Application-based Small Animal Imaging segmentation is dominated by oncology, which accounts for roughly 42 % of global demand. The need to serially track subcutaneous and orthotopic tumor growth, quantify vascular perfusion, and evaluate early therapeutic response drives pre-clinical PET, MRI, and optical system purchases. Neurology follows with a 23 % share; stroke, glioblastoma, and neurodegeneration models require high-resolution functional and structural read-outs, pushing labs toward 7 T MRI and multispectral optoacoustic platforms. Cardiology contributes 15 %, propelled by myocardial infarction and atherosclerosis studies where micro-ultrasound and micro-CT deliver rapid 3-D wall-motion data. Inflammation / arthritis and infectious disease together add 12 %, capitalizing on near-infrared fluorescence to follow leukocyte trafficking. The residual 8 % comprises metabolism, toxicology, and rare phenotyping, each too fragmented to command dedicated modalities yet collectively sustaining service-based core facilities.