Contrast-Enhanced Microcomputed Tomography Using Intraperitoneal Contrast Injection for the Assessment of Tumor-Burden in Liver Metastasis Models

OBJECTIVES:To determine if intraperitoneally (IP) administered contrast (iohexol), used in conjunction with a liver-specific agent (Fenestra), can improve measurement precision and accuracy when quantifying tumor volume from micro-CT images of a liver metastasis model. MATERIALS AND METHODS:We compared images acquired with Fenestra alone to images acquired with the combination of Fenestra and IP iohexol. The variability in tumor volume and tumor-burden measurement was evaluated for both techniques. The tumor-burden measurement accuracy of both in vivo techniques was determined by comparison with tumor-burden quantified from ex vivo images. RESULTS:The addition of IP iohexol decreased measurement variability for individual tumors and overall tumor-burden by 4–8 fold and 2–3 fold, respectively. IP iohexol significantly improved the accuracy of tumor-burden measurement for both low and high tumor-burdened animals. CONCLUSIONS:The combination of IP iohexol with Fenestra provides superior delineation of liver tumors, in comparison to Fenestra alone. The complete tumor delineation provided by this imaging strategy allows for noninvasive quantification of liver tumor-burden.