The experimental study on the prediction of bone lesion extent by radionuclide bone imaging

Objective: To investigate the difference between the extent of bone lesions measured by bone scintigraphy or SPECT and its actual size and compare with radiography. Methods: Static planar imaging was performed on linear models of various lengths, which were filled with Tc-99m pertechnetate. The energy photon-peak was set at 140 keV with a 20% symmetric window. Artificial tibial injury was established on twenty-two rabbit models. Bone scintigraphy (SPECT when required) and radiography were carried out on twenty rabbits. All scintigraphic data obtained from semiquantitative analysis were evaluated by two readers. Results: The length of linear model was in concordant with that measured by scintigraphy with each pixel equal to 1.1 mm in the 512 x 512 matrix. The actual extent of bone injury was overestimated at an average of 1.02 cm displayed by bone scintigraphy in animal model. Contrary to the linear model, each pixel represents 0.71 mm in the 512 x 512 matrix, with a statistically significance difference. Two of the twenty bone trauma contiguous to joint were measured 2 cm larger. However, in four cases, radiography showed nothing but the implanted metal. Conclusion: Compared with radiography, bone scintigraphy is sensitive enough to estimate bone lesions and may offer specific guidelines in determining the appropriate extent of bone resection while entirely clearing the tumor cells and preserving functions whenever possible