Search research articles

关于 JoVE

概览领导团队博客 JoVE 帮助中心

作者

出版流程编辑委员会范围与政策同行评审常见问题投稿

图书馆员

用户评价订阅访问资源图书馆顾问委员会常见问题

研究

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments 存档

教育

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual 教师资源中心教师网站

使用条款与条件

相关概念视频

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.

Parallel RLC Circuits

Parallel RLC Circuits

Street lamps equipped with RLC surge protectors are an excellent example of applying circuit analysis in practical scenarios. These surge protectors safeguard the lamp's components against sudden voltage spikes.
A simplified parallel RLC circuit model with a DC input source generating a step response is employed in this context. When the switch is turned on, Kirchhoff's current law is applied, leading to a second-order differential equation.

Special considerations while measuring pulse

Special considerations while measuring pulse

Assessing a patient's pulse is a fundamental skill in healthcare, but certain situations require special attention:

您也可能阅读

相关文章

通过共同作者、期刊和引用图与本文相关的文章。

排序

Same author

On the Utility of Foundation Models for Fast MRI: Vision-Language-Guided Image Reconstruction.

Magnetic resonance in medicine·2026

Same author

Accessible cartilage tumor malignancy prediction via vision-language foundation model adaptation.

Skeletal radiology·2026

Same author

Accelerating Multiparametric Quantitative MRI Using Self-Supervised Scan-Specific Implicit Neural Representation With Model Reinforcement.

Magnetic resonance in medicine·2025

Same author

MC BTS: Simultaneously Resolving Magnetization Transfer Effect and Relaxation for Multiple Components.

Magnetic resonance in medicine·2025

Same author

Visual-language artificial intelligence system for knee radiograph diagnosis and interpretation: a collaborative system with humans.

Radiology advances·2025

Same author

Simultaneous 3D quantitative magnetization transfer imaging and susceptibility mapping.

Magnetic resonance in medicine·2025

Same journal

A Comparison of Tissue Property Values Estimated Using Conventional Cardiac MRF and MT-Cardiac MRF.

Magnetic resonance in medicine·2026

Same journal

Dependence of the Extra-Cellular Diffusion Coefficient on the Fractions of Neurites and Cell Bodies in Gray Matter.

Magnetic resonance in medicine·2026

Same journal

Triple-Pulse <sup>23</sup>Na MRI Sequence (TriNa) for Simultaneous Acquisition of Spin-Density-Weighted and Fluid-Attenuated Images.

Magnetic resonance in medicine·2026

Same journal

Evaluation of Phantom Doping Materials in Quantitative Susceptibility Mapping.

Magnetic resonance in medicine·2026

Same journal

Design of an 8-Channel Transmit 32-Channel Receive 11.7T Head Coil and Evaluation of SNR Gains.

Magnetic resonance in medicine·2026

Same journal

The Potential for Absolute Temperature Imaging Based on Brain Metabolites Using an FID-Shifting Approach in Gradient Echo Planar Spectroscopic Imaging (GREPSI).

Magnetic resonance in medicine·2026

查看所有相关文章

Search research articles

相关实验视频

Updated: Jun 11, 2025

A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions

A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions

Published on: March 25, 2014

物理指导的自我监督学习:对通用射频脉冲设计的演示.

Albert Jang^1,2, Xingxin He^1,2, Fang Liu^1,2

¹Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts, USA.

Magnetic resonance in medicine

|October 10, 2024

概括

此摘要是机器生成的。

物理指导的自我监督学习 (GPS) 提供了一种新的,多功能方法,用于设计磁共振成像 (MRI) 中的射频 (RF) 脉冲. 这种方法有效地弥补了系统的缺陷,在各种射频脉冲设计任务中展示了广泛的适用性.

关键词:

布洛赫方程是什么意思布洛赫方程这是GPS的GPSGPS的GPS.这是一个RF脉冲脉冲.深度学习是一种深度学习.在线适应在线适应自主监督学习学习

更多相关视频

Topographical Estimation of Visual Population Receptive Fields by fMRI

Topographical Estimation of Visual Population Receptive Fields by fMRI

Published on: February 3, 2015

Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles

Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles

Published on: March 13, 2017

相关实验视频

Last Updated: Jun 11, 2025

A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions

A Simple Stimulatory Device for Evoking Point-like Tactile Stimuli: A Searchlight for LFP to Spike Transitions

Published on: March 25, 2014

Topographical Estimation of Visual Population Receptive Fields by fMRI

Topographical Estimation of Visual Population Receptive Fields by fMRI

Published on: February 3, 2015

Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles

Microfluidic Platform with Multiplexed Electronic Detection for Spatial Tracking of Particles

Published on: March 13, 2017

科学领域:

磁共振成像 (MRI) 是一种磁共振成像技术.
医学物理医学物理
计算成像技术的成像

背景情况:

设计射频 (RF) 脉冲用于MRI传统上需要针对每个脉冲类型的专用算法.
现有的方法可能很复杂,可能不容易适应实验变化或系统不完美.

研究的目的:

通过物理引导的自我监督学习 (GPS) 引入RF脉冲设计的通用方法.
为了利用布洛赫方程作为指导物理模型在RF脉冲生成的自我监督的学习框架内.

主要方法:

GPS框架将一个神经网络与Bloch模拟器 (物理模块) 集成在一起.
神经网络学习设计射频脉冲,通过优化针对由Bloch模拟器监督的目标配置文件.
应用了GPS来设计各种RF脉冲,包括选择性,增值,和和多维脉冲,并证明了在线适应以纠正系统缺陷.

主要成果:

在模拟和实验中,GPS成功设计了各种RF脉冲,其配置与目标输入相匹配.
用GPS设计的脉冲表现出独特的特征,例如新的增电机制和降低的峰值功率.
实验证实了GPS在线适应的实用性,以纠正B1不均性等缺陷.

结论:

在多个应用中,GPS方法证明了RF脉冲设计的通用性和灵活性.
这种以物理为导向的方法为传统的专用射频脉冲设计算法提供了多功能替代方案.
通过自适应和高效的射频脉冲生成,GPS显示了提高MRI性能的巨大潜力.