Animal Models for Preclinical Imaging - Nanotechnology for Biomedical Imaging and Diagnostics - page 456

16

AnimAl models for PreclinicAl
imAging

Grayson Talcott and Walter J. Akers
Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA

16.1 introduction

The purpose of biomedical imaging is to noninvasively detect the presence and inves-
tigate the progression of pathologic processes (disease). The requirements for imaging
are dependent on the level of detail needed for adequate characterization of the disease
at hand. Diagnosis of a broken bone may only require planar X-ray, while diagnosis of
metastatic cancer requires molecular imaging with 18 F-fluorodeoxyglucose ( 18 F-FDG)
positron emission tomography (PET).
Biomedical imaging has been driven by the need to see below the surface into the
intricate workings of the body in health and disease. Interrogation of anatomical
structures is accomplished via X-ray, X-ray CT, and MRI, which have become higher
in quality over the last 30 years. Contrast enhancement has further improved the
capability of these modalities to evaluate physical structures of the cardiovascular
system and central nervous system (CNS). Physiologic imaging began with nuclear
medicine using radiotracers to assess renal clearance and blood flow. We are now in
the age of molecular imaging in which expression and activity of disease-specific
molecules and genes can be assessed using targeted contrast agents.
The goals of preclinical imaging are not the same as clinical biomedical imaging. In
general, animal models are selected based on predictable and reproducible outcomes
with known anatomy, physiology, and even molecular and genetic expressions. Imaging
modalities are generally utilized in basic research for noninvasive or minimally invasive