Articles
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24 results found
Article
Enteric contrast medium (CT)
Enteric contrast media can be given to patients before their CT exam to improve its diagnostic accuracy. Historically, a combination of oral and intravenous contrast media were always given prior to a CT abdomen. Contemporaneously, improved CT scanners mean that oral contrast agents are no longe...
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
Octreotide scintigraphy
Octreotide scintigraphy uses 111In-labeled octreotide, which is a somatostatin analog; it is also known as Octreoscan, a brand name for 111In-labeled pentetreotide. Pentetreotide is a DTPA-conjugated form of octreotide, originally manufactured by Mallinckrodt Nuclear Medicine LLC, which now form...
Article
SeHCAT
SeHCAT™ (23-seleno-25-homo-tauro-cholic acid or tauroselcholic acid) is a radiopharmaceutical used in the investigation of bile salt malabsorption, which is a cause of chronic diarrhea.
Characteristics
physical half-life: 118 days
Uses, dosage and timings
A capsule containing SeHCAT is inge...
Article
CT gastrointenstinal bleed (protocol)
A CT gastro-intestinal bleed protocol utilizes a multiphasic technique to detect active gastrointestinal bleeding (as well as other potential non-bleeding bowel disease 1.
Note: This article is a general guideline for evaluating CT gastrointestinal bleeds. Protocol factors are variable as they...
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
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
MR enterography
MR enterography (MRE), also known as MRI small bowel study, is a non-invasive technique for the diagnosis of small bowel disorders.
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
Chronic appendicitis
Chronic appendicitis (rare plural: appendicitides) is defined by inflammation of the appendix over time with symptoms lasting for more than three weeks duration (cf. acute appendicitis) 1. The condition should be differentiated from recurrent appendicitis, in which one or more episodes of flares...
Article
Chemical shift artifact
Chemical shift artifact or misregistration is a type of MRI artifact. It is a common finding on some MRI sequences and used in magnetic resonance spectroscopy (MRS). This artifact occurs in the frequency-encoding direction and is due to spatial misregistration of fat and water molecules.
Chemi...
Article
Twinkling artifact
Twinkling artifact is seen with color flow Doppler ultrasound 1. It occurs as a focus of alternating colors on Doppler signal behind a reflective object (such as a calculus or air), which gives the appearance of turbulent blood flow 2. It appears with or without an associated color comet tail ar...
Article
Indium-111 OncoScint
Indium-111 OncoScint is a radiopharmaceutical used in SPECT imaging. It is a labeled monoclonal antibody that is directed against TAG-72, which is a tumor-associated antigen associated with ~95% of colorectal carcinomas and 100% of ovarian carcinomas 1,2. Background hepatic uptake limits sensiti...
Article
Timed barium esophagogram
The timed barium esophagogram (TBO) is a simple physiologic assessment and objective method for assessing the esophageal emptying used in patients with suspected achalasia and to evaluate and follow up patients who have been treated with myotomy or pneumatic dilatation1,3.
Technique
Several te...
Article
CT enteroclysis (protocol)
Computed tomographic (CT) enteroclysis refers to a hybrid technique that combines the methods of fluoroscopic intubation-infusion small bowel examinations with that of abdominal CT.
Indications
CT enteroclysis is complementary to capsule endoscopy in the elective investigation of small-bowel d...
Article
Portosystemic shunt ratio
The portosystemic shunt ratio is a measure performed using ultrasound to quantify the abnormal flow of portal venous blood that is shunted away from the hepatic sinusoidal circulation in the context of a congenital portosystemic shunt 1.
Measurement
The ratio is determined on ultrasound using ...
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
Scintigraphy performed with Tc-99m labeled RBCs
Tc-99m labeled RBCs - with radiolabelling technique in vivo or in vitro of red cells 3 - is one of the technetium radiopharmaceuticals used in the non-invasive assessment of gastrointestinal (GI) bleeding 2, characterized by high sensitivity (93%) and specificity (95%) 4. It is capable, in fact,...
Article
CT colonography (protocol)
Computed tomographic (CT) colonography, also called CTC, virtual colonoscopy (VC) or CT pneumocolon, is a powerful minimally invasive technique for colorectal cancer screening.
Indications
screening test for colorectal carcinoma
colon evaluation after incomplete or unsuccessful optical (conv...
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