Computed Tomography and Magnetic Resonance Imaging Guided Anatomical Assessment of Organ Pathologies in Laboratory Rats.

Non-invasive imaging modalities, particularly computed tomography (CT) and magnetic resonance imaging (MRI), play a pivotal role in preclinical research by enabling detailed evaluation of organ anatomy without invasive procedures. This study comparatively assessed the anatomical characteristics and imaging-based structural abnormalities of the liver, kidneys, heart, and brain in laboratory rats to evaluate the complementary imaging value of CT and MRI. Healthy anesthetized rats were allocated into imaging-reference and imaging-evaluation groups and subjected to standardized CT and MRI examinations. A total of 10 anesthetized laboratory rats underwent standardized CT and MRI examinations in this pilot exploratory imaging study. Animals were classified after imaging assessment into imaging-reference (n = 5) and imaging-evaluation (n = 5) groups according to predefined radiological criteria; no experimental disease model was induced. Cross-sectional images were reconstructed in multiple anatomical planes and evaluated using predefined radiological criteria. CT analysis focused on organ morphology, structural integrity, tissue attenuation, and anatomical boundaries, whereas MRI emphasized soft-tissue architecture and signal-intensity characteristics. CT provided excellent visualization of organ shape, radiodensity, and focal structural alterations, including irregular organ contours, heterogeneous attenuation, and localized hypodense regions. MRI demonstrated superior soft-tissue contrast and greater sensitivity for detecting subtle alterations in tissue architecture and signal intensity. Comparative evaluation showed that CT was particularly effective for gross anatomical assessment, while MRI offered enhanced characterization of internal tissue abnormalities. The complementary information obtained from both modalities improved the overall interpretation of imaging findings across multiple organs. These findings highlight the value of integrating CT and MRI for comprehensive, non-invasive anatomical assessment in laboratory rats and support their potential utility in preclinical anatomical imaging and multimodal structural assessment.