Login to Access Video or Poster Abstract: MP08-20
Sources of Funding: Supported in part by 4R01DK078121-09 from the NIDDK to DJL

Introduction

Mouse models serve as an excellent tool for studying human disease. Yet, the small size of the mouse presents technical challenges in characterizing organ defects. The use of micro-computed tomography (micro-CT) in biomedical research has historically been limited to studying osseous structures. However, development of iodine staining techniques has allowed for improved ex vivo study of soft tissue structures. Images acquired through micro-CT allow for limitless virtual sectioning (as thin as 2 µm), a distinct advantage over traditional tissue sectioning. In this study, we demonstrate the successful use of iodine staining and micro-CT to rapidly phenotype genitourinary (GU) anomalies in mice.

Methods

Mice GU specimens were excised, fixed in formalin, and dehydrated in 70% ethanol. Iodine staining was performed by soaking the tissue in 0.1 N iodine (Fluka). The specimen was suspended in agar in preparation for imaging. Images were acquired using the SkyScan 1272 High-Resolution X-Ray Microtomograph (Bruker microCT, Kontich, Belgium). A 0.5 µm aluminum filter was utilized. Imaging parameters were 5 µm and 11 µm pixel size for penis and kidney specimens, respectively, and 2016 x 1344 resolution. Images were reconstructed using NRecon (Bruker microCT) and visualized using 3D Slicer v4 (slicer.org).

Results

Both embryonic and adult mice GU specimens were imaged. Micro-CT scan time varied with specimen size and desired resolution, but was at longest 120 minutes. Normal and pathologic GU phenotypes were characterized on three-dimensional, reconstructed images. Embryonic GU systems were examined, including a number of hydronephrotic kidneys (top left). Normal, hydronephrotic, duplex (top right), and polycystic kidneys (bottom left) were identified in adult specimens. Adult penile specimens (bottom right) were reconstructed to allow for morphometric measurements.

Conclusions

We demonstrate successful generation of three-dimensional, high-resolution, contrast-enhanced images of GU organs in the murine model using micro-CT. The use of micro-CT possesses a vast potential in rapid phenotyping and study of GU anomalies in the murine model._x000D_

Funding

Supported in part by 4R01DK078121-09 from the NIDDK to DJL