Radial View Research Articles

Accelerated free-breathing liver fat and quantification using multi-echo stack-of-radial MRI with motion-resolved multidimensional regularized reconstruction: Initial retrospective evaluation.

To improve image quality, mitigate quantification biases and variations for free-breathing liver proton density fat fraction (PDFF) and quantification accelerated by radial k-space undersampling. A free-breathing multi-echo stack-of-radial MRI method was developed with compressed sensing with multidimensional regularization. It was validated in motion phantoms with reference acquisitions without motion and in 11 subjects (6 patients with nonalcoholic fatty liver disease) with reference breath-hold Cartesian acquisitions. Images, PDFF, and maps were reconstructed using different radial view k-space sampling factors and reconstruction settings. Results were compared with reference-standard results using Bland-Altman analysis. Using linear mixed-effects model fitting (p < 0.05 considered significant), mean and SD were evaluated for biases and variations of PDFF and , respectively, and coefficient of variation on the first echo image was evaluated as a surrogate for image quality. Using the empirically determined optimal sampling factor of 0.25 in the accelerated in vivo protocols, mean differences and limits of agreement for the proposed method were [-0.5; -33.6, 32.7] s-1 for and [-1.0%; -5.8%, 3.8%] for PDFF, close to those of a previous self-gating method using fully sampled radial views: [-0.1; -27.1, 27.0] s-1 for and [-0.4%; -4.5%, 3.7%] for PDFF. The proposed method had significantly lower coefficient of variation than other methods (p < 0.001). Effective acquisition time of 64 s or 59 s was achieved, compared with 171 s or 153 s for two baseline protocols with different radial views corresponding to sampling factor of 1.0. This proposed method may allow accelerated free-breathing liver PDFF and mapping with reduced biases and variations.

Robotic-assisted bronchoscopy for the diagnosis of peripheral pulmonary lesions: A systematic review and meta-analysis.

Robotic-assisted bronchoscopy (RAB) is a newly developed bronchoscopic technique for the diagnosis of peripheral pulmonary lesions (PPLs). The objective of this meta-analysis was to analyze the diagnostic yield and safety of RAB in patients with PPLs. Five databases (PubMed, Embase, Web of Science, CENTRAL, and ClinicalTrials.gov) were searched from inception to April 2023. Two independent investigators screened retrieved articles, extracted data, and assessed the study quality. The pooled diagnostic yield and complication rate were estimated. Subgroup analysis was used to explore potential sources of heterogeneity. Publication bias was assessed using funnel plots and the Egger test. Sensitivity analysis was also conducted to assess the robustness of the synthesized results. A total of 725 lesions from 10 studies were included in this meta-analysis. No publication bias was found. Overall, RAB had a pooled diagnostic yield of 80.4% (95% CI: 75.7%-85.1%). Lesion size of >30 mm, presence of a bronchus sign, and a concentric radial endobronchial ultrasound view were associated with a statistically significantly higher diagnostic yield. Heterogeneity exploration showed that studies using cryoprobes reported better yields than those without cryoprobes (90.0%, 95% CI: 83.2%-94.7% vs. 79.0%, 95% CI: 75.8%-82.2%, p < 0.01). The pooled complication rate was 3.0% (95% CI: 1.6%-4.4%). In conclusion, RAB is an effective and safe technique for PPLs diagnosis. Further high-quality prospective studies still need to be conducted.

Scrollable Display of Radial Sectional Computed Tomography Images for Complex Mitral Valve Anatomy

BackgroundAdvances in computed tomography (CT) technology have increased its utility in the diagnosis of mitral regurgitation (MR). Herein, we report on a unique dual-panel display for high-resolution valve images of radial multiplanar reconstruction named mitral valve–radial sectional view (MV-RSV) and a case of mitral valve repair for MR that demonstrates the usefulness of this display method. MethodsWhole-heart images from contrast-enhanced CT were acquired with electrocardiographic gating and processed to reconstruct 3-dimensional and cross-sectional images. The new display consisted of the selection panel and cross section panel, the latter showing the desired radial section selected by scrolling to present the morphologic features of the mitral valve leaflets and subvalvular structures. The patient was a 63-year-old man with MR who underwent valve repair. In addition to echocardiography, the mitral valve was evaluated preoperatively and postoperatively by CT using MV-RSV. ResultsPreoperative MV-RSV revealed P2 prolapse where severe MR with chordal rupture was assessed by transesophageal echocardiography. After the mitral valve repair with chordal plasty and ring annuloplasty, MV-RSV clarified the gap between leaflets at the P2-P3 indentation, which was associated with mild residual leakage. ConclusionsThe new scrollable CT display is a simple and convenient method to show the structure of lesions that cause MR and is useful for developing treatment strategies and postoperative evaluation.

The Intraoperative Dorsal Tangential View and the Radial Groove View of the Distal Radius to Detect Dorsal Screw Protrusion in Volar Plating: Teaching Effect and Value in Clinical Practise

Abstract Background Dorsal screw tip protrusion (DSTP) with extensor tendon injury is a well-known complication of volar plating for distal radius fractures. The dorsal tangential view (DTV) and the radial groove view (RGV) have been recommended to detect DSTP. The value of these views depends on their quality and reproducibility. Aims It was the aim of this study to investigate the quality of these views before and after teaching of the involved surgeons. Methods All adult patients treated with volar plating for distal radius fractures between 10/2019 and 10/2020 were included. Prior to their first case in the study period, all involved surgeons were instructed in a standardized manner how to perform technically correct DTV and RGV. Patients from an earlier period served as controls. Image quality was rated independently by two investigators. Detection of DSTP based on fluoroscopy was documented and protruding screws were exchanged. The impact of teaching was assessed. Furthermore, reliability of DTV and RGV to detect DSTP was compared to postoperative ultrasound. Results A total of 124 patients were included in the study group, 125 patients served as controls. Interobserver agreement for the image quality was 97% for DTV and 98% for RGV. Image quality significantly improved with teaching (p&amp;lt;0.001). Correct images were observed in 81% vs. 58% for DTV and 81% vs. 53% for RGV. From a total of 571 evaluated screws intraoperative fluoroscopy identified 24 DSTP (4.2%) in 23 patients (18.5%). Postoperative ultrasound revealed 4 DSTP (0.8-1.2mm; 0.7%) in 4 patients (3.2%). Conclusions Teaching surgeons how to perform technically good DTV and RGV leads to a significant improvement of image quality. DTV and RGV are reliable tools to detect DSTP. However, despite correct views, some minor dorsal cortex penetrations may be missed. Thus, early further investigations are recommended in patients with extensor tendon irritation.

Design of an electron cyclotron emission diagnostics suite for COMPASS Upgrade tokamak.

COMPASS Upgrade is a medium size and high field tokamak that is capable of addressing key challenges for reactor grade tokamaks, including power exhaust and advanced confinement scenarios. Electron cyclotron emission will be available among the first diagnostics to provide measurements of high spatial and temporal resolution of electron temperature profiles and electron temperature fluctuation profiles through a radial view. A separate oblique view at 12° from normal will be utilized to study non-thermal electrons. Both the radial and oblique views are envisioned to be located in a wide-angle midplane port, which has dimensions that enable simultaneous hosting of the front-end of their quasi-optical (QO) designs. Each QO design will have an in situ hot calibration source in the front-end to provide standalone and calibrated Te (R,t) measurements. The conceptual design for each QO system, the Gaussian beam analysis, and the details of the diagnostic channels are presented.

Installation of a solid state neutral particle analyzer array on mega ampere spherical tokamak upgrade.

A compact solid state neutral particle analyzer (SSNPA) diagnostic, previously installed at NSTX-U, has been moved to MAST-U and successfully operated in the first physics campaign (MU01). The SSNPA operates by detecting the flux of fast neutral particles produced by charge exchange (CX) reactions to diagnose the fast ion distribution. The diagnostic consists of three 16-channel sensors, which provide a radial view of the plasma and have a sightline intersection with the South-South neutral beam line. From this radial geometry, active CX signals from mostly trapped particles are observed. Each channel has a spatial resolution of 3-4cm, a temporal resolution of 200kHz, and an average pitch angle resolution of a few degrees. The three-sensor configuration allows for coarse energy resolution of the CX signals; each sensor sees similar sightlines but different filter thicknesses alter the energy cutoffs by known amounts. Experimental data show that all channels are collecting data as intended. The signal to noise ratio is typically around 15. Preliminary data analysis shows a correlation between the SSNPA signal and magnetohydrodynamic activity in the plasma as expected.

An Experimental Study of a 3D Bone Position Estimation System Based on Fluoroscopic Images.

To compare a 3D preoperative planning image and fluoroscopic image, a 3D bone position estimation system that displays 3D images in response to changes in the position of fluoroscopic images was developed. The objective of the present study was to evaluate the accuracy of the estimated position of 3D bone images with reference to fluoroscopic images. Bone positions were estimated from reference points on a fluoroscopic image compared with those on a 3D image. The four reference markers positional relationships on the fluoroscopic image were compared with those on the 3D image to evaluate whether a 3D image may be drawn by tracking positional changes in the radius model. Intra-class correlations coefficients for reference marker distances between the fluoroscopic image and 3D image were 0.98–0.99. Average differences between measured values on the fluoroscopic image and 3D bone image for each marker corresponding to the direction of the bone model were 1.1 ± 0.7 mm, 2.4 ± 1.8 mm, 1.4 ± 0.8 mm, and 2.0 ± 1.6 mm in the anterior-posterior view, ulnar side lateral view, posterior-anterior view, and radial side lateral view, respectively. Marker positions were more accurate in the anterior-posterior and posterior-anterior views than in the radial and ulnar side lateral views. This system helps in real-time comparison of dynamic changes in preoperative 3D and intraoperative fluoroscopy images.

Size and vision: Impact of fluoroscopic navigation, digital tomosynthesis, and continuous catheter tip tracking on diagnostic yield of small, bronchus sign negative lung nodules

IntroductionAccurate biopsies of lung nodules, including small (<2 cm), bronchus sign negative lesions, remain challenging. Technological advances, however, may improve outcomes. We describe our experience using a novel system combining fluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking to guide lung nodule biopsies. MethodsDemographic data, procedural characteristics, and biopsy results from prospectively enrolled patients were collected. Results159 nodules (144 patients) were biopsied. Average nodule size was 22.2 ± 15.2 mm (axial), 21.7 ± 13.9 mm (coronal), and 33.2 ± 20.5 mm (sagittal), with 45% (n = 72) <2 cm in all dimensions and 66% (n = 105) without a bronchus sign.Diagnostic yield was 84% (134/159), with malignancy (n = 75, 47%) most common. A diagnosis was obtained in 75% (n = 54/72) of lesions that were <2 cm in all dimensions and 79% (n = 83/105) of bronchus sign negative lesions.Unadjusted generalized mixed-effects logistic regression models showed that nodule size as a categorical variable (>2 cm in any dimension) and as a continuous variable in the coronal dimension, the presence of a bronchus sign, and a concentric radial EBUS view had an increased odds ratio for diagnosis. A concentric radial EBUS view also had an increased OR for diagnosis in a fully adjusted mixed-effects logistic regression model. ConclusionFluoroscopic navigation with digital tomosynthesis and continuous catheter tip tracking shows an overall improved diagnostic accuracy compared to historical controls, including for small, bronchus sign negative lesions. Future studies clarifying the optimal modality for patients with different nodules will be of importance to provide the most appropriate procedure tailored to each individual lesion's unique characteristics.

Fabrication and Characterizations of Axial View Liquid Electrode Plasma Atomic Emission Spectrometry for the Sensitive Determination of Trace Zinc, Cadmium, and Lead.

Axial view liquid electrode plasma-atomic emission spectrometry (axial view LEP-AES) was proposed and fabricated successfully in this work. The emission spectra from Zn, Cd, Pb, Ca, and K were applied for characterization and optimization. Comparing with conventional radial view LEP-AES devices, the newly designed axial view-LEP provided better sensing ability toward trace heavy metals. Moreover, pulsed voltage discharge was found to be advantageous over continuous discharge under the same discharge time for detection. The optimized parameters facilitate the limit of detection to achieve 0.24, 0.051, and 0.85 μg L-1 for Zn, Cd, and Pb, respectively. Furthermore, the axial view LEP-AES possessed excellent reproducibility and good durability. The real sample tests using two different certified reference water samples revealed the great potential of the axial view LEP-AES as a novel practical elemental analysis tool.

EFFECT OF 1% Nа ON THE INTENSITY DISTRIBUTION OF THE SAMPLE ATOMS IN NITROGEN MICROWAVE PLASMA WITH AXIAL AND RADIAL OBSERVATION

The effect of 1% Na with axial and radial observation of microwave plasma on the analytical characteristics of the optical spectrometer “Grand-Microwave” is investigated. The presence of 1% Na in the analyzed sample leads to a decrease in the intensities of spectral lines with energies of 6 - 14 eV with the axial observation method by 8 - 50 times, and with the radial method by 2,5 - 8 times, depending on the observation area. The intensity of lines with energies of 1.6 - 6 eV increases by up to 20 times in the axial view, and by 4 to 6 times in the radial view. In the presence of Na, the ratio of the intensities of Mg (II) 280 nm and Mg (I) 285 nm decreases by 2 orders of magnitude for both observation methods, the temperature at the periphery of the axial view of the plasma decreases by 1300 K, and the temperature at the lower boundary of the radial view decreases by 2300 K. The method and scope of the review for the analysis of 25 chemical elements with minimal matrix influences Na and the efficiency of using the recommended areas was evaluated.

Improved diagnostic accuracy for ulnar-sided TFCC lesions with radial reformation of 3D sequences in wrist MR arthrography

ObjectivesTriangular fibrocartilage complex (TFCC) injuries frequently cause ulnar-sided wrist pain and can induce distal radioulnar joint instability. With its complex three-dimensional structure, diagnosis of TFCC lesions remains a challenging task even in MR arthrograms. The aim of this study was to assess the added diagnostic value of radial reformatting of isotropic 3D MRI datasets compared to standard planes after direct arthrography of the wrist.MethodsNinety-three patients underwent wrist MRI after fluoroscopy-guided multi-compartment arthrography. Two radiologists collectively analyzed two datasets of each MR arthrogram for TFCC injuries, with one set containing standard reconstructions of a 3D thin-slice sequence in axial, coronal and sagittal orientation, while the other set comprised an additional radial plane view with the rotating center positioned at the ulnar styloid. Surgical reports (whenever available) or radiological reports combined with clinical follow-up served as a standard of reference. In addition, diagnostic confidence and assessability of the central disc and ulnar-sided insertions were subjectively evaluated.ResultsInjuries of the articular disc, styloid and foveal ulnar attachment were present in 20 (23.7%), 10 (10.8%) and 9 (9.7%) patients. Additional radial planes increased diagnostic accuracy for lesions of the styloid (0.83 vs. 0.90; p = 0.016) and foveal (0.86 vs. 0.94; p = 0.039) insertion, whereas no improvement was identified for alterations of the central cartilage disc. Readers’ confidence (p < 0.001) and assessability of the ulnar-sided insertions (p < 0.001) were superior with ancillary radial reformatting.ConclusionsAccess to the radial plane view of isotropic 3D sequences in MR arthrography improves diagnostic accuracy and confidence for ulnar-sided TFCC lesions.Key Points• In multi-compartment arthrography of the wrist, ancillary radial plane view aids assessability of the foveal and styloid ulnar-sided insertions of the triangular fibrocartilage complex.• Assessment of peripheral TFCC injuries is more accurate with access to radial multiplanar reconstructions.• Additional radial planes provide greater diagnostic confidence.

Evaluation of Cam Deformity on 3-Dimensional Computed Tomography With the Best-Fit Sphere Technique and the Alpha Angle Marking Method

Background: Three-dimensional computed tomography (3D-CT) is commonly used for the evaluation of cam deformity; however, it does not display the cam border directly. Purpose: To compare the efficacy of the best-fit sphere (BFS) method and the alpha angle marking (AAM) method in 3D-CT evaluation for the cam border. Study Design: Cohort study (Diagnosis); Level of evidence, 3. Methods: Twenty-six cases of cam deformity, confirmed during hip arthroscopy, were included in this study. All patients underwent a CT scan before surgery. Using multiplanar reconstruction, we obtained reformatted CT images of oblique axial, oblique coronal, and radial views. The alpha angle and femoral head-neck offset ratio (hnoR) were measured on the reformatted CT images. The cam area on 3D-CT was displayed in 4 different ways: by importing the markers from the reformatted CT images of the oblique axial view (cam-oa), the oblique coronal view (cam-oc), or the radial view (cam-r) using the AAM method, or by using the BFS method (cam-bfs). The sizes and locations of the displayed cams were compared. Results: All hips in this study had an alpha angle greater than 60° and an hnoR smaller than 0.17. The radial view measured a larger alpha angle and smaller hnoR than the oblique axial and coronal views (P < .05). The areas of cam-oa, cam-oc, cam-r, and cam-bfs were 161.47 ± 27.96, 89.78 ± 19.23, 241.73 ± 34.55, and 329.75 ± 42.73 mm2, respectively, and their medial-to-lateral ranges along the acetabulum (clockface referents) were 12:30 to 03:00, 11:30 to 01:30, 11:30 to 03:00, and 11:00 to 03:30, respectively. Among the 4 displays, cam-bfs had the largest area and medial-to-lateral range (P < .05), and cam-r had the second largest area and range (P < .05). No significant difference in the mean distances from the acetabular rim to the superior border was detected among the 4 displays (P > .05). Conclusion: The cam area displayed by the BFS method on 3D-CT was larger than those evaluated by the AAM method. In the reformatted CT, the sizes and locations of cam deformity differed among the oblique axial, oblique coronal, and radial views, with the radial view showing the greatest area.

Closed-loop control of k-space sampling via physiologic feedback for cine MRI.

BackgroundSegmented cine cardiac MRI combines data from multiple heartbeats to achieve high spatiotemporal resolution cardiac images, yet predefined k-space segmentation trajectories can lead to suboptimal k-space sampling. In this work, we developed and evaluated an autonomous and closed-loop control system for radial k-space sampling (ARKS) to increase sampling uniformity.MethodsThe closed-loop system autonomously selects radial k-space sampling trajectory during live segmented cine MRI and attempts to optimize angular sampling uniformity by selecting views in regions of k-space that were not previously well-sampled. Sampling uniformity and the ability to detect cardiac phase in vivo was assessed using ECG data acquired from 10 normal subjects in an MRI scanner. The approach was then implemented with a fast gradient echo sequence on a whole-body clinical MRI scanner and imaging was performed in 4 healthy volunteers. The closed-loop k-space trajectory was compared to random, uniformly distributed and golden angle view trajectories via measurement of k-space uniformity and the point spread function. Lastly, an arrhythmic dataset was used to evaluate a potential application of the approach.ResultsThe autonomous trajectory increased k-space sampling uniformity by 15±7%, main lobe point spread function (PSF) signal intensity by 6±4%, and reduced ringing relative to golden angle sampling. When implemented, the autonomous pulse sequence prescribed radial view angles faster than the scan TR (0.98 ± 0.01 ms, maximum = 1.38 ms) and increased k-space sampling mean uniformity by 10±11%, decreased uniformity variability by 44±12%, and increased PSF signal ratio by 6±6% relative to golden angle sampling.ConclusionThe closed-loop approach enables near-uniform radial sampling in a segmented acquisition approach which was higher than predetermined golden-angle radial sampling. This can be utilized to increase the sampling or decrease the temporal footprint of an acquisition and the closed-loop framework has the potential to be applied to patients with complex heart rhythms.

Burl formation in mango (Mangifera indica): a neglected tumour disorder and the structure of its secondary xylem

Abstract Mango burl is an important disease affecting many mango plantations in India and causes great loss in yield and decrease of vigour. We carried out a diagnostic survey for burl disease (sometimes also referred to as crown gall) in different varieties of mango (Mangifera indica L., Anacardiaceae) throughout India during 2015 and 2016. More than 500 mango genotypes were screened for disease susceptibility and more than twenty-three mango genotypes in different parts of India were found susceptible to this disease. Burls initiate as small tumorous growths and become more pronounced as warty outgrowths with the increasing age of the individual tree. Samples of burl were collected from all popular varieties from different parts of the country and subjected to histological investigations. The present study confirms that mango burl disease is caused by Agrobacterium tumefaciens using evidence from the “carrot assay” and molecular identification of the presumed causal organism. The latter was isolated and inoculated on carrot disks to induce typical symptoms. The xylem of the burl tissue was deformed and showed no specific orientation of the wood cells. Dimensional details and morphology of xylem cells vary at different positions within the burl. In a 10 cm diameter burl, the marginal portion showed xylem cells in circular arrangement. Vessel elements and fibres were very short while rays were relatively low and biseriate rays were observed rarely. Orientation of the xylem tissue was lost and all three plains (i.e. transverse, tangential and radial view) were observed in the same section. Cells from the middle portion of the burl were isodiametric, oval to circular, thick-walled and lignified, in morphology not dissimilar from callus tissue. Tyloses were common in all the cell types viz. fibres, ray cells, tracheids, axial parenchyma cells, and vessel elements.

Improved diagnostic yield for lung nodules with digital tomosynthesis-corrected navigational bronchoscopy: Initial experience with a novel adjunct.

The diagnostic yield of electromagnetic navigation bronchoscopy (ENB) is inferior to that of computed tomography (CT)-guided needle biopsy for pulmonary nodules. One explanation for this is divergence between the nodule location on the pre-procedure CT scan and its actual location during the procedure. Fluoroscopic ENB (F-ENB) consists of digital tomosynthesis using a conventional C-arm to re-register the target lesion based on near real-time imaging. We performed a retrospective review of ENB cases at our institution before and after introduction of F-ENB to assess diagnostic yield. All consecutive ENB procedures performed at our institution from 25 December 2017 to 25 August 2018 were reviewed. F-ENB was introduced on 25 April 2018. Two cohorts were analysed: standard ENB (S-ENB) from 25 December 2017 to 24 April 2018 and F-ENB from 25 April 2018 to 25 August 2018. All procedural, demographic and diagnostic data were collected. Descriptive statistics, chi-square, Wilcoxon test and Student's t-test were used where appropriate. A multivariable regression analysis was performed to assess factors associated with diagnostic yield. A total of 101 and 67 nodules were biopsied in the S-ENB and F-ENB groups, respectively. Diagnostic yield was 54% in S-ENB cohort and 79% in the F-ENB group (P = 0.0019). Factors independently associated with a positive diagnosis were F-ENB and a positive radial ultrasound view (odds ratio (OR): 3.57, 95% CI: 1.56-8.18 and OR: 3.74, 95% CI: 1.37-11.05, respectively). Complications were minimal (pneumothorax: 1.5%). The use of F-ENB may increase the diagnostic yield of ENB and has a low complication rate.

Finite Element Simulation of Equal Channel Angular Pressing: Effect of Die Angle and Number of Passes

Equal channel angular pressing (ECAP) is one of the popular severe plastic deformation processes used to produce bulk nanostructured materials. The degree of homogeneity of nanostructured is affected by various die parameters. In this paper, the effect of internal die angle (ϕ) and number of passes (N) on the strain behaviour of Aluminium Alloy 6061 (AA6061) during ECAP was investigated by using three-dimensional finite element analysis. The effect of number of passes and die angle on the homogeneity within the workpiece was analysed in terms of contours, radial view contour and inhomogeneity index. The analysis is done by comparing workpiece extruded up to 8 passes at die angle of 120° and 126°. It is observed that the resulting strain is higher at 120° die. However, the inhomogeneity index is decreasing in a similar pattern in both dies. The simulation results shed some lights on the optimum design of ECAP die for homogeneous microstructure.

Volar Plating: Imaging Modalities for the Detection of Screw Penetration.

Background Volar plating for distal radius fractures exposes the risk of extensor tendon rupture, mechanical problems, and osteoarthritis due to protruding screws. Purposes The purpose of this review was to identify the best intraoperative diagnostic imaging modality to identify dorsal and intra-articular protruding screws in volar plating for distal radius fractures. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines were followed for this review. In vitro and in vivo studies that analyzed the reliability, efficacy, and/or accuracy of intraoperatively available imaging modalities for the detection of dorsal or intra-articular screw protrusion after volar plating for distal radius fractures were included. Results Described additional imaging modalities are additional fluoroscopic views (pronated views, dorsal tangential view [DTV], radial groove view [RGV], and carpal shoot through [CST] view), three-dimensional (3D) and rotational fluoroscopies, and ultrasound (US). For detection of dorsal screw penetration, additional fluoroscopic views show better results than conventional views. Based on small (pilot) studies, US seems to be promising. For intra-articular screw placement, 3D or 360 degrees fluoroscopy shows better result than conventional views. Conclusion Based on this systematic review, the authors recommend the use of at least one of the following additional imaging modalities to prevent dorsal protruding screws: CST view, DTV, or RGV. Tilt views are recommended for intra-articular assessment. Of all additional fluoroscopic views, the DTV is most studied and proves to be practical and time efficient, with higher efficacy, accuracy, and reliability compared with conventional views. Level of Evidence The level of evidence is Level III.

ИССЛЕДОВАНИЕ РАДИАЛЬНОГО СПОСОБА НАБЛЮДЕНИЯ ИСТОЧНИКА ВОЗБУЖДЕНИЯ СПЕКТРОВ НА ОСНОВЕ МИКРОВОЛНОВОЙ ПЛАЗМЫ

The results of the research of the radial method of observation of the spectrum excitation source based on microwave plasma (MP) are presented in the article. Using of a combination of a three-slot torch and a longitudinal magnetic microwave field for the formation of MP makes it possible to obtain an axisymmetric plasma shape similar to ICP flame. The visual similarity of the MP and ICP confirms the existence of various analytical zones in plasma, both in height (with a radial view) and radius (with an axial view) caused by differences in temperature and electron density in the observed zones. Using of the radial method of MP observation makes it possible to increase the ratio of the intensities of the spectral lines to MP background for some elements and to reduce the detection limits achieved with the axial method of observation, especially when analyzing highly mineralized samples with a total mineralization of more than 1 % wt. Another important advantage of the radial method of MP observation in comparison with the axial is the increase of the linearity range of the calibration curve.

Rapid dual-RF, dual-echo, 3D ultrashort echo time craniofacial imaging: A feasibility study.

To develop a dual-radiofrequency (RF), dual-echo, 3D ultrashort echo-time (UTE) pulse sequence and bone-selective image reconstruction for rapid high-resolution craniofacial MRI. The proposed pulse sequence builds on recently introduced dual-RF UTE imaging. While yielding enhanced bone specificity by exploiting high sensitivity of short T2 signals to variable RF pulse widths, the parent technique exacts a 2-fold scan time penalty relative to standard dual-echo UTE. In the proposed method, the parent sequence's dual-RF scheme was incorporated into dual-echo acquisitions while radial view angles are varied every pulse-to-pulse repetition period. The resulting 4 echoes (2 for each RF) were combined by view-sharing to construct 2 sets of k-space data sets, corresponding to short and long TEs, respectively, leading to a 2-fold increase in imaging efficiency. Furthermore, by exploiting the sparsity of bone signals in echo-difference images, acceleration was achieved by solving a bone-sparsity constrained image reconstruction problem. In vivo studies were performed to evaluate the effectiveness of the proposed acceleration approaches in comparison to the parent method. The proposed technique achieves 1.1-mm isotropic skull imaging in 3 minutes without visual loss of image quality, compared to the parent technique (scan time = 12 minutes). Bone-specific images and corresponding 3D renderings of the skull were found to depict the expected craniofacial anatomy over the entire head. The proposed method is able to achieve high-resolution volumetric craniofacial images in a clinically practical imaging time, and thus may prove useful as a potential alternative to computed tomography.

Motional Stark effect imaging first results on the DIII-D tokamak.

A motional Stark effect (MSE) imaging diagnostic was benchmarked against existing conventional MSE polarimeters on the DIII-D tokamak and delivered new capabilities for measuring the magnetic pitch angle from 2 neutral beams and on the high field side of DIII-D. Line integration across flux surfaces was considerable for the radial view utilised; nevertheless, the imaging MSE measurements from both beams were self-consistent and in close agreement with conventional MSE measurements. The ferroelectric liquid crystal waveplate used in the imaging polarimeter was discovered to have spatially non-uniform retardance; hence, it is necessary for the calibration source to replicate the ray paths of the neutral beam emission through the optical system.