Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
716 results found
Article
Electrical impedance tomography
Electrical impedance tomography (EIT) is a type of imaging based on sending small amounts of electrical current across tissue (when used for medical imaging) and measuring conductivity.
Terminology
There are several ways in which the EIT signal can be generated and processed, and these are oft...
Article
CheckList for EvaluAtion of Radiomics research (CLEAR)
The CheckList for Evaluation of Radiomics Research (CLEAR) is a 58-item reporting guideline designed specifically for radiomics. It aims to improve the quality of reporting in radiomics research 1. CLEAR is endorsed by the European Society of Radiology (ESR) and the European Society of Medical I...
Article
MR cisternography
MR cisternography is an MR imaging technique useful in evaluating abnormalities in subarachnoid cisterns 1,2. It is the intracranial equivalent to MR myelography and can similarly be non-contrast-enhanced or, less commonly, contrast-enhanced (off-label).
Clinical applications
MR cisternography...
Article
Mu-metal
Mu-metal is an alloy of primarily nickel and iron, with high magnetic permeability 1. It provides a low resistance pathway for external magnetic fields to flow, thereby 'shielding' the area housed within 1. It is therefore a useful component of the housing for medical imaging devices which requi...
Article
Whole-body diffusion-weighted MRI
Whole-body diffusion-weighted MRI (WB-MRI) is an advanced imaging technique that combines anatomical and functional MRI sequences to provide a comprehensive assessment of the whole-body in a single examination.
WB-MRI uses the properties of diffusion-weighted imaging for oncological disease sta...
Article
Meta-analysis
Meta-analysis (plural: meta-analyzes) is a statistical technique that returns in a single numerical estimate (synthesis) the results of multiple clinical trials relating, for example, to the same pharmacological treatment 1,2. Meta-analyzes of RCTs specifically, are the most robust evidence of e...
Article
MRI in patients with pacemaker systems
MRI in patients with cardiac implantable electronic devices (CIED) has increasingly become a requirement in radiological departments 1-8. Especially in the setting of patients with MR conditional pacemaker systems, where all the manufacturer's instructions are followed and a standardized institu...
Article
Augmented reality
Augmented reality (AR) is a technology that uses computer-generated virtual content e.g. image rendering that is superimposed onto the user’s real environment 1. This is in contrast to virtual reality (VR) whereby the user is immersed into a completely virtual setting 1. One example is the use o...
Article
Amide proton transfer imaging
Amide proton transfer (APT) imaging is the most common type of chemical exchange saturation transfer technique that generates image contrast due to proton exchange between labeled protons in solute and free water protons1. APT imaging does not require exogenous gadolinium-based contrast and thus...
Article
Intravoxel incoherent motion
Intravoxel incoherent motion (IVIM) is a technique used in diffusion MRI to measure translational movements of water molecules within a voxel.
IVIM-based perfusion MRI does not require the injection of any tracer or contrast agent. IVIM is a concept and method used in diffusion MRI to assess ...
Article
Dimensionless index (DI)
Dimensionless index (DI) is the ratio of the velocity-time integral of the left ventricular outflow tract (LVOT-VTI) to that of the aortic valve jet (AV VTI)1-2.
Dimensionless index (DI) = LVOT VTI / AV VTI
Usage
Dimensionless index is a classic marker of severity in aortic stenosis that does...
Article
Reverse Bernheim phenomenon
Reverse Bernheim phenomenon, also known as reverse Bernheim syndrome or reverse Bernheim effect, describes the compromise of left ventricular filling caused by the interventricular septum bulging into the left ventricle. When there is right ventricular pressure and volume overload, the intervent...
Article
Bernheim phenomenon
Bernheim phenomenon, also known as the Bernheim syndrome or the Bernheim effect, is the development of right heart failure before left heart failure and has been described in patients with a hypertrophied ventricular septum bulging into the right ventricle, restricting right ventricular diastoli...
Article
Spin (physics)
Spin, an intrinsic quantum property associated with elementary particles, challenges classical intuition by presenting an angular momentum quantized in half-integer or integer values.
Electron spin
Electrons, charged particles central to atomic structure, possess a spin of 1/2, leading to an a...
Article
Optically stimulated luminescent dosimeter
Optically stimulated luminescent dosimeters (OSL) are passive radiation detection devices used for personal dose monitoring.
Unlike thermoluminescent dosimeter (TLD). OSL does not need heating for the reading of radiation dose. OSL dosimeters can be read multiple times and stored for several ye...
Article
TWIST (time-resolved angiography with interleaved stochastic trajectories)
Time-resolved angiography with interleaved stochastic trajectories (TWIST) is a 3D time-resolved MR angiography (MRA) sequence - being vendor-specific to Siemens.
In comparison to contrast-enhanced MRA techniques that obtain images at a single point in time, time-resolved MRA obtains a series o...
Article
Cyclotron
A cyclotron is a type of particle accelerator that uses a uniform magnetic field to accelerate particles in a spiral path. The accelerated particles are then used to bombard target nuclei to produce a wide variety of radionuclides 1.
Cyclotron is an improvement on the linac (linear particle acc...
Article
TRUFI sequence
The TRUFI sequence which is an abbreviation for "True Fast Imaging with Steady-State Free Precession" is a form of MRI pulse sequence. It is thought to represent a form of gradient echo seqeunce.
Blood vessels and fluid filled spaces in the body may look bright on this sequence.
See also
MRI ...
Article
Spatial resolution (gamma camera)
Spatial resolution is the ability of a gamma camera to differentiate two close radioactive sources. It takes "full width at half maximum" (FWHM) of the radioactivity count rate from a point source or a line source. FWHM in this case is defined as possible positions of the source when the count r...
Article
Mitral leaflet separation index
The mitral leaflet separation (MLS) index is a semi-quantitative and complementary approach for assessing the degree of mitral stenosis by using two-dimensional echocardiography. It strongly correlates with the mitral valve area using planimetry and pressure half-time techniques 1-3.
Measuremen...
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