scholarly journals Accuracy of radiographic measurement techniques for the Taylor spatial frame mounting parameters

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jan Gessmann ◽  
Sven Frieler ◽  
Matthias Königshausen ◽  
Thomas A. Schildhauer ◽  
Yannik Hanusrichter ◽  
...  
Keyword(s):  
Measurement Techniques ◽  
Image Intensifier ◽  
Precise Determination ◽  
Taylor Spatial Frame ◽  
Radiographic Measurement ◽  
Image Method ◽  
X Ray ◽  
Spatial Frame ◽  
Radiographic Measurements ◽  
Soft Copy

Abstract Aim The correction accuracy of the Taylor Spatial Frame (TSF) fixator depends considerably on the precise determination of the mounting parameters (MP). Incorrect parameters result in secondary deformities that require subsequent corrections. Different techniques have been described to improve the precision of MP measurement, although exact calculation is reportedly impossible radiologically. The aim of this study was to investigate the accuracy of intraoperative and postoperative radiographic measurement methods compared to direct MP measurement from TSF bone mounting. Methods A tibial Sawbone® model was established with different origins and reference ring positions. First, reference MPs for each origin were measured directly on the frame and bone using a calibrated, digital vernier calliper. In total 150 MPs measured with three different radiographic measurement techniques were compared to the reference MPs: digital radiographic measurements were performed using soft-copy PACS images without (method A) and with (method B) calibration and calibrated image intensifier images (method C). Results MPs measured from a non-calibrated X-ray image (method A) showed the highest variance compared to the reference MPs. A greater distance between the origin and the reference ring corresponded to less accurate MP measurements with method A. However, the MPs measured from calibrated X-ray images (method B) and calibrated image intensifier images (method C) were intercomparable (p = 0.226) and showed only minor differences compared to the reference values but significant differences to method A (p < 0,001). Conclusion The results demonstrate that MPs can be accurately measured with radiographic techniques when using calibration markers and a software calibration tool, thus minimizing the source of error and improving the quality of correction.

RADIOGRAPHIC MEASUREMENT TECHNIQUES

Neurosurgery ◽  
2008 ◽  
Vol 63 (suppl_3) ◽  
pp. A40-A45 ◽  
Author(s):  
Peter D. Angevine ◽  
Michael G. Kaiser
Keyword(s):  
Treatment Plan ◽  
Measurement Techniques ◽  
Radiographic Measurement ◽  
Spinal Deformities ◽  
X Ray ◽  
Appropriate Treatment ◽  
Key Characteristics

ABSTRACT THE EVALUATION AND treatment of spinal deformities begins with the accurate measurement of appropriate spinal parameters. The surgeon must ensure that the patient is positioned properly for all necessary x-ray scans and that the proper studies are completed. The relevant measurements must be identified and recorded for each study. Understanding the proper measurement techniques will increase the accuracy and reliability of the measurements. From these precise measurements the surgeon can begin to determine key characteristics of the deformity and develop an appropriate treatment plan.

scholarly journals X-Ray Imaging Calibration for Fuel-Coolant Interaction Experimental Facilities

2021 ◽  
Vol 253 ◽  
pp. 06005
Author(s):  
Christophe Journeau ◽  
Michael Johnson ◽  
Shifali Singh ◽  
Fréderic Payot ◽  
Ken-ichi Matsuba ◽  
...  
Keyword(s):  
Test Section ◽  
High Speed ◽  
Limit Of Detection ◽  
Image Intensifier ◽  
Precise Determination ◽  
Severe Accident ◽  
X Ray ◽  
X Ray Imaging ◽  
Experimental Facilities ◽  
Lower Limits

During a severe accident in either sodium-cooled or water-cooled nuclear reactors, jets of molten nuclear fuel may impinge on the coolant resulting in fuel-coolant interactions (FCI). Experimental programs are being conducted to study this phenomenology and to support the development of severe accident models. Due to the optical opacity of the test section walls, sodium coolant, and the apparent optical opacity of water in the presence of intense ebullition, high-speed X-ray imaging is the preferred technique for FCI visualization. The configuration of these X-ray imaging systems, whereby the test section is installed between a fan-beam X-ray source and a scintillator-image intensifier projecting an image in the visual spectrum onto a high-speed camera, entails certain imaging artefacts and uncertainties. The X-ray imaging configuration requires precise calibration to enable detailed quantitative characterization of the FCI. To this end, ‘phantom’ models have been fabricated using polyethylene, either steel or hafnia powder, and empty cavities to represent sodium, molten fuel and sodium vapor phases respectively. A checkerboard configuration of the phantom enables calibration and correction for lens distortion artefacts which magnify features towards the edge of the field of view. Polydisperse steel ball configurations enable precise determination of the lower limit of detection and the estimation of parallax errors which introduce uncertainty in an object’s silhouette dimensions. Calibration experiments at the MELT facility determined lower limits of detection in the order of 4 mm for steel spheres, and 1.7-3.75 mm for vapor films around a molten jet.

scholarly journals Comparing goniometric and radiographic measurement of Q angle of the knee

2017 ◽  
Vol 9 (5) ◽  
pp. 631-636 ◽  
Author(s):  
Mohamed Faisal Chevidikunnan ◽  
Amer Al Saif ◽  
Harish Pai K ◽  
Lawrence Mathias
Keyword(s):  
Pearson Correlation ◽  
Radiographic Measurement ◽  
X Rays ◽  
X Ray ◽  
Radiographic Measurements ◽  
Q Angle ◽  
X Ray Imaging ◽  
The Common ◽  
Diagnostic Measurement ◽  
Acute Knee

AbstractBackgroundThe Q angle is a relevant clinical diagnostic measurement to detect various disorders of the knee. The common method used to measure the Q angle in the routine clinical practice is by radiography. An alternative to radiographic measurement is goniometry, by which exposure to x-rays can be avoided.ObjectivesTo compare and correlate the goniometric measurement of Q angle with radiographic measurement of the Q angle in patients with acute knee pain.MethodsWe selected 45 patient participants with a mean age of 32.5 years who satisfied the inclusion criteria for this study. All the patients underwent goniometric measurement of the Q angle followed by x-ray imaging of the entire lower limb. Later the bony prominences were marked on the x-ray image and the Q angle formed was measured using a protractor. The Pearson correlation coefficient between the goniometric and radiographic measurements was determined.ResultsWe found a significant relationship between Q angles obtained using a goniometer and x-ray imaging in the supine position (r = 0.91, P = 0.001). The mean difference between the goniometric measurement of Q angle and the radiographic measurement was 0.1°, which is not significant.ConclusionsGoniometry can be used to measure Q angle as accurately as radiography, and can be used as an inexpensive and radiation free alternative.

scholarly journals A Frame-Mounted X-Ray Guide for the Taylor Spatial Frame

2007 ◽  
Vol 89 (7) ◽  
pp. 729-729 ◽  
Author(s):  
DE Deakin ◽  
T Rolands ◽  
A Taylor
Keyword(s):  
Taylor Spatial Frame ◽  
X Ray ◽  
Spatial Frame

scholarly journals Study of the radiographic parameters of normal ankles

2020 ◽  
Vol 14 (1) ◽  
pp. 84-88
Author(s):  
Pedro Costa Benevides ◽  
Caio Augusto de Souza Nery ◽  
Alexandre Leme Godoy-Santos ◽  
José Felipe Marion Alloza ◽  
Marcelo Pires Prado
Keyword(s):  
Ankle Instability ◽  
Radiographic Measurement ◽  
Radiographic Evaluation ◽  
Diagnostic Study ◽  
Ankle Arthritis ◽  
Level Of Evidence ◽  
X Ray ◽  
Radiographic Parameters ◽  
Radiographic Measurements ◽  
Bibliographic Search

Objective: The authors carried out a bibliographic search for the radiographic parameters used to determine tibiotalar joint alignment, and suggest a set of parameters that constitute the minimum radiographic evaluation sufficient for the proper assessment of tibiotalar alignment. Methods: The search was conducted between May 2019 and January 2020 on the online platforms PudMed and Google Scholar with the following terms, used separately or jointly: “ankle arthritis, radiographic measurement, ankle alignment, alignment, anterior ankle instability, X-ray, and ankle injury”. Results: We selected twelve studies evaluating radiographic patterns of normal ankles, and identified a total of 15 radiographic measurements. Conclusion: The authors believe that a minimum radiographic assessment of tibiotalar alignment should include the following parameters on the anteroposterior radiograph: the distal tibial articular angle, the talar tilt and talus center migration. On the lateral radiograph, it should include: lateral distal tibial angle and lateral talar station. Level of Evidence V; Diagnostic Study; Expert Opinion.

scholarly journals The reliability of full-length lower limb radiographic alignment measurements in skeletally immature youth

2019 ◽  
Vol 13 (1) ◽  
pp. 67-72
Author(s):  
G. A. Schmale ◽  
A. F. Bayomy ◽  
A. O. O’Brien ◽  
V. Bompadre
Keyword(s):  
Lower Extremity ◽  
Acl Reconstruction ◽  
Interobserver Reliability ◽  
Cruciate Ligament ◽  
Measurement Techniques ◽  
Tibial Slope ◽  
Intraobserver Reliability ◽  
Radiographic Measurement ◽  
Orthopaedic Resident ◽  
Radiographic Measurements

Purpose Reliable radiographic measurement techniques are important for investigating limb alignments prior to and following paediatric anterior cruciate ligament (ACL) reconstruction. We investigated the inter- and intraobserver reliability of alignment measurements from lower extremity anteroposterior and lateral radiographs of adolescents having undergone transphyseal ACL reconstruction Methods A total of 15 of 90 patients who had undergone transphyseal ACL reconstruction were randomly selected for alignment measurements of radiographs of operative and nonoperative limbs. Radiographs were de-identified, randomized to three varying sequences and made available in electronic format to three blinded investigators: a junior orthopaedic resident, a senior orthopaedic resident and a paediatric orthopaedic attending. Coronal measurements comprised the mechanical lateral distal femoral angle (mLDFA), mechanical medial proximal tibial angle (mMPTA) and mechanical axis deviation (MAD), measured from standing teleoroentgenograms of the lower extremities. Tibial slope was measured on lateral knee radiographs of operative limbs. The intra-class correlation coefficient (ICC) was calculated for each of the three coronal measures and for tibial slope. Results Intraobserver reliability was excellent across all measures (ICC > 0.75) except for tibial slope in one investigator’s measurements (good or ICC = 0.68 for the operative limbs) and mLDFA in another investigator’s measurements (fair or ICC = 0.49 for the operative limbs, and poor ICC = 0.27 for the nonoperative limbs). Interobserver reliability was excellent across all investigators for all measurements for operative and nonoperative limbs. Conclusions Radiographic measurements of lower extremity alignment may be reliably measured on teleoroentgenograms in a subset of youth who underwent transphyseal ACL reconstruction. Level of Evidence III

scholarly journals Correction of radiographic measurements of acetabular cup wear for variations in pelvis orientation

2018 ◽  
Vol 232 (3) ◽  
pp. 299-309
Author(s):  
Brian Derbyshire
Keyword(s):  
Mathematical Method ◽  
Pelvic Tilt ◽  
Radiographic Measurement ◽  
Linear Wear ◽  
Two Dimensional ◽  
Acetabular Cup ◽  
Correction Formula ◽  
X Ray ◽  
Radiographic Measurements

Radiographic measurement of two-dimensional acetabular cup wear is usually carried out on a series of follow-up radiographs of the patient’s pelvis. Since the orientation of the pelvis might not be consistent at every X-ray examination, the resulting change in view of the wear plane introduces error into the linear wear measurement. This effect is amplified on some designs of cup in which the centre of the socket is several millimetres below the centre of the cup or circular wire marker. This study describes the formulation of a mathematical method to correct radiographic wear measurements for changes in pelvis orientation. A mathematical simulation of changes in cup orientation and wear vectors caused by pelvic tilt was used to confirm that the formulae corrected the wear exactly if the radiographic plane of the reference radiograph was parallel to the true plane of wear. An error analysis showed that even when the true wear plane was not parallel to the reference radiographic plane, the formulae could still provide a useful correction. A published correction formula was found to be ineffective.

An Electron Diffraction Study on Litnerized Potato Starch

1990 ◽  
Vol 48 (1) ◽  
pp. 580-581
Author(s):  
Jean-Claude Jésior ◽  
Roger Vuong ◽  
Henri Chanzy
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Signal To Noise Ratio ◽  
Potato Starch ◽  
Image Intensifier ◽  
Electron Diffraction Study ◽  
Starch Granules ◽  
X Ray ◽  
Individual Grains ◽  
Diamond Knife

Starch is arranged in a crystalline manner within its storage granules and should thus give sharp X-ray diagrams. Unfortunately most of the common starch granules have sizes between 1 and 100μm, making them too small for an X-ray study on individual grains. There is only one instance where an oriented X-ray diagram could be obtained on one sector of an individual giant starch granule. Despite their small size, starch granules are still too thick to be studied by electron diffraction with a transmission electron microscope. The only reported study on starch ultrastructure using electron diffraction on frozen hydrated material was made on small fragments. The present study has been realized on thin sectioned granules previously litnerized to improve the signal to noise ratio.Potato starch was hydrolyzed for 10 days in 2.2N HCl at 35°C, dialyzed against water until neutrality and embedded in Nanoplast. Sectioning was achieved with a commercially available low-angle “35°” diamond knife (Diatome) after a very carefull trimming and a pre-sectioning with a classical “45°” diamond knife. Sections obtained at a final sectioning angle of 42.2° (compared with the usual 55-60°) and at a nominal thickness of 900Å were collected on a Formvar-carbon coated grid. The exact location of the starch granules in their sections was recorded by optical microscopy on a Zeiss Universal polarizing microscope (Fig. 1a). After rehydration at a relative humidity of 95% for 24 hours they were mounted on a Philips cryoholder and quench frozen in liquid nitrogen before being inserted under frozen conditions in a Philips EM 400T electron microscope equipped with a Gatan anticontaminator and a Lhesa image intensifier.

scholarly journals The Degree of Oxidation of Graphene Oxide

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 560
Author(s):  
Alexandra Carvalho ◽  
Mariana C. F. Costa ◽  
Valeria S. Marangoni ◽  
Pei Rou Ng ◽  
Thi Le Hang Nguyen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Ab Initio ◽  
State Of The Art ◽  
High Accuracy ◽  
Precise Determination ◽  
Photoemission Spectroscopy ◽  
Pristine Graphene ◽  
X Ray ◽  
Degree Of Oxidation

We show that the degree of oxidation of graphene oxide (GO) can be obtained by using a combination of state-of-the-art ab initio computational modeling and X-ray photoemission spectroscopy (XPS). We show that the shift of the XPS C1s peak relative to pristine graphene, ΔEC1s, can be described with high accuracy by ΔEC1s=A(cO−cl)2+E0, where c0 is the oxygen concentration, A=52.3 eV, cl=0.122, and E0=1.22 eV. Our results demonstrate a precise determination of the oxygen content of GO samples.

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