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Utilizing magnetization transfer imaging to investigate tissue remodeling in a murine model of autosomal dominant polycystic kidney disease

View Article: PubMed Central - PubMed

ABSTRACT

Purpose: Noninvasive imaging techniques that quantify renal tissue composition are needed to more accurately ascertain prognosis and monitor disease progression in polycystic kidney disease (PKD). Given the success of magnetization transfer (MT) imaging to characterize various tissue remodeling pathologies, it was tested on a murine model of autosomal dominant PKD.

Methods: C57Bl/6 Pkd1 R3277C mice at 9, 12, and 15 months were imaged with a 16.4T MR imaging system. Images were acquired without and with RF saturation in order to calculate MT ratio (MTR) maps. Following imaging, the mice were euthanized and kidney sections were analyzed for cystic and fibrotic indices, which were compared with statistical parameters of the MTR maps.

Results: The MTR‐derived mean, median, 25th percentile, skewness, and kurtosis were all closely related to indices of renal pathology, including kidney weight/body weight, cystic index, and percent of remaining parenchyma. The correlation between MTR and histology‐derived cystic and fibrotic changes was R2 = 0.84 and R2 = 0.70, respectively.

Magn reson med 75:1466–1473, 2016. © 2015 the authors. magnetic resonance in medicine published by wiley periodicals, inc. on behalf of international society for magnetic resonance.: MT imaging provides a new, noninvasive means of measuring tissue remodeling PKD changes and may be better suited for characterizing renal impairment compared with conventional MR techniques.

No MeSH data available.


Related in: MedlinePlus

A: Comparison of global measurement of mean kidney MTR values with the cystic index measured by histology. Although the mean MTR values are only a crude representation of the wealth of information contained in the MTR maps, the fact that they correlated closely with the cystic burden of the kidneys suggests that deeper probing can reliably extract not only macroscopic presentations of the disease but also subresolution tissue changes. B: Comparison of local measurement of mean kidney MTR values with the cystic index measured by histology. In this case, a much closer correlation between the results obtained by MT imaging and the ground truth histological measurements were obtained. Thus, at the local level, MT imaging conveys information regarding subresolution microscopic cysts.
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mrm25701-fig-0002: A: Comparison of global measurement of mean kidney MTR values with the cystic index measured by histology. Although the mean MTR values are only a crude representation of the wealth of information contained in the MTR maps, the fact that they correlated closely with the cystic burden of the kidneys suggests that deeper probing can reliably extract not only macroscopic presentations of the disease but also subresolution tissue changes. B: Comparison of local measurement of mean kidney MTR values with the cystic index measured by histology. In this case, a much closer correlation between the results obtained by MT imaging and the ground truth histological measurements were obtained. Thus, at the local level, MT imaging conveys information regarding subresolution microscopic cysts.

Mentions: We found that MTR values were well correlated with cystic index. Global measurements were compared in all 22 cases. Figure 2A shows the global measurement comparisons of the mean MTR signal and the cystic index as measured by histology. Increasing cystic index caused a decrease in overall MTR with linear least squares regression yielding a slope of −0.007, R2 = 0.82, and P ≪ 0.01. In addition, subregions were matched between MT and histology in order to compare local measurements. In the case of local measurements (Fig. 2B, 33 comparison data points), a closer correlation (R2 = 0.87, and P ≪ 0.01) was found between the mean MTR signal and cystic index.


Utilizing magnetization transfer imaging to investigate tissue remodeling in a murine model of autosomal dominant polycystic kidney disease
A: Comparison of global measurement of mean kidney MTR values with the cystic index measured by histology. Although the mean MTR values are only a crude representation of the wealth of information contained in the MTR maps, the fact that they correlated closely with the cystic burden of the kidneys suggests that deeper probing can reliably extract not only macroscopic presentations of the disease but also subresolution tissue changes. B: Comparison of local measurement of mean kidney MTR values with the cystic index measured by histology. In this case, a much closer correlation between the results obtained by MT imaging and the ground truth histological measurements were obtained. Thus, at the local level, MT imaging conveys information regarding subresolution microscopic cysts.
© Copyright Policy - creativeCommonsBy-nc
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644111&req=5

mrm25701-fig-0002: A: Comparison of global measurement of mean kidney MTR values with the cystic index measured by histology. Although the mean MTR values are only a crude representation of the wealth of information contained in the MTR maps, the fact that they correlated closely with the cystic burden of the kidneys suggests that deeper probing can reliably extract not only macroscopic presentations of the disease but also subresolution tissue changes. B: Comparison of local measurement of mean kidney MTR values with the cystic index measured by histology. In this case, a much closer correlation between the results obtained by MT imaging and the ground truth histological measurements were obtained. Thus, at the local level, MT imaging conveys information regarding subresolution microscopic cysts.
Mentions: We found that MTR values were well correlated with cystic index. Global measurements were compared in all 22 cases. Figure 2A shows the global measurement comparisons of the mean MTR signal and the cystic index as measured by histology. Increasing cystic index caused a decrease in overall MTR with linear least squares regression yielding a slope of −0.007, R2 = 0.82, and P ≪ 0.01. In addition, subregions were matched between MT and histology in order to compare local measurements. In the case of local measurements (Fig. 2B, 33 comparison data points), a closer correlation (R2 = 0.87, and P ≪ 0.01) was found between the mean MTR signal and cystic index.

View Article: PubMed Central - PubMed

ABSTRACT

Purpose: Noninvasive imaging techniques that quantify renal tissue composition are needed to more accurately ascertain prognosis and monitor disease progression in polycystic kidney disease (PKD). Given the success of magnetization transfer (MT) imaging to characterize various tissue remodeling pathologies, it was tested on a murine model of autosomal dominant PKD.

Methods: C57Bl/6 Pkd1 R3277C mice at 9, 12, and 15 months were imaged with a 16.4T MR imaging system. Images were acquired without and with RF saturation in order to calculate MT ratio (MTR) maps. Following imaging, the mice were euthanized and kidney sections were analyzed for cystic and fibrotic indices, which were compared with statistical parameters of the MTR maps.

Results: The MTR‐derived mean, median, 25th percentile, skewness, and kurtosis were all closely related to indices of renal pathology, including kidney weight/body weight, cystic index, and percent of remaining parenchyma. The correlation between MTR and histology‐derived cystic and fibrotic changes was R2 = 0.84 and R2 = 0.70, respectively.

Magn reson med 75:1466–1473, 2016. © 2015 the authors. magnetic resonance in medicine published by wiley periodicals, inc. on behalf of international society for magnetic resonance.: MT imaging provides a new, noninvasive means of measuring tissue remodeling PKD changes and may be better suited for characterizing renal impairment compared with conventional MR techniques.

No MeSH data available.


Related in: MedlinePlus