In vivo small animal imaging: Current status and future prospects

Abstract

The use of small animal models in basic and preclinical sciences constitutes an integral part of testing new pharmaceutical agents prior to commercial translation to clinical practice. Whole-body small animal imaging is a particularly elegant and cost-effective experimental platform for the timely validation and commercialization of novel agents from the bench to the bedside. Biomedical imaging is now listed along with genomics, proteomics, and metabolomics as an integral part of biological and medical sciences. Miniaturized versions of clinical diagnostic modalities, including but not limited to microcomputed tomography, micromagnetic resonance tomography, microsinglephoton-emission tomography, micropositron-emission tomography, optical imaging, digital angiography, and ultrasound, have all greatly improved our investigative abilities to longitudinally study various experimental models of human disease in mice and rodents. After an exhaustive literature search, the authors present a concise and critical review of in vivo small animal imaging, focusing on currently available modalities as well as emerging imaging technologies on one side and molecularly targeted contrast agents on the other. Aforementioned scientific topics are analyzed in the context of cancer angiogenesis and innovative antiangiogenic strategies under-the-way to the clinic. Proposed hybrid approaches for diagnosis and targeted site-specific therapy are highlighted to offer an intriguing glimpse of the future.

Real-Time Microfluidic Blood-Counting System for PET and SPECT Preclinical Pharmacokinetic Studies

“…However, dispersion of the radioactive bolus inside the catheter of an external blood counter distorts the AIF relative to the sampling site and leads to error in kinetic parameters. For example, Votaw et al (34) measured a 0.3% error in cerebral blood flow estimated with H 2 15 O for a dispersion of 1.3 s. This error rises to 33% for a dispersion of 10 s. Dispersion can be reduced by minimizing the animalto-detector distance, by decreasing the cannula internal diameter, and by maximizing the withdrawal rate. Unfortunately, dispersion is always significant in typical experiments with mice, mainly because of the limited withdrawal rate.…”

“…In research applications, small-animal models are needed to facilitate the development of new drugs, radiotracers, and therapies that can eventually be translated to humans (2). Quantification of metabolic or physiologic disorders using radiotracer pharmacokinetic models requires dynamic blood analysis in addition to tissue imaging data (3).…”

Design and development of a hybrid preclinical PET/SPECT/X-ray system

“…Multimodal molecular imaging is considered as the optimal technology to study non-invasively the biodistribution of new biomolecules, as well as understand molecular mechanisms [1]. While many imaging systems are commercially available, their cost does not allow their purchase by many small and medium research groups.…”

Small Animal Imaging in Development of New Generation Diagnostic and Therapeutic Agents

“…Magnetic resonance imaging (MRI) and resonance (MRS), single photon emission computed tomography (SPECT), positron emission tomography (PET) and optical imaging (OI) are widely used and several reviews (King et al 2002, Gröhn & Pitkänen, 2007, Kagadis et al 2010, Snoeks et al 2011 have been published about these techniques, their strengths and faults. Choosing the most suitable imaging application for a certain study depends of the prioritization of features.…”