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.
23 results found
Article
CT chest abdomen-pelvis (protocol)
The CT chest-abdomen-pelvis protocol serves as an outline for an examination of the trunk covering the chest, abdomen and pelvis. It is one of the most common CT examinations conducted in routine and emergencies. It can be combined with a CT angiogram.
Note: This article aims to frame a genera...
Article
Vicarious contrast media excretion
Vicarious contrast media excretion (VCME) refers to the excretion of intravascularly-administered water-soluble iodinated contrast media in a way other than via normal renal excretion. More rarely it may occur following oral contrast medium administration 6.
Epidemiology
The most common vicari...
Article
Gallbladder ultrasound
Gallbladder ultrasound is a non-invasive diagnostic imaging technique used to evaluate the structure and function of the gallbladder as well as the adjacent anatomy.
Preparation
Patients are typically advised to fast for 6-8 hours prior to the ultrasound examination. This allows the gallbladde...
Article
Liver protocol (MRI)
Examination of the liver with MRI requires numerous sequences and imaging at multiple times after the administration of contrast.
Note: This article is intended to outline some general principles of protocol design. The specifics will vary depending on MRI hardware and software, radiologist's...
Article
MR liver iron quantification
MR liver iron quantification is a non-invasive means of measuring liver iron concentration, a key indicator in the management of patients with hemochromatosis (primary or secondary).
Advantages
Apart from being non-invasive, sampling occurs in a large cross-section of the liver, as opposed to ...
Article
Liver ultrasound
Liver ultrasound is a valuable diagnostic tool for assessing liver anatomy, size, and pathology. It is a non-invasive, painless, and relatively quick procedure that does not involve exposure to ionizing radiation.
Indications
Liver ultrasound is commonly utilized in the evaluation of various h...
Article
Tc-99m sulfur colloid
Technetium-99m sulfur colloid is one of the technetium radiopharmaceuticals.
Characteristics
photon energy: 140 keV
physical half-life: 6 hours
biological half-life: 2 to 3 minutes
normal distribution:
liver: 85%
spleen: 10%
bone marrow: 5%
excretion: hepatic
target organ: liver, splee...
Article
Thorotrast
Thorotrast was the trade name of a radioactive thorium dioxide suspension radiographic contrast media widely used between the 1930s and 1940s. It was popular for its use as an intravascular contrast agent, particularly for cerebral angiography. An estimated 2-10 million people are thought to hav...
Article
Spectral Doppler (ultrasound)
Utilizing automated Fourier analysis to convert returning sound waves into a series of individual frequencies, spectral Doppler refers to ultrasound modalities which yield graphical representations of flow velocity over time.
Terminology
The frequency of the sound waves returned to an ultraso...
Article
Pulsatile portal venous flow
A pulsatile portal venous flow pattern is an abnormal form of portal venous flow and can result from both physiological and pathological causes.
In well subjects, mild to marked pulsatility has been described. This is especially so in thin subjects, with a venous pulsatility index of >0.5, inve...
Article
Transient arterial phase respiratory motion-related artifact
Transient arterial phase respiratory motion-related artifact refers to common self-limited dyspnea observed immediately after administering gadoxetate disodium during liver MRI studies. Awareness about this potential artefact when choosing this hepatospecific contrast agent (Primovist/Eovist) is...
Article
Comet tail artifact
The comet tail artifact is a grey scale ultrasound finding seen when small calcific / crystalline / highly reflective objects are interrogated and is believed to be a special form of reverberation artifact.
It is similar to the color comet tail artifact and is seen in similar situations, althou...
Article
SPACE (MRI sequence)
The SPACE MRI sequence, is a spin echo type MRI sequence, which creates high spatial resolution three-dimensional datasets. SPACE is an abbreviation for Sampling Perfection with Application optimized Contrast using different flip angle Evolution. The sequence was developed by Siemens.
The SPACE...
Article
CT pancreas (protocol)
The CT pancreas protocol serves as an outline for a dedicated examination of the pancreas. As a separate examination, it is usually conducted as a biphasic contrast study and might be conducted as a part of other scans such as CT abdomen-pelvis, CT chest-abdomen-pelvis.
Note: This article aims...
Article
CT abdomen-pelvis (protocol)
The CT abdomen-pelvis protocol serves as an outline for an examination of the whole abdomen including the pelvis. It is one of the most common CT protocols for any clinical questions related to the abdomen and/or in routine and emergencies. It forms also an integral part of trauma and oncologic ...
Article
Contrast-enhanced ultrasound
Contrast-enhanced ultrasound (CEUS) involves the administration of intravenous contrast agents consisting of microbubbles/nanobubbles of gas.
Clinical applications
liver
hepatic metastasis
cystadenoma/cystadenocarcinoma
cholangiocarcinoma
hepatocellular carcinoma
hepatic adenoma
focal no...
Article
Fat suppressed imaging
Fat suppression is commonly used in magnetic resonance imaging (MRI) imaging to suppress the signal from adipose tissue or detect adipose tissue 1. It can be applied to both T1 and T2 weighted sequences.
Due to short relaxation times, fat has a high signal on MRI. This high, easily recognized ...
Article
CT liver volumetry (protocol)
CT liver volumetry is an essential imaging study in preoperative assessment for living donor liver transplantation.
NB: This article is intended to outline some general principles of protocol design. The specifics will vary depending on CT hardware and software, radiologists' and referrers' pre...
Article
Meglumine iotroxate (Biliscopin)
Meglumine iotroxate (BiliscopinTM) is an iodinated, intravenous contrast agent that is preferentially excreted into the biliary tree and is used in CT intravenous cholangiography.
The typical dose is 100 mL Biliscopin (105 mg meglumine iotroxate/mL; 5.0 g iodine), which is administered via slow...
Article
MR elastography
MR elastography (MRE) is an MRI technique that can be used to assess liver stiffness. This is useful not only to detect the development of fibrosis in diffuse liver disease but also to quantify it and monitor liver fibrosis change with (or without) therapy.
The main advantage over ultrasound el...
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