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Tau i , A high-resolution metabolic imaging biomarker for myocardium

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Even more importantly, intercompartmental water exchange kinetics are inaccessible... The mean intracellular water molecule lifetime [taui] is assumed effectively 0; though it is a fraction of a second... These are fitted with a shutter-speed (SS) two-site-exchange [2SX] expression approximating CA extravasation steady-state, [CAo] = [CAp] (o, interstitial); the solid curve [only ve and taui varied]... The extracellular volume fraction ve(SS) [≡ ECV(SS)] is 0.38... The tracer paradigm (TP) predicts a straight line for the R1t R1p-dependence, with slope ve: the dashed asymptote... In order to fit the non-linear data, the TP straight line must be pivoted down about the origin: this yields ECV(TP) = 0.25, a 34% reduction... SS success is not a fitting goodness issue: the TP line through the data incurs residuals scarcely larger than for the 2SX curve... Crucial is the systematic TP ECV depression, which increases in pathology... Even more important is the SS access to taui - because of the active trans membrane water cycling link to metabolic activity... We obtain taui = 0.34 s for this subject, the first reported for human myocardium [means in Table 1]. (Since [CAo] > [CAp], ve and taui are over- and underestimated.) Pixel by-pixel ve and taui values allow parametric mapping... For control mice taui = 0.19 s, and for a hypertensive mouse model taui = 0.44 s, values have been reported... The very large (132%) taui increase is accompanied by an only 30% d increase; from 20 to 26 μm.

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SSP fitting of DCE-MRI data collected from normal human heart in vivo. The points represent data collected at four times: one prior to CA administration, and three post-CA administration. R1t is the myocardial tissue 1H2O R1 value, and R1p is the blood plasma 1H2O R1 value calculated for a hematocrit (Hct) of 0.4. The solid curve represents the best SS model fitting to the data with parameters shown in the inset. The dashed asymptotic line is expected for the tracer paradigm.
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Figure 1: SSP fitting of DCE-MRI data collected from normal human heart in vivo. The points represent data collected at four times: one prior to CA administration, and three post-CA administration. R1t is the myocardial tissue 1H2O R1 value, and R1p is the blood plasma 1H2O R1 value calculated for a hematocrit (Hct) of 0.4. The solid curve represents the best SS model fitting to the data with parameters shown in the inset. The dashed asymptotic line is expected for the tracer paradigm.

Mentions: Figure 1 plots ROI 1H2O LV wall tissue (R1t) vs. corresponding LV plasma (R1p) values during the bolus passage [R1 ≡ T1-1]: 3 post-CA points and 1 pre-CA, for one subject. These are fitted with a shutter-speed (SS) two-site-exchange [2SX] expression approximating CA extravasation steady-state, [CAo] = [CAp] (o, interstitial); the solid curve [only ve and taui varied]. The extracellular volume fraction ve(SS) [≡ ECV(SS)] is 0.38. The tracer paradigm (TP) predicts a straight line for the R1t R1p-dependence, with slope ve: the dashed asymptote. In order to fit the non-linear data, the TP straight line must be pivoted down about the origin: this yields ECV(TP) = 0.25, a 34% reduction. SS success is not a fitting goodness issue: the TP line through the data incurs residuals scarcely larger than for the 2SX curve. Crucial is the systematic TP ECV depression, which increases in pathology. Even more important is the SS access to taui - because of the active trans membrane water cycling link to metabolic activity. We obtain taui = 0.34 s for this subject, the first reported for human myocardium [means in Table 1]. (Since [CAo] > [CAp], ve and taui are over- and underestimated.) Pixel by-pixel ve and taui values allow parametric mapping.


Tau i , A high-resolution metabolic imaging biomarker for myocardium
SSP fitting of DCE-MRI data collected from normal human heart in vivo. The points represent data collected at four times: one prior to CA administration, and three post-CA administration. R1t is the myocardial tissue 1H2O R1 value, and R1p is the blood plasma 1H2O R1 value calculated for a hematocrit (Hct) of 0.4. The solid curve represents the best SS model fitting to the data with parameters shown in the inset. The dashed asymptotic line is expected for the tracer paradigm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4043702&req=5

Figure 1: SSP fitting of DCE-MRI data collected from normal human heart in vivo. The points represent data collected at four times: one prior to CA administration, and three post-CA administration. R1t is the myocardial tissue 1H2O R1 value, and R1p is the blood plasma 1H2O R1 value calculated for a hematocrit (Hct) of 0.4. The solid curve represents the best SS model fitting to the data with parameters shown in the inset. The dashed asymptotic line is expected for the tracer paradigm.
Mentions: Figure 1 plots ROI 1H2O LV wall tissue (R1t) vs. corresponding LV plasma (R1p) values during the bolus passage [R1 ≡ T1-1]: 3 post-CA points and 1 pre-CA, for one subject. These are fitted with a shutter-speed (SS) two-site-exchange [2SX] expression approximating CA extravasation steady-state, [CAo] = [CAp] (o, interstitial); the solid curve [only ve and taui varied]. The extracellular volume fraction ve(SS) [≡ ECV(SS)] is 0.38. The tracer paradigm (TP) predicts a straight line for the R1t R1p-dependence, with slope ve: the dashed asymptote. In order to fit the non-linear data, the TP straight line must be pivoted down about the origin: this yields ECV(TP) = 0.25, a 34% reduction. SS success is not a fitting goodness issue: the TP line through the data incurs residuals scarcely larger than for the 2SX curve. Crucial is the systematic TP ECV depression, which increases in pathology. Even more important is the SS access to taui - because of the active trans membrane water cycling link to metabolic activity. We obtain taui = 0.34 s for this subject, the first reported for human myocardium [means in Table 1]. (Since [CAo] > [CAp], ve and taui are over- and underestimated.) Pixel by-pixel ve and taui values allow parametric mapping.

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AUTOMATICALLY GENERATED EXCERPT
Please rate it.

Even more importantly, intercompartmental water exchange kinetics are inaccessible... The mean intracellular water molecule lifetime [taui] is assumed effectively 0; though it is a fraction of a second... These are fitted with a shutter-speed (SS) two-site-exchange [2SX] expression approximating CA extravasation steady-state, [CAo] = [CAp] (o, interstitial); the solid curve [only ve and taui varied]... The extracellular volume fraction ve(SS) [≡ ECV(SS)] is 0.38... The tracer paradigm (TP) predicts a straight line for the R1t R1p-dependence, with slope ve: the dashed asymptote... In order to fit the non-linear data, the TP straight line must be pivoted down about the origin: this yields ECV(TP) = 0.25, a 34% reduction... SS success is not a fitting goodness issue: the TP line through the data incurs residuals scarcely larger than for the 2SX curve... Crucial is the systematic TP ECV depression, which increases in pathology... Even more important is the SS access to taui - because of the active trans membrane water cycling link to metabolic activity... We obtain taui = 0.34 s for this subject, the first reported for human myocardium [means in Table 1]. (Since [CAo] > [CAp], ve and taui are over- and underestimated.) Pixel by-pixel ve and taui values allow parametric mapping... For control mice taui = 0.19 s, and for a hypertensive mouse model taui = 0.44 s, values have been reported... The very large (132%) taui increase is accompanied by an only 30% d increase; from 20 to 26 μm.

No MeSH data available.