SoundScape: A portable small animal imager to accelerate drug development

SUMMARY Drug development plays an invaluable role in bringing life-saving pharmaceuticals to patients, but the process is slow and can take many years. Animal imaging plays a prominent role in the pre-clinical development phase which can make up a significant portion of the timeline (5-10 years). A major factor that impacts the duration of this phase is the high capital and recurrent costs of imaging lab equipment that limit the number of available labs that participate in drug development. While medical imaging is currently used for noninvasive, in vivo longitudinal small-animal studies, these studies often require access to complex equipment, and dedicated personnel who are properly trained in their use, which results in high costs. The most common current imaging modalities include Micro-CT, MRI, fluorescence imaging, photoacoustic imaging and ultrasound. The first two methods provide high-resolution and are de-facto standards, but they are expensive, non-portable, and require active shielding for ionizing radiation and magnetic fields, respectively. Fluorescence imaging is commonly used to track tumor growth, but generally suffers from poor resolution in deep tissue, and it requires external contrast agents. The emerging photoacoustic tomography method offers cross-sectional 3D imaging, but at the expense of portability, increased cost, and reduced reliability due to the usage of pulsed lasers. Traditional preclinical pulse-echo ultrasound is fast, portable, delivers high (~30 μm) resolution and allows for vascular and blood flow imaging; however, the imaging results depend strongly on the operator skills, and the images are limited to partial cross-sections of the animal that often do not provide quantitative physical tissue characteristics. There is therefore a need for more cost-effective imaging solutions with high image quality. As a first step in fulfilling this need, the objective of our study is to design a small animal scanner that operates on the principles of ultrasound tomography (UST), a novel technique for visualizing tissue properties with computed tomography that uses sound waves instead of X-rays. Ultimately, we wish to develop the “SoundScape mini”, a commercial product that will generate MRI-like images of small animals at a fraction of the cost of MRI, making it available to the multitude of smaller labs that currently lack the resources to perform their own pre-clinical imaging. By making pre-clinical imaging accessible to all labs, we seek to harness their collective power to crowdsource drug development, thereby substantially shortening the pre-clinical development and testing phase. The system will have the additional advantages of being desktop portable and fully automated without the need for a dedicated technician. In summary, we believe that any lab/investigator will be able to accommodate a SoundScape mini. Our long- term goal is to empower a large scientific community with SoundScape, thereby greatly expanding the bandwidth of drug development, accelerating time to market and generating substantial positive impact on global health.