRI successfully detected 42 cases out of the 45 cases of surgically proved cholesteatoma, it has accuracy 95%, sensitivity 93.33%, specificity 100%, PPV 100% and NPV 83.33%. MRI is better than CT in tissue characterization for diagnosis of recurrent cholesteatoma, and can replace the unnecessary second look surgery of cholesteatoma.

Otitis Media with Effusion Revealing Underlying Meningioma

Otitis media with effusion (OME) is a very common condition in the current clinical practice. Usually idiopathic, it may sometimes be the consequence of primary diseases. Extracranial meningioma is rare, and even more when involving the ear and temporal bone. We report a case of temporal meningioma spreading to the middle ear and mastoid presenting as an OME. The diagnosis relies on a thorough imaging evaluation with computed tomography and magnetic resonance imaging. This short report aims to warn the otolaryngologist of this rare situation to prevent any delay in diagnosing and managing such a condition.

[Techniques and progress in the imaging of the ear]

Ear and temporal bone imaging is essential for the diagnostic and preoperative management of middle ear lesions. The scanner is the exam of choice to analyze the walls and the contents of the middle ear. MRI is used to characterize the opacities of the middle ear and to evaluate possible neurological complications. Modern imaging techniques allow intraoperative guidance in otological surgery. Hearing implants are not always a contraindication to MRI but require precautions according to the type of implant.

Early Postoperative Imaging of the Labyrinth by Cone Beam CT After Stapes Surgery for Otosclerosis With Correlation to Audiovestibular Outcome

BACKGROUND

Sensorineural complications of stapes surgery are rare but potentially serious. Imaging is usually performed to identify an underlying cause, such as excessive intravestibular penetration of the prosthesis or pneumolabyrinth suggesting perilymphatic fistula. Unfortunately, there is very little data in an unselected series of uneventful patients.The aim of this study was to analyze the depth of prosthesis penetration within the vestibule and the rate of pneumolabyrinth the day or the day after the procedure by performing a cone beam computed tomography of the temporal bone in a cohort of unselected patients, and to correlate imaging findings to clinical outcome.

METHODS

A prospective monocentric study was conducted in a tertiary referral medical center. A cone beam computed tomography was performed in 80 consecutive patients having undergone stapes surgery for otosclerosis, the day or the day after the procedure. Penetration length and location of the prosthesis within the vestibule, as well as presence or absence of a pneumolabyrinth, were recorded, and compared with clinical data (vertigo, nystagmus, hearing measurement).

RESULTS

Pneumolabyrinth was found in 15% of the patients. The mean penetration length of the prosthesis within the vestibule was 1 mm (0-1.9 mm). No serious complication occurred during the study period. No correlations were found when comparing imaging findings to clinical outcome.

CONCLUSION

Our results do not support empirically insights into detrimental effects of postoperative pneumolabyrinth or too long prosthesis after stapes surgery. Further studies are needed to better understand the causes of postoperative complications of stapes surgery.

Diffusion weighted imaging for the detection and evaluation of cholesteatoma

Cholesteatoma is a collection of keratinous debris and stratified squamous epithelium. It is trapped in the middle ear and can lead to bony erosion. The disease is treated surgically often followed by a second-look procedure to check for residual tissue or recurrence. Cholesteatoma has specific signal-intensity characteristics on magnetic resonance imaging with very high signal intensity on diffusion weighted imaging (DWI). Various DWI techniques exist: Echo-planar imaging (EPI)-based and non-EPI-based techniques as well as new approaches like multi-shot EPI DWI. This article summarizes all techniques, discusses the significance in detecting cholesteatoma and mentions actual studies. Further recommendations for daily clinical practise are provided.

Magnetic resonance imaging at one year for detection of postoperative residual cholesteatoma in children: Is it too early?

OBJECTIVE

To compare the residual cholesteatoma detection accuracy of diffusion-weighted (DW) and T1 delayed sequences for magnetic resonance at one year postoperative with second-look surgery in pediatric patients who have undergone primary middle ear surgery for cholesteatoma.

METHODS

This was a prospective monocentric consecutive study conducted in a tertiary academic referral center. Children were referred for MR imaging (MRI) one year after surgery. A 1.5T MRI was utilized, using nonecho-planar DW images and delayed gadolinium-enhanced T1-weighted images. Accuracy of magnetic resonance imaging was assessed by two radiologists before surgery. Interobserver and intraobserver agreements were assessed using the κ test. Magnetic resonance imaging data were compared with surgery, which was considered as the gold standard.

RESULTS

Twenty-four consecutive unselected pediatric patients were included. Sensitivity, specificity, positive predictive value, and negative predictive value for the first observer were of 40%, 86%, 67%, and 67%, respectively, and those for the second observer were 30%, 86%, 60%, and 63%, respectively. The only two cholesteatoma with a size superior to 3mm were diagnosed before surgery, but the majority of small cholesteatoma were not detected.

CONCLUSIONS

MRI is a key examen to diagnosed the residual cholesteatoma but is limited by the size of the lesion under 3mm. Delaying the realization of MRI during follow-up could increase sensitivity, thus avoiding misdiagnosis as well as unnecessary second look surgery.

CT Findings in the External Auditory Canal after Transcanal Surgery

BACKGROUND AND PURPOSE

Middle ear surgery is often performed through the external auditory canal, and the CT appearance of the external auditory canal after transcanal middle ear surgery can mimic erosive pathology such as carcinoma, external auditory canal cholesteatoma, or necrotizing external otitis. We reviewed the CT findings in a group of patients following transcanal surgery to highlight this potential pitfall in interpretation.

MATERIALS AND METHODS

Twenty-seven temporal bones in 25 patients with a history of a transcanal approach to the middle ear and available postoperative CT imaging were identified. Images were assessed for changes along or involving the walls of the external auditory canal, including widening, irregularity, bony defects, and soft tissue opacification.

RESULTS

Osseous changes along the floor of the external auditory canal were demonstrated in 25 of 27 (92.6%) temporal bone CT scans. Similar changes were present in the superior and anterior walls of the external auditory canal in 21 and 18 temporal bones, respectively. The anterior wall was the most common site for complete bony defects (10 of 27 temporal bones). The posterior wall was the least often involved, with osseous changes in 15 of 27 temporal bones and bony defects in 3 cases. Soft tissue thickening was seen most commonly along the floor. No patient was found to have a superimposed pathologic process of the external auditory canal.

CONCLUSIONS

CT findings in the external auditory canal after transcanal surgery include thinning, irregularity and/or flattening of the bone, soft tissue thickening, and bony wall defects. Although these changes may be subtle, they may mimic pathology and should be included in the differential diagnosis of osseous abnormality of the external auditory canal.

Intraoperative Cone-Beam Computed Tomography and Multi-Slice Computed Tomography in Temporal Bone Imaging for Surgical Treatment

Objective

Conventional computed tomography (CT) imaging is the standard imaging technique for temporal bone diseases, whereas cone-beam CT (CBCT) imaging is a very fast imaging tool with a significant less radiation dose compared with conventional CT. We hypothesize that a system for intraoperative cone-beam CT provides comparable image quality to diagnostic CT for identifying temporal bone anatomical landmarks in cadaveric specimens.

Study Design

Cross-sectional study.

Setting

University tertiary care facility.

Subjects and Methods

Twenty cadaveric temporal bones were affixed into a head phantom and scanned with both a prototype cone-beam CT C-arm and multislice helical CT. Imaging performance was evaluated by 3 otologic surgeons and 1 head and neck radiologist. Participants were presented images in a randomized order and completed landmark identification questionnaires covering 21 structures.

Results

CBCT and multislice CT have comparable performance in identifying temporal structures. Three otologic surgeons indicated that CBCT provided statistically equivalent performance for 19 of 21 landmarks, with CBCT superior to CT for the chorda tympani and inferior for the crura of the stapes. Subgroup analysis showed that CBCT performed superiorly for temporal bone structures compared with CT. The radiologist rated CBCT and CT as statistically equivalent for 18 of 21 landmarks, with CT superior to CBCT for the crura of stapes, chorda tympani, and sigmoid sinus.

Conclusion

CBCT provides comparable image quality to conventional CT for temporal bone anatomical sites in cadaveric specimens. Clinical applications of low-dose CBCT imaging in surgical planning, intraoperative guidance, and postoperative assessment are promising but require further investigation.

MRI for the diagnosis of recurrent middle ear cholesteatoma in children--can we optimize the technique? Preliminary study

BACKGROUND

Recurrent cholesteatoma after surgical excision occurs frequently in children. Until recently, a surgical second look was mandatory and considered as standard reference. MRI including a delayed T1 sequence after gadolinium injection and diffusion-weighted imaging (DWI) has proved its efficiency but has been evaluated mainly in adults.

OBJECTIVE

Our purpose was to evaluate the accuracy of DWI to diagnose recurrence of cholesteatoma in children.

MATERIALS AND METHODS

We evaluated prospectively with MRI 20 ears in 18 children who had had surgery for cholesteatoma. We compared DWI and delayed T1-weighted images following gadolinium administration with intraoperative or follow-up findings. We calculated the sensitivity and specificity of each sequence for the diagnosis of recurrent cholesteatoma.

RESULTS

Sensitivity to diagnose recurrent cholesteatoma was 87% for both DWI and delayed post-gadolinium sequences, specificity was 71% and 83%, respectively. Adding both sequences, the sensitivity was 87%, the specificity 100%. There was one false negative probably due to small size recurrence.

CONCLUSION

In our series, DWI was reliable to diagnose recurrent cholesteatoma in children and allows avoiding surgery when negative. However, because small recurrences less than 5 mm may be missed, follow-up must be prolonged (5 years).

Controlling the position and the dislocation of the middle ear transducer with high-resolution computed tomography and digital volume tomography: implications for the transducers' design

A minimal tip dislocation of the middle ear transducer (MET(®), Otologics Ltd) may result in poor hearing performance. Our objective was to examine if a defined MET dislocation can be diagnosed by high-resolution computed tomography (HRCT) or digital volume tomography (DVT). A human cadaver head was sequentially implanted with different MET tips (incus application) including a ceramic tip (T 1c), a titanium tip (T 1t), a new, thinner titanium tip (T 2), and a spherical titanium tip (Ts). HRCT and DVT studies were performed. Afterward, the tips were pulled back 0.5 mm, so that they were not attached to the incus. HRCT and DVT scans were repeated to identify the dislocation. Using the best plain in HRCT images, the dislocation of the transducer could be measured reliably and reproducibly in half of the cases. In particular, the precise positioning and the dislocation could be identified when T 1t and Ts were implanted, with the Ts showing the best visibility. DVT failed in recognizing the dislocation in all cases. The identification of MET tip's dislocation with HRCT depends on the shape, size, and material of the tip. This knowledge is useful for the design of the implants, as determination of the right position of the middle ear transducer may be proven important for the hearing outcome. In some cases, however, surgical exploration may still be required. Although DVT represents a promising imaging method for the otologists, it can barely help when MET dislocation is suspected.

Giant Cholesteatoma: Recommendations for Follow-up

This report presents the management of five patients who presented with giant recurrent or residual cholesteatoma after periods of 2 to 50 years. Their case histories are highly diverse, but all provide evidence of the need for long-term follow-up.

Childhood cholesteatoma

Although cholesteatoma was first described in 1683, its etiopathogeny remains unexplained. In children, there are two forms: acquired cholesteatoma, resembling the adult form, and congenital cholesteatoma. The acquired form has become less frequent in recent years, thanks to progress in the treatment of childhood otitic pathology. Diagnosis of congenital cholesteatoma, on the contrary, is increasing, due to improvements in information to health care professionals and in diagnostic tools. Clinical and histological evidence points to greater aggressiveness in childhood forms, although this difference cannot, at present, be precisely explained. Diagnosis is clinical, but CT and MR imaging is indispensable for preoperative assessment and postoperative follow-up. New delayed gadolinium-enhanced T1-weighted and diffusion-weighted MRI sequences have recently been developed and provide more precise radiological diagnosis. Treatment is surgical; alternatives, notably by laser, have proved unsuccessful. Complications concern involvement of neighbouring structures, and are mainly infectious; some can be life-threatening, and should be systematically screened.

Diffusion-weighted MR imaging for evaluation of pediatric recurrent cholesteatomas

OBJECTIVE

To compare the efficiency of diffusion-weighted MR imaging (MRI) vs. high resolution CT in predicting recurrent or residual cholesteatoma in children who underwent prior middle ear surgery.

DESIGN

Prospective study.

SETTING

Tertiary care university hospital.

PATIENTS

Seventeen patients (4 with 2 recurrences) aged 5-17 years (mean 11.4) previously surgically treated for a cholesteatoma of the middle ear, were included for follow-up with systematic CT scan and MRI, between 2005 and 2007.

METHODOLOGY

CT scan was performed on a Siemens Somaton 64 (0.5/0.2 mm slices reformatted in 0.5/0.3 mm images), parallel and perpendicular to the lateral semi-circular canal for each ear (100 mmx100 mm FOV). MRI was undertaken on a Siemens Avanto 1.5 T unit, with an adapted protocol for young children. Diagnosis of recurrent cholesteatoma was based on the evidence of a hyperintense image at B1000 on diffusion-weighted images. Results of CT scan and MRI were compared with operative diagnosis.

RESULTS

Nine patients had a positive MRI, among which 8 had cholesteatoma confirmed during revision surgery. In the 12 negative MRI cases, 5 were positive on revision surgery. None of these lesions was over 3mm. Two of them were diagnosed on the CT scan. CT scan alone had a positive predictive value of 75%, and a negative predictive value of 58%.

CONCLUSION

Diffusion-weighted MRI is associated with a high positive predictive value for the detection of recurrent cholesteatoma. CT scan remains the first choice imaging technique. In case of doubtful CT scan, diffusion-weighted MRI could confirm a recurrence or, when negative, avoid second-look surgery.

CT versus MR: still a tough decision

CT and MRI are the two most widely used imaging modalities for evaluating head and neck pathology. There is continued controversy in the literature about which modality is superior for imaging different areas of the head and neck. This article summarizes the literature supporting the use of CT, MRI, or both for specific clinical scenarios in otolaryngology. Familiarity with the benefits and potential pitfalls of each modality allows referring physicians and radiologists to tailor imaging regimens to the needs of individual patients.

Déhiscence du canal semi-circulaire antérieur mimant une otospongiose: intérêt de l'imagerie

OBJECTIVES

To emphasize the role of computerized tomography (CT) in the etiologic work-up of stapes surgery failure.

MATERIAL AND METHODS

Helical high resolution CT scan of the temporal bone with axial and coronal views and multiplanar reconstructions was performed in a patient who had undergone unsuccessful stapedectomy.

RESULTS

CT scan demonstrated a well located prosthesis, the absence of the radiological hallmarks of otosclerosis, and revealed a superior semicircular canal dehiscence (SSCD). The diagnosis of SSCD was retrospectively considered accountable for the preoperative clinical and audiometric presentation that had mimicked otosclerosis.

CONCLUSION

CT is the diagnostic test of choice in elucidating stapes surgery failure (with persistent or recurrent conductive hearing loss), whereas SSCD should be systematically considered among its causes.

Imagerie des otites chroniques de l’adulte

Chronic otitis media (COM) can be divided into two subtypes: COM with cholesteatoma (including precholesteatomatous states) is an aggressive form of otitis. Surgical treatment is mandatory because of the risk for labyrinthine or cerebromeningeal complications. CT is very important in the preoperative work-up (extension of cholesteatoma, anatomic variants). In patients who have undergone middle ear surgery, CT and presently MRI play an increasing role in the detection of recurrent or relapsing cholesteatoma. COM without cholesteatoma does not have an osteolytic potential, but may leave auditive sequelae that in selected cases may warrant surgical treatment to improve hearing. CT is useful in the etiological work-up of patients with severe hypoacusis. CT also plays an important role in cases of surgical failure, to detect a dislocation of the ossiculoplasty or impairment of the middle ear caused by fluid effusion. The objective of this paper is to specify the indications, the results and the limits of pre- and postoperative imaging in COM.

Serous otitis media revealing temporal en plaque meningioma

OBJECTIVES

To present a series of temporal en plaque meningiomas involving the middle ear or mastoid, whose main symptoms suggested a serous otitis media.

STUDY DESIGN AND SETTINGS

Multicentric retrospective study reviewing clinical records originating from eight tertiary referral centers.

MATERIALS AND METHODS

The clinical records of 10 patients presenting with signs and symptoms suggesting serous otitis media and whose neuroimaging studies revealed a temporal en plaque meningioma involving the middle ear or mastoid are reported.

RESULTS

All the patients were women, ranging from 49 to 71 years old. The delay between the onset of symptoms and the diagnosis of meningioma varied from 1 to 10 years. All the patients underwent various procedures usually applied for the treatment of serous otitis media, which failed in all the cases, particularly ventilating tube placement, which was followed by severe episodes of discharge. In all cases, the computed tomographic scans showed three imaging signs: soft tissue mass filling the middle ear or mastoid, hyperostosis of the petrous bone, and hairy aspect of the intracranial margins of the affected bone. This imaging triad must alert the otologist of the possibility of intracranial meningioma. Magnetic resonance imaging was the method of choice to assess the diagnosis of intracranial meningioma involving the middle ear or mastoid. When analyzing management options, it appeared that conventional middle ear procedures were inefficient.

CONCLUSION

Temporal en plaque meningioma involving the middle ear or mastoid can mimic a serous otitis media. A computed tomographic scan is recommended for cases of atypical or prolonged unilateral serous otitis media to investigate indirect signs of a meningioma, which has to be confirmed with magnetic resonance imaging.

[Middle ear cholesteatoma]

Cholesteatoma is a serious form of chronic otitis media. The aim of this paper is to present the state of the art of disease management, including recent data from the literature and the authors' derived from their Mentors' teaching, Professor Pierre Roulleau (Paris, France) and Professor Robert Charachon (Grenoble, France). The main recent advances concern the use of cartilage grafts to reconstruct the canal wall and/or tympanic membrane (allowing a significant reduction in residual cholesteatoma) and progress in medical imaging allowing more acute preoperative determination of extension of the cholesteatoma (in order to propose an optimally designed surgical technique) and a less invasive postoperative follow-up.

High-Resolution Computed Tomography of Temporal Bone

The purpose of this 4-part series is to illustrate the nuances of temporal bone anatomy using a high-resolution (200 micro isotropic) prototype volume computed tomography (CT) scanner. The normal anatomy in axial and coronal sections is depicted in the first and second parts. In this, the fourth part, and the third part, the structures that are removed and/or altered in 9 different surgical procedures are color coded and inscribed in the same coronal (article IV) and axial (article III) sections. The text stresses clinically important imaging features, including the normal postoperative appearance, and common complications after these operations. The superior resolution of the volume CT images is vital to the comprehensive and accurate representation of these operations. Minuscule intricate structures that are currently only localized in the mind's eye because of the resolution limit of conventional CT are clearly seen on these scans. This enhanced visualization, together with the information presented in the text, should assist in interpreting temporal bone scans, communicating with surgeons, and teaching this complex anatomy.

High-resolution computed tomography of temporal bone: Part III: Axial postoperative anatomy

The purpose of this 4-part series is to illustrate the nuances of temporal bone anatomy using a high-resolution (200-mu isotropic) prototype volume computed tomography (CT) scanner. The normal anatomy in axial and coronal sections is depicted in the first and second parts. In this and the subsequent part, the structures that are removed and/or altered in 9 different surgical procedures are color coded and inscribed in the same axial (article III) and coronal (article IV) sections. The text stresses clinically important imaging features, including the normal postoperative appearance, and common complications after these operations. The superior resolution of the volume CT images is vital to the comprehensive and accurate representation of these operations. Minuscule intricate structures that are currently only localized in the mind's eye because of the resolution limit of conventional CT are clearly seen on these scans. This enhanced visualization, together with the information presented in the text, should assist in interpreting temporal bone scans, communicating with surgeons, and teaching this complex anatomy.

Usefulness of delayed postcontrast magnetic resonance imaging in the detection of residual cholesteatoma after canal wall-up tympanoplasty

OBJECTIVES/HYPOTHESIS

Imaging takes an increasing place in the follow-up of patients who have undergone surgery for cholesteatoma, with computed tomography (CT) as the first line imaging technique. However, in case of complete opacity of the tympanomastoid cavities, CT is not able to differentiate residual cholesteatoma from postoperative scar tissue. The aim of this study was to assess the usefulness of magnetic resonance imaging (MRI) using delayed postcontrast T1-weighted images for the detection of residual cholesteatoma after canal wall-up tympanoplasty (CWU) in cases where CT was not conclusive.

STUDY DESIGN

Prospective study.

METHODS

MRI, with delayed postcontrast T1-weighted images (30-45 minutes after contrast injection), was performed before revision surgery in 41 consecutive patients who had undergone CWU for cholesteatoma and presenting with a nonspecific complete opacity of the mastoid bowl on CT. In all the cases, imaging results were compared with operative findings at surgical revision.

RESULTS

A residual cholesteatoma was found in 19 of 41 patients at revision surgery and was correctly detected on MRI in 17 patients. In the two remaining cases, cholesteatoma pearls smaller than 3 mm were not seen. There was no false-positive case. Statistics were as follows: sensitivity 90%; specificity 100%; positive predictive value 100%; negative predictive value 92%.

CONCLUSION

When postoperative CT is not conclusive because of complete opacity of the tympanomastoid cavities, MRI with delayed postcontrast T1-weighted images is a reliable additional technique for the detection of a residual cholesteatoma when its diameter is at least 3 mm.