Figure 7

Assessment of renal cortical damage by density analysis based on CT data sets. (A and B) Two different 2D cross section CT visualization protocols (“cool” and “grey scale” implemented in SCRY) of sham operated versus UUO treated kidneys stained with PTA illustrate the loss of cortical integrity, from the capsule’s site as well as from the inner part of the kidney. The structural loss of renal medulla (m) and renal pelvis (rp) in UUO kidneys is also notable. (C and E) X-ray opacities in the cortex were confirmed by density histograms, which were generated from six cubes (0.125mm³), evenly ditributed in the cortical region. As already observed in the cross sections of the kidneys (A,B) grey scale values within the renal cortex are lower in UUO kidneys compared to values of sham treated kidneys. (E,F) Subsequent anti-αSMA immunostaining of these kidney sections confirms the augmented presence of activated fibroblasts (arrows), surrounding tubules and glomeruli (gm) in UUO kidneys as feature of fibrosis (F) which were less observed in sham operated kidneys (D). (G,H) To illustrate the structural loss of cortical tissue, micrographs of Masson trichrom staining (MTS) stained kidney sections from sham (G) and UUO kidneys (H) According to the quantification of the radio-opacity (A–E), the sham renal cortex appears compactly filled with a dense tubular system and glomeruli (gm). In the UUO operated kidney (H) a loose tubular organization with distinct dilated tubules (#), glomerular sparing and overexpression of collagen fibers (arrows), represented by a blue staining within the cortex, is visible. These histopathological findings are in line with the cortical radio-opacity in UUO kidneys and explain the lower grey values in comparison to the unaltered controls.