TY - JOUR
T1 - Deconvolution of compartmental water diffusion coefficients in yeast-cell suspensions using combined T1 and diffusion measurements
AU - Silva, Matthew D.
AU - Helmer, Karl G.
AU - Han, Sam S.
AU - Sotak, Christopher H.
AU - Lee, Jing Huei
AU - Springer, Charles S.
AU - Springer, Charles S.
AU - Sotak, Christopher H.
AU - Sotak, Christopher H.
N1 - Funding Information:
We thank Gabor Vétek and Ildiko Palyka for help with initial experiments and Christian Labadie for help with the 2D ILT. We thank the NIH (RO1 GM32125 and RO1 NS40801) and the DOE (Contract AC02-98CH10884) for partial support of this work. Part of this work was performed during the tenure of an Established Investigatorship from the American Heart Association (CHS).
PY - 2002
Y1 - 2002
N2 - An NMR method is presented for measuring compartment-specific water diffusion coefficient (D) values. It uses relaxography, employing an extracellular contrast reagent (CR) to distinguish intracellular (IC) and extracellular (EC) 1H2O signals by differences in their respective longitudinal (T1) relaxation times. A diffusion-weighted inversion-recovery spin-echo (DW-IRSE) pulse sequence was used to acquire IR data sets with systematically and independently varying inversion time (TI) and diffusion-attenuation gradient amplitude (g) values. Implementation of the DW-IRSE technique was demonstrated and validated using yeast cells suspended in 3 mM Gd-DTPA2- with a wet/dry mass ratio of 3.25: 1.0. Two-dimensional (2D) NMR data were acquired at 2.0 T and analyzed using numerical inverse Laplace transformation (2D- and sequential 1D-ILT) and sequential exponential fitting to yield T1 and water D values. All three methods gave substantial agreement. Exponential fitting, deemed the most accurate and time efficient, yielded T1: D (relative contribution) values of 304 ms: 0.023 × 10−5 cm2/s (47%) and 65 ms: 1.24 × 10−5 cm2/s (53%) for the IC and EC components, respectively. The compartment-specific D values derived from direct biexponential fitting of diffusion-attenuation data were also in good agreement. Extension of the DW-IRSE method to in vivo models should provide valuable insights into compartment-specific water D changes in response to injury or disease.
AB - An NMR method is presented for measuring compartment-specific water diffusion coefficient (D) values. It uses relaxography, employing an extracellular contrast reagent (CR) to distinguish intracellular (IC) and extracellular (EC) 1H2O signals by differences in their respective longitudinal (T1) relaxation times. A diffusion-weighted inversion-recovery spin-echo (DW-IRSE) pulse sequence was used to acquire IR data sets with systematically and independently varying inversion time (TI) and diffusion-attenuation gradient amplitude (g) values. Implementation of the DW-IRSE technique was demonstrated and validated using yeast cells suspended in 3 mM Gd-DTPA2- with a wet/dry mass ratio of 3.25: 1.0. Two-dimensional (2D) NMR data were acquired at 2.0 T and analyzed using numerical inverse Laplace transformation (2D- and sequential 1D-ILT) and sequential exponential fitting to yield T1 and water D values. All three methods gave substantial agreement. Exponential fitting, deemed the most accurate and time efficient, yielded T1: D (relative contribution) values of 304 ms: 0.023 × 10−5 cm2/s (47%) and 65 ms: 1.24 × 10−5 cm2/s (53%) for the IC and EC components, respectively. The compartment-specific D values derived from direct biexponential fitting of diffusion-attenuation data were also in good agreement. Extension of the DW-IRSE method to in vivo models should provide valuable insights into compartment-specific water D changes in response to injury or disease.
KW - Contrast reagent
KW - Diffusigraphy
KW - Relaxography
KW - Water apparent diffusion coefficient
KW - Yeast-cell suspension
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U2 - 10.1006/jmre.2002.2527
DO - 10.1006/jmre.2002.2527
M3 - Article
C2 - 12081442
AN - SCOPUS:0035983167
SN - 1090-7807
VL - 156
SP - 52
EP - 63
JO - Journal of Magnetic Resonance
JF - Journal of Magnetic Resonance
IS - 1
ER -