Phantoms for magnetic resonance imaging-guided focused ultrasound and associated robotic systems research

Magnetic resonance-guided high-intensity focused ultrasound (MRgHIFU) has emerged as a powerful noninvasive therapy with expanding applications in oncology, neurology, and beyond. Reliable preclinical evaluation relies on tissue-mimicking phantoms (TMPs), which provide controlled platforms for assessing the acoustic, thermal, and imaging performance of MRgHIFU protocols and related equipment. This review employs a narrative methodology to integrate representative findings from the field, drawing on PubMed and Google Scholar searches using keyword combinations related to MRgHIFU, phantom development, and associated research areas. The reviewed literature highlights the main principles and materials underlying HIFU phantom design, their application in evaluating MRgHIFU physics and their role in preclinical and clinical quality assurance (QA) of magnetic resonance imaging (MRI)-compatible robotic systems—including assessments of targeting accuracy and thermal delivery reliability—as well as their integration with MR thermometry. The analysis also identifies ongoing challenges and future directions, emphasizing the value of phantom-based studies that support greater reliability and translatability in MRgHIFU research. TMPs provide an indispensable basis for QA and controlled MRgHIFU assessment, yet improved physiological realism is needed to enhance suitability for thermal-response assessment and translatability, and further standardization is required to ensure consistency across studies.