Figure 1

Radiological and histochemical analysis of tumor development in the tibia. (A-D) To confirm bone destruction of the tibia by tumor, rats were radiographed on 6 (Figure B and b), 12 (Figure C and c) and 18 days (Figure D and d) after carcinoma cell inoculation of the ipsilateral hind limb. Arrows indicate structural destruction of the proximal cortical bone. In addition, for the control, bilateral hind limb of group K1 rats on days 18 was showed in Figure A. (E) Whole body bone SPECT imaging at day 12 post-injection was showed in Figure E. SPECT detected bone formation to be active in the left proximal tibia (see the arrows). (F) HE staining of the left tibia showed that bone marrow spaces were infiltrated with malignant tumor (Cancer nest, see the arrow) on day 12 after Walker 256 cell inoculation. (G-K) On day 18 after carcinoma cell inoculation, rats were also investigated with MRI (Magnetic Resonance Imaging) of the hind limbs (Figure G-K). After optimal adjustment of contrast, axial T1-weighted imaging (A × T1, Figure G), axial T2-weighted imaging (A × T2, Figure H), coronal fat suppressed sequence T2-weighted imaging (Cor × T2+, Figure I), axial enhanced T1-weighted imaging (A × T1+, Figure J), and coronal enhanced T1-weighted imaging (Cor × T1+, Figure K) data were analyzed by visually identifying and encircling areas of abnormal signal intensity for each MR section using a side to side comparison on the screen. Full thickness bicortical bone loss, cortical destruction, and soft tissue tumors were observed obviously (Arrow).