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result(s) for
"LEINUNG, MARTIN"
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Radiomics of high-resolution computed tomography for the differentiation between cholesteatoma and middle ear inflammation: effects of post-reconstruction methods in a dual-center study
by
Arnoldner, Christoph
,
Lenga, Lukas
,
Burck, Iris
in
Artificial neural networks
,
Autoregressive models
,
Cholesteatoma
2021
Objectives
To evaluate the performance of radiomic features extracted from high-resolution computed tomography (HRCT) for the differentiation between cholesteatoma and middle ear inflammation (MEI), and to investigate the impact of post-reconstruction harmonization and data resampling.
Methods
One hundred patients were included in this retrospective dual-center study: 48 with histology-proven cholesteatoma (center A: 23; center B: 25) and 52 with MEI (A: 27; B: 25). Radiomic features (co-occurrence and run-length matrix, absolute gradient, autoregressive model, Haar wavelet transform) were extracted from manually defined 2D-ROIs. The ten best features for lesion differentiation were selected using probability of error and average correlation coefficients. A multi-layer perceptron feed-forward artificial neural network (MLP-ANN) was used for radiomics-based classification, with histopathology serving as the reference standard (70% of cases for training, 30% for validation). The analysis was performed five times each on (a) unmodified data and on data that were (b) resampled to the same matrix size, and (c) corrected for acquisition protocol differences using ComBat harmonization.
Results
Using unmodified data, the MLP-ANN classification yielded an overall median area under the receiver operating characteristic curve (AUC) of 0.78 (0.72–0.84). Using original data from center A and resampled data from center B, an overall median AUC of 0.88 (0.82–0.99) was yielded, while using ComBat harmonized data, an overall median AUC of 0.89 (0.79–0.92) was revealed.
Conclusion
Radiomic features extracted from HRCT differentiate between cholesteatoma and MEI. When using multi-centric data obtained with differences in CT acquisition parameters, data resampling and ComBat post-reconstruction harmonization clearly improve radiomics-based lesion classification.
Key Points
• Unenhanced high-resolution CT coupled with radiomics analysis may be useful for the differentiation between cholesteatoma and middle ear inflammation.
• Pooling of data extracted from inhomogeneous CT datasets does not appear meaningful without further post-processing.
• When using multi-centric CT data obtained with differences in acquisition parameters, post-reconstruction harmonization and data resampling clearly improve radiomics-based soft-tissue differentiation.
Journal Article
In vitro comparison of surgical techniques in times of the SARS-CoV-2 pandemic: electrocautery generates more droplets and aerosol than laser surgery or drilling
by
Weiß, Roxanne
,
Guderian, Daniela B.
,
Diensthuber, Marc
in
Aerosols
,
Aerosols - adverse effects
,
Animals
2021
Introduction
Based on current knowledge, the SARS-CoV-2 is transmitted via droplet, aerosols and smear infection. Due to a confirmed high virus load in the upper respiratory tract of COVID-19 patients, there is a potential risk of infection for health care professionals when performing surgical procedures in this area. The aim of this study was the semi-quantitative comparison of ENT-typical interventions in the head and neck area with regard to particle and aerosol generation. These data can potentially contribute to a better risk assessment of aerogenic SARS-CoV-2-transmission caused by medical procedures.
Materials and methods
As a model, a test chamber was created to examine various typical surgical interventions on porcine soft and hard tissues. Simultaneously, particle and aerosol release were recorded and semi-quantitatively evaluated time-dependently. Five typical surgical intervention techniques (mechanical stress with a passive instrument with and without suction, CO
2
laser treatment, drilling and bipolar electrocoagulation) were examined and compared regarding resulting particle release.
Results
Neither aerosols nor particles could be detected during mechanical manipulation with and without suction. The use of laser technique showed considerable formation of aerosol. During drilling, mainly solid tissue particles were scattered into the environment (18.2 ± 15.7 particles/cm
2
/min). The strongest particle release was determined during electrocoagulation (77.2 ± 30.4 particles/cm
2
/min). The difference in particle release between electrocoagulation and drilling was significant (
p
< 0.05), while particle diameter was comparable. In addition, relevant amounts of aerosol were released during electrocoagulation (79.6% of the maximum flue gas emission during laser treatment).
Discussion
Our results demonstrated clear differences comparing surgical model interventions. In contrast to sole mechanical stress with passive instruments, all active instruments (laser, drilling and electrocoagulation) released particles and aerosols. Assuming that particle and aerosol exposure is clinically correlated to the risk of SARS-CoV-2-transmission from the patient to the physician, a potential risk for health care professionals for infection cannot be excluded. Especially electrocautery is frequently used for emergency treatment, e.g., nose bleeding. The use of this technique may, therefore, be considered particularly critical in potentially infectious patients. Alternative methods may be given preference and personal protective equipment should be used consequently.
Journal Article
Postoperative radiological assessment of the mastoid facial canal in cochlear implant patients in correlation with facial nerve stimulation
2022
Objectives
To correlate the radiological assessment of the mastoid facial canal in postoperative cochlear implant (CI) cone-beam CT (CBCT) and other possible contributing clinical or implant-related factors with postoperative facial nerve stimulation (FNS) occurrence.
Methods
Two experienced radiologists evaluated retrospectively 215 postoperative post-CI CBCT examinations. The mastoid facial canal diameter, wall thickness, distance between the electrode cable and mastoid facial canal, and facial-chorda tympani angle were assessed. Additionally, the intracochlear position and the insertion angle and depth of electrodes were evaluated. Clinical data were analyzed for postoperative FNS within 1.5-year follow-up, CI type, onset, and causes for hearing loss such as otosclerosis, meningitis, and history of previous ear surgeries. Postoperative FNS was correlated with the measurements and clinical data using logistic regression.
Results
Within the study population (mean age: 56 ± 18 years), ten patients presented with FNS. The correlations between FNS and facial canal diameter (
p
= 0.09), wall thickness (
p
= 0.27), distance to CI cable (
p
= 0.44), and angle with chorda tympani (
p
= 0.75) were statistically non-significant. There were statistical significances for previous history of meningitis/encephalitis (
p
= 0.001), extracochlear-electrode-contacts (
p
= 0.002), scala-vestibuli position (
p =
0.02), younger patients’ age (
p
= 0.03), lateral-wall-electrode type (
p
= 0.04), and early/childhood onset hearing loss (
p
= 0.04). Histories of meningitis/encephalitis and extracochlear-electrode-contacts were included in the first two steps of the multivariate logistic regression.
Conclusion
The mastoid-facial canal radiological assessment and the positional relationship with the CI electrode provide no predictor of postoperative FNS. Histories of meningitis/encephalitis and extracochlear-electrode-contacts are important risk factors.
Key Points
• Post-operative radiological assessment of the mastoid facial canal and the positional relationship with the CI electrode provide no predictor of post-cochlear implant facial nerve stimulation.
• Radiological detection of extracochlear electrode contacts and the previous clinical history of meningitis/encephalitis are two important risk factors for postoperative facial nerve stimulation in cochlear implant patients.
• The presence of scala vestibuli electrode insertion as well as the lateral wall electrode type, the younger patient’s age, and early onset of SNHL can play important role in the prediction of post-cochlear implant facial nerve stimulation.
Journal Article
A robot-guided minimally invasive approach for cochlear implant surgery: preliminary results of a temporal bone study
2009
PurposeThe aim of this study was to create an access canal to the inner ear, by drilling, and perform the cochleostomy for cochlear implant surgery using robot guidance.MethodsA robot, a surgical drill and an Image-Guided Surgery (IGS) system were combined in a closed-loop setup. Ten temporal bones were scanned at the planning stages of the procedure. The robot guided the drill along the preplanned trajectory and created the approach. Postoperative scans were obtained.ResultsThe cochleostomy was performed completely in nine out of ten cases. This did not prove possible for one of the specimens, the target site selected being in too superficial a location in relation to the round window. No violation of the facial nerve took place, although the chorda tympani nerve was violated in one case and the stapes in two. It was obvious during preoperative planning that these structures would be violated, but this was accepted in order to maintain a safety margin from the facial nerve. No other unforeseen damage occurred.ConclusionsThis preliminary study suggests that robot-guided drilling of a minimally invasive approach to the cochlea might be feasible, but further improvements are necessary before any clinical application becomes possible. Where the width of the facial recess is less than 2.5 mm, the chorda tympani nerve and the ossicles are at risk.
Journal Article
Bilateral simultaneous cochlear implantation is a safe method of hearing rehabilitation in adults
by
Gröger, Maximilian
,
Helbig, Silke
,
Loth, Andreas
in
Head and Neck Surgery
,
Medicine
,
Medicine & Public Health
2023
Purpose
Bilateral cochlear implantation is an effective treatment for patients with bilateral profound hearing loss. In contrast to children, adults mostly choose a sequential surgery. This study addresses whether simultaneous bilateral CI is associated with higher rates of complications compared to sequential implantation.
Methods
169 bilateral CI surgeries were analyzed retrospectively. 34 of the patients were implanted simultaneously (group 1), whereas 135 patients were implanted sequentially (group 2). The duration of surgery, the incidence of minor and major complications and the duration of hospitalization of both groups were compared.
Results
In group 1, the total operating room time was significantly shorter. The incidences of minor and major surgical complications showed no statistically significant differences. A fatal non-surgical complication in group 1 was particularly extensively reappraised without evidence of a causal relationship to the chosen mode of care. The duration of hospitalization was 0.7 days longer than in unilateral implantation but 2.8 days shorter than the combined two hospital stays in group 2.
Conclusion
In the synopsis of all considered complications and complication-relevant factors, equivalence of simultaneous and sequential cochlear implantation in adults in terms of safety was found. However, potential side effects related to longer surgical time in simultaneous surgery must be considered individually. Careful patient selection with special consideration to existing comorbidities and preoperative anesthesiologic evaluation is essential.
Journal Article
Prospective study on magnetic resonance imaging in cochlear implant patients
by
Helbig, Silke
,
Hattingen, Elke
,
Loth, Andreas
in
Aged
,
Cochlear Implantation - adverse effects
,
Cochlear Implants - adverse effects
2024
Purpose
Monocentric, prospective study to investigate whether concomitant support of cochlear implant (CI) patients by CI-trained otolaryngologists and application of a standardized head bandage can minimize potential complications during magnetic resonance imaging (MRI).
Methods
Thirty-seven patients with 46 CIs underwent MRI with a prophylactic head bandage. All participants and the otolaryngologist at the CI center completed pre- and post-MRI questionnaires documenting body region scanned, duration of MRI and bandage wear, field strength during the scan, and any complications. If pain was experienced, it was assessed using a visual analog scale (1–10).
Results
MRI was performed without adverse events in 37.8% of cases. Magnet dislocation requiring surgical revision occurred in 2% of cases. Pain was reported in 86% of cases, often due to the tightness of the dressing. Patients with rotating, MRI-compatible magnets reported significantly less pain than participants with older-generation implants. In 11% of cases, the MRI was discontinued.
Conclusion
Serious complications during MRI in cochlear implant patients are rare. Pain is the most common adverse event, probably mainly due to the tight bandage required by most implant types. With newer generations of magnets, these patients experience less pain, no dislocation of the magnets, and no need for bandaging. Although magnet dislocation cannot be completely prevented in older generations of implants, it appears to be reduced by good patient management, which recommends examination under the guidance of physicians trained in the use of hearing implants.
Journal Article
Cochlear implant magnet dislocation after MRI: surgical management and outcome
by
Burck, Iris
,
Vogl, Thomas
,
Gröger, Maximilian
in
Biomimetics
,
Cochlear Implantation - adverse effects
,
Cochlear Implants
2020
Purpose
An increasing number of cochlear implant (CI) users is examined by magnetic resonance imaging which may cause the displacement of the implant magnet. This complication prevents the usage of the external processor and has to be treated surgically in most cases. The purpose of this study is to analyze the results of the surgical intervention and the consequences for the CI recipients.
Methods
The retrospective study was conducted at a tertiary referral center. From the patient care records between October 2014 and July 2018, 9 cases were reviewed that had undergone MRI after cochlear implantation and had experienced magnet displacement.
Results
Nine patients from 9 to 74 years of age were identified with MRI-induced magnet displacement. Implants of different manufacturers were affected (8 × Cochlear
®
, 1 Advanced Bionics
®
) but did not include the latest 3 T MR conditional product generation. The patients reported pain, swelling, redness above the implant and/or a noticeably dislocated magnet. One-third of the MRI examination were conducted in external radiological sites without any precautions such as a compression bandage. Surgical magnet repositioning was successful in all but one case with postoperative implant infection and consecutive explantation. In total, the patient was unable to use his CI for 420 days (1.2 years) after the MRI examination. The remaining eight patients averaged 29 days between MRI-related magnet dislocation and CI re-activation.
Conclusions
The present study shows that in the majority of cases a surgical magnet reposition is possible without complications, and thus the time of nonuse of the CI is usually low. Nevertheless, there is a risk that in individual cases significant medical, functional, social and economic consequences for patients may occur. The presented data demonstrate that the indication to perform MRI scans in CI users needs to be further critically considered. An attentive, critical assessment of an MRI indication by both the initiating physician (usually not an ENT specialist) and the performing radiologist is mandatory.
Journal Article
Improvement of speech perception in quiet and in noise without decreasing localization abilities with the bone conduction device Bonebridge
2017
The aim of this study was to examine the functional hearing results regarding speech perception and auditory sound localization in a high-resolution directional hearing setup following implantation with a new bone conduction device (MED-EL Bonebridge, Innsbruck, Austria). In addition, we assessed the patient acceptance of the Bonebridge system using a questionnaire. The study design is retrospective study. The setting is University Hospital Frankfurt. 18 patients implanted with a Bonebridge device from May 2012 to January 2015 were participated in this study. Speech perception in quiet was tested with the Freiburg monosyllable test at a presentation level of 65 dB SPL. Speech perception in noise was tested post-operatively with the Oldenburg sentence test (OLSA) in best-aided condition. We assessed auditory sound localization with a high-resolution directional hearing setup. To evaluate the acceptance by patients using the Bonebridge in daily life, we used a modified questionnaire. The overall average of functional hearing gain (
n
= 18) was 29.3 dB (±20.7 dB). Speech perception of monosyllabic words in quiet improved by 20.7% on average, compared with the pre-operative aided condition. Mean speech reception thresholds (SRTs) of the Oldenburg sentence test (OLSA) improved significantly from −3.8 dB SNR (range −5.7 to 5.8 dB SNR) to −5.2 dB SNR (range −6.3 to −0.6 dB SNR) after implantation. Regarding localization abilities, no significant difference was found between the unaided and aided conditions following Bonebridge implantation. A survey of patients’ acceptance and handling of the Bonebridge implant in daily life revealed high patient satisfaction. All patients accepted and benefited from the implanted system. No infections or adverse surgical effects occurred. Speech perception significantly improved in quiet and in noise. No significant difference in sound localization was observed. Acceptance of the Bonebridge implant, tested with a modified questionnaire, was high.
Journal Article
Thematic coverage and readability of online patient information on cochlear implant care
by
Weissgerber, Tobias
,
Guderian, Daniela
,
Helbig, Silke
in
Cochlear Implantation
,
Cochlear Implants
,
Comprehension
2024
Introduction
The treatment of patients with a cochlear implant (CI) is usually an elective, complex and interdisciplinary process. As an important source of information, patients often access the internet prior to treatment. The quality of internet-based information regarding thematic coverage has not yet been analysed in detail. Therefore, the aim of this study was to analyse the information on CI care available on the internet regarding its thematic coverage and readability.
Material methods
Eight search phrases related to CI care were defined as part of the study. A checklist for completeness of thematic coverage was then created for each search phrase. The current German CI clinical practice guideline and the white paper on CI care in Germany were used as a basis. As a further parameter, readability was assessed using Flesch Reading Ease Scores. The search phrases were used for an internet search with Google. The first ten results were then analysed with regard to thematic coverage, readability and the provider of the website.
Results
A total of 80 websites were identified, which were set up by 54 different providers (16 providers were found in multiple entries) from eight different provider groups. The average completeness of thematic coverage was 41.6 ± 28.2%. Readability according to the Flesch Reading Ease Score was categorised as \"hard to read\" on average (34.7 ± 14.2 points, range: 0–72). There was a negative statistically significant correlation between the thematic coverage of content and readability (Spearman's rank correlation: r = − 0.413, p = 0.00014).
Summary
The completeness of thematic coverage of information on CI care available on the internet was highly heterogeneous and had a significant negative correlation with the readability. This result should be taken into account by both the providers of internet information and by patients when using internet-based information on CI care and help to further improve the quality of web-based information.
Journal Article
A new adhesive bone conduction hearing system as a treatment option for transient hearing loss after middle ear surgery
2020
Objective
The objective of this prospective, single-subject, repeated measures study was to evaluate the audiological benefit and patient satisfaction with an adhesive, pressure-free bone conduction hearing system (ADHEAR; MED-EL, Innsbruck, Austria) in patients who underwent middle ear surgery with transient hearing loss due to auditory canal tamponade.
Methods
Eleven adult subjects suffering from transient conductive hearing loss were enrolled in the study and followed up to 3 weeks after middle ear surgery. Bone and air conduction thresholds were measured pre and postoperatively to evaluate eligibility for enrollment. Postoperative unaided and aided sound-field thresholds, as well as speech tests in quiet and noise were compared to confirm hearing improvement with the hearing system. To determine patient satisfaction, the SSQ12 and a system-specific quality of life questionnaire was administered to all subjects.
Results
Speech perception for monosyllables in quiet improved by 46%, with statistical significance for the ADHEAR system compared to the unaided condition after one week. The functional hearing gain improved by 19 dB. Speech perception in noise with the device was − 6.7 dB SNR on average, with a statistically significant improvement of 2.7 dB SNR. The results of the questionnaire showed a high level of patient satisfaction and subjective hearing improvement. No serious skin reactions or other severe complications occurred.
Conclusion
As long as the auditory canal is blocked due to tamponade, patients benefit from hearing rehabilitation. This adhesive hearing system is a safe and effective device to treat transient conductive hearing loss and may considerably improve treatment for patients even with short-term hearing loss.
Journal Article