Post-processing correction of the endorectal coil reception effects in MR spectroscopic imaging of the prostate.
OBJECTIVE
To develop and validate a post-processing correction algorithm to remove the effect of the inhomogeneous reception profile of the endorectal coil on MR spectroscopic imaging (MRSI) data.


METHODS
A post-processing algorithm to correct for the endorectal coil reception effects on MRSI data was developed based upon theoretical modeling of the endorectal coil reception profile and of the spatial saturation pulse profiles. This algorithm was evaluated on three-dimensional (3D) MRSI data acquired at 3T from a uniform phantom and from 18 patients with known or suspected prostate cancer.


RESULTS
For the phantom data, the coefficient of variation of metabolite peak areas decreased 16% to 46% and the peak area distributions became more Gaussian with correction, as demonstrated by higher Q-Q plot linear correlations (R(2) = 0.98 +/- 0.007 vs. R(2) = 0.89 +/- 0.066). Across the 18 patients, the mean coefficient of variation for suppressed water decreased significantly, from 0.95 +/- 0.18, to 0.66 +/- 0.11, (P < 10(-6), paired t-test) and the linear correlations of the Q-Q plots for the suppressed water increased from R(2) = 0.91 to R(2) = 0.95 (P = 0.0083, paired t-test) with correction.


CONCLUSIONS
An algorithm for reducing the effect of the inhomogeneous reception profile in endorectal coil acquired 3D MRSI prostate data was demonstrated, illustrating increased homogeneity and more Gaussian peak area distributions.
Noworolski
Susan M
SM
The Center for Molecular and Functional Imaging, Department of Radiology and Biomedical Imaging, The University of California, San Francisco, California 94107, USA. sue@radiology.ucsf.edu
Reed
Galen D
GD
Kurhanewicz
John
J
Vigneron
Daniel B
DB
D000328:Adult; D000368:Aged; D000465:Algorithms; D015331:Cohort Studies; D003198:Computer Simulation; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011470:Prostatic Hyperplasia / Q000175:diagnosis*; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012007:Rectum; D013382:Subtraction Technique
Magn Reson Imaging. 2006 Sep;24(7):825-32
16916699
Magn Reson Imaging. 2006 Dec;24(10):1295-302
17145400
Magn Reson Med. 2005 May;53(5):1033-9
15844147
Invest Radiol. 2004 Nov;39(11):671-80
15486528
J Magn Reson Imaging. 2007 Jul;26(1):23-30
17659562
Magn Reson Imaging. 2006 Jan;24(1):69-74
16410180
IEEE Trans Med Imaging. 1991;10(1):53-65
18222800
Magn Reson Med. 2000 Jan;43(1):23-33
10642728
Radiology. 2004 Nov;233(2):441-8
15375223
J Magn Reson Imaging. 1997 Jul-Aug;7(4):745-57
9243397
Magn Reson Med. 1993 Mar;29(3):285-91
7680746
Radiology. 1994 Dec;193(3):703-9
7972810
Radiol Med. 2004 Nov-Dec;108(5-6):530-41
15722999
Magn Reson Med. 1995 Sep;34(3):440-5
7500884
Med Phys. 2005 Dec;32(12):3569-78
16475755
AJR Am J Roentgenol. 1996 May;166(5):1157-63
8615261
Neoplasia. 2000 Jan-Apr;2(1-2):166-89
10933075
Radiology. 1996 Mar;198(3):795-805
8628874
Magn Reson Med. 2008 Sep;60(3):542-7
18727040
Magn Reson Med. 1999 Jan;41(1):21-9
10025607
Magn Reson Med. 2005 Feb;53(2):249-55
15678552
Magn Reson Med. 2006 May;55(5):1164-9
16596629
Int J Clin Oncol. 2007 Dec;12(6):408-15
18071859
Magn Reson Med. 2001 Aug;46(2):228-39
11477625
Magn Reson Med. 2007 Feb;57(2):249-57
17260356
Radiology. 1996 Mar;198(3):807-11
8628875
Radiology. 1989 Aug;172(2):570-4
2748842
J Magn Reson Imaging. 1995 Mar-Apr;5(2):139-44
7766974