Bland-Altman plot of GFR values estimated by both methods.

<p>On the x-axis, the average of both methods is plotted whereas the y-axis shows the differences between the methods.</p

Example of colour-coded goodness of fit maps of the kidney for a) a healthy SD rat and b) a UNX rat.

<p>Fit error maps (χ²) are superimposed to the corresponding slice of the T2 weighted morphological image for better visualization.</p

Comparison of GFR values obtained by MRI and FITC-sinistrin techniques in healthy SD rats.

<p>Mean GFR between methods differ by a factor of two.</p

Comparison of GFR values obtained by MRI and FITC-sinistrin techniques in UNX SD rats.

<p>Mean GFR between methods differ by a factor of two.</p

Kidney volumes for healthy and UNX rats estimated by weighting, water displacement and manual segmentation of MR images.

<p>Unilateral nephrectomy was performed on the left kidney. In case of the MRI, also cortical volumes were estimated for GFR calculations. Values are mean ± standard deviation.</p

Boxplot of GFR values for each group and method.

<p>Differences between healthy and UNX rats are clearly visible as well as the offset between GFR measured by FITC-sinistrin and DCE-MRI. The boxes represent the 25th–75th percentiles, the horizontal lines within the boxes represent the median. The whiskers indicate 1.5 times the interquartile range (IQR) from the first quartile and 1.5 times the IQR from the third quartile; the circles represent outliers outside the whiskers.</p

Image examples obtained by the MR measurements.

<p>A) depicts one slice of a T2 weighted morphological MR image used for cortex delineation, B) shows a parametric map of the tubular flow (filtration) calculated from the DCE- MRI perfusion data in units of ml/min/100 ml tissue. The map is superimposed onto the corresponding slice of the T2 weighted image.</p

Plot of concentrations (mmol/ml) versus signal intensities (arbitrary units) obtained from a phantom consisting of tubes filled with water and different contrast agent concentrations (0, 0.01, 0.025, 0.05, 0.1 0.25, 0.5, 1.0, 2.5 mmol/ml).

<p>The error bars depict the standard deviation within a ROI of size 0.3² placed within the tubes.</p

Optical devices for FITC-sinistrin clearance measurement.

<p>A: original devices with LEDs and photodiode for signal excitation and reception (bottom side) and electronics (upper side). B: the devices are shielded by copper foil, only the LEDs, the photodiode and the battery plug are spared. The device is powered by a small battery that was covered in copper foil, too.</p

Example of FITC-sinistrin clearance curve from one animal.

<p>The dashed line depicts the background signal, which is subtracted from the signal for quantification of the GFR.</p