Search results for “also”
361 results found
Article
Gastrointestinal MRI contrast agents
Gastrointestinal MRI contrast agents may be helpful in certain clinical scenarios in distinguishing bowel from intra-abdominal masses and normal organs. The contrast agents can be divided into positive agents (appearing bright on MRI) or negative agents (appearing dark on MRI).
Positive contras...
Article
Grids
Grids are placed between the patient and the x-ray film to reduce the scattered radiation reaching the detector (produced mainly by the Compton effect) and thus improve image contrast.
They are made of parallel strips of high attenuating material such as lead with an interspace filled with low ...
Article
Susceptibility weighted imaging
Susceptibility weighted imaging (SWI) is an MRI sequence that is particularly sensitive to compounds which distort the local magnetic field and as such make it useful in detecting blood products, calcium, etc.
Physics
SWI is a 3D high-spatial-resolution fully velocity corrected gradient-echo M...
Article
William D Coolidge
William D Coolidge (1873-1975) was an American physicist who revolutionised radiology with his groundbreaking x-ray tube, the underlying technology of which remains at the core of every machine more than a century later.
Early life
William David Coolidge was born on 23 October 1873 on a small ...
Article
Pierre Curie
Pierre Curie (1859–1906) was a French physicist who was co-awarded the Nobel Prize for Physics in 1903, with his wife Marie Curie, and Henri Becquerel, for their pioneering work on radioactivity, which included the joint discovery with his wife of radium and polonium. He also discovered piezoele...
Article
Radioactivity
Radioactivity, also known as radioactive decay, describes the process of spontaneous breakdown of unstable (or radioactive) nuclides, with the formation of daughter nuclei and release of subatomic particles and/or gamma radiation. A single decay (a.k.a. disintegration) refers to the degradation ...
Article
Iodinated contrast media
Iodinated contrast media are contrast agents that contain iodine atoms used for x-ray-based imaging modalities such as computed tomography (CT). They can also be used in fluoroscopy, angiography and venography, and even occasionally, plain radiography. Although the intravenous route of administr...
Article
Myocardial mapping
Myocardial mapping or parametric mapping of the heart is one of various magnetic resonance imaging techniques, which has evolved and been increasingly used in the last decade for non-invasive tissue characterization of the myocardium 1-5. Unlike normal T1-, T2- or T2*- images, parametric mapping...
Article
MRI sequences (overview)
An MRI sequence is a number of radiofrequency pulses and gradients that result in a set of images with a particular appearance. This article presents a simplified approach to recognizing common MRI sequences, but does not concern itself with the particulars of each sequence.
For a more complete...
Article
HRCT chest (protocol)
High-resolution CT (HRCT) of the chest, also referred to as HRCT chest or HRCT of the lungs, refers to a CT technique in which thin-slice chest images are obtained and post-processed in a high-spatial-frequency reconstruction algorithm. This technique obtains images with exquisite lung detail, w...
Article
Contrast-enhanced mammography
There are 2 types of contrast-enhanced mammography examination – temporal subtraction and dual-energy.
Initial work in the early 2000s used temporal subtraction, but artifacts due to patient movement during prolonged compression limited its diagnostic usefulness. Travieso et al produced a usef...
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
CT localizer radiograph
The CT localizer radiograph, also known as scanogram, scout and surview, is the name given to the initial images obtained at the start of a CT before the main volume is obtained. These initial images have two main functions: they ensure that the correct anatomy is being covered by the CT and per...
Article
Ultrasound probe defect
Ultrasound probe defects are hardware failures of the ultrasound transducer manifesting as various abnormalities of the scan image, in severe cases even causing complete signal loss. These are a form of ultrasound artifact.
Therefore, awareness of the various signs of equipment damage is crucia...
Article
Photoacoustic imaging
Photoacoustic or optoacoustic imaging (PAI) is an emerging imaging modality that utilizes a hybrid approach by using optical illumination of endogenous materials or administered fluorescent tracers, and consequent detection of the ultrasound waves released due to thermoelastic expansion.
Physi...
Article
Contrast-enhanced ultrasound
Contrast-enhanced ultrasound (CEUS) involves the administration of intravenous contrast agents consisting of microbubbles/nanobubbles of gas.
Uses
liver
hepatic metastasis
cystadenoma/cystadenocarcinoma
cholangiocarcinoma
hepatocellular carcinoma
hepatic adenoma
...
Article
Deep brain ultrasound therapy
Deep brain ultrasound (DBUS) therapy, also known as transcranial MR-guided focused ultrasound (MRgFUS), is a form of precision medicine using a technique based on the principle of high-intensity focused ultrasound (HIFU), also referred to as focused ultrasound surgery (FUS).
Technique
The meth...
Article
X-ray tube
An x-ray tube functions as a specific energy converter, receiving electrical energy and converting it into two other forms of energy: x-radiation (1%) and heat (99%). Heat is considered the undesirable product of this conversion process; therefore x-radiation is created by taking the energy from...
Article
Acoustic enhancement
Acoustic enhancement also called posterior enhancement or enhanced through transmission, refers to the increased echoes deep to structures that transmit sound exceptionally well.
This is characteristic of fluid-filled structures such as cysts, the urinary bladder and the gallbladder. The fluid ...
Article
MRI
MRI (an abbreviation of magnetic resonance imaging) is an imaging modality that uses non-ionizing radiation to create useful diagnostic images.
In simple terms, an MRI scanner consists of a large, powerful magnet in which the patient lies. A radio wave antenna is used to send signals to the bod...
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