Renal Damages in Deoxycorticosterone Acetate-Salt Hypertensive Rats: Assessment with Diffusion Tensor Imaging and...

Area of Science:

• Nephrology
• Radiology
• Biomedical Engineering

Background:

• Hypertension-induced renal damage is a significant health concern.
• Early detection of renal damage is crucial for effective management.
• Diffusion tensor imaging (DTI) and T2-mapping offer non-invasive methods for assessing tissue microstructure and water content.

Purpose of the Study:

• To evaluate the feasibility of DTI and T2-mapping for monitoring temporal renal damage in DOCA-salt hypertensive rats.
• To correlate imaging findings with histopathologic and immunohistochemical results.
• To establish DTI and T2-mapping as reliable tools for assessing hypertensive nephropathy.

Main Methods:

• DOCA-salt hypertension was induced in Sprague-Dawley rats.
• Renal MRI, including DTI (measuring fractional anisotropy [FA] and apparent diffusion coefficient [ADC]) and T2-mapping, was performed at various time points.
• Histopathologic and immunohistochemical analyses were conducted to assess glomerular and tubular injury, fibrosis, and other damage markers.

Main Results:

• DOCA-salt rats showed a significant decrease in renal cortical FA from week 4 to 8, correlating with increased glomerular damage, arteriolosclerosis, macrophage infiltration, and fibrosis.
• Cortical ADC and T2 values increased significantly at weeks 6 and 8, associated with fluid-filled microcysts.
• While medullary fibrosis increased, FA changes in the medulla were not significant, indicating limited microstructural alterations.

Conclusions:

• Renal cortical FA is a sensitive biomarker for early detection and monitoring of renal damage in DOCA-salt hypertensive rats.
• DTI and T2-mapping can effectively assess temporal changes in renal tissue during hypertension.
• These imaging techniques hold promise for non-invasively evaluating hypertensive nephropathy.