How does echo planar imaging work?
Echo planar imaging (EPI) is performed using a pulse sequence in which multiple echoes of different phase steps are acquired using rephasing gradients instead of repeated 180-degree radiofrequency pulses following the 90°/180° in a spin echo sequence.
What does planar imaging mean?
Planar imaging is the acquisition of 2D nuclear images, similar to plain films in x-ray imaging.
What is echo in imaging?
An echocardiogram (echo) is an ultrasound test that images the moving heart. A cardiac sonographer will move a hand-held device called a transducer over the chest area. High-frequency sound waves are sent to the heart and transmitted back to the ultrasound machine as live moving images.
How fast is echo planar imaging?
Echo-planar imaging is a fast magnetic resonance (MR) imaging tech- nique that allows acquisition of single images in as little as 20 msec and performance of multiple-image studies in as little as 20 seconds.
What is echo planar imaging in fMRI?
Abstract. Echo-planar imaging is a very fast magnetic resonance (MR) imaging technique capable of acquiring an entire MR image in only a fraction of a second. In single-shot echo-planar imaging, all the spatial-encoding data of an image can be obtained after a single radio-frequency excitation.
What is the difference between SPECT and Planar?
Overall, SPECT imaging yielded a higher sensitivity (93% vs 82% for SPECT and planar imaging respectively, p < 0.05), especially in the inferior and anterior regions. SPECT was also more sensitive for the detection of a single-vessel disease (90% vs 74% for SPECT and planar imaging respectively, p < 0.01).
How does a SPECT scan work?
SPECT scans use radioactive material called tracers. The tracers mix with your blood and are taken up by living heart muscle. A special “gamma” camera picks up signals from the tracer as it moves around your chest. The tracer’s signals are converted into images by a computer.
What do echo results mean?
An echocardiogram checks how your heart’s chambers and valves are pumping blood through your heart. An echocardiogram uses electrodes to check your heart rhythm and ultrasound technology to see how blood moves through your heart. An echocardiogram can help your doctor diagnose heart conditions.
What does an echocardiogram do?
An echocardiogram is a noninvasive (the skin is not pierced) procedure used to assess the heart’s function and structures. During the procedure, a transducer (like a microphone) sends out sound waves at a frequency too high to be heard.
HOW IS MR spectroscopy performed?
MR spectroscopy is conducted on the same machine as conventional MRI. The MRI scan uses a powerful magnet, radio waves, and a computer to create detailed images. Spectroscopy is a series of tests that are added to the MRI scan of your brain or spine to measure the chemical metabolism of a suspected tumor.
What is diffusion tensor imaging used for?
Diffusion tensor imaging tractography, or DTI tractography, is an MRI (magnetic resonance imaging) technique that measures the rate of water diffusion between cells to understand and create a map of the body’s internal structures; it is most commonly used to provide imaging of the brain.
What is echo planar imaging?
Pulse Sequences Echo-planar imaging (EPI) is a fast-imaging technique whereby a two-dimensional (2-D) image can be obtained in less than a second, by quickly switching the magnetic gradients back and forth after a single excitation pulse.
What is phase-encoding in echo planar imaging?
phase-encoding is along the vertical. As originally defined, echo planar imaging referred to a sequence in which data from all of k -space for an entire 2D plane was collected following a single RF-excitation pulse.
What is electecho-planar imaging?
Echo-planar imaging (EPI) is a fast-imaging technique whereby a two-dimensional (2-D) image can be obtained in less than a second, by quickly switching the magnetic gradients back and forth after a single excitation pulse.
What is echo-planar imaging (EPI)?
Generically, this acquisition mode is known as echo-planar imaging (EPI) . Although EPI may seem like a recent development, the technique is among the oldest methods of spatial localization in MRI, first described by Mansfield in 1977.