scholarly journals Three-Dimensional Volumetric Measurement of Endolymphatic Hydrops in Meniere's Disease

2021 ◽  
Vol 12 ◽  
Author(s):  
Tae-Soo Noh ◽  
Moo Kyun Park ◽  
Jun Ho Lee ◽  
Seung Ha Oh ◽  
Ji-Hoon Kim ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Inner Ear ◽  
Phased Array ◽  
Endolymphatic Hydrops ◽  
Three Dimensional ◽  
3D Analysis ◽  
Volumetric Measurement ◽  
Advantages And Disadvantages ◽  
Perilymphatic Space ◽  
Array Coil

Objective: We used volumetric three-dimensional (3D) analysis to quantitatively evaluate the extent of endolymphatic hydrops (EH) in the entire inner ear. We tested for correlations between the planimetric and volumetric measurements, to identify their advantages and disadvantages.Methods: HYDROPS2-Mi2 EH images were acquired for 32 ears (16 patients): 16 ipsilateral ears of MD patients (MD-ears) and 16 contralateral ears. Three-T MR unit with a 32-channel phased-array coil/the contrast agent to fill the perilymphatic space and the HYDROPS2-Mi2 sequence. We calculated the EH% [(endolymph)/(endolymph+perilymph)] ratio and analyzed the entire inner ear in terms of the volumetric EH% value, but only single cochlear and vestibular slices were subjected to planimetric EH% evaluation. The EH% values were compared between MD ears and non-MD ears, to evaluate the diagnostic accuracy of the two methods.Results: The volumetric EH% was significantly higher for MD vestibules (50.76 ± 13.78%) than non-MD vestibules (39.50 ± 8.99%). The planimetric EH% was also significantly higher for MD vestibules (61.98 ± 20.65%) than non-MD vestibules (37.22 ± 12.95%). The vestibular and cochlear volumetric EH% values correlated significantly with the planimetric EH% values of the MD ear.Conclusion: Volumetric and planimetric EH measurements facilitate diagnosis of MD ears compared to non-MD ears. Both methods seem to be reliable and consistent; the measurements were significantly correlated in this study. However, the planimetric EH% overestimates the extent of vestibular hydrops by 26.26%. Also, planimetric data may not correlate with volumetric data for non-MD cochleae with normal EH% values.

Diagnostic value of three-dimensional magnetic resonance imaging of inner ear after intratympanic gadolinium injection, and clinical application of magnetic resonance imaging scoring system in patients with delayed endolymphatic hydrops

2013 ◽  
Vol 128 (1) ◽  
pp. 53-59 ◽  
Author(s):  
X Gu ◽  
Z-M Fang ◽  
Y Liu ◽  
S-L Lin ◽  
B Han ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Inner Ear ◽  
Endolymphatic Hydrops ◽  
Three Dimensional ◽  
Resonance Imaging ◽  
Positive Identification ◽  
Delayed Endolymphatic Hydrops ◽  
Intratympanic Injection ◽  
Perilymphatic Space

AbstractObjective:Three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging of the inner ear after intratympanic injection of gadolinium, together with magnetic resonance imaging scoring of the perilymphatic space, were used to investigate the positive identification rate of hydrops and determine the technique's diagnostic value for delayed endolymphatic hydrops.Methods:Twenty-five patients with delayed endolymphatic hydrops underwent pure tone audiometry, bithermal caloric testing, vestibular-evoked myogenic potential testing and three-dimensional magnetic resonance imaging of the inner ear after bilateral intratympanic injection of gadolinium. The perilymphatic space of the scanned images was analysed to investigate the positive identification rate of endolymphatic hydrops.Results:According to the magnetic resonance imaging scoring of the perilymphatic space and the diagnostic standard, 84 per cent of the patients examined had endolymphatic hydrops. In comparison, the positive identification rates for vestibular-evoked myogenic potential and bithermal caloric testing were 52 per cent and 72 per cent respectively.Conclusion:Three-dimensional magnetic resonance imaging after intratympanic injection of gadolinium is valuable in the diagnosis of delayed endolymphatic hydrops and its classification. The perilymphatic space scoring system improved the diagnostic accuracy of magnetic resonance imaging.

scholarly journals Store Separation: Photogrammetric Solution for the Static Ejection Test

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Luiz Eduardo Guarino de Vasconcelos ◽  
Nelson Paiva Oliveira Leite ◽  
André Yoshimi Kusumoto ◽  
Leandro Roberto ◽  
Cristina Moniz Araujo Lopes
Keyword(s):  
Real Time ◽  
Analytical Model ◽  
Three Dimensional ◽  
Flight Test ◽  
3D Analysis ◽  
Trajectory Data ◽  
Position Measurement ◽  
Advantages And Disadvantages ◽  
Store Separation ◽  
Development And Validation

The process of developing and certifying aircraft and aeronautical systems requires the execution of experimental flight test campaigns to determine the actual characteristics of the system being developed and/or validated. In this process, there are many campaigns that are inherently dangerous, such as the store separation. In this particular case, the greatest risk is the collision of the store with the fuselage of the aircraft. To mitigate the risks of this campaign, it is necessary to compare the actual trajectory of a separation with its simulated estimates. With such information, it is possible to decide whether the next store release can be done with the required safety and/or whether the model used to estimate the separation trajectory is valid or not. Consequently, exact determination of the trajectory of the separation is necessary. Store separation is a strategic, relevant, and complex process for all nations. The two main techniques for determining the quantitative store trajectory data with 6DoF (six degrees of freedom) are photogrammetry and instrumented telemetry packages (data obtained from inertial sensors that are installed in the store). Each presents advantages and disadvantages. In regard to photogrammetry, several market solutions can be used to perform these tests. However, the result of the separation trajectory is only obtained after the test flight, and therefore, it is not possible to safely carry out more than one on the same flight. In this context, the development and validation of a solution that will allow the realization of near real-time separation analysis are in fact an innovative and original work. This paper discusses the development and validation, through actual static ejection tests, of the components that will compose a new onboard optical trajectory system for use in store separation campaigns. This solution includes the implementation of a three-dimensional (3D) calibration field that allows calibration of the optical assembly with just one photo per optical assembly, development of a complete analytical model for camera calibration, and development of specific software for identification and tracking of targets in two-dimensional (2D) coordinate images and three-dimensional (3D) coordinate trajectory calculation. In relation to the calibration, the analytical model is based on a pinhole type camera and considers its intrinsic parameters. This allowed for a mean square error smaller than ±3.9 pixels @1σ. The 3D analysis software for 6DoF trajectory expression was developed using photogrammetry techniques and absolute orientation. The uncertainty associated with the position measurement of each of the markers varies from ±0.02 mm to ±8.00 mm @1σ, depending on the geometry of the viewing angles. The experiments were carried out at IPEV (Flight Test Research Institute)/Brazil, and the results were considered satisfactory. We advocate that the knowledge gained through this research contributes to the development of new methods that permit almost real-time analysis in store separation tests.

scholarly journals Three-dimensional imaging of podocyte ultrastructure using FE-SEM and FIB-SEM tomography

2019 ◽  
Vol 379 (2) ◽  
pp. 245-254 ◽  
Author(s):  
Takayuki Miyaki ◽  
Yuto Kawasaki ◽  
Yasue Hosoyamada ◽  
Takashi Amari ◽  
Mui Kinoshita ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
3D Visualization ◽  
Ion Beam ◽  
Three Dimensional ◽  
3D Analysis ◽  
Subcellular Compartment ◽  
Advantages And Disadvantages ◽  
Powerful Approach ◽  
Foot Process ◽  
Serial Images

AbstractPodocytes are specialized epithelial cells used for glomerular filtration in the kidney. They can be divided into the cell body, primary process and foot process. Here, we describe two useful methods for the three-dimensional(3D) visualization of these subcellular compartments in rodent podocytes. The first method, field-emission scanning electron microscopy (FE-SEM) with conductive staining, is used to visualize the luminal surface of numerous podocytes simultaneously. The second method, focused-ion beam SEM (FIB-SEM) tomography, allows the user to obtain serial images from different depths of field, or Z-stacks, of the glomerulus. This allows for the 3D reconstruction of podocyte ultrastructure, which can be viewed from all angles, from a single image set. This is not possible with conventional FE-SEM. The different advantages and disadvantages of FE-SEM and FIB-SEM tomography compensate for the weaknesses of the other. The combination renders a powerful approach for the 3D analysis of podocyte ultrastructure. As a result, we were able to identify a new subcellular compartment of podocytes, “ridge-like prominences” (RLPs).

scholarly journals Mr Spectroscopic Imaging of Peripheral Zone in Prostate Cancer Using a 3t Mri Scanner: Endorectal versus External Phased Array Coils

2013 ◽  
Vol 6 ◽  
pp. MRI.S10861
Author(s):  
Rajakumar Nagarajan ◽  
Daniel JA Margolis ◽  
Steven S. Raman ◽  
David Ouellette ◽  
Manoj K. Sarma ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Phased Array ◽  
Three Dimensional ◽  
Spectroscopic Imaging ◽  
Peripheral Zone ◽  
3T Mri ◽  
Endorectal Coil ◽  
Metabolite Ratio ◽  
Phased Array Coils ◽  
Array Coil

Magnetic resonance spectroscopic imaging (MRSI) detects alterations in major prostate metabolites, such as citrate (Cit), creatine (Cr), and choline (Ch). We evaluated the sensitivity and accuracy of three-dimensional MRSI of prostate using an endorectal compared to an external phased array “receive” coil on a 3T MRI scanner. Eighteen patients with prostate cancer (PCa) who underwent endorectal MR imaging and proton (1H) MRSI were included in this study. Immediately after the endorectal MRSI scan, the PCa patients were scanned with the external phased array coil. The endorectal coil-detected metabolite ratio [(Ch+Cr)/Cit] was significantly higher in cancer locations (1.667 ± 0.663) compared to non-cancer locations (0.978 ± 0.420) ( P < 0.001). Similarly, for the external phased array, the ratio was significantly higher in cancer locations (1.070 ± 0.525) compared to non-cancer locations (0.521 ± 0.310) ( P < 0.001). The sensitivity and accuracy of cancer detection were 81% and 78% using the endorectal ‘receive’ coil, and 69% and 75%, respectively using the external phased array ‘receive’ coil.

Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

Ultrasonographic 3D Evaluation in the Diagnosis of Bladder Endometriosis: A Prospective Comparative Diagnostic Accuracy Study

2021 ◽  
pp. 1-8
Author(s):  
Fabio Barra ◽  
Franco Alessandri ◽  
Carolina Scala ◽  
Simone Ferrero
Keyword(s):  
Diagnostic Accuracy ◽  
Three Dimensional ◽  
3D Ultrasound ◽  
Diagnostic Accuracy Study ◽  
Extensive Experience ◽  
Deep Endometriosis ◽  
3D Reconstructions ◽  
Analysis Group ◽  
Bladder Endometriosis ◽  
Accuracy Study

<b><i>Objective:</i></b> The use of three-dimensional (3D) transvaginal ultrasonography (TVS) has been investigated for the diagnosis of deep endometriosis (DE). This study aimed to evaluate if 3D reconstructions improve the performance of TVS) in assessing the presence and characteristics of bladder endometriosis (BE). <b><i>Design:</i></b> This was a single-center comparative diagnostic accuracy study. <b><i>Participants/Materials, Setting, Methods:</i></b> Patients referred to our institution (Piazza della Vittoria 14 Srl, Genova, Italy) with clinical suspicion of DE were included. In case of surgery, women underwent systematic preoperative ultrasonographic imaging; an experienced sonographer performed a conventional TVS; another experienced sonographer, blinded to results of the previous exam, performed TVS, with the addition of 3D modality. The presence and characteristics of BE nodules were described in accord with International DE Analysis group consensus. Ultrasound data were compared with surgical and histological results. <b><i>Results:</i></b> Overall, BE was intraoperatively found in 34 out of 194 women who underwent surgery for DE (17.5%; 95% confidence interval: 12.8–23.5%). TVS without and with 3D reconstructions were able to detect endometriotic BE in 82.2% (<i>n</i> = 28/34) and 85.3% (<i>n</i> = 29/34) of the cases (<i>p</i> = 0.125). Both the exams similarly estimated the largest diameter of BE (<i>p</i> = 0.652) and the distance between the endometriotic nodule and the closest ureteral meatus (<i>p</i> = 0.341). However, TVS with 3D reconstructions was more precise in estimating the volume of BE (<i>p</i> = 0.031). In one case (2.9%), TVS without and with 3D reconstructions detected the infiltration of the intramural ureter, which was confirmed at surgery and required laparoscopic ureterovesical reimplantation. <b><i>Limitations:</i></b> The extensive experience of the gynecologists performing the ultrasonographic scans, the lack of prestudy power analysis, and the population selected, which may have been influenced by the position of the institution as a referral center specialized in the treatment of severe endometriosis, are limitations of the current study. <b><i>Conclusion:</i></b> Our results demonstrated the high accuracy of ultrasound for diagnosing BE. The addition of 3D reconstructions does not improve the performance of TVS in diagnosing the presence and characteristics of BE. However, the volume of BE may be more precisely assessed by 3D ultrasound.

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