The ejection fraction is one of the most widely used measurements of left ventricular systolic function. Angiographic measurement of ejection fraction is based on determination of roentgenographic magnification and calculation of end-diastolic and end-systolic volumes, assuming a prolated ellipse. Because it is simple and radiographic magnification may not have been determined, some laboratorie...

Price changes create a range of factor price adjustments in the three factor, two good general equilibrium model of production. Comparative static adjustments in the model have been described by magnification effects and sign patterns. This note supplements the diagrammatic technique of Jones and Easton (1983, Journai of International Economics) and derives eleven magnification effects implied ...

The purpose of this study was to evaluate the precision of dimensional measurements of the mandible on orthopantomographic images and thus to evaluate their dimensional reliability. Different distances denoted by metal markers were measured on 25 dry mandibles. The same mandibles were then positioned in an orthopantomographic machine, and radiographic images of them were made. Measurements of t...

PURPOSE To identify the factors which significantly contribute to the thickness variabilities in macular retinal layers measured by optical coherence tomography with or without magnification correction of analytical areas in normal subjects. METHODS The thickness of retinal layers {retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCLIPL), RNFL plus GCLIPL (gan...

Accurately evaluating the size of a neurovascular lesion is essential for properly devising treatment strategies. The magnification factor must be considered in order to measure the dimension of a lesion from an angiogram. Although a method to calculate the magnification of the lesion by linear interpolation of the measurable magnification factors of two markers has been in use, this paper show...

Errors resulting from magnification variations of optical system are largely generated in threemensional shape measurements based on depth-from-focus. Focus measures are wrongly or ambiguously tracted, due to the variations. In this paper, a DFF-based methodology considering these magnification riations is proposed to make accurate measurements in surface morphology with high depth discontinuit...

Cephalometric analyses using computer software have more advantages than manual analyses. However, the software should be evaluated for the accuracy and reproducibility before it can be used. The aims of the present study were: 1) to compare the differences in accuracy and precision between utilizing scanned images and soft copy images with the software 2) to assess the reproducibility of softw...