"Many thousands of metabolite peaks have been described, although most are not identifiable using routine imaging techniques and it is the Time of Echo (TE) that conditions the number of measurable metabolites: long TE (136-272 ms) vs short TE (10-50 ms) 7-8."
"Peaks are plotted from right to left along the x-axis and the y-axis (height) is the degree of chemical shift as expressed in part-per-million (ppm). The reason for ppm to be used rather than a shift of frequency in hertz (Hz) is so that spectra can be compared independent of magnet field strength 11-12. Normal choline, creatine, and NAA peaks form a straight line that if extended, create an angle of 45 degrees with the x-axis. This is known as Hunter's angle and can be used to determine quickly whether the MRS is most probably normal or not."
"Non-glial tumours "
"Radiation effects "
"Ischaemia and infarction "
"Infection "
"Hepatic encephalopathy "
"My: Myo-inositol 3.5"
"Cho: Choline 3.2"
"Cr: Creatine 3.0"
"Naa: Naa 2.0"
"L: Lactate 1.3"
"The technique of magnetic resonance spectroscopy (usually shortened to MR spectroscopy or MRS) allows tissue to be interrogated for the presence and concentration of various metabolites. Grossman and Yousem said "If you need this to help you, go back to page 1; everything except Canavan (disease) has low NAA, high choline" 1. This is perhaps a little harsh, however, it is fair to say that MRS often does not add a great deal to an overall MR study but does increase specificity, and may help in improving our ability to predict histological grade."
"Peaks are plotted from right to left along the x-axis and the y-axis (height) is the degree of chemical shift as expressed in part-per-million (ppm). The reason for ppm to be used rather than a shift of frequency in hertz (Hz) is so that spectra can be compared independent of magnet field strength 11-12. Normal choline, creatine, and NAA peaks form a straight line that if extended, create an angle of 45 degrees with the x-axis. This is known as Hunter's angle and can be used to determine quickly whether the MRS is most probably normal or not."
"Choline usually comes from some choline containing compounds that are important in membrane synthesis and degradation. Thus, brain tumours usually show high choline peak due to increased membrane turnover. NAA comes from normal neuronal or axonal tissue. In brain tumours, there is a loss of neuronal tissue, thus leading to reduced NAA peak 13."
"GABA: resonates at 2.2-2.4 ppm"
"Peaks"
"myo-inositol: resonates at 3.5 ppm and. 4.06 ppm"
"scyllo-inositol: resonates at 3.36 ppm"
"progressive multifocal leukoencephalopathy (PML) may demonstrate elevated myo-inositol"
"Markedly reduced myo-inositol, and to a lesser degree choline. Glutamine is increased."
"My: Myo-inositol 3.5"
"MRS of intact biological tissues was first reported by two groups: Moon and Richards using P-31 MRS to examine intact red blood cells in 1973, and Hoult et al. using P-31 MRS to examine excised leg muscle from the rat in 1974. The first MR spectrum of a human brain in vivo was published in 1985 by Paul A Bottomley 9."
"My ChoCrNaaLa (think of a new chocolate energy bar or something)"
"Cho: Choline 3.2"
"Naa: Naa 2.0"
"MRS of intact biological tissues was first reported by two groups: Moon and Richards using P-31 MRS to examine intact red blood cells in 1973, and Hoult et al. using P-31 MRS to examine excised leg muscle from the rat in 1974. The first MR spectrum of a human brain in vivo was published in 1985 by Paul A Bottomley 9."
Expected headings
"Physics"
"Peaks"
"Less common peaks"
"Glioma"
"Non-glial tumours "
"Radiation effects "
"Ischaemia and infarction "
"Infection "
"White matter diseases"
"Hepatic encephalopathy "
"Mitochondrial disorders"
"Meningioma"
"Mnemonic"
"The technique of magnetic resonance spectroscopy (usually shortened to MR spectroscopy or MRS) allows tissue to be interrogated for the presence and concentration of various metabolites. Grossman and Yousem said "If you need this to help you, go back to page 1; everything except Canavan (disease) has low NAA, high choline" 1. This is perhaps a little harsh, however, it is fair to say that MRS often does not add a great deal to an overall MR study but does increase specificity, and may help in improving our ability to predict histological grade."
"MRS can help increase our ability to predict grade. As the grade increases, NAA and creatine decrease and choline, lipids and lactate increase."
"MRS can help increase our ability to predict grade. As the grade increases, NAA and creatine decrease and choline, lipids and lactate increase."
"Distinguishing radiation change and tumour recurrence can be problematic. In recurrent tumour choline will be elevated, whereas in radiation change, NAA, choline and creatine will all be low."