Indian College of Radiology and Imaging Evidence-Based Guidelines for Interventions in Portal Hypertension and Its Complications

Portal hypertension is a complication of chronic liver disease. Various radiological interventions are being done to aid in the diagnosis of portal hypertension; further, an interventional radiologist can offer various treatments for the complications of portal hypertension. Diagnosis of portal hypertension in its early stage may require hepatic venous pressure gradient measurement. Measurement of gradient also guides in diagnosing the type of portal hypertension, measuring response to treatment and prognostication. This article attempts to provide evidence-based guidelines on the management of portal hypertension and treatment of its complications.

A Novel Technique for Invasive Aortic Valve Pressure Gradient Measurement Using a 6Fr Swan-Ganz Catheter - Case Series

Background Simultaneous left ventricular and aortic pressure gradient assessment has been rendered challenging since the recall of the Langston catheter. Here we describe a simple method for simultaneous left ventricular and aortic pressure gradient assessment using a Swan-Ganz catheter. Case Summary We describe 2 cases where assessment of simultaneous left ventricle and aortic valve gradients was done using a Swan-Ganz Catheter to assess the degree of aortic stenosis and dynamic left ventricular outflow obstruction. Discussion Using Swan-Ganz catheter assessment of simultaneous left ventricle and aortic valve gradients can simplify the procedure with reduced cost and increased patient safety.

GEOGRAPHICAL GRADIENTS - AS A MEASUREMENT OF GEOGRAPHICAL SPACE

Предлагается более широкий круг градиентных измерений географического пространства. В природной сфере – различия в биоразнообразии и ландшафтном разнообразии. В природно-ресурсной сфере – различия в запасах и продуктивности природных ресурсов, имеющих пространственно непрерывное распределение (лесных, земельных), а также – различия в сочетаниях природных ресурсов. Возможны градиентные оценки различий расчетных величин, например, суммарного природно-ресурсного потенциала. В экологической сфере в виде градиентов можно оценивать различия в загрязнении или нарушенности земельного, растительного покрова. В социально-экономической сфере с помощью градиентов можно оценивать различия ряда расчетных величин: плотности населения, экономической плотности, полей тяготения поселений, поля потенциальных затрат и т.п. Предлагается градиентное измерение различий однородных характеристик поселения-центра и сочетания поселений, входящих в круг с условно единичным радиусом, проведенным из центра. A wider range of gradient dimensions of geographical space is proposed. In the natural sphere these are differences in biodiversity and landscape diversity. In the natural resource sphere these are differences in the reserves and productivity of natural resources, which have a spatially continuous distribution (forest, land), as well as differences in the combinations of natural resources. Gradient estimates of differences in the calculated values, such as the total natural resource potential, are possible. In the environmental sphere, differences in pollution or disturbance of land and vegetation cover can be estimated as gradients. In the socio-economic sphere, the gradients can be used to estimate differences in a number of calculated values: population density, economic density, gravity fields of settlements, potential cost fields, etc. A gradient measurement of differences in the homogeneous characteristics of a settlement-center and a combination of settlements, entering the circle with a conventionally single radius drawn from the center, is proposed.

Measuring Analytic Gradients of General Quantum Evolution with the Stochastic Parameter Shift Rule

Hybrid quantum-classical optimization algorithms represent one of the most promising application for near-term quantum computers. In these algorithms the goal is to optimize an observable quantity with respect to some classical parameters, using feedback from measurements performed on the quantum device. Here we study the problem of estimating the gradient of the function to be optimized directly from quantum measurements, generalizing and simplifying some approaches present in the literature, such as the so-called parameter-shift rule. We derive a mathematically exact formula that provides a stochastic algorithm for estimating the gradient of any multi-qubit parametric quantum evolution, without the introduction of ancillary qubits or the use of Hamiltonian simulation techniques. The gradient measurement is possible when the underlying device can realize all Pauli rotations in the expansion of the Hamiltonian whose coefficients depend on the parameter. Our algorithm continues to work, although with some approximations, even when all the available quantum gates are noisy, for instance due to the coupling between the quantum device and an unknown environment.