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1,396 result(s) for "Nose - diagnostic imaging"
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Automatic vocal tract landmark localization from midsagittal MRI data
The various speech sounds of a language are obtained by varying the shape and position of the articulators surrounding the vocal tract. Analyzing their variations is crucial for understanding speech production, diagnosing speech disorders and planning therapy. Identifying key anatomical landmarks of these structures on medical images is a pre-requisite for any quantitative analysis and the rising amount of data generated in the field calls for an automatic solution. The challenge lies in the high inter- and intra-speaker variability, the mutual interaction between the articulators and the moderate quality of the images. This study addresses this issue for the first time and tackles it by means of Deep Learning. It proposes a dedicated network architecture named Flat-net and its performance are evaluated and compared with eleven state-of-the-art methods from the literature. The dataset contains midsagittal anatomical Magnetic Resonance Images for 9 speakers sustaining 62 articulations with 21 annotated anatomical landmarks per image. Results show that the Flat-net approach outperforms the former methods, leading to an overall Root Mean Square Error of 3.6 pixels/0.36 cm obtained in a leave-one-out procedure over the speakers. The implementation codes are also shared publicly on GitHub.
Quantitative measurement of the flow depending nasal valve function by elastography with electro-optical distance sensors. A pilot study
[Display omitted] Nasal valve function depends on the intensity of the inspiratory nasal airflow, the geometry of the nasal entrance and the mechanical properties of the lateral nasal wall. It is desirable to obtain objective information on the relation between flow and valve movement. In this study, the deflection of the lateral nasal wall and the inspiratory flow were measured on 30 healthy volunteers, aged 18 to 82 without a history of severe trauma or nasal surgery. Electro-optical distance sensors were housed under a full-face protective mask attached to an analogue inspiratory flowmeter. The mean values for normal breathing were assessed at 675 [cm3/s] for the bilateral flow and −0.57 mm for the total movement. With forced breathing, the mean values for the flow of both nostrils were found to be 1434 cm3/s and for the total movement −1.21 mm. Statistically significant differences between normal and forced breathing were found in all participants and in both sexes, but no significant correlation by age. Electro-optical distance measurement, representing a novel technical way for the ‘elastography’ of the nasal valve should be added to advanced 4-phase-rhinomanometers.
Visualization and Quantification of Nasal and Olfactory Deposition in a Sectional Adult Nasal Airway Cast
Purpose To compare drug deposition in the nose and olfactory region with different nasal devices and administration techniques. A Sar-Gel based colorimetry method will be developed to quantify local deposition rates. Methods A sectional nasal airway cast was developed based on an MRI-based nasal airway model to visualize deposition patterns and measure regional dosages. Four nasal spray pumps and four nebulizers were tested with both standard and point-release administration techniques. Delivered dosages were measured using a high-precision scale. The colorimetry correlation for deposited mass was developed via image processing in Matlab and its performance was evaluated through comparison to experimental measurements. Results Results show that the majority of nasal spray droplets deposited in the anterior nose while only a small fraction (less than 4.6%) reached the olfactory region. For all nebulizers considered, more droplets went beyond the nasal valve, leading to distinct deposition patterns as a function of both the nebulizer type (droplet size and initial speed) and inhalation flow rate. With the point-release administration, up to 9.0% (±1.9%) of administered drugs were delivered to the olfactory region and 15.7 (±2.4%) to the upper nose using Pari Sinus. Conclusions Standard nasal devices are inadequate to deliver clinically significant olfactory dosages without excess drug losses in other nasal epitheliums. The Sar-Gel based colorimetry method appears to provide a simple and practical approach to visualize and quantify regional deposition.
Resting-state functional MRI of the nose as a novel investigational window into the nervous system
Besides being responsible for olfaction and air intake, the nose contains abundant vasculature and autonomic nervous system innervations, and it is a cerebrospinal fluid clearance site. Therefore, the nose is an attractive target for functional MRI (fMRI). Yet, nose fMRI has not been possible so far due to signal losses originating from nasal air-tissue interfaces. Here, we demonstrated feasibility of nose fMRI by using novel ultrashort/zero echo time (TE) MRI. Results obtained in the resting-state from 13 healthy participants at 7T and in 5 awake mice at 9.4T revealed a highly reproducible resting-state nose functional network that likely reflects autonomic nervous system activity. Another network observed in humans involves the nose, major brain vessels and CSF spaces, presenting a temporal dynamic that correlates with heart rate and breathing rate. These resting-state nose functional signals should help elucidate peripheral and central nervous system integrations.
Defining the caudal limits of the endoscopic endonasal approach to the craniovertebral junction: anatomic study correlating radiographic measures
Objective The endoscopic endonasal approach (EEA), has become the preferred alternative to traditional open and transoral approaches to the ventral craniovertebral junction (CVJ) region. However, preoperative prediction of the limitations of caudal reach remains challenging. This cadaveric study aimed to quantify the CVJ area of exposure and access afforded by the EEA, evaluate the accuracy of previously described radiographic anthropometric lines, and identify the lowest limit of the EEA corridor. Methods Endoscopic endonasal dissections of the CVJ were completed in 35 cadaveric specimens. The area of exposure (AoE) and caudal-most reach were measured using a navigation system. Radiographic measurements included the distance of the odontoid process from the hard palate, length of the hard palate, distance of the lowest point reached from the hard palate level, and angles such as the nasopalatine line (NPL) angle, nasoaxial line (NAxL) angle, nostril-hard palate line (NTL) angle, and rhinopalatine line (RPL) angle. Results The mean CVJ AoE was 931.22 ± 79.36 mm2. The NPL, NAxL, and RPL angles showed significant negative correlations with the distance of the odontoid process from the hard palate line ( r  = -0.521, p  = 0.001; r  = -0.538, p  = 0.001; r  = -0.500, p  = 0.002, respectively), while the NTL angle did not ( r  = -0.241, p  = 0.162). No significant correlation was found between achieved AoE via EEA and NPL, NAxL, NTL, or RPL ( p  > 0.05). Importantly, hard palate length was the sole predictor of CVJ AoE variability ( r  = -0.416, p  = 0.013), with shorter lengths associated with increased exposure. The mean distance of the lowest point reached in the AoE from the hard palate level was 9.47 ± 1.24 mm. Conclusions This anatomic study highlights the variability in CVJ anatomy and the limitations of using previously defined radiographic anthropometric lines for predicting the caudal limits of the EEA. Hard palate length emerged as the only reliable predictor of the surgical area of exposure via the endonasal corridor. Clinical studies are warranted to validate these findings and define the potential need for adjunctive surgical routes in managing complex CVJ pathologies.
Impact of Dorsal Preservation Rhinoplasty Versus Dorsal Hump Resection on the Internal Nasal Valve: a Quantitative Radiological Study
BackgroundThis study evaluates the impact of different hump takedown techniques, namely the conventional hump resection with midvault reconstruction, the push-down (PD) and the let-down (LD) procedures, on the INV dimensions.MethodsIn this cadaveric study, six heads were divided randomly into either the conventional hump resection technique (Group A; n = 6 sides) or DPR techniques (n = 6 sides). This latter group was subdivided such that initially a PD procedure was performed (Group B; n = 6 sides), followed by a LD procedure on the same heads (Group C; n = 6 sides). A validated radiological method was used to measure the INV angle and cross-sectional area (CSA) in a modified coronal plane both pre- and post-procedurally.ResultsGroup A did not show significant reduction in the INV angle nor in CSA (p = 0.068 and p = 0.156, respectively). In the push-down group (B), we observed a mean change of 2.05° in the angles and 0.3 cm2 in the CSA (p = 0.0163 and p < 0.001, respectively). The LD group (C) did not show significant reduction in the INV angle nor in CSA (p = 0.437 and p = 0.331, respectively).ConclusionNeither the conventional hump resection nor the LD DPR technique reduced the INV dimensions. However, the PD preservation technique significantly reduced the INV dimensions.Level of Evidence IIIThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.
3D anthropometry of the nasolabial region in children aged 3 to 9 months as reference database for clinical assessment
Treatment for a cleft lip can result in significant functional and aesthetic changes to the nasolabial region. Although three-dimensional (3D) measurements are the gold standard for evaluating cleft surgery, most short- and long-term evaluations still rely on subjective assessment or the measurement of patient photographs. To our knowledge, this work establishes the first baseline and reference group for the nasolabial region in children aged 3 to 9 months without cleft lip or palate. This group can be used for future evaluations, such as those of surgical outcomes or NAM therapy, via 3D anthropometric measurement. Data was collected cross-sectionally from 25 children aged 3 to 9 months using a validated intraoral scanner (Trios 4, 3Shape). Scans were analysed according to 3D anthropometric criteria by metrically accurate measurements of distances, surface curves and angles using 3D inspection software (GOM Inspect, Co. Zeiss, Jena, Germany). Results are presented as reference database combined with a step-by-step guide on the measurement methodology. For easy application all data are additionally presented in the form of formulae in which clinical data can be inserted. Based on the data from healthy children, we propose a new classification of alar base types ranging from 1 to 3. Unlike conventional assessment methods, surface curves and other 3D anthropometric tools provide a highly accurate and objective quantification of the anatomy of the nasolabial region and thus serve as a foundation for future clinical research on cleft lip surgery. Alar base type classification may influence future surgical approaches to cleft lip surgery.
Smartphone-generated 3D facial images: reliable for routine assessment of the oronasal region of patients with cleft or mere convenience? A validation study
Objectives To evaluate the validity and reliability of smartphone-generated three-dimensional (3D) facial images for routine evaluation of the oronasal region of patients with cleft by comparing their accuracy to that of direct anthropometry (DA) and 3dMD. Materials and methods Eighteen soft-tissue facial landmarks were manually labelled on each of the 17 (9 males and 8 females; mean age 23.3 ± 5.4 years) cleft lip and palate (CLP) patients’ faces. Two surface imaging systems, 3dMDface and Bellus3D FaceApp, were used to perform two imaging operations on each labelled face. Subsequently, 32 inter-landmark facial measurements were directly measured on the labelled faces and digitally measured on the 3D facial images. Statistical comparisons were made between smartphone-generated 3D facial images (SGI), DA, and 3dMD measurements. Results The SGI measurements were slightly higher than those from DA and 3dMD, but the mean differences between inter-landmark measurements were not statistically significant across all three methods. In terms of clinical acceptability, 16% and 59% of measures showed differences of ≤ 3 mm or ≤ 5º, with good agreement between DA and SGI and 3dMD and SGI, respectively. A small systematic bias of ± 0.2 mm was observed generally among the three methods. Additionally, the mean absolute difference between the DA and SGI methods was the highest for linear measurements (1.31 ± 0.34 mm) and angular measurements (4.11 ± 0.76º). Conclusions SGI displayed fair trueness compared to DA and 3dMD. It exhibited high accuracy in the orolabial area and specific central and flat areas within the oronasal region. Notwithstanding this, it has limited clinical applicability for assessing the entire oronasal region of patients with CLP. From a clinical application perspective, SGI should accurately encompass the entire oronasal region for optimal clinical use. Clinical relevance SGI can be considered for macroscopic oronasal analysis or for patient education where accuracy within 3 mm and 5º may not be critical.
Craniofacial anthropometric investigation of relationships between the nose and nasal aperture using 3D computed tomography of Korean subjects
This study investigated the relationships of morphology and locations of the nose and nasal aperture by using major craniofacial landmarks on the human skull and face for craniofacial reconstruction/approximation of Koreans. In the frontal view, the positions of bony landmarks on the skull, including the nasal aperture, were correlated with the positions of nasal landmarks vertical to the transverse plane. In profile, the positions of bony landmarks on the skull were correlated with the positions of nasal landmarks horizontal to the coronal plane. Overall, 26 of the 76 measurements demonstrated significant correlations between the corresponding landmarks on the nose and nasal aperture. Simple regression equations were produced from the results. This study showed that the nose and nasal aperture are significantly related to each other in terms of their morphology and location in Koreans. The prediction guidelines, produced as regression formulas, can be applied to craniofacial reconstruction/approximation and bio-anthropological research of Korean skulls. The study results can also be used clinically in rhinoplasty and nasal reconstruction surgery.
Utilization of images and three-dimensional custom-made nostril retainer fabricate for patients with cleft lip and cleft lip nose deformities at Siriraj Hospital: preliminary phase
A prospective study utilizing image analysis to assess nostril openings in post-operative patients with cleft lip and cleft lip nose deformities. This preliminary study seeks to employ two-dimensional (2D) images to fabricate a custom-made nostril retainer. This study was performed at Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand. This study included 30 healthy volunteers and 15 patients with cleft lip and cleft lip nose deformities. The nostril opening width and height for all participants were measured, and photographs were taken. An image analysis application was used to fabricate a three-dimensional (3D) custom-made nostril retainer. The mean differences between the direct measurements of the nostril aperture and the measurements obtained through the program did not exceed 2 mm in terms of nostril height, width, or columella. Two-dimensional photographs can be used to create a custom-made, three-dimensional nostril retainer. This retainer allows post-operative patients to maintain their nares without needing to visit the hospital, thereby reducing the cost of care.