Advanced

AJNR - American Journal of Neuroradiology

Published ahead of print on September 3, 2008
doi: 10.3174/ajnr.A1131

This Article Abstract Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Liu, H.-S. Articles by Chen, C.-Y. Search for Related Content PubMed PubMed Citation Articles by Liu, H.-S. Articles by Chen, C.-Y.

Anomalous J-Modulation Effects on Amino Acids in Clinical 3T MR Spectroscopy

H.-S. Liu^a,b, H.-W. Chung^a, C.-J. Juan^b, S.-Y. Tsai^a, C.-Y. Wang^a,b, C.-C. Chan^c, G.-S. Huang^b, M.-C. Chou^a, C.-S. Lee^d, C.-W. Ko^e, N.-Y. Cho^f and C.-Y. Chen^b

^a Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan
^b Department of Radiology, Tri-Service General Hospital, Taipei, Taiwan
^c Philips Medical Systems, Best, the Netherlands
^d Department of Chemistry, Tamkang University, Taipei, Taiwan
^e Department of Computer Science and Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
^f Institute of Biomedical Engineering, National Yang-Ming University, Taipei, Taiwan

View larger version (23K): [in this window] [in a new window]   Fig 1. Transverse T2 fluid-attenuated inversion recovery MR image (A) and single-voxel spectra obtained in a 19-year-old male patient with brain abscess by using PRESS localization at 3T with TE = 40 ms (B) and TE = 144 ms (C). Succ indicates succinate; Ac, acetate; Ala, alanine; Lac, lactate; Lip, lipids; AA, amino acids.

View larger version (22K): [in this window] [in a new window]   Fig 2. Transverse postcontrast T1-weighted MR image (A) and single-voxel proton MR spectra obtained in a 42-year-old female patient with brain abscess by using PRESS localization at 3T with TE = 144 ms (B) and TE = 288 ms (C). Ala, indicates alanine; Lac, lactate; AA, amino acids.

View larger version (10K): [in this window] [in a new window]   Fig 3. Spectra from a phantom that contained 10 mmol/L of alanine to illustrate the anomalous J-modulation effect of the PRESS sequence at TE = 144 ms obtained from a 3T scanner, with the identical setting in the receiver gain at TE = 144 (A) and TE = 288 ms (B). Note at 1.47 ppm the incompletely inverted phase and reduced amplitude of the methyl doublet in the TE = 144 ms spectrum, evidence of the presence of an anomalous J-modulation effect.

View larger version (8K): [in this window] [in a new window]   Fig 4. Spectra from a phantom that contained only valine at TE = 40 ms (A) and TE = 144 ms (B). The complex doublets between 0.90 and 1.06 ppm show a clearly inverted phase at TE = 144 ms.