High Resolution X-ray Computed Tomography: An Emerging Tool for Small Animal Cancer Research

Abstract

Dedicated high-resolution small animal imaging systems have recently emerged as important new tools for cancer research. These new imaging systems permit researchers to noninvasively screen animals for mutations or pathologies and to monitor disease progression and response to therapy. One imaging modality, X-ray microcomputed tomography (microCT) shows promise as a cost-effective means for detecting and characterizing soft-tissue structures, skeletal abnormalities, and tumors in live animals. MicroCT systems provide high-resolution images (typically 50 microns or less), rapid data acquisition (typically 5 to 30 minutes), excellent sensitivity to skeletal tissue and good sensitivity to soft tissue, particularly when contrast-enhancing media are employed. The development of microCT technology for small animal imaging is reviewed, and key considerations for designing small animal microCT imaging protocols are summarized. Recent studies on mouse prostate, lung and bone tumor models are overviewed.

Characterization of a rat model with site‐specific bone metastasis induced by MDA‐MB‐231 breast cancer cells and its application to the effects of an antibody against bone sialoprotein

“…Visualization of bone ultrastructure would require the use of a novel Volume CT or Micro CT scanner. 15 Although much has been learned about the pathogenesis of bone metastasis, many important interactions and processes remain to be elucidated. For the aspect of tumor cell extravasation, Mastro et al 16 concluded that mechanical arrest of cancer cells is more common to occur in nonskeletal sites with capillaries of smaller diameters (e.g., lungs) than in the wide-channeled sinusoids of bone.…”

Small Animal Imaging Center Design: The Facility at the UCLA Crump Institute for Molecular Imaging

“…These parameters vary considerably, depending on the imaging device. In our facility, the supported devices are microPET ® [4], microCAT ™ [5], optical imaging [1,6], and digital autoradiography with a cryosectioning and imaging system. The proper and best use of these systems, including the rules and regulations stipulated by the Biohazardous Materials, Radiation Safety and Animal Research committees, were all considered in the design plan.…”

High-Resolution CT for Small-Animal Imaging Research

“…Apart from a single case known in the literature of high-resolution CT reconstruction of a rat kidney from the digitization of multiple film radiographs (Kujoory et al, 1980), early prototype micro-CT systems employed x-ray image intensifiers read by charged coupled devices (CCDs) (Boone et al, 1993;Feldkamp et al, 1989;Holdsworth et al, 1993). Later in the mid-1990s, combined detection systems made up of scintillator screens coupled to CCDs via fiber-optic bundles, with various demagnifying ratios, became the standard for micro-CT imaging (Goertzen et al, 2004;Paulus et al, 2000). More recently, the advances in CMOS technology led to the production of large-area detectors with high frame rates, which are the most widely used systems for in vivo small-animal imaging (Kalender and Kyriakou, 2007;Lee et al, 2003).…”

“…A typical micro-CT scanner uses an x-ray source and a highresolution digital x-ray detector (Paulus et al, 2000(Paulus et al, , 2001, with two possible design geometries: (1) rotating gantry (x-ray source and detector) or (2) rotating specimen (see Figure 1(a) and 1(b)). The majority of current commercial systems for in vivo scanning use the rotating gantry geometry, that is, they are scaled versions of the clinical CT scanners (Figure 1(a)).…”