A phantom study to determine the theoretical accuracy and precision of radial MRI to measure cross-sectional area differences for the application of coronary endothelial function assessment

2017 ◽  
Vol 79 (1) ◽  
pp. 108-120 ◽  
Author(s):  
Jérôme Yerly ◽  
Danilo Gubian ◽  
Jean-Francois Knebel ◽  
Ali Schenk ◽  
Jerome Chaptinel ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Cross Sectional Area ◽  
Phantom Study ◽  
Sectional Area ◽  
Cross Sectional ◽  
Coronary Endothelial Function ◽  
Accuracy And Precision ◽  
Radial Mri ◽  
Theoretical Accuracy ◽  
Function Assessment

scholarly journals Precision and accuracy of cross-sectional area measurements used to measure coronary endothelial function with spiral MRI

2018 ◽  
Vol 81 (1) ◽  
pp. 291-302 ◽  
Author(s):  
Michael Schär ◽  
Sahar Soleimanifard ◽  
Gabriele Bonanno ◽  
Jérôme Yerly ◽  
Allison G. Hays ◽  
...  
Keyword(s):  
Endothelial Function ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Coronary Endothelial Function ◽  
Precision And Accuracy ◽  
Spiral Mri

Accuracy and precision of MR velocity mapping in measurement of stenotic cross-sectional area, flow rate, and pressure gradient

1993 ◽  
Vol 3 (2) ◽  
pp. 433-437 ◽  
Author(s):  
Lars Søndergaard ◽  
Freddy Ståhlberg ◽  
Carsten Thomsen ◽  
Anders Stensgaard ◽  
Knud Lindvig ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Flow Rate ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Velocity Mapping ◽  
Cross Sectional ◽  
Accuracy And Precision

Accuracy and precision of measuring cross-sectional area in stem disks of Douglas-fir infected by Armillaria root disease

2002 ◽  
Vol 32 (9) ◽  
pp. 1542-1547 ◽  
Author(s):  
Mike G Cruickshank
Keyword(s):  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Irregular Shapes ◽  
Accuracy And Precision ◽  
Armillaria Root Disease ◽  
Root Collar ◽  
Disk Area

Stem cross-sectional areas were checked for accuracy and precision of area measurements in healthy and Armillaria ostoyae (Romagn.) Herink infected 18-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco). Ten trees were randomly selected in each combination of two size classes and four infection classes, and stem disks were taken at the soil line (0 m) and at 1.3 m. Disks were marked at the longest radius, 90° to the longest radius, the shortest radius, and at radii determined by the sum of the largest diameter and the diameter at 90° divided by four. These radii were used to calculate cross-sectional area, then these calculated areas were compared with the corresponding digitized areas. Cross-sectional areas calculated from radial measurements were generally not within 5% of digitized areas. Radii were also drawn on the disks corresponding to the positions at which healthy and infected roots arose from the root collar below. For 0-m disks, the stem radii over healthy roots averaged 7 mm longer than over infected roots. At 1.3 m, the stem radii over healthy roots were 4 mm longer, but this was reduced with increasing infection of the root system. Offset piths and irregular shapes formed because of radial reduction over infected roots, and corresponding radial expansion over healthy roots affected the accuracy of disk area estimation.

Pelvic Canal Narrowing Caused by Triple Pelvic Osteotomy in the Dog

1994 ◽  
Vol 07 (03) ◽  
pp. 110-113 ◽  
Author(s):  
D. L. Holmberg ◽  
M. B. Hurtig ◽  
H. R. Sukhiani
Keyword(s):  
Postoperative Complications ◽  
Pelvic Osteotomy ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Canal Width ◽  
Operative Complications ◽  
Post Operative Complications

SummaryDuring a triple pelvic osteotomy, rotation of the free acetabular segment causes the pubic remnant on the acetabulum to rotate into the pelvic canal. The resulting narrowing may cause complications by impingement on the organs within the pelvic canal. Triple pelvic osteotomies were performed on ten cadaver pelves with pubic remnants equal to 0, 25, and 50% of the hemi-pubic length and angles of acetabular rotation of 20, 30, and 40 degrees. All combinations of pubic remnant lengths and angles of acetabular rotation caused a significant reduction in pelvic canal-width and cross-sectional area, when compared to the inact pelvis. Zero, 25, and 50% pubic remnants result in 15, 35, and 50% reductions in pelvic canal width respectively. Overrotation of the acetabulum should be avoided and the pubic remnant on the acetabular segment should be minimized to reduce postoperative complications due to pelvic canal narrowing.When performing triple pelvic osteotomies, the length of the pubic remnant on the acetabular segment and the angle of acetabular rotation both significantly narrow the pelvic canal. To reduce post-operative complications, due to narrowing of the pelvic canal, overrotation of the acetabulum should be avoided and the length of the pubic remnant should be minimized.

DETERMINATION OF THE FUNCTION OF THE ROD’S CROSS-SECTIONAL AREA USING VIBRATION EIGENFREQUENCIES

2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  
Keyword(s):  
Cross Sectional Area ◽  
Variable Cross ◽  
Sectional Area ◽  
Longitudinal Vibrations ◽  
Cross Sectional ◽  
Method Error ◽  
Various Boundary Conditions ◽  
Elastic Fixation ◽  
Crosssectional Area

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.

Changes in the parameters of nasal breathing and parameters of the upper respiratory tract during orthognathic operations in patients with II and III skeletal class of jaw anomalies

2020 ◽  
pp. 22-27
Author(s):  
S.Sh. Gammadaeva ◽  
M.I. Misirkhanova ◽  
A.Yu. Drobyshev
Keyword(s):  
Respiratory Tract ◽  
Nasal Cavity ◽  
Nasal Septum ◽  
Cross Sectional Area ◽  
Upper Respiratory Tract ◽  
Sectional Area ◽  
Nasal Breathing ◽  
Cross Sectional ◽  
Skeletal Class ◽  
Upper Respiratory

The study analyzed the functional parameters of nasal breathing, linear parameters of the nasal aperture, nasal cavity and nasopharynx, volumetric parameters of the upper airways in patients with II and III skeletal class of jaw anomalies before and after orthognathic surgery. The respiratory function of the nose was assessed using a rhinomanometric complex. According to rhinoresistometry data, nasal resistance and hydraulic diameter were assessed. According to the data of acoustic rhinometry, the minimum cross-sectional area along the internal valve, the minimum cross-sectional area on the head of the inferior turbinate and nasal septum and related parameters were estimated. According to the CBCT data, the state of the nasal septum, the inferior turbinates, the nasal aperture, the state of the nasal cavity, and the linear values of the upper respiratory tract (nasopharynx) were analyzed. The patients were divided into 4 groups according to the classification of the patency of the nasal passages by

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