Data analysis: evaluation of nanoscale contrast agent enhanced CT scan to differentiate between benign and malignant lung cancer in mouse model.

Proposed is a method for statistical analysis for a small sample size, repeated measure experiment with nesting factors. In the original experiment the Student t-test was used for analysis. Using the same data, we modeled the experiment into two groups of mice with benign and malignant primary lung tumors. 4 tumor nodules were selected from each mouse (N= 36). The dependent variables are the volume, diameter, and signal attenuation measured using computed tomography (CT). The measurements are made before injecting the contrast and at 0, 72, and 168 hours after injection. The contrast agent enhances tumor nodule volume and volume differences between benign and malignant tumor nodules measured across time (p < 0.05). The signal attenuation measured across time differentiates between benign and malignant groups (p < 0.05). There is significant correlation between rate of change of volume and diameter of tumor. The advantages of this statistical method are discussed.