TY - JOUR
T1 - High resolution 13C MRI with hyperpolarized urea
T2 - In vivo T 2 mapping and 15N labeling effects
AU - Reed, Galen D.
AU - Von Morze, Cornelius
AU - Bok, Robert
AU - Koelsch, Bertram L.
AU - Van Criekinge, Mark
AU - Smith, Kenneth J.
AU - Shang, Hong
AU - Larson, Peder E.Z.
AU - Kurhanewicz, John
AU - Vigneron, Daniel B.
PY - 2014/2
Y1 - 2014/2
N2 - 13C steady state free precession (SSFP) magnetic resonance imaging and effective spin-spin relaxation time (T2) mapping were performed using hyperpolarized [13C] urea and [13C, 15N2] urea injected intravenously in rats. 15N labeling gave large T2 increases both in solution and in vivo due to the elimination of a strong scalar relaxation pathway. The T2 increase was pronounced in the kidney, with [13C,15N 2] urea giving T2 values of 6.3±1.3s in the cortex and medulla, and 11±2s in the renal pelvis. The measured T2 in the aorta was 1.3±0.3s. [13C] urea showed shortened T 2 values in the kidney of 0.23±0.03s compared to 0.28±0.03s measured in the aorta. The enhanced T2 of [ 13C,15N2] urea was utilized to generate large signal enhancement by SSFP acquisitions with flip angles approaching the fully refocused regime. Projection images at 0.94 mm in-plane resolution were acquired with both urea isotopes, with [13C,15N2] urea giving a greater than four-fold increase in signal-to-noise ratio over [ 13C] urea.
AB - 13C steady state free precession (SSFP) magnetic resonance imaging and effective spin-spin relaxation time (T2) mapping were performed using hyperpolarized [13C] urea and [13C, 15N2] urea injected intravenously in rats. 15N labeling gave large T2 increases both in solution and in vivo due to the elimination of a strong scalar relaxation pathway. The T2 increase was pronounced in the kidney, with [13C,15N 2] urea giving T2 values of 6.3±1.3s in the cortex and medulla, and 11±2s in the renal pelvis. The measured T2 in the aorta was 1.3±0.3s. [13C] urea showed shortened T 2 values in the kidney of 0.23±0.03s compared to 0.28±0.03s measured in the aorta. The enhanced T2 of [ 13C,15N2] urea was utilized to generate large signal enhancement by SSFP acquisitions with flip angles approaching the fully refocused regime. Projection images at 0.94 mm in-plane resolution were acquired with both urea isotopes, with [13C,15N2] urea giving a greater than four-fold increase in signal-to-noise ratio over [ 13C] urea.
KW - Angiography
KW - Dynamic nuclear polarization
KW - Hyperpolarized
KW - Steady state free precession (SSFP)
KW - Urea
UR - http://www.scopus.com/inward/record.url?scp=84894033046&partnerID=8YFLogxK
U2 - 10.1109/TMI.2013.2285120
DO - 10.1109/TMI.2013.2285120
M3 - Article
C2 - 24235273
AN - SCOPUS:84894033046
SN - 0278-0062
VL - 33
SP - 362
EP - 371
JO - IEEE Transactions on Medical Imaging
JF - IEEE Transactions on Medical Imaging
IS - 2
M1 - 6648454
ER -