Ultrasound imaging in orthotopic hepatocellular carcinoma models: Promise, practicality, and points for refinement

Table 1 Comparative overview of imaging modalities utilized in preclinical hepatocellular carcinoma models

Imaging modality	Advantages	Limitations	Ref.
High-frequency ultrasound	Real-time, non-invasive, affordable; enables serial monitoring and correlates well with histology or MRI	Limited soft-tissue contrast for small or heterogeneous lesions; accuracy may decrease for deep or poorly defined tumors	Devan et al[1], Roth et al[2], Molière et al[3]
Histology	Gold standard for cellular detail; assessment of necrosis, vessels and immune cells	Requires tissue harvest; terminal procedure; not suitable for longitudinal studies	Herrero de la Parte et al[5], Choi et al[10]
Micro computed tomography	High-resolution three dimensional anatomy and vasculature; volume quantification	Involves radiation exposure and need for contrast agents; limited soft-tissue contrast	Singh et al[8], Cigliano et al[11]
MRI	Excellent soft-tissue contrast; quantitative; reproducible; translational	Expensive; long scan time; limited accessibility in small animal settings	Rojas et al[4], Renzulli and Giampalma[12]
Photoacoustic imaging	Combines optical and ultrasound contrast to visualize vascular oxygenation and perfusion	Restricted penetration depth; often relies on exogenous optical contrast agents; specialized setup required (operator dependent)	Nyayapathi et al[7]
Super-resolution ultrasound	Allows visualization of microvascular changes beyond conventional resolution	Requires contrast microbubbles and operator dependent complex data processing; limited availability and standardization	Hoyt[6], Riberdy et al[9]

Comparison of major imaging modalities used in preclinical hepatocellular carcinoma models, highlighting their respective advantages and limitations. MRI: Magnetic resonance imaging.