RT Journal Article
SR Electronic
T1 Metabolite Phantom Correction of the Nonuniform Volume-Selection Profiles in MR Spectroscopic Imaging: Application to Temporal Lobe Epilepsy
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1072
OP 1077
VO 26
IS 5
A1 J. O. Jesper Lundbom
A1 Kim E. Vuori
A1 Eija K. Gaily
A1 R. I. Marja-Liisa Granström
A1 Göran C. Blomstedt
A1 Anna-Maija Häkkinen
A1 Sami M. Heikkinen
A1 Nina M. I. Lundbom
YR 2005
UL http://www.ajnr.org/content/26/5/1072.abstract
AB BACKGROUND AND PURPOSE: In MR spectroscopic imaging (MRSI), the volume-selection profiles of metabolites differ from each other. These differences cause variations in metabolite intensities, which are particularly prominent when the hippocampi are evaluated. We hypothesize that the errors arising from these effects cause notable artifact when temporal lobe epilepsy (TLE) is lateralized with MRSI.METHODS: We examined a metabolite phantom, control subjects, and patients with TLE by using MRSI. We calculated the error arising from the different volume-selection profiles of metabolites in vitro and evaluated this correction in the examination of the control subjects and in the lateralization of epilepsy in the patients.RESULTS: Without a correction, a considerable error in the metabolite content existed, even deep inside the spectroscopic volume of interest. The result was false asymmetry (P < .008) in the hippocampi of control subjects. Among the 11 patients, TLE was correctly lateralized in three only after the correction was made, and in one, TLE was incorrectly lateralized.CONCLUSION: The volume-selection profiles of N-acetylaspartate, choline, and creatine differ enough to cause a significant error, even in the metabolite ratios, when patients with TLE are examined with MRSI. We propose a simple phantom method to correct for this error without a need to modify the pulse sequence.