Table 2.
Overview of the advantages and disadvantages of micro-CT (Skyscan 1176), nano-CT (Subµ-CT Lab, Fraunhofer EZRT), UM (Ultramicroscope II) and LSM (LSM 510 meta) employed for multiscale vascular network analysis.
| Imaging modality | Suited applications | Advantages | Disadvantages |
|---|---|---|---|
| micro-CT | ++ Coronary artery | Medium resolution (µm) | Vessel perfusion with contrast agent not always possible |
| + Whole vasculature of the kidney | In and ex vivo technique | Signal to background ratio even with contrast agents not always high enough | |
| ++ Kidney artery/ veins | Several blood pool contrast agents commercially available | Acquisition time 1 h 45 min | |
| ++ Carotid artery | Robust segmentation of vessel filled with contrast agent | Raw data size: 13 GB, reconstructed data size: 0.3 GB-1.1 GB | |
| High sample coverage (2 cm) or more with sub scan | Movement artifacts of biological samples | ||
| nano-CT | + Coronary artery | High resolution (nm-µm) | Vessel perfusion with contrast agent not always possible |
| ++ Kidney artery/ veins | Several blood pool contrast agents commercially available | Acquisition time 1 h 55 min - 4 h | |
| + Carotid artery | Robust segmentation of vessel filled with contrast agent, many contrast agents available | Raw data size: 6.25 GB, reconstructed data size: 17 GB | |
| ++ Atherosclerotic plaque vasa vasora | “Cell type” specific soft tissue contrast to distinguish atherosclerotic plaque tissue, fat and vessel | Medium sample coverage (2 mm), depends on magnification | |
| Movement artifacts of biological samples | |||
| Sample sectioning necessary for high resolution images | |||
| UM | ++ Heart capillaries | High resolution (1 µm-2 µm) | Tissue clearing and bleaching of fluorescent signal |
| ++ Kidney glomeruli | Multi target-, color application, fluorescence proximity analysis | Whole mount staining needs optimization processes | |
| ++ Kidney artery/ veins | Homogenous Isolectin staining | Raw data size 8.5 GB-43 GB, reconstructed data size: 6 GB-28 GB | |
| ++ Kidney capillaries | Acquisition time 20 min-40 min | Tissue shrinkage | |
| ++ Cell based matrigel assay | No movement artifacts due to dehydration | Segmentation of big vessel is time consuming | |
| ++ Matrigel capillaries | Medium sample coverage (0.7 cm), sample sectioning enhance fluorescence signal intensity | ||
| + Atherosclerotic plaque vasa vasora | Decay of fluorescence signal over time | ||
| ++ Atherosclerotic plaque capillaries | |||
| LSM | + Kidney glomeruli | High resolution (nm-µm) | Sectioning is time consuming and destructive to the sample |
| + Kidney artery/ veins | Multi target-, color application, fluorescence proximity analysis | 3D orientation has to be defined before sectioning and has and impact on results | |
| + Kidney capillaries | Homogenous Isolectin staining | Bleaching of fluorescent signal | |
| + Cell based matrigel assay | Acquisition time 3 min-20 min | Low sample coverage (~4 µm-50 µm/slide), observer-dependent as the analyzed region of interest is usually smaller compared to UM or micro-CT | |
| + Matrigel capillaries | Many staining protocols in the literature available | Tissue shrinkage | |
| + Atherosclerotic plaque vasa vasora | Raw data size 0.01 GB-0.1 GB | ||
| + Atherosclerotic plaque capillaries |
+: suited; ++: well suited; CT: computed tomography; GB: gigabyte; LSM: laser scanning confocal microscopy; UM: ultra-microscopy.