Noninvasive monitoring of a murine model of metastatic pheochromocytoma: A comparison of contrast‐enhanced microCT and nonenhanced MRI

Abstract

Purpose To compare contrast-enhanced micro computed tomography (microCT) and non-enhanced respiratory-triggered MRI in an animal model of metastatic pheochromocytoma. Animal models are becoming important in the study of cancer treatment and imaging is useful in minimizing the number of animals needed and reducing costs associated with autopsies. However, the choice of imaging modality is still evolving. Materials and Methods Adult female nude mice were injected by tail vein with a mouse pheochromocytoma (MPC) cell line (MPC 4/30PRR) to create a metastatic model. After optimizing imaging techniques eight mice were imaged with both respiratory triggered MRI and microCT and the findings were verified histologically. Results MicroCT and MRI were approximately equal in their ability to detect hepatic metastases at a size threshold of 350 μm. In the lungs, MRI was more sensitive than microCT, detecting lesions 0.6 mm in diameter vs. 1mm for microCT. Additionally, MRI was more sensitive for lesions in the kidneys, bone, ovaries and adrenal glands. MRI demonstrated higher contrast-to-noise ratio (CNR) than microCT. Conclusion In addition to the advantage of not exposing the animal to ionizing radiation, MRI provided a more complete assessment of the extent of metastases in this model, compared to microCT.

Increased uptake of [123I]meta-iodobenzylguanidine, [18F]fluorodopamine, and [3H]norepinephrine in mouse pheochromocytoma cells and tumors after treatment with the histone deacetylase inhibitors

“…The metastatic mouse pheochromocytoma model used in this study was previously described (22, 30). Briefly, female 6-8 week old (20-22 g) athymic nude mice (NCr-nu; Taconic, Germantown, NY) were injected by tail vein with 1×10 6 MPC (MPC 4/30 PRR) cells.…”

Structural imaging of the pancreas in rat using micro-CT: application to a non-invasive longitudinal evaluation of pancreatic ductal carcinoma monitoring

“…This accuracy in small tumor detection [5,7,8,10,14,15,22] is an advantage of using CT [22] for longitudinal evaluation of tumors. However, MRI using magnetic fields is assumed to be a harmless imaging procedure [20][21][22][23][24][25] even if newly controversial, [30,31] whilst CT, an X-raybased approach, raises concerns about immunological and general physiological changes that might affect the experimental outcome [32].…”

“…Small animal imaging technologies have been already extensively applied for liver imaging using CT or MRI [20][21][22] at a lesser degree, but not for pancreas. Few MRI [23][24][25] and one CT studies [16] for pancreatic tumor detection in mice are available in the literature.…”

“…However, MRI using magnetic fields is assumed to be a harmless imaging procedure [20][21][22][23][24][25] even if newly controversial, [30,31] whilst CT, an X-raybased approach, raises concerns about immunological and general physiological changes that might affect the experimental outcome [32]. Indeed, if the irradiation level (2.5 cGy for 10 min acquisition with an Imtek CT in rats) [33] is notably lower than sub-lethal doses [14,33,34], it can transiently damage the support of genetic information [35].…”

Noninvasive Monitoring and Evaluation of the Renal Structure and Function in a Mouse Model of Unilateral Ureteral Occlusion Using Microcomputed Tomography

“…The authors concluded that, in addition to the advantages of not exposing the animal to ionizing radiation, MRI provides a more complete assessment. 15 In contrast, micro-CT imaging can be performed easily and also allows for functional studies, while also being readily implemented in animal facilities.…”