Cardiac imaging
Encyclopedia
Cardiac imaging techniques include Coronary catheterization
, echocardiogram, and Intravascular ultrasound
.
uses pressure
monitoring and blood sampling through a catheter
inserted into the heart
through blood vessels in the leg to determine the functioning of the heart
, and, following injections of radiocontrast dye, uses X-ray fluoroscopy, typically at 30 frames per second, to visualize the position and size of blood within the heart
chambers and arteries
. Coronary angiography is used to determine the patency and configuration of the coronary artery lumen
s.
uses ultrasonic
waves for continuous heart
chamber and blood movement visualization. In recent times, it has become one of the most commonly used tools in diagnosis of heart problems, as it allows non-invasive visualization of the heart and the blood flow through the heart, using a technique known as Doppler.
Transoesophageal echocardiogram uses a specialized probe containing an ultrasound transducer at its tip is passed into the patient's esophagus. It is used in diagnosis of various thoracic defects or damage, i.e. heart and lung imaging. It has some advantages and disadvantages over thoracic or intravasular ultrasound.
, also known as a percutaneous echocardiogram is an imaging methodology using specially designed, long, thin, complex manufactured catheter
s attached to computerized ultrasound
equipment to visualize the lumen
and the interior wall of blood vessel
s.
, an imaging methodology for positron
emitting radioisotopes. PET enables visual image analysis of multiple different metabolic chemical processes and is thus one of the most flexible imaging technologies. Cardiology uses are growing very slowly due to technical and relative cost difficulties. Most uses are for research
, not clinical
purposes. Appropriate radioisotopes of elements within chemical compounds of the metabolic pathway being examined are used to make the location of the chemical compounds of interest visible in a PET scanner constructed image.
(CTA), an imaging methodology using a ring-shaped machine with an X-Ray
source spinning around the circular path so as to bathe the inner circle with a uniform and known X-Ray density. Cardiology uses are growing with the incredible developments in CT technology. Currently, multidetector CT, specially the 64 detector-CT are allowing to make cardiac studies in just a few seconds (less than 10 seconds, depending on the equipment and protocol used). These images are reconstructed using algorithms and software. Great development and growth will be seen in the short term, allowing radiologists to diagnose cardiac artery disease without anesthesia
and in a non-invasive way.
(originally called nuclear magnetic resonance imaging), an imaging methodology based on aligning the spin axis of nuclei within molecule
s of the object being visualized using both powerful superconducting magnet
s and radio frequency
signals and detectors. Cardiology
uses are growing, especially since MRI differentiates soft tissue
s better than CT and allows for comprehensive exams including the quantitative assessment of size, morphology functino and tissue characteristics in one single session. Current implementations for Cardiology
uses are sometimes limited by lengthy protocols, claustrophobia and contraindications based on some complex metallic implants (pacemakers, defibrillators, insulin pumps), while artificial valves and coronary stents are generally not problematic. Image quality can be reduced by the continuous movement of heart
structures. There is a promising future in cardiac MRI by more efficient scans, increasing availability of scanners and more widespread knowledge about its clinical application.
Coronary catheterization
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional purposes....
, echocardiogram, and Intravascular ultrasound
Intravascular ultrasound
Intravascular ultrasound is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment...
.
Coronary catheterization
Coronary catheterizationCoronary catheterization
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional purposes....
uses pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
monitoring and blood sampling through a catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
inserted into the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
through blood vessels in the leg to determine the functioning of the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
, and, following injections of radiocontrast dye, uses X-ray fluoroscopy, typically at 30 frames per second, to visualize the position and size of blood within the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
chambers and arteries
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
. Coronary angiography is used to determine the patency and configuration of the coronary artery lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
s.
Echocardiogram
Transthoracic echocardiogramTransthoracic echocardiogram
A standard echocardiogram is also known as a transthoracic echocardiogram , or cardiac ultrasound. In this case, the echocardiography transducer is placed on the chest wall of the subject, and images are taken through the chest wall. This is a non-invasive, highly accurate and quick assessment...
uses ultrasonic
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
waves for continuous heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
chamber and blood movement visualization. In recent times, it has become one of the most commonly used tools in diagnosis of heart problems, as it allows non-invasive visualization of the heart and the blood flow through the heart, using a technique known as Doppler.
Transoesophageal echocardiogram uses a specialized probe containing an ultrasound transducer at its tip is passed into the patient's esophagus. It is used in diagnosis of various thoracic defects or damage, i.e. heart and lung imaging. It has some advantages and disadvantages over thoracic or intravasular ultrasound.
Intravascular ultrasound
Intravascular ultrasoundIntravascular ultrasound
Intravascular ultrasound is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment...
, also known as a percutaneous echocardiogram is an imaging methodology using specially designed, long, thin, complex manufactured catheter
Catheter
In medicine, a catheter is a tube that can be inserted into a body cavity, duct, or vessel. Catheters thereby allow drainage, administration of fluids or gases, or access by surgical instruments. The process of inserting a catheter is catheterization...
s attached to computerized ultrasound
Ultrasound
Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Ultrasound is thus not separated from "normal" sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it is...
equipment to visualize the lumen
Lumen (anatomy)
A lumen in biology is the inside space of a tubular structure, such as an artery or intestine...
and the interior wall of blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s.
Positron emission tomography
Positron emission tomographyPositron emission tomography
Positron emission tomography is nuclear medicine imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide , which is introduced into the body on a...
, an imaging methodology for positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
emitting radioisotopes. PET enables visual image analysis of multiple different metabolic chemical processes and is thus one of the most flexible imaging technologies. Cardiology uses are growing very slowly due to technical and relative cost difficulties. Most uses are for research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...
, not clinical
Physical examination
Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
purposes. Appropriate radioisotopes of elements within chemical compounds of the metabolic pathway being examined are used to make the location of the chemical compounds of interest visible in a PET scanner constructed image.
Computed tomography angiography
Computed tomography angiographyComputed tomography
X-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
(CTA), an imaging methodology using a ring-shaped machine with an X-Ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
source spinning around the circular path so as to bathe the inner circle with a uniform and known X-Ray density. Cardiology uses are growing with the incredible developments in CT technology. Currently, multidetector CT, specially the 64 detector-CT are allowing to make cardiac studies in just a few seconds (less than 10 seconds, depending on the equipment and protocol used). These images are reconstructed using algorithms and software. Great development and growth will be seen in the short term, allowing radiologists to diagnose cardiac artery disease without anesthesia
Anesthesia
Anesthesia, or anaesthesia , traditionally meant the condition of having sensation blocked or temporarily taken away...
and in a non-invasive way.
Magnetic resonance imaging
Magnetic resonance imagingMagnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
(originally called nuclear magnetic resonance imaging), an imaging methodology based on aligning the spin axis of nuclei within molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s of the object being visualized using both powerful superconducting magnet
Superconducting magnet
A superconducting magnet is an electromagnet made from coils of superconducting wire. They must be cooled to cryogenic temperatures during operation. In its superconducting state the wire can conduct much larger electric currents than ordinary wire, creating intense magnetic fields...
s and radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
signals and detectors. Cardiology
Cardiology
Cardiology is a medical specialty dealing with disorders of the heart . The field includes diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology...
uses are growing, especially since MRI differentiates soft tissue
Soft tissue
In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...
s better than CT and allows for comprehensive exams including the quantitative assessment of size, morphology functino and tissue characteristics in one single session. Current implementations for Cardiology
Cardiology
Cardiology is a medical specialty dealing with disorders of the heart . The field includes diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease and electrophysiology...
uses are sometimes limited by lengthy protocols, claustrophobia and contraindications based on some complex metallic implants (pacemakers, defibrillators, insulin pumps), while artificial valves and coronary stents are generally not problematic. Image quality can be reduced by the continuous movement of heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
structures. There is a promising future in cardiac MRI by more efficient scans, increasing availability of scanners and more widespread knowledge about its clinical application.