Surface-Coil MRI for Small Peripheral Choroidal Melanoma: Imaging in a Rabbit Eye Model

Abstract

Introduction: Imaging of small peripheral choroidal melanomas remains challenging in clinical and experimental settings, requiring wide-field ophthalmoscopy modalities. In this study, we applied surface-coil MRI to assess imaging feasibility for small peripherally located choroidal melanoma in a rabbit eye model. Methods: A female albino rabbit with a body weight of 2.8 kg was immunosuppressed with intramuscular cyclosporine 15 mg/kg daily for 3 days prior to inoculation of 14 million 92.1 line melanoma cells into the peripheral suprachoroidal space of the right eye. The experimental animal continued to receive the same dosage of cyclosporine daily for 26 days postinoculation until the day of sacrifice. On that interval, it underwent surface-coil MRI scanning using various protocols and models subsequently sacrificed to allow histological evaluation. A comparative examination of various MRI sequences for optimal lesion imaging was performed, based on semiquantitative criteria. Results: Imaging quality and superimposed artifacts varied across different sequences and the optimal tumor delineation from adjacent tissues was achieved in T1-weighted sequences. Conclusions: MRI of small peripheral choroidal melanomas is feasible in a rabbit model using surface coils, particularly in T1-weighted sequences. Findings may be used as a basis for further development of this technique for experimental and clinical applications.