scholarly journals Triaging of eccentric gestational sac in early pregnancy using two dimensional and three dimensional transvaginal ultrasound

2021 ◽  
Vol 25 (2) ◽  
pp. 11-18
Author(s):  
ahmed el-habashy
Keyword(s):  
Early Pregnancy ◽  
Transvaginal Ultrasound ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Gestational Sac

scholarly journals Bladder Volume Determination: Two-dimensional Versus Three-dimensional Transvaginal Ultrasound

2009 ◽  
Vol 48 (3) ◽  
pp. 258-261 ◽  
Author(s):  
Ching-Chung Liang ◽  
Tien-Yung Wei ◽  
Shuenn-Dhy Chang ◽  
Ching-Chang Hsieh
Keyword(s):  
Transvaginal Ultrasound ◽  
Three Dimensional ◽  
Bladder Volume ◽  
Two Dimensional ◽  
Volume Determination

scholarly journals Mean Sac Diameter Minus Crown Rump Length as a Predector of Early Pregnancy Outcome

2021 ◽  
pp. 93-104
Author(s):  
Hasnaa M. Mosbah ◽  
Mona K. Omar ◽  
Manal F. Hemisa ◽  
Elsayed F. Rakha
Keyword(s):  
Pregnancy Outcome ◽  
Early Pregnancy ◽  
Transvaginal Ultrasound ◽  
Normal Pregnancy ◽  
Accurate Estimation ◽  
P Value ◽  
Good Prediction ◽  
Crown Rump Length ◽  
Gestational Sac ◽  
The Difference

Background: Mean sac diameter (MSD) is a sonographic measurement of the gestational sac which is usually first seen at around 5 weeks, when it measures about 2-3 mm, It's the average of measurements taken in three dimensions.Crown rump length (CRL) defined as the length of the embryo or fetus from the top of it's head to bottom of torso, it's the most accurate estimation of gestational age in early pregnancy, it's determined by the average of three measurements of the longest fetal length. Aim of the study Determine efficacy of mean sac diameter minus crown rump length  (MSD-CRL) in prediction of early pregnancy outcome. Methods: The study included 80 cases at (6:9) gestational weeks with singletone pregnancy. We examined the case at the initial visit, Mean sac diameter and Crown rump length were calculated for each case. The difference between the MSD and CRL in mm was calculated. Then follow up visit after two weeks later. Pregnancy outcome was then recorded between (11:14w). During transvaginal ultrasound (TVUS) we observed location, size, number and regularity of gestational sac. Cardiac pulsation & Presence or absence of sub-chorionic hematoma. Results: 73 cases (91, 3%) continued normal pregnancy and 7 cases (8, 8%) had pregnancy failure. It was found that the age, body mass index, gravidity and history of abortion show insignificant relation with outcome (p >0.05).  Area under a curve was 0.984, p Value was <0.001, 95% CI was (0.961 – 1.000), at the cut off value (MSD-CRL) less than or equal 4, the sensitivity was 71.4%, the specificity was 97.2%, PPV was 71.4% and NPV was 97.3%, while at cut off value less than or equal 5, the sensitivity was 100.0%, specificity was 95.89, PPV was 70.0% and NPV was 100.0%. Conclusions: (MSD- CRL) is good prediction for early pregnancy outcome but, the optimum threshold for predicting pregnancy outcome needed to be established by further studies, also bigger sample size will provide more advantage.

High Resolution Microscopy of Multi-Layered Biological Crystals

1982 ◽  
Vol 40 ◽  
pp. 80-83
Author(s):  
H.A. Cohen ◽  
T.W. Jeng ◽  
W. Chiu
Keyword(s):  
High Resolution ◽  
Low Dose ◽  
Three Dimensional ◽  
Data Interpretation ◽  
Two Dimensional ◽  
Biological Objects ◽  
Density Maps ◽  
Density Map ◽  
Complex Crystal ◽  
High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

Instrumentation For Quantitative Microscopy

1977 ◽  
Vol 35 ◽  
pp. 206-209
Author(s):  
B. Ralph ◽  
A.R. Jones
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Automatic Data ◽  
Phase Volume Fraction ◽  
Statistical Confidence ◽  
Resultant Data ◽  
Automatic Data Collection ◽  
Third Dimension ◽  
Evolution Of Microstructure

In all fields of microscopy there is an increasing interest in the quantification of microstructure. This interest may stem from a desire to establish quality control parameters or may have a more fundamental requirement involving the derivation of parameters which partially or completely define the three dimensional nature of the microstructure. This latter categorey of study may arise from an interest in the evolution of microstructure or from a desire to generate detailed property/microstructure relationships. In the more fundamental studies some convolution of two-dimensional data into the third dimension (stereological analysis) will be necessary.In some cases the two-dimensional data may be acquired relatively easily without recourse to automatic data collection and further, it may prove possible to perform the data reduction and analysis relatively easily. In such cases the only recourse to machines may well be in establishing the statistical confidence of the resultant data. Such relatively straightforward studies tend to result from acquiring data on the whole assemblage of features making up the microstructure. In this field data mode, when parameters such as phase volume fraction, mean size etc. are sought, the main case for resorting to automation is in order to perform repetitive analyses since each analysis is relatively easily performed.

A linearity test for thick specimens imaged by HVEM over a 180° angular range

1991 ◽  
Vol 49 ◽  
pp. 552-553
Author(s):  
Yu Liu
Keyword(s):  
Phase Contrast ◽  
Three Dimensional ◽  
Angular Range ◽  
Two Dimensional ◽  
Back Projection ◽  
Line Integral ◽  
Exponential Law ◽  
Transmission Electron ◽  
Absorption Law ◽  
Linearity Test

The image obtained in a transmission electron microscope is the two-dimensional projection of a three-dimensional (3D) object. The 3D reconstruction of the object can be calculated from a series of projections by back-projection, but this algorithm assumes that the image is linearly related to a line integral of the object function. However, there are two kinds of contrast in electron microscopy, scattering and phase contrast, of which only the latter is linear with the optical density (OD) in the micrograph. Therefore the OD can be used as a measure of the projection only for thin specimens where phase contrast dominates the image. For thick specimens, where scattering contrast predominates, an exponential absorption law holds, and a logarithm of OD must be used. However, for large thicknesses, the simple exponential law might break down due to multiple and inelastic scattering.

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