Polycystic kidney disease (PKD) is a life-threatening disease that leads to a grotesque enlargement of the kidney and significant loss of function. Several imaging studies with MRI have demonstrated that
cyst size in
polycystic kidneys can determine disease severity and progression. In the present study, we found that, although kidney volume and
cyst volume decreased with
drug treatment, renal function did not improve with treatment. Here, we applied dynamic contrast-enhanced MRI to study PKD in a Glis3 (GLI-similar 3)-deficient mouse model.
Cysts from this model have a wide range of sizes and develop at an early age. To capture this crucial stage and assess
cysts in detail, we imaged during early development (3-17 weeks) and applied high spatiotemporal resolution MRI (125 × 125 × 125 cubic microns every 7.7 s). A
drug treatment with
rapamycin (also known as
sirolimus) was applied to determine whether
disease progression could be halted. The effect and synergy (interaction) of aging and treatment were evaluated using an analysis of variance (ANOVA). Structural measurements, including kidney volume,
cyst volume and
cyst-to-kidney volume ratio, changed significantly with age.
Drug treatment significantly decreased these metrics. Functional measurements of time-to-peak (
TTP) mean and
TTP variance were determined.
TTP mean did not change with age, whereas
TTP variance increased with age. Treatment with
rapamycin generally did not affect these functional metrics. Synergistic effects of treatment and age were not found for any measurements. Together, the size and volume ratio of
cysts decreased with
drug treatment, whereas renal function remained the same. The quantification of renal structure and function with MRI can comprehensively assess the pathophysiology of PKD and response to treatment.