Figure 1

Spatial Correlation between ⁶⁴ Cu-ATSM and pimonidazole uptake in a cat with maxillary ostesarcoma. Formalin-fixation and sectioning of the entire tumor from cat #12 was performed to compare spatial distribution of pimonidazole in relation to ⁶⁴Cu-ATSM uptake on PET. Panel A: Diagrammatic representation of a 5.1-cm osteosarcoma on the right lateral maxilla of a 7 year old spayed female domestic shorthair cat. The position of two transverse sections are indicated by the letters B and C are shown in the diagram. The imaging and histologic sections at these locations are provided in the panels below. Panels B and C: Top row: Transverse fused PET/CT image (left). H&E stained tissue section at 4× magnification (middle). Pimonidazole at 4× magnification (reconstructed from tiled images) stained tissue section (right). Corresponding regions in the PET/CT and histologic sections are marked by the numbers 1 and 2. Bottom Row (20× magnification of histologic sections): H&E stained image from area marked “1” (Far left); Pimonidazole stained image from area marked “1” (Middle left). H&E stained image from area marked “2” (Middle right); Pimonidazole stained image from area marked “2” (Far right). Note: The tumor tissue was friable and there were areas of necrotic debris, such as the area marked by a star in panel B, that were lost during processing.