Abstract Background This study aimed at defining the variance of vessel density (VD) characteristics in macula children with normal eyes. Methods was a cross-sectional which subjects eyes aged 3–18 years were enrolled. The scanned by optical coherence tomography angiography (OCTA). Four age groups as under 7 years, 7–10 11–14 and more than 14 defined. influences age, gender, body mass index on ...

BACKGROUND The rate of transient dilatation can be determined by exercise testing or pharmacological stress test. It is unknown whether the type of stress has an impact on average transient dilatation index values. OBJECTIVE To compare average transient dilation index values in 99mTc-sestamibi scintigraphy in patients undergoing treadmill stress test, versus dipyridamole stress test. The seco...

UNLABELLED The topographic matching of alveolar ventilation (V(A)) and perfusion (Q) is the main determinant of gas exchange efficiency of the lung. However, no pulmonary functional imaging technique has been shown to predict whole-lung gas exchange in health and disease. This study aims to present a PET-based method to estimate regional alveolar ventilation-to-perfusion ratios (V(A)/Q) predict...

Arterial Spin Labeling (ASL) techniques potentially allow the absolute, non-invasive quantification of brain perfusion. This can be achieved either by fitting a kinetic model to the data acquired at a number of inversion times (TI) or by applying the model to a single TI assuming values for all other parameters. The accuracy of the model estimation strongly depends on the distribution of the TI...

For the case of pharyngeal carcinomas, the clinical value as well as the stability of several evaluation methods of MR tomographic perfusion measurement are compared. Eighteen patients suffering from histologically proven squamous cell carcinomas were investigated by MR tomography (1.5 T, 0.2 mmol/kg Gd-DTPA) prior to and during radiation therapy. Perfusion measurements were performed using a d...

A system for quantitative analysis of myocardial perfusion tomograms is proposed. The system starts with an automated delineation of the total left ventricle, including possible perfusion defects, to determine the mass and shape of the myocardium. Next, polar maps or bulls-eyes are computed from the delineation, which can then be compared to reference bulls-eyes to detect perfusion defects. The...

UNLABELLED BACKGROUND Several algorithms from the literature were compared with the original random walk (RW) algorithm for brain perfusion heterogeneity quantification purposes. Algorithms are compared on a set of 210 brain single photon emission computed tomography (SPECT) simulations and 40 patient exams. METHODS Five algorithms were tested on numerical phantoms. The numerical anthropom...