Figure 1.
Schematic diagram of the modified two-compartment model with impulse residue function for glomerular filtration.
A is the vascular compartment includes intrarenal arteries and glomerular vessels, and T is the tubules compartment. The retention function RA and RT in compartment A and T (represented in solid arrow within the box) are the convolution of the input and each impulse residue function. Dashed lines denote the outflow of each compartment and the outflow of compartment A partially flows into compartment T.
Figure 2.
Concentration curves in Monte Carlo simulation for a.) the artificial AIF and b.) the tissue curve which is generated with the known initial parameters and added with 5% level noise.
Figure 3.
Monte Carlo simulation results for each compartment model in estimating a.) GFR and b.) RPF, only three models could extract RPF.
Lowest variability of estimated GFR and RPF (red dotted line) are found in the proposed two-compartment model at 2%, 3%, 5%, 10% and 15% noise, respectively.
Figure 4.
A representative image from DCE-MRI acquisition.
a.) showing the region of interest after segmentation; b.) the manually drawn cortical ROI (white line); c.) the image in which a branch of renal artery is clearly seen is used for aortic ROI drawing; and d.) the concentration curves of each corresponding ROI. The original aortic input function (black line) fits its tail with a biexponential method (shown in red line). The blue line is the cortical concentration curve.
Figure 5.
Typical retention function curves for vascular compartment (RA, red), tubule compartment (RT, green) and the cortex region (Rcortex, blue).
Table 1.
Estimated parameters of normal kidneys using the proposed two-compartment model and goodness of fit for the nonlinear fitting.
Figure 6.
GFR mapping of a.) the normal kidney (right kidney) and b.) the acute ischemia kidney (left kidney) by using the new model.
The left kidney of the rabbit is under surgical ligation for totally 45 minutes, and lower GFR values are clearly observed in the cortex and outer stripes of the outer medulla regions while corresponding regions are high in the control group.
Figure 7.
Histology sections of a.) the normal kidney (H&E, ×100) and the acute ischemia kidney with histological findings of b.) tubular dilatation (×100), c.) cast deposition (open arrow, ×100) and d.) cell necrosis (black arrow, ×200).
Table 2.
Pixel-wise estimation of GFR for dysfunction kidneys by using the proposed two-compartment model.
Table 3.
Estimated results of GFR for each two-compartmental model.
Table 4.
RPF values in literature studies.