Published November 1st by Wiley-Blackwell first published June 15th More Details Original Title. Other Editions Friend Reviews. To see what your friends thought of this book, please sign up. To ask other readers questions about MRI at a Glance , please sign up. Lists with This Book. This book is not yet featured on Listopia. Community Reviews. Showing Rating details. All Languages. More filters. Sort order. Reyhaneh Alimohammadi rated it it was amazing Nov 14, Siva Kumar rated it really liked it Feb 06, Aine McGovern rated it it was amazing Dec 28, Nuria rated it really liked it May 02, Armin rated it it was amazing Mar 13, Osama Assari rated it really liked it Feb 18, Jovany Agathe rated it liked it Mar 08, Shehab Salem rated it it was amazing Dec 25, John Barnes rated it it was ok Aug 02, M Tahlak rated it liked it Jul 29, Alberto Rivera marked it as to-read Apr 12, Toryn Green added it Oct 21, Minoo marked it as to-read Dec 30, Abhijit Debnath marked it as to-read Jan 06, Reshard JuQuin Alexander marked it as to-read Jan 02, Thuzar Myint marked it as to-read Dec 15, Jeet Ghosh marked it as to-read Mar 09, Definition high signal intensity- bright.
Term hypointense. Definition low signal intensity- dark. Term Hydrogen. Definition the most abundant atom in the body. Definition International society for MR in medicine. Definition Institute for MR safety, education and research. Term Incoherent. Definition the magnetic moments of hydrogen are at different places on the precessional path- out of phase. Term Incoherent gradient echoe. Definition gradient echo sequence that uses RF spoiling for T1 weighting. Term Induced electric current. Definition oscillating current that occurs when a magnet is moved in a closed circuit.
Term Inflow effect. Definition another term for entry slice phenomenon. Term Inhomogeneities. Definition areas where the magnetic field strength is not exactly the same as the main field strength- magnetic field unevenness. Term In phase. Definition magnetic moments that are in the same place on the precessional path around Bo at any given time.
Term Interleaving. Definition a method of acquiring data from alternate slices and dividing the sequence into two acquisitions- no slice gap is required. Term Intra-voxel dephasing. Definition phase difference between flow and stationary nuclei in a voxel. Term Intrinsic contrast parameters. Definition those parameters that cannot be changed because they are inherent to the body tissues.
Term Inversion recovery IR. Definition sequence that uses an inverting pulse to saturate or null tissue. Term Ions. Definition atoms with an excess or deficit of electrons.
Term Isointense. Definition same signal intensity. Term Isotopes. Definition atoms of the same element with an odd mass number. Term Isotropic. Definition voxels that have the same dimension in all three planes. Term J coupling. Definition a process that describes the reduction the spin spin interactions cause in fat, caused by multiple RF pulses as in fast spin echo, thereby increasing its T2 decay time.
Term Kilogauss kG. Definition unit of field strength gauss. Term K space. Definition an area in the array processor where data on spatial frequencies are stored. Term Larmor equation. Definition used to caculate the frequency or speed of precession for a specific nucleus in a specific magnetic field strength.
Term Longitudinal plane. Definition the axis parallel to Bo. Term Lenz's law. Definition states that induced emf is in a direction so that it opposes the change in magnetic field that causes it. Term Magnetic field gradient. Definition field created by passing current through a gradient coil. Term Magnetic flux density. Definition number of flux lines per unit area. Term Magneto-hemodynamic effect. Definition effect that causes elevation of the T wave of the ECG of the patient when placed in a magnetic field.
Term Magnetic Isocentre. Definition the centre of the bore of the magnet in all plances.
Term Magnetic lines of flux. Definition lines of force running from the magnetic south to the north poles of the magnet. Term Magnetic moment. Term Magnetic susceptibility. Definition ability of a substance to become magnetized. Definition technique used to suppress background tissue and increase CNR.
Term Magnetism. Definition a property of all matter that depends on the magnetic susceptibility of the atom. Term Magnetization prepared. Definition a prepulse applied before the main sequence to null the signal from certain tissues in fast gradient echo. Term Magnetization transfer. Definition transfer of RF energy from free to bound protons. Term Magnitude image. Definition un-subtracted image combination of flow sensitized data.
Term Mass number. Definition sum of neutrons and protons in the nucleus. Term Maximum intensity projection MIP. Definition technique that uses a ray passed through an imaging volume to assign signal intensity according to their proximity to the observer. Term Mean transit time MTT. Definition used in perfusion imaging to indicate the transit time of blood through a tissue. Term Molecules. Definition where two or more atoms are arranged together.
Term MR active nuclei. Definition nuclei that possess an odd number of protons. Definition method of visualizing vessels that contain flowing nuclei by producing a contrast between them and the stationary nuclei. Term MR signal. Definition the voltage induced in the receiver coil. Definition method combining a number of high resolution 3D acquisitions to produce an image that has good resolution and a large area of coverage.
Term Multishot MS. Definition technique that fills K space in multiple sections. K space is divided into segments and one segment is acquired per TR. Term Multi voxel. Definition technique that acquires multiple voxels by encoding in K space in MR signal. Definition the magnetic vector produced as a result of the alignment of excess hydrogen nuclei with Bo. Term Neutron. Definition particles in the nucleus that have no charge. Definition number of excitations, the number of times an echo is encoded with the same slope of phas encoding gradient.
Term Noise. Definition frequencies that exist randomly in time and space. Term Nucleons. Definition particles in the nucleus. Term Null point. Definition the point at which there is no longitudinal magnetization in a tissue in an inversion recovery sequence. Term Nyquist theorem. Definition states that frequencies must be sampled at a rate at least twice that of the highest frequency in the echo in order to reliably reproduce it.
Term Ohm's law. Term Off resonant. Definition RF pulses applied at a frequency slightly different to the larmor frequency of a tissue. Term On resonant. Definition RF pulses applied at the larmor frequency of a particular tissue. Term Outer lines. Definition area of K space filled with the steepest phase encoding gradient slopes. Term Out of phase. Definition when magnetic moments are not in the same place on the precessional path. Term Out of phase artefact. Definition artefact along the phase axis caused by the phase difference between fat and water.
Term Parallel alignment. Definition describes the alignment of magnetic moments in the same direction as the main field. Term Parallel imaging. Definition a technique that uses multiple coils to fill segments of K space. Term Paramagnetism. Definition property whereby substances affect external magnetic fields in a positive way, resulting in a local increase in the magnetic field.
Term Partial averaging. Definition filling only a proportion of K space with data and putting zeros in the remainder. Term Partial echo imaging. Definition sampling only part of the echo and extrapolating the remainder in K space. Term Partially saturated.
Definition occurs when the NMV is flipped beyond 90 degrees degrees. Term Partial voluming. Definition loss of spatial resolution when large voxels are used. Term Passive shielding. Definition shielding accomplished by surrounding the magnet with steel plates. Term Perfusion. Definition a measure of the quality of vascular supply to a tissue.
Term Passive shimming. Term Pathology weighting. Definition achieved in IR pulse sequence with a long TE, pathology appears bright even though the image is T1 weighted. Term Periodicity. Definition the time interval between the magnetic moments of fat and water being in phase. Term Permanent magnets. Definition magnets that retain their magnetism. Term Phase. Definition the position of a magnetic moment on its precessional path at any given time. Definition technique that generates vascular contrast by applying a bipolar gradient using the phase difference between stationary and flowing spins.
Term Phase curve. Definition a waveform derived from plotting different phase postions over a distance in the patient.
Term Phase encoding. Definition locating a signal according to its phase. Term Phase image. Definition Subtracted image combination of flow sensitized data.
Term Phase wrap. Definition aliasing along the phase encoding axis. Term Phase matrix. Definition number of pixels in the phase direction of an image. Term Phase reordering. Definition the order that lines of K space are filled is altered from linear to non linear. Term Phase shift. Definition difference in phase between spins located along a gradient. Term Pixel. Definition picture element in the FOV.
Term Polarity. Definition single voxel technique in MRS. Term Precession. Definition the secondary spin of the magnetic moments around Bo. Term Precessional Larmor frequency. Definition The speed of precession; frequency with which MR active nuclei precess when exposed to an external magnetic field. Term Precessional path. Definition the circular pathway of magnetic moments as they precess around Bo. Term Presaturation. Definition technique that uses RF pulses before the sequence to null the signal from moving spins or from certain types of tissue.
Term Protium. Definition isotope of hydrogen that has a mass and atomic number of 1, MR active nucleus used in MRI. Term Proton Density. Definition number of protons per unit volume of that tissue. Term Proton density weighting. Definition image that demonstrates the differences in the proton densities of the tissues. Term Proton. Definition positively charged element of an atomic nucleus.
Term Pseudo-frequency. Definition the frequency that is indirectly derived from a change of phase. Term Pulse control unit. Definition coordinates the switching on and off of the gradient and RF transmitter coils at appropriate times during the pulse sequence. Term Pulse sequence. Definition a series of RF pulses, gradient applications and intervening time periods, used to control contrast.
Term Quantum theory. Definition uses the energy level of the nuclei to illustrate alignment. Term Quenching. Definition process by which there is a sudden loss of the superconductivity of the magnet coils so that the magnet becomes resistive. Definition the units of K space. Term Radiowaves. Definition waves of electromagnetic radiation that oscillate with a radiofrequency. Term Radioactivity. Definition emission of energy caused by a deficit in the number of electrons compared with protons.
Term Radio Frequency RF. Definition low energy, low frequency electromagnetic radiation. Used to excite hydrogen nuclei in MRI.
Term Ramp Sampling. Definition where sampling data points are collected when the gradient rise time is almost complete-sampling occurs while the gradient is still reaching max amplitude, while the gradient is at max amplitude and as it begins to decline. Term Readout gradient. Definition the frequency encoding gradient. Term Receive bandwith. Definition range of frequencies that are sampled during readout- determines sampling rate.
Term Recovery. Definition growth of longitudinal magnetisation. Term Rectangular FOV. Term Relaxation. Definition process by which the NMV loses energy. Term Relaxitivity. Definition process by which relaxation rates of a tissue are altered by administering contrast agents. Term Reduction factor.
Definition the factor by which the scan time is reduced using parallel imaging. Equals the number of coils used. Term Repetition Time TR. Definition time between each excitation pulse. Term Rephasing. Definition creating in phase magnetization, usually by using and RF pulse or a gradient.
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Term Residual transverse magnetization. Definition transverse magnetization left over from previous RF pulses in steady state conditions. Term Resistive magnet. Definition another term for solenoid magnet, an electromagnet created by passing current through loops of wire. Term Resonance. Definition an energy transition that occurs when an object is subjected to a frequency the same as its own. Term Respiratory Compensation. Definition uses mechanical motion of air in bellows to order K space filling and reduce respiratory motion.
Definition scan initiated when the patient is not breathing. Term Rewinding. Definition the use of a gradient to rephase magnetic moments. Term RF amplifier. Definition supplies power to the RF transmitter coil. Term RF pulse. Definition short burst of RF energy that excites nuclei into a high energy state. Term RF spoiling. Definition the use of digitized RF to transmit and receive at a certain phase. Term RF transmitter coil. Definition coil that transmits RF at the resonant frequency of hydrogen to excite nuclei and move them into a high energy state.
Term Rise time. Definition the time it takes a gradient to switch on, achieve the required gradient slope and switch off again. Term R to R interval. Definition time between each R wave in gated studies. Term Rotating time frame of reference. Definition where you, the observer, ride along with the object that is moving.
Term Sampling rate or frequency. Definition rate at which samples are taken during readout. Term Sampling time. Definition the time for which the readout gradient is switched on. Term SAR. Definition Standardized absorbtion rate a way of measuring the usa food and drug admin limit for RF exposure.
Specific Absorption Rate. Definition time between each pre-sat pulse. Term Saturation. Definition occurs when the NMV is flipped to a full degrees. Term Sequential Acquisition. Definition acq where all the data from each slice is acquired before going on to the next. Term Shim coil. Definition extra coils used to make the magnetic field as homogeneous as possible.
Term Shimming. Definition process whereby the evenness of the magnetic field is optimized. Term Signal. Definition voltage induced in the receiver coil. Definition ratio of signal relative to noise. Definition a fast spin echo sequence where all the lines of K space are acquired during a single TR period. Term Single voxel. Definition techniques that use three intersecting slices to locate a single voxel in MR. Term Slew rate. Definition function of gradient rise time and amplitude, the strength of a gradient over distance. Term Slice encoding. Definition the separation of individual slice locations b phase in volume acquisitions.
Term Slice selection. Definition selecting a slice using a gradient. Term Spatial encoding.
Definition spatially locating a signal in three dimensions. Definition creates a saturation effect which produces a cross hatching of stripes on the image. Term Spatial resolution. Definition the ability to distinguish two points as separate. Term Spectroscopy. Definition provides a frequency spectrum of a given tissue based on the molecular and chemical structures of that tissue.
Term Spin down. Definition the population of high energy hydrogen nuclei that align their magnetic moments anti parallel to the main field Bo. Term Spin Echo SE. Definition echo produced as a result of a degree rephasing pulse. Term Spin lattice relaxation. Definition process by which energy is given up to the surrounding lattice. Term Spin spin relaxation. Definition process by which interactions between the magnetic fields of adjacent nuclei causes dephasing. Term Spin up. Definition the population of low energy hydrogen nuclei that align their magnetic moments parallel to Bo.
Signal to noise ratio. Resonance and signal generation. Customers who bought this item also bought. Illustrated in full colour throughout, its concise text explains complex information, to provide the perfect revision aid. All topics are included from magnetism to safety, K space to pulse sequences, image contrast to artefacts.
Definition a process of dephasing spins either with a gradient or RF pulse. Term Steady state.