関連する実験動画

Updated: Jan 31, 2026

Three-Dimensional Phase Resolved Functional Lung Magnetic Resonance Imaging

Three-Dimensional Phase Resolved Functional Lung Magnetic Resonance Imaging

Published on: June 21, 2024

MRIエンコーディング磁場特性評価におけるグラデーションシステム伝達関数およびグラデーションシステム周波数応答の命名規則に関するコメント

Niklas Wehkamp¹, Patrick Hucker², Johannes Fischer²

¹Division of Medical Physics, Department of Diagnostic and Interventional Radiology, University Medical Center Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany. niklas.wehkamp@uniklinik-freiburg.de.

Magma (New York, N.Y.)

|January 30, 2026

Abstract:

The frequency response and transfer function of a system are closely related, but distinct concepts from a control system theory and signal processing perspective. Unfortunately, these concepts have been used inconsistently in the magnetic resonance imaging (MRI) literature for gradient characterization. This note highlights the differences, with the intention to establish a common naming convention, consistent with other engineering fields. This will facilitate communication between colleagues with a different research background, promoting knowledge transfer and potentially alleviate shortcomings that have resulted from the incorrect usage of the term "transfer function" for gradient characterization in the past.

キーワード:

周波数応答関数 (FRF)グラデーション周波数応答 (GFR)グラデーションインパルス応答関数 (GIRF)グラデーション変調伝達関数 (GMTF)グラデーションシステム伝達関数 (GSTF)グラデーション伝達関数 (GTF)磁気共鳴画像法 (MRI)システム特性評価

さらに関連する動画

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

Published on: May 10, 2012

Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds

Functional Magnetic Resonance Imaging fMRI with Auditory Stimulation in Songbirds

Published on: June 3, 2013

関連する概念動画

What is an Electrochemical Gradient?

What is an Electrochemical Gradient?

Adenosine triphosphate, or ATP, is considered the primary energy source in cells. However, energy can also be stored in the electrochemical gradient of an ion across the plasma membrane, which is determined by two factors: its chemical and electrical gradients.
The chemical gradient relies on differences in the abundance of a substance on the outside versus the inside of a cell and flows from areas of high to low ion concentration. In contrast, the electrical gradient revolves around an...

Magnetic Resonance Imaging

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI...

Energy Line and Hydraulic Gradient Line

Energy Line and Hydraulic Gradient Line

Based on Bernoulli's equation, the energy line (EL) and hydraulic grade line (HGL) provide graphical representations of energy distribution in a fluid flow system. For steady, incompressible, inviscid flows, Bernoulli's equation is expressed as:

Gradient and Del Operator

Gradient and Del Operator

In mathematics and physics, the gradient and del operator are fundamental concepts used to describe the behavior of functions and fields in space. The gradient is a mathematical operator that gives both the magnitude and direction of the maximum spatial rate of change. Consider a person standing on a mountain. The slope of the mountain at any given point is not defined unless it is quantified in a particular direction. For this reason, a "directional derivative" is defined, which is a vector...

Imaging Studies IV: Magnetic Resonance Imaging

Imaging Studies IV: Magnetic Resonance Imaging

Introduction:Magnetic Resonance Imaging, or MRI, can include a specialized imaging technique of the urinary system known as Magnetic Resonance Urography (MRU). This radiation-free technique uses strong magnetic fields and radio waves to produce detailed images with the help of a computer. MRU is particularly effective for visualizing fluid-filled structures like the kidneys, ureters, and bladder.Applications of MRI in the Genitourinary SystemKidneys and Ureters: MRI detects tumors, cysts,...

Electrochemical Gradient and Channel Proteins: An Overview

Electrochemical Gradient and Channel Proteins: An Overview

An electrochemical gradient is a fundamental concept in biology and chemistry. It regulates the movement of ions across cell membranes. This movement is influenced by two factors:
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to...