MRI From A to Z: A Definitive Guide for Medical Professionals

More documents

Recommendations

Info

Ff■ FADEThe fast acquisition with dual echo sequence. Picker sequencesimilar to DESS.■ FAIRType of arterial spin labelling (ASL) sequence known asflow-sensitive alternating inversion recovery. A non-selectiveinversion pulse excites the whole volume and an image slice isrecorded. Subsequently, a selective inversion is performed onthe imaging slice only.■ Fall timeOpposite of the rise time of a gradient waveform.■ Faraday cageThe copper lining within the walls of the scan room to preventextraneous radio-frequency sources from entering thescanner, the result of which is RF artefacts. The scan roomdoor must be closed to maintain the integrity of the cage andusually the scanner notifies the user if the door is left openprior to scanning. See Figure 25.■ Faraday’s LawAn emf (electromotive force or voltage) is induced in aconductor when surrounded by a changing magnetic field.This is the basis of the eddy currents caused by the action of theF 69
gradient coils. The emf (ε)isproportional to the rate of changeof the magnetic field/flux (φ):ε =− ∂ϕ∂tThe negative sign is due to Lenz’s law.■ FASTFourier acquired steady state.■ Fast fourier transformThe computer implementation of a fourier transformation.■ Fast recovery FSEGE driven equilibrium sequence.■ Fast spin echoSee FSE.■ FatSecond most dominant contribution to proton MR signal. Thefat peak is made up of different lipid resonances, which mayneed suppressing to obtain MR spectra in certain areas of thebody (e.g. brain/scalp, breast). At 1.5 tesla the fat resonance is220 Hz from water.See also chemical shift artefact.■ Fat suppressionReferring to one of the many methods of reducing thecontribution of the fat signal in the image. Commontechniques include CHESS, STIR, Dixon and SPIR.70 F
Page 4 and 5:
MRIfrom AtoZADefinitive Guide forMe
Page 8:
ContentsPrefacepage ixMain glossary
Page 12:
Main glossary
Page 15 and 16:
where [w] isthe concentration of wa
Page 17 and 18:
■ Active shieldingRefers to eithe
Page 19 and 20:
■ Agarose gelCommon material used
Page 21 and 22:
■ AngiogenesisPhenomenon typical
Page 23 and 24:
■ ArtefactReferring to any undesi
Page 25 and 26:
SSRLAPIIARLPFigure 2. Images of the
Page 28 and 29: Bb■ b-factorTerm relating to the
Page 30 and 31: ■ B 1 domingInhomogeneity observe
Page 32 and 33: ■ Binomial pulseType of composite
Page 34 and 35: can be represented by the correlati
Page 36 and 37: ■ BlurringThe effect of reduced s
Page 38 and 39: ■ Bolus timingThe synchronisation
Page 40 and 41: ■ BPHBenign prostatic hyperplasia
Page 42 and 43: Cc■ Cable lossCorrection factor u
Page 44 and 45: ■ Centre frequencyThe frequency t
Page 46 and 47: Figure 3. An egg gives a clear demo
Page 48 and 49: of cell turnover, and its elevation
Page 50 and 51: ■ Composite pulsesSee binomial pu
Page 52 and 53: Figure 4. Example of contrast enhan
Page 54 and 55: dope water in phantoms. The T 1 and
Page 56 and 57: ■ Cross-excitationRefers to the e
Page 58: ■ CSFCerebrospinal fluid.■ CSIC
Page 61 and 62: ■ Dead timeThe period following t
Page 63 and 64: Modern high-resolution MRI is being
Page 65 and 66: possible to examine restricted diff
Page 67 and 68: ■ DopingThe use of a chemical age
Page 69 and 70: 1 ppm for 40 cm DSV. For open magne
Page 71 and 72: ■ DWIDiffusion weighted imaging.
Page 73 and 74: ■ Echo planar (imaging)See EPI.
Page 75 and 76: third dimension or ‘slice’ dire
Page 77 and 78: ■ Eurospin test objectsCommonly u
Page 82 and 83: Figure 6. Breast images acquired in
Page 84 and 85: Typically, accounts for 5-10 G loss
Page 86 and 87: ■ FLAIRFluid attenuated inversion
Page 88 and 89: Reynolds number. In-flow enhancemen
Page 90 and 91: ■ Fourier transformMathematical a
Page 92 and 93: ound protons (there are also interm
Page 94: When applied to the brain, fMRI spe
Page 97 and 98: ■ GaussUnit of magnetic field, wh
Page 99 and 100: Figure 9. Motion of this test objec
Page 101 and 102: ■ GradientA (linear) change in ma
Page 103 and 104: ■ GRASSGradient recalled acquisit
Page 105 and 106: Figure 12. Halo artefact seen here
Page 107 and 108: Figure 13. Herringbone artefact dem
Page 109 and 110: ■ High pass filteringRemoving low
Page 111 and 112: ■ HypoxiaCellular oxygen deficien
Page 113 and 114: ■ Imaging, 3-DVolume image acquis
Page 115 and 116: ■ Infusion pumpsA device for the
Page 117 and 118: ■ Inverse imageDisplaying the ima
Page 120: Jj■ J-couplingThe phenomenon of s
Page 123 and 124: The order in which k-space is fille
Page 125 and 126: plasma and the extracellular extrav
Page 127 and 128: zM 0yxB 0z = z′y′x′Figure 16.
Page 129 and 130:
■ LinewidthA measure of the spect
Page 131 and 132:
direction of the motion of the cond
Page 133 and 134:
pro-drug in-active drug when admini
Page 135 and 136:
■ Magnetisation transferUse ofoff
Page 137 and 138:
more variable (e.g. 512, 256, 128,
Page 139 and 140:
■ MIPMaximum Intensity Projection
Page 141 and 142:
non-projectile). It may still cause
Page 143 and 144:
east lesion detection. May be used
Page 145 and 146:
increase or decrease temperature in
Page 147 and 148:
Figure 18. Example of multi-voxel M
Page 150 and 151:
Nn■ NAAN-acetyl aspartate. Metabo
Page 152 and 153:
■ NickelCommon relaxation (doping
Page 154:
at 1.5 tesla is approximately 200 m
Page 157 and 158:
■ OOPSOut ofphase scanning. Delib
Page 159 and 160:
oxygen exhibits a weak paramagnetic
Page 161 and 162:
where g is a coil specific geometry
Page 163 and 164:
■ Partial saturationOperating wit
Page 165 and 166:
to show opposite changes to the num
Page 167 and 168:
pulse rate. Changes in blood volume
Page 169 and 170:
2.52.0Enhancement1.51.0.50.0-.50 10
Page 171 and 172:
this is often the smaller matrix di
Page 173 and 174:
■ PhotoplethysmographA device for
Page 175 and 176:
advantage of using the ppm scale is
Page 177 and 178:
■ PROBEGE single or multiple voxe
Page 179 and 180:
■ PROSETPhilips utilisation of a
Page 181 and 182:
■ PulseSee RF pulse.■ Pulse con
Page 184 and 185:
Qq■ QuadratureThe use of two rece
Page 186 and 187:
Eβ_E = +1/2γ hB 0B 0α_h = E = γ
Page 188 and 189:
Rr■ R 1Longitudinal relaxation ra
Page 190 and 191:
■ RARERapid acquisition with rela
Page 192 and 193:
■ ReformatDisplaying image data i
Page 194 and 195:
where D is the concentration of the
Page 196 and 197:
■ Reynolds numberDimensionless qu
Page 198 and 199:
■ RF powerThe amount of RF energy
Page 200 and 201:
■ RODEORotating delivery of excit
Page 202 and 203:
Ss■ SaddleRF coil design, which p
Page 204 and 205:
■ Scalar couplingSee J-coupling a
Page 206 and 207:
■ SegmentationRemoval or isolatio
Page 208 and 209:
Global shimming refers to the whole
Page 210 and 211:
■ Silicon specificSuppression of
Page 212 and 213:
■ Slew rateGradient specification
Page 214 and 215:
(i) subtraction method: two separat
Page 216 and 217:
Usually the resolution is poorer in
Page 218 and 219:
(a)y′x′(b)(c)t = TE/2(d)(e)t =
Page 220 and 221:
■ Spiral EPIType of EPI sequence
Page 222 and 223:
MRA the imaging may be performed at
Page 224 and 225:
Reference E. O. Stejskal & J. E. Ta
Page 226 and 227:
See also permanent and resistive ma
Page 228:
■ SusceptibilityProperty of matte
Page 231 and 232:
T 1 is the time taken for the net m
Page 233 and 234:
Reference C. S. Poon & R. M. Henkel
Page 235 and 236:
■ Temporal resolutionThe time int
Page 237 and 238:
■ Time domain signalThe signal th
Page 239 and 240:
■ TractographyReferring to use of
Page 241 and 242:
■ TriggeringSee gating.■ Trigge
Page 244 and 245:
Uu■ UniformityA measure of how ho
Page 246 and 247:
Vv■ Vacuum boreThe use of an evac
Page 248 and 249:
have been reported near to the entr
Page 250 and 251:
Ww■ WADA testHighly invasive proc
Page 252 and 253:
■ Weinmann dataMeasurement of blo
Page 254:
Xx■ XenonThe isotope 129 Xe may b
Page 257 and 258:
Figure 33.image.RF or zipper artefa
Page 260:
Appendices249
Page 263 and 264:
Appendix IIProperties ofMR visible
Page 265 and 266:
110.5M x0.5M y00-0.5-0.5-1 0 50 100
Page 267 and 268:
Appendix VUseful fouriertransform p
Page 269 and 270:
Note: The positions of the two prot
Page 271:
Appendix VIIIGreek lettersUpper Low
show all

MRI From A to Z: A Definitive Guide for Medical Professionals

Create successful ePaper yourself

Delete template?

Save as template?