Small for gestational age very preterm infants present a higher risk of developing bronchopulmonary dysplasia.

INTRODUCTION: Several studies assessed the influence of a low birth weight on bronchopulmonary dysplasia (BPD), but not all could find a significant association. Our aim was to assess the association between low birth weight and BPD in preterm infants, prospectively recruited at 11 level III Portuguese neonatal centers. METHODS: Obstetrical and neonatal data on mothers and preterm infants with gestational ages between 24 and 30 weeks, born during 2015 and 2016 after a surveilled pregnancy, were analyzed. Neonates were considered small for gestational age (SGA) when their birthweight was below the 10th centile of Fenton's growth chats and BPD was defined as the dependency for oxygen therapy until 36 weeks of corrected age. Statistical analysis was performed using IBM SPSS® statistics 23 and a p-value <0.05 was considered statistically significant. RESULTS: Out of 614, a total of 494 preterm infants delivered from 410 women were enrolled in the study; 40 (8.0%) infants with SGA criteria. SGA were more often associated with a single pregnancy, had greater use of antenatal corticosteroids, increased prevalence of gestational hypertensive disorders, C-section, rupture of membranes below 18 hours, rate of intubation in the delivery room, use of surfactant treatment, oxygen therapy, mechanical ventilation need, BPD, cystic periventricular leukomalacia, nosocomial sepsis and pneumonia; had lower prevalence of chorioamnionitis, and lower Apgar scores. The multivariate analysis by logistic regression, adjusted for BPD risk factors revealed a significant association between SGA and BPD: OR = 5.2 [CI: 1.46-18.58]; p = 0.01. CONCLUSION: The results of this study increase the scientific evidence that SGA is an independent risk factor for BPD.

Indications of cone beam CT in head and neck imaging in children.

For imaging of bony structures, especially for the anterior and lateral skull base in ORL medicine, cone beam computed tomography (CBCT) is an increasingly used alternative to CT, with a lower exposition to plain radiography that makes its use for imaging, particularly in children, very interesting. The aim of this study was to analyse possible indications and settings for CBCT in children and compare them to those of adults. A total of 554 patients (age range 0-18 years, mean age 10.36 years), who underwent CBCT between 01/2004-06/2013 in the ENT department at the university clinic of Marburg were enrolled in this retrospective analysis to evaluate technical parameters and indications. Data on CBCT of all children were compared with previously published data collected from 1730 adults who were diagnosed with the help of CBCT in the ENT department at the university clinic of Marburg, during the years 2012-2013. The most frequent indications of CBCT in children vs. adults were in the anterior skull base region: mid-facial trauma (60.4%) vs. chronic rhinosinusitis (54.8%), disturbed nasal breathing (13.9% vs. 13.0%) and chronic rhinosinusitis (12%) vs. mid-facial trauma (10.8%). For the lateral skull base the main indications were cholesteatoma (20.3%) vs. position control of cochlear implant (CI) electrode (31.2%), chronic otorrhoea (17.5%) vs. cholesteatoma (20.9%), and position control of CI electrode (11.8%) vs. chronic otitis media mesotympanalis (6.8%). CBCT is a suitable imaging modality for bony structures in adults and children. Settings mainly depend on the region of interest. One aim should also be to reduce exposure to radiation in both adults and children.

Evaluation of different time schedules in training with the Da Vinci simulator.

BACKGROUND: This prospective study analyzed the effect of different time schedules in training on the main performance outcomes: overall score, time to complete, and economy of motion. METHODS: The study was performed on the da Vinci Skills Simulator from December 2014 to April 2016. Forty robotic novices were randomized into two groups of 20 participants, which trained in the same three exercises but with different intervals between their training sessions. Each group performed training in Peg Board 1 in their first week, Match Board 2 in their second week, and Ring and Rail 2 in their third week. On their last day, Needle Targeting and Energy Dissection 2, for which no previous training had been received, were performed. Regarding the different training intervals, group 1 trained each exercise six times in a row once a week. Group 2 performed their training once a day for 5 days. Technical performance parameters were recorded by the Mimics simulator software for further analysis. In addition, the participants were asked to fill out a questionnaire concerning the robotics training. RESULTS: Group 2 performed significantly better compared to group 1 in the main metrics in the more advanced exercises. For the easier exercises, the training frequency did not lead to significant differences in performance outcome. A significant skills gain was seen between the first and last training sessions for all exercises in both groups. CONCLUSIONS: Performance in the final exercise NT was significantly better in group 2 than group 1. Regarding ED 2, no difference was found between the two groups. As the training of group 2 led to significantly better outcomes, we suggest that, especially for advanced exercises, it seems to be more favorable to perform training every day for a short period than to train once a week six times in a row.

The effect of different training exercises on the performance outcome on the da Vinci Skills Simulator.

BACKGROUND: Increasing usage of robotic surgery presents surgeons with the question of how to acquire the special skills required. This study aimed to analyze the effect of different exercises on their performance outcomes. METHODS: This prospective study was conducted on the da Vinci Skills Simulator from December 2014 till August 2015. Sixty robotic novices were included and randomized to three groups of 20 participants each. Each group performed three different exercises with comparable difficulty levels. The exercises were performed three times in a row within two training sessions, with an interval of 1 week in between. On the final training day, two new exercises were added and a questionnaire was completed. Technical metrics of performance (overall score, time to complete, economy of motion, instrument collisions, excessive instrument force, instruments out of view, master work space range, drops, missed targets, misapplied energy time, blood loss and broken vessels) were recorded by the simulator software for further analysis. RESULTS: Training with different exercises led to comparable results in performance metrics for the final exercises among the three groups. A significant skills gain was recorded between the first and last exercises, with improved performance in overall score, time to complete and economy of motion for all exercises in all three groups. CONCLUSIONS: As training with different exercises led to comparable results in robotic training, the type of exercise seems to play a minor role in the outcome. For a robotic training curriculum, it might be important to choose exercises with comparable difficulty levels. In addition, it seems to be advantageous to limit the duration of the training to maintain the concentration throughout the entire session.

Possibility of differentiation of cochlear electrodes in radiological measurements of the intracochlear and chorda-facial angle position.

Due to an increasing number of cochlear implantations, quality control has become more important. In addition to intraoperative biophysical measurements, radiological imaging is another possibility. An upcoming technique regarding this is Cone Beam CT (CBCT). Sixty-five data sets (35 Nucleus Contour Advance-Cochlear; 30 Flex Soft-MedEl) of postoperative imaging by CBCT (Accu-I-tomo F17, Morita, Kyoto, Japan) underwent further evaluation. Insertion angle, height of the cochlea, distance of the electrode to the medial or lateral wall, angle between chorda tympani and facial nerve and the precise position of the electrode cable in the facial-chordal angle were determined. The typical difference between the perimodiolar and lateral course of the electrodes could also be shown in radiological measurements. This demonstrates the accuracy and advantage of CBCT in visualisation of small structures with fewer metal artifacts. Furthermore, in 75% of patients, the angle of the chorda and facial nerve could be visualised. Significant differences in dependence of the electrode type for the relation of them to the facial nerve could be seen. In conclusion, CBCT achieves reliable visualisation and detailed imaging-based measurements of the intracochlear position of different cochlea electrodes. Additionally, clinically known differences can be reproduced. Even visualisation of the position of the electrode in the chorda-facial angle is possible. Therefore, CBCT is a useful tool in intra- and postoperative control of cochlear implants.

Prospective evaluation of reliability of cone-beam computed tomography in detecting different position of vibroplasty middle ear implants.

OBJECTIVES: This study had the following objectives: (i) to determine the accuracy of determination of Vibrant Soundbridge position in the spectrum of typically implanted sites in the middle ear, (ii) to assess interobserver agreement between three observers with different levels of radiology experience and (iii) to determine the suitability of cone-beam computed tomography (CT) to be used as the baseline radiological assessment post implantation, confirm ferromagnetic transducer (FMT) position. DESIGN: Prospective research study. Using four fresh human cadaveric heads, different types of vibroplasty were performed. After each step, cone-beam CT was performed for each of the four cadaveric heads. SETTING: University hospital (ENT and Neuroradiology). PARTICIPANTS: Four fresh cadaveric heads of human donors were operated and analysed by radiological imaging. MAIN OUTCOME MEASURES: There are different ways of coupling an ferromagnetic transducer to the anatomical structures of the middle and inner ear. Possibilities of differentiation between these coupling variants should be presented. RESULTS: The individual reconstruction view was significantly different from a standardised view for each observer (observer 1: P = 0.003; observer 2: P = 0.001; observer 3: P = 0.002) for all coupling variants combined as well as for each individual coupling variant (overall correct diagnosis: 100% versus 60%). Regarding the frequency of correct diagnosis, no significant differences were found between the three observers (P > 0.500) for each individual coupling variant as well as for all coupling variants combined. The worst rates of correct diagnosis were found in the standardised view for incus (42%), stapes (0%) and TORP (17%) vibroplasty. CONCLUSION: Cone-beam CT as a radiological control for Vibrant Soundbridge is safe and adequately sensitive and reliable and is therefore suitable for clinical investigation. The position of the ferromagnetic transducer in the middle ear and the presence or absence of an additional coupler could be determined in this study. Therefore, cone-beam-CT is useful for the assessment of device failure when there has been gross displacement of the ferromagnetic transducer (or smaller displacements in case of a baseline postoperative cone-beam CT). Regarding the quality of imaging, cone-beam CT produced accurate results with different observers with widely varying radiological experience.

[Imaging quality and dosage in ENT--what do we really need?]. / Dosisreduktion unter Betrachtung der erforderlichen Bildqualität--Wie viel Dosis braucht ein Bild?

BACKGROUND: Today, imaging of nose, paranasal sinuses and temporal bone by CT is standard in preoperative diagnostics. The need of reduction of applied dosage leads to the necessity of research in necessary imaging quality. Therefore this paper deals with new developed anatomical checklists and the analysis of imaging quality on anterior and lateral skull base. MATERIAL AND METHODS: With 3 human complete heads over 400 examinations were performed on one cone beam CT device under varying x-ray-tube adjustments. 31 anatomic parameters were evaluated (Excellent, well, poor, not evaluable) for every data set. A summation score was built for every examination. RESULTS: As well for paranasal sinuses as for temporal bone a constant excellent imaging quality could be seen in high dosages. Certainly, in low dosages a reduction of imaging quality was detected. The optimal range (all parameters visualized well as average) could be evaluated for paranasal sinuses between 2,0 and 3,0 mGy and between 3,0 and 4,0 mGy for temporal bone. So, a reduction of 70-80% in comparison to highest adjustments of today is possible and realistic. In comparison to standard protocols, a reduction of about 50% can be reached. CONCLUSION: The possibility of dose reduction by discussion of the necessary imaging quality from clinical point of view could be shown.

Potential of dosage reduction in cone-beam-computed tomography (CBCT) for radiological diagnostics of the paranasal sinuses.

More than 10 years ago, cone-beam-computed tomography (CBCT) was introduced in ENT radiology. Until now, the focus of research was to evaluate clinical limits of this technique. The aim of this work is the evaluation of specific dosages and the identification of potential optimization in the performance of CBCT of the paranasal sinuses. Based on different tube parameters (tube current, tube voltage, and rotation angles), images of the nose and the paranasal sinuses were taken on a phantom head with the Accu-I-tomo F17 (Morita, Kyoto, Japan). The dosages applied to the lens and parotid gland were measured with OSL dosimetry. The imaging quality was evaluated by independent observers. All datasets were reviewed according to a checklist of surgically important anatomic structures. Even for lowest radiation exposure (4 mA, 76 kV, 180°, computed tomography dosage index (CTDI) = 1.8 mGy), the imaging quality was sufficient. Of course a significant reduction of the imaging quality could be seen, so a reliable mean was set for 4 mA, 84 kV, and 180° rotation angle (CTDI = 2.4 mGy). In this combination, a reduction of 92 % in lens-dose and of 77 % of dosage at the parotid gland was observed in comparison to the maximal possible adjustments (8 mA, 90 kV, 360°, CTDI = 10.9 mGy). There is potential for optimization in CBCT. Changing the rotation angle (180° instead of 360°) leads to a dose reduction of 50 %. Furthermore from clinical point of view in case of chronic rhinosinusitis a relevant reduction of dosage is possible. Therefore, it is necessary to intensify the interdisciplinary discussion about the disease specifics required quality of imaging.

[Intracochlear electrode position: evaluation after deep insertion using cone beam computed tomography]. / Intracochleäre Elektrodenlage : Beurteilung mittels "cone beam computed tomography" nach tiefer Insertion.

INTRODUCTION: Due to the increasing number of cochlear implantations (CI), postoperative radiological verification of the electrode position, e.g., with respect to quality control, plays a central role. The aim of this study was to evaluate the intracochlear position of deep inserted electrodes by cone beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT data sets (Accu-I-tomo, Morita, Kyoto, Japan) of 22 patients (28 ears operated between 2008 and 2011) were retrospectively analyzed. All patients underwent a CI (round window approach) with deep insertion of the electrode (Flex soft or standard electrode from MedEl©). CBCT data were analyzed for intracochlear position of the electrode (scala vestibuli, scala tympani, malposition between the scalae) and the certainty of this evaluation. RESULTS: All ears could be evaluated with the status certain or relatively certain in the basal turn of the cochlea. Thereby, the electrode array was inserted into the scala tympani in 93% (n = 26). Primary insertion into the scala vestibuli and the scala media was observed in 3.5% of the ears, respectively. In the apical part of the cochlea, only 32% (n = 9 ears) could be evaluated with relative certainty. The remaining 68% of cases could not be evaluated. Of the 32% interpretable cases in the apical part of the cochlea, 25% (n = 7) were inserted into the scala tympani, 3.5% (n = 1) into the scala vestibuli, and 3.5% (n = 1) were malpositioned between the scalae. CONCLUSION: The exact evaluation of the intracochlear position of the electrode by CBCT is only possible in the basal turn of the cochlea. In deep insertion, determination of the position in the medial and apical parts of the cochlea by CBCT is still not possible. Furthermore, the round window approach allows reliable implantation into the scala tympani.

Artifacts of the electrode in cochlea implantation and limits in analysis of deep insertion in cone beam tomography (CBT).

Until now more than 250,000 cochlea implantations have been performed worldwide. The surgical procedure is well standardized. A discussion about the kind of postoperative radiological control has started since cone beam tomography (CBT) has been established in ENT and hearing preservation operations have come more into the focus. Further research has been concentrated on the role of CBT and the insertion of the basal turn. The aim of this study was to look for the possibilities of CBT and deep insertion. The second aim was to analyze the artifacts of cochlea implants in CBT. Three human cadaver ears were implanted with a flex soft electrode of MedEl© in a standard operation procedure with round window insertion and a full insertion. Afterwards 72 CBT sets per ear were performed with different X-ray-tube currents (2-10 mA), voltages (72-90 kV), and exposure times (9 and 17 s). On each data set, the radiological diameter of the electrode 9 (basal), electrode 2 (apical), the diameter of the cable next to the electrodes 9 and 2, and the associated diameter of the cochlea next to the electrodes 9 and 2 were evaluated. Additionally, a comparison to the real diameter was done. The mean radiological diameters of the measure point at electrode 9 were: electrode = 1.19 mm; cable = 0.65 mm; cochlea = 1.77 mm. Results for measure point at electrode 2 were: electrode = 0.98 mm; cable = 0.48 mm; cochlea = 1.21 mm. The real diameters were at electrode 9 in lateral view 0.58 mm and in top view 0.63 mm and at electrode 2 in lateral view 0.36 mm and in top view 0.50 mm. Differences between the diameters of the electrode 9 and 2 were highly significant. Interestingly, the real diameter of the electrode is half in comparison to the radiological one. Also in comparison to the diameter of the cable and the associated electrode is nearly half. Nearly 50% artifact exists on radiologic evaluation of the diameter of the electrode. Varying the X-ray adjustments did not lead to optimized results. The difficulties in evaluating a cochlea electrode with CBT could be shown. The high rate of artifacts (50%) makes it extremely difficult to predict the inserted scale, especially when evaluating the intracochlear position in the medial and apical turn of the cochlea. In conclusion, until now CBT allows a relatively safe evaluation of the electrode in the basal turn, whereas in deep insertion it is not really a useful tool to answer the question of insertion trauma, implanted scale, or scale displacements.

SU-E-I-05: Dose Reduction in Head CBCT Examinations After Protocol Optimization.

PURPOSE: CBCT systems for head examinations especially in otorhinolaryngology offer better than required image quality at relatively low purchasing costs. Due to this fact the number of dedicated head scanners increases steadily. Regarding image quality in relation to patient dose these systems are frequently not optimized. Examination parameter optimization is an iterative process, which should be done carefully by physicians in cooperation with physicists. After a successful optimization, Monte Carlo Simulations can be used to quantify the dose reduction to the patient. METHODS: Images of an anatomic head phantom were obtained using different settings of kVp, mAs and rotation angle (360°, 210°). The resulting images were anonymized and the examination parameters were removed. Radiologists and otorhinolaryngologists evaluated these images and rated them into excellent image quality, good image quality, bad image quality and not readable. Based on the ratings new parameters for the adequate image quality were set. The dose reduction was calculated using Monte Carlo simulations. RESULTS: The organ dose of radiation sensitive organs was reduced significantly. The dose reductions compared to the standard settings are: eyes: 85%, eye lenses: 88%, salivary glands: 40%, thyroid: 60%, blood vessels: 40%, brain: 60%, teeth: 80% and tonsils: 65%. Dose reduction was best, when a short scan (210° rotation angle) was used, where the eyes are not in the direct exposure field. CONCLUSIONS: The results show the potential for dose optimizations in otorhinolaryngological CBCT examinations compared to standard vendor settings without loss in diagnostic information. Furthermore this study points out the great opportunities that Monte Carlo-based dose-calculations methods offer to quantify the increase of dose efficiency after examination protocol optimizations. It could also be shown that CBCT has advantages when doing short scan mode around the rear head. This protects radiation sensitive organs such as the eye lenses from being directly radiated.

Multicenter evaluation of a new 4th generation HIV screening assay Elecsys HIV combi.

Fourth-generation screening assays which permit a simultaneous detection of human immunodeficiency virus (HIV) antigen and antibody reduce the diagnostic window on average by four days in comparison to third-generation antibody assays. Recently, the new automated Elecsys HIV combi was compared in a multicenter study to alternative fourth- and third-generation assays, p24 antigen test and HIV-1 RNA RT-PCR. A total of 104 serocon-version panels, samples of the acute phase of infection after seroconversion (n = 33), anti-HIV-1 positive specimens (n = 572) from patients in different stages of the disease, 535 subtyped samples from different geographical locations, including group M (subtypes A-J) and group O, anti-HIV-2 positive sera (n = 364), dilutions of cell culture supernatants (n = 60) infected with different HIV-1 subtypes, selected performance panels, 8406 unselected samples from blood donors originating from different blood transfusion centers, 3810 unselected sera from daily routine and from hospitalized patients, 9927 unselected samples from South Africa and 1943 potentially interfering samples were tested with the Elecsys HIV combi. Elecsys HIV combi showed a comparable sensitivity to HIV-1 Ag stand-alone assays for early detection of HIV infection in seroconversion panels. The mean time delay of Elecsys HIV combi (last negative sample + 1 day) in comparison to HIV-1 RT-PCR for 92 panels tested with both methods was 3.23 days. The diagnostic window was reduced with Elecsys HIV combi between 1.56 and 5.32 days in comparison to third-generation assays. The specificity of Elecsys HIV combi in blood donors was 99.80% after repeated testing. Our results show that a fourth-generation assay with improved specificity and sensitivity like the Elecsys HIV combi is suitable for blood donor screening due to its low number of false positives and since it detects HIV p24 antigen with a comparable sensitivity to single antigen assays.