Patient Head Position Research Articles

Measurements of oculo-palpebral landmarks and evaluation of patient's head position.

Keeping the head in a neutral position is requisite for glasses/lenses/head-up designs, the suitability of oculo-plastic surgery and for the grading the eye shift. Anatomically incompatible glasses are one of the common problems affecting accommodation, reducing comfort and disturbing by causing symptoms such as dizziness and nausea. The oculo-palpebral measurements act as a key determinant in symmetrical facial attractiveness. This study aims to investigate the most effective oculo-palpebral landmarks, head-neutral as the ideal position, taking into account of individual anatomical differences of these patients. 100 females and 100 males aged between 18 and 20 years were photographed. Digital photogrammetric measurements were made with the ImageJ program. Interpupillary and interhelical distances, besides bilateral palpebral fissure length and height, and iris diameter were calculated on front-facing photographs. Mean interpupillary distance was measured wider in males than in females. The mean length of palpebral fissure was 31mm; palpebral fissure height was 10mm. These figures were valid in both eyes and gender. The interhelical distance was calculated as the mean and was measured longer in men. Since the measurement values were the same in both sexes and on both sides, they were determined as important landmarks for controlling the head-neutral position, evaluating whether there was a deviation in the eye, and measuring the numerical value when detected. It is essential to check the side-symmetry of the patient's palpebral fissure height, palpebral fissure length, diameter of iris and corneal depth during oculo-plastic invention and artificial design.

The impact of surgical set-up of endoscopic two surgeon four hand anterior skull base surgeries on surgeons' ergonomics.

The impact of different surgical set-ups of endoscopic two surgeon four hand anterior skull base surgeries on surgeons' ergonomics remain unclear. This study aims to explore the effect of surgeon, patient and surgical screen positioning on surgeons' ergonomics using the Rapid Entire Body Assessment (REBA) tool. A total of 20 different surgical positions of anterior skull base surgery were simulated and the ergonomic impact on surgeons' neck, truck, leg and wrist were measured using the validated Rapid Entire Body Assessment (REBA) tool. To investigate the ergonomic effect of different surgical setups, the operating surgeon, assisting surgeon, patient head, camera and screen positions were positioned differently in each surgical position. The lowest REBA Score recorded is 3 whereas the highest score is 8. The REBA scores for the majority of positions are 3 highlighting that these positions are ergonomically favorable. Position 12 is the least ergonomically favorable position with a total REBA score of 19. In this position, operating surgeon is positioned to the right of the patient, assisting surgeon to the left of patient, patient head in central position with camera held by operating surgeon and one screen is placed to the right of patient. Positions 13 and 17 are the most ergonomically favorable positions with a total REBA score of 12. In these positions, the patient's head is positioned to the center, two screens were utilized, and the surgeons were positioned on either side of the patient. The utilization of 2 screens with a central patient head position with the surgeons placed on either side of the patient contribute towards a more ergonomically state in these positions. Certain positional behaviors are better at reducing musculoskeletal injury risk when compared to other. Positions with two screens and central head positions are more favourable ergonomically and surgeons should consider this set-up to reduce musculoskeletal injuries during anterior skull base surgery.

Head elevation during preoxygenation can delay desaturation time: A randomized-controlled trial

BackgroundPreoxygenation before anesthesia induction is an important part of airway management to reduce the risk of hypoxemia when the patient is apneic. The effectivity of preoxygenation is influenced by several things such as patient's head position. This study aimed to compare preoxygenation between various degrees of head elevation (20°, 30°, and 45°) and 0° or no elevation position towards desaturation time before tracheal intubation in patients undergoing general anesthesia. MethodThis was a single-blinded randomized clinical trial of 48 patients, assigned into four groups (0°, 20°, 30°, and 45° head elevation group). All subjects were preoxygenated for 3 min with 100% oxygen. Induction of anesthesia was started with fentanyl and propofol, followed by rocuronium after the patient lost consciousness. Time was recorded from the beginning of induction until the oxygen saturation decreased to 93% or a time limit of 5 min was reached. ResultThe desaturation time in 45° head elevation group was significantly the longest, followed by 30°, 20°, and 0° group (224,0 ± 49,4; 196,4 ± 41,7; 187,2 ± 29,8; and 166,1 ± 51,3 s, respectively; P < 0.05). ConclusionsPatients with 45° head elevation had significant longer mean desaturation time compared to 0° and 20° head elevation group. In patients undergoing general anesthesia, preoxygenation with head elevation slowed down the time for desaturation before tracheal intubation compared to the conventional position. Clinical trial registrationNCT05688722.

Patient and physician positioning during anterior skull base surgery impacts physician ergonomics

Background The effects of anterior skull base surgery on surgeon’s ergonomics remain unclear and this study explores the impact of patient, surgeon and screen positioning on surgeon’s ergonomics during anterior skull base surgery using the Rapid Upper Limb Assessment (RULA) tool. Method A total of 20 different surgical positions involving the operating surgeon, assisting surgeon, patient head position, camera position and screen position/number were simulated. For each position, the ergonomic effects on the upper limb, neck, trunk and lower limb of surgeons were analysed using the Rapid Upper Limb Assessment (RULA) tool. Results The lowest RULA score is 2 and the maximum score is 6. The majority of scores ranged from 2 to 3 suggesting the majority of positions have acceptable postures. The average RULA score of the right side of operating surgeon was 2.8 versus 2.95 on the left-side (p = 0.297). For the assisting surgeon, the average RULA score of the right side was 3.65 versus 3.25 for the left side (p = 0.053). The average combined (left and right) RULA score for the operating surgeon was 5.76 versus 6.9 for the assisting surgeon (p < 0.001). Position 17 (operating surgeon to the right of patient, assisting surgeon to the left of patient, central patient head position and two screens) is the most ergonomically favourable position. Position 2 (operating and assisting surgeon to the right of patient, patient head position to the right and one screen position to the left of patient) is the least favourable position. Conclusion This simulation raises awareness of risk of musculoskeletal injury in anterior skull base surgery and highlights that certain positional behaviours are better for reducing injury risk than others. Two screens should be considered when performing a two-surgeon, four-hand anterior skull base surgery and surgeons should consider applying this to their own ergonomic environment in theatre.

Real-time Detection of Patient Head Position and Cephalometric Landmarks from Neuro-Interventional Procedure Images Using Machine Learning for Patient Eye-Lens Dose Prediction.

A deep learning (DL) model has been developed to estimate patient-lens dose in real-time for given exposure and geometric conditions during fluoroscopically-guided neuro-interventional procedures. Parameters input into the DL model for dose prediction include the patient head shift from isocenter and cephalometric landmark locations as a surrogate for head size. Machine learning (ML) models were investigated to automatically detect these parameters from the in-procedure fluoroscopic image. Fluoroscopic images of a Kyoto Kagaku anthropomorphic head phantom were taken at various known X (transverse) and Y (longitudinal) shifts, as well as different magnification modes, to create an image database. For each image, anatomical landmark coordinate locations were obtained manually using ImageJ and are used as ground-truth labels for training. This database was then used to train the two separate ML models. One ML model predicts the patient head shift in both the X and Y directions and the other model predicts the coordinates of the anatomical landmarks. From the coordinates, the distance between these anatomical landmarks is calculated, and input into the DL dose-prediction model. Model performance was evaluated using mean absolute error (MAE) and mean absolute percentage error (MAPE) for the head-shift and landmark-coordinate models, respectively. The goal is to implement these two separate models into the Dose Tracking System (DTS) developed by our group. This would allow the DTS to automatically detect the patient head size and position for eye-lens dose prediction and eliminate the need for manual input by the clinical staff.

47 Patient and Physician Positioning During Anterior Skull Base Surgery Impacts Physician Ergonomics

Abstract Aim The effects of anterior skull base surgery on surgeon’s ergonomics remain unclear and this study explore the impact of patient, surgeon, and screen positioning on surgeon’s ergonomics during the surgery. Method A total of 20 different surgical positions involving the operating surgeon, assisting surgeon, patient head position, camera position and screen position/number were simulated. For each position, the ergonomic effects on the upper limb, neck, trunk, and lower limb of surgeons were analysed using the Rapid Upper Limb Assessment (RULA) tool. Results The majority of scores ranged from 2 to 3 suggesting the majority of positions have acceptable postures. The average RULA score of the right side of operating surgeon was 2.8 versus 2.95 on the left-side (p = 0.297). For the assisting surgeon, the average RULA score of the right side was 3.65 versus 3.25 for the left side (p = 0.053). The average combined (left and right) RULA score for the operating surgeon was 5.76 versus 6.9 for the assisting surgeon (p&amp;lt;0.001). Position 17 (operating surgeon to the right of patient, assisting surgeon to the left of patient, central patient head position and two screens) is the most ergonomically favourable position. Position 2 (operating and assisting surgeon to the right of patient, patient head position to the right and one screen position to the left of patient) is the least favourable position. Conclusions This simulation raises awareness of risk of musculoskeletal injury in anterior skull base surgery and highlights those certain positional behaviours are better for reducing injury risk than others.

The accessory to ace Face bow records in clinical practice - Laser Levels assisted Face bow Records

An accurate determination, recording and transfer of jaw relation records from patients to the articulator is essential for appropriate dental restoration function, facial appearance and maintenance of patient’s oral health.1 An unsatisfactory and inaccurate record of maxilla-mandibular relationship will eventually lead to failure of the restoration or prosthesis. Facebow plays an integral part of this maxilla-mandibular relationship transfer from the patient mouth to that of the articulator. The use of facebows is emphasized in prosthodontic textbooks and is widely taught in dental schools, but is still perceived as a complex procedure by most students.2 This article attempts to discuss the utilization of a cross beam laser level as a simple accessory to simplify face bow use and to obtain a repeatable and reliable patient head position while recording jaw relations using face bows. The laser cross beam also serves the purpose of improving the accuracy and speed of making face bow records.

A Protocol for Imaging of Cochlear Implantation.

Correct electrode placement is a challenge of cochlear implant surgery, which occurs because electrode position cannot be directly visualized. This work aims to 1) develop a protocol for a practical, consistent, single view plain radiograph able to be used to confirm cochlear implantation, 2) confirm its usefulness on patients, and 3) confirm its usefulness for identifying misplaced electrodes in cadaveric ears. Imaging procedure and quality improvement initiative. Tertiary academic hospital. Cadaveric ears, and patients undergoing cochlear implantation. An intraoperative imaging protocol was developed specifying patient head position, machine position, and exposure setting. This was tested to confirm proper cochlear implantation in patients, including one revision case. This technique allowed the electrode placement to be reliably identified in patients of all ages. Its usefulness for identifying maligned electrodes (partial insertion, and insertion into the vestibule or hypotympanum) was confirmed using four cadaveric hemi-heads. Ability to accurately identify correct or incorrect electrode insertion based on radiographic images. After adjusting radiographic exposure to account for the embalming process of the cadaveric heads, this new protocol was confirmed to be able to identify incorrect placement. This was also successfully used to confirm proper placement of cochlear implants in patients. Following a standardized radiographic protocol for cochlear implantation is a quick and easy method for checking electrode position.Supplemental Digital Content, http://links.lww.com/MAO/B253.

Effect of head position on cochlear implant MRI artifact.

A new generation of cochlear implant (CI) magnets and specific surgical techniques (e.g., implant positioning) has changed the relationship between a CI and magnet resonance imaging (MRI). MRI allows a pain free in vivo evaluation of the inner ear fluid state and internal auditory canal after the insertion of an electrode. The aim of this study is to evaluate how the patient's head position in the MRI scanner influences the CI magnet-related artefact. We performed in vivo measurement of MRI artefacts at 3T with a CI system containing a bipolar diametrical magnet. The implant magnet was positioned with a head bandage at different positions from the nasion and external auditory canal in three volunteers. We used a turbo spin echo (TSE) T2w sequence on the axial and coronal planes and observed three positions: (1) regular position, (2) chin to chest (anteflexion), and (3) hyperextension (retroflexion). By comparing the positions, anteflexion of the cervical spine in a chin-to-chest position allowed us to place the artefact in a more apical position from the IAC in the coronal plane. The hyperextension of the cervical spine position shifts the artefact father towards the cochlea's direction. The head's position can influence the location of MRI artefacts. In cases where the artefact diminished the IAC or cochlea, anteflexion of the cervical spine in the chin-to-chest position of the head in the MRI scanner should be attempted to allow a visualization of the IAC.

Towards Best Practices in Clinical Magnetoencephalography: Patient Preparation and Data Acquisition.

A magnetoencephalography (MEG) recording for clinical purposes requires a different level of attention and detail than that for research. As contrasted with a research subject, the MEG technologist must work with a patient who may not fully cooperate with instructions. The patient is on a clinical schedule, with generally no opportunity to return due to an erroneous or poor acquisition. The data will generally be processed by separate MEG analysts, who require a consistent and high-quality recording to complete their analysis and clinical report. To assure a quality recording, (1) MEG technologists must immediately recheck their scalp measurement data during the patient preparation, to catch disturbances and ensure registration accuracy of the patient fiducials, electrodes, and head position indicator coils. During the recording, (2) the technologist must ensure that the patient remains quiet and as far as possible into the helmet. After the recording, (3) the technologist must consistently prepare the data for subsequent clinical analysis. This article aims to comprehensively address these matters for practitioners of clinical MEG in a helpful and practical way. Based on the authors' experiences in recording over three thousand patients between them, presented here are a collection of techniques for implementation into daily routines that ensure good operation and high data quality. The techniques address a gap in the clinical literature addressing the multitude of potential sources of error during patient preparation and data acquisition, and how to prevent, recognize, or correct those.

Orbital Magnetic Resonance Imaging Demonstrates Better Contact between the Gas and Anterior Inferior Retina in Side versus Face-Down Position

To demonstrate the relationship between an intraocular gas bubble, the retina, and the residual intraocular fluid in different head positions using orbital magnetic resonance imaging (MRI) in 3 patients who underwent pars plana vitrectomy (PPV) with gas tamponade. Novel study. Patients undergoing PPV with gas-fluid exchange (sulfurhexafluoride [SF6] or perfluoropropane [C3F8]). Magnetic resonance imaging scans were obtained in 3 patients undergoing PPV with gas-fluid exchange (SF6 or C3F8). All surgeries were performed by a single surgeon (E.D.M.). On the first postoperative day, the volume of intraocular gas fill was estimated separately by 2 surgeons (A.H. and E.D.M). Four orbital MRI scans were obtained from different head positions, including face up (supine), face down (prone on a massage pillow), flat on the right side, and flat on the left side. Relationship between the gas bubble and residual vitreous fluid. The MRI images demonstrated, with excellent contrast, the gas and fluid locations in the vitreous cavity in all scans. The relationship between the gas bubble and residual vitreous fluid showed a rapid shift when the patient's head position changed. The MRI images demonstrated that with both 70% gas fill and 95% gas fill, lying on the side can give better support to the inferior retina than face-down positioning. The images demonstrated the importance of accurate head positioning, because a slight change in head position resulted in inadequate contact between the anterior inferior retina and the gas bubble. To our knowledge, this is the first time that the relationship between an intraocular gas bubble and contact with the retina has been evaluated in different head positions invivo using MRI imaging. The MRI images demonstrated that side positioning gives better contact between the gas bubble and the inferior and anterior retina than prone positioning even when the gas fill is only 70% of the vitreous cavity.

Effect of patient head position on the aspirated volume of regurgitated clear fluid. Afresh human cadaver study.

The relationship between regurgitated and aspirated volume of clear fluids remains undetermined and may depend on anatomical factors and patient position. We aimed to assess whether head position (sniffing vs. extension position) affected this relationship in fresh human cadavers. We also determined the critical volume of water regurgitated that led to pulmonary aspiration of volume ≥ 0.8 mL kg-1 and ≥ 1.5 mL kg-1 for each head position. Six volumes of water (40, 80, 100, 120, 150, and 200 mL) were injected each twice, in a randomised order, at a flow rate of 20 mL per second, into the oesophagus of seven fresh human cadavers lying in the supine position on a non-tilted table, with the head in the sniffing position and in the extension position. Aspirated volume was measured in the trachea, blindly to the volume injected. Overall, more than 85% of the regurgitated volume was aspirated into the trachea. The volume of aspirated water was significantly greater in the sniffing position than in the extension position. The cut-off volumes of water injected into the oesophagus leading to aspirated volume ≥ 0.8 mL kg-1 and ≥ 1.5 mL kg-1 were, respectively, 0.8 mL kg-1 and 1.5 mL kg-1 in the sniffing position, and 1.2 mL kg-1 and 1.8 mL kg-1 in the extension position. These results confirm that most of the regurgitated clear fluid enters the trachea in humans lying in the supine position on a non-tilted table, especially when the head is in the sniffing position.

Three-Dimensional Volume Rendering: An Underutilized Tool in Neurosurgery

Two-dimensional radiologic images of computed tomography (CT) and magnetic resonance imaging (MRI) examinations are insufficient to provide three-dimensional conception of intracranial or spinal lesions, especially for an inexperienced neurosurgeon. We share our experience of applications of volume rendering (VR) images of CT and MRI studies of brain and spine for the purpose of training and surgical planning in neurosurgery. Digital Imaging and Communications in Medicine viewer software was used on a personal computer/laptop to view CT and MRI examinations of various lesions of brain, spine, and spinal cord. Various user-friendly applications of the software enable users to edit the images acquired. Imaging technique (CT and MRI) incorporating continuous or overlapping slice with slice thickness of 1 mm with zero gap provides adequate three-dimensional image quality on personal computer/laptop acquired by VR. It was especially helpful for assessment of lesions of the skull base, intracranial vessels (aneurysm and arteriovenous malformation), craniovertebral junction and contrast-enhancing lesions of the brain. Displaying VR images in the operating room as per the patient's head position orients the surgeon to identify various structures in the surgical field. VR is underused in neurosurgery. It enables inexperienced neurosurgeons to understand morphologic details of a lesion and important osteoneurovascular structures around it. It is also helpful for training and preoperative planning in selected patients in neurosurgery.

Assessment of Postural Compliance After Pneumatic Retinopexy.

PurposeWe describe the functioning of a novel device, aimed to assess patient head position after a pneumatic retinopexy.MethodsWe enrolled patients with the clinical diagnosis of rhegmatogenous retinal detachment. All patients were asked to wear a specially designed headband with a monitoring device composed of an accelerometer, gyroscope, and magnetometer, powered by a 3.7V lithium battery. Every 200 ms, the device measured neck flexion and extension, left and right rotation, and left and right flexion. Patients were asked to come back the next morning for follow-up and headband retrieving.ResultsThe device was worn an average of 19.17 ± 2.1 hours and performed a mean number of 57,670 ± 8663 measurements without power failures or program errors. An acceptable head position was kept for a mean of 3.33 ± 1.8 hours. The hardest axis to maintain was the right and left flexion of the neck (5.5 ± 2.54 hours of acceptable positioning).ConclusionReal-time monitoring of patient head position after a vitreoretinal procedure is feasible. Maintaining a fixed head position for more than 5 consecutive hours is difficult to achieve and physicians should consider this difficulty when planning treatment.Translational RelevanceIn addition to a significant improvement to the basic design of similar devices, our device allows for assessment of patient adherence to postoperative instructions objectively for the first time to our knowledge. This information could be used in the future to elaborate more detailed position nomograms to improve outcomes

Contralateral Approach Based on a Preoperative 3-Dimensional Virtual Osteotomy Technique for Anterior Circulation Aneurysms

Objective: Our objective was to review 15 consecutive patients with anterior circulation aneurysms managed through a contralateral approach. Individualized surgical simulation using three-dimensional (3D) imaging was adopted to enable safe performance of clipping surgery. Methods: Five patients had multiple intracranial aneurysms, and 10 patients had a single aneurysm on the contralateral side of the craniotomy. Preoperatively, the unique architecture of aneurysms was fully understood in their 3-dimensionality reconstructed by Mimics software. The location of the cranial bone window and the patient's head position was individually optimized using a preoperative simulation system. Results: In this cohort, 17 contralateral aneurysms showed no wall calcifications. Projections of the aneurysms were superomedial (3/17, 17.6%), medial (8/17, 47.1%), posterior (3/17, 17.6%), and superior (3/17, 17.6%).The visual similarity between the simulating scene and the operative view was excellent in 100% of the cases. Four patients were treated with a contralateral pterional approach, and the remaining 11 patients were treated with a contralateral supraorbital keyhole approach. All of them were well-clipped, except 1 blister-like aneurysm being wrapped. All 15 patients had good outcomes (mRS ≤ 3) after a mean 13 months follow-up. There were no recurrences after surgical treatment. Conclusions: The contralateral approach for the selected anterior circulation aneurysms is feasible in experienced hands with acceptable morbidity. This approach should be the choice only under judicious case-to-case planning based on a preoperative 3D virtual osteotomy technique.

Artifact reduction techniques in Cone Beam Computed Tomography (CBCT) imaging modality

Introduction: Cone beam computed tomography (CBCT) was introduced and became more common based on its low cost, fast image procedure rate and low radiation dose compared to CT. This imaging modality improved diagnostic and treatment-planning procedures by providing three-dimensional information with greatly reduced level of radiation dose compared to 2D dental imaging modalities for investigation of maxillofacial skeleton, dentition and the relationship of anatomical structures. However, CBCT is associated with multiple artifacts like. Extinction artifacts, beam hardening artifacts, partial volume effect, aliasing artifacts, ring artifacts and motion artifacts (misalignment artifacts), Noise and scatter. All of them leads to image quality reduction and have capability of Mistakenly considering as a pathological lesion. This study aimed to investigate Cone Beam Computed Tomography artifacts and their reduction procedures. Materials and Methods: A systematic search of the literature published from 2000 to 2017 in the PubMed, scopus and web of science databases was performed. The following key words combined in different ways: cone beam computed tomography, CBCT Artifacts and artifact reduction. Results: Artifact is caused by several factors containing reconstruction parameters like small field of views (FOVs), presence of metal objects, patient movement, etc. Artifact reduction methods can have divided into two categorize preprocessing in the projection domain and post processing in the image domain. Limitation of field of view, modification of patient head position or separating dental arches for scatter reduction, Application of high KVP in order to beam hardening reduction, iterative method and projection modification method for metal artifacts are recommended. In addition, Filtration, interpolation, iterative reconstruction and filtering algorithms, application of the smaller voxel size and respiratory gating are other suggested items for artifact reduction in CBCT. Conclusion: Multiple artifacts accompany CBCT imaging procedures. There for With the aim of improving the quality of the CBCT images; reducing the artifact caused scatter photons , various software-based and hardware-based correction methods are recommended .

Results of surgical treatment using minimally invasive methods in patients with endocrine ophthalmopathy

The study objective is to analyze the results of surgical treatment of patients with endocrine ophthalmopathy using minimally invasive transorbital approaches and intraoperative frameless neuronavigation.Materials and methods. The study was based on the results of examination and surgical treatment of 9 patients with endocrine ophthalmopathy (17 orbits) in the period from 2015 to 2017. At the first stage the preoperative computed tomography images of the orbits was imported into the navigation software program, and then the area of the proposed resection of the orbit walls was marked. Further, in the operating room, the patient head position was registered in the navigation system. To perform bone decompression of the orbit and lipectomy, we used preseptal, transcaruncular and lateral retrocanthal approaches. These approaches are transconjunctival and do not leave postoperative scars. Upon completion of the orbitotomy, its accuracy and dimensions were determined by the intraoperative pointer of the neuronavigation system.Results. The postoperative period was uneventful. In all patients, according to clinical examination and computed tomography, good cosmetic and functional results were achieved. Only 1 patient developed a simblypharon after transconjunctival access, which required additional intervention to reconstruct the lower eyelid. There were no other complications of surgical treatment. The minimum degree of regression of exophthalmos was 3 mm, the maximum 7 mm. Diplopia completely regressed in 2 patients. The observation period was 6 months.Conclusion. Minimally invasive transorbital approaches allow the transconjunctival view of all orbital walls to perform decompression of the orbit and lipectomy without cutaneous incisions, to achieve good cosmetic and functional results. The intraoperative use of the neuronavigation system ensures the bone decompression of the orbit in full.

Patient movement characteristics and the impact on CBCT image quality and interpretability.

To assess the impact of patient movement characteristics and metal/radiopaque materials in the field-of-view (FOV) on CBCT image quality and interpretability. 162 CBCT examinations were performed in 134 consecutive (i.e. prospective data collection) patients (age average: 27.2 years; range: 9-73). An accelerometer-gyroscope system registered patient's head position during examination. The threshold for movement definition was set at ≥0.5-mm movement distance based on accelerometer-gyroscope recording. Movement complexity was defined as uniplanar/multiplanar. Three observers scored independently: presence of stripe (i.e. streak) artefacts (absent/"enamel stripes"/"metal stripes"/"movement stripes"), overall unsharpness (absent/present) and image interpretability (interpretable/not interpretable). Kappa statistics assessed interobserver agreement. χ2 tests analysed whether movement distance, movement complexity and metal/radiopaque material in the FOV affected image quality and image interpretability. Relevant risk factors (p ≤ 0.20) were entered into a multivariate logistic regression analysis with "not interpretable" as the outcome. Interobserver agreement for image interpretability was good (average = 0.65). Movement distance and presence of metal/radiopaque materials significantly affected image quality and interpretability. There were 22-28 cases, in which the observers stated the image was not interpretable. Small movements (i.e. <3 mm) did not significantly affect image interpretability. For movements ≥ 3 mm, the risk that a case was scored as "not interpretable" was significantly (p ≤ 0.05) increased [OR 3.2-11.3; 95% CI (0.70-65.47)]. Metal/radiopaque material was also a significant (p ≤ 0.05) risk factor (OR 3.61-5.05). Patient movement ≥3 mm and metal/radiopaque material in the FOV significantly affected CBCT image quality and interpretability.

Update on Intranasal Medications in Rhinosinusitis.

This review describes beneficial effects and adverse events of various intranasal medications in treating rhinosinusitis. Application of intranasal steroids has been described in treating all subtypes of adult rhinosinusitis, but reports are limited in pediatrics and mostly in acute pediatric subgroups resulted in benefits While saline irrigation is effective for patients with chronic rhinosinusitis without polyps and in pediatric acute rhinosinusitis, there is no evidence yet for saline drips and sprays. Application of intranasal antifungals and nasal irrigation with surfactant brings more harm than benefits. There is no evidence supporting the use of intranasal antibiotics. We also review influence of devices, methods, and patient head position on nasal and paranasal sinus drug delivery.

Recording natural head position using an accelerometer and reconstruction from computed tomographic images.

ObjectivesThe concept of natural head position (NHP) was first introduced by Broca in 1862, and was described as a person's stable physiologic position “when a man is standing and his visual axis is horizontal.” NHP has been used routinely for clinical examination; however, a patient's head position is random during cone-beam computed tomography (CBCT) acquisition. To solve this problem, we developed an accelerometer to record patients' NHP and reproduce them for CBCT images. In this study, we also tested the accuracy and reproducibility of our accelerometer.Materials and MethodsA total of 15 subjects participated in this study. We invented an accelerometer that measured acceleration on three axes and that could record roll and pitch calculations. Recorded roll and pitch data for each NHP were applied to a reoriented virtual image using three-dimensional (3D) imaging software. The data between the 3D models and the clinical photos were statistically analyzed side by side. Paired t-tests were used to statistically analyze the measurements.ResultsThe average difference in the angles between the clinical photograph and the 3D model was 0.04° for roll and 0.29° for pitch. The paired ttests for the roll data (P=0.781) and the pitch data (P=0.169) showed no significant difference between the clinical photographs and the 3D model (P>0.05).ConclusionBy overcoming the limitations of previous NHP-recording techniques, our new method can accurately record patient NHP in a time-efficient manner. Our method can also accurately transfer the NHP to a 3D virtual model.