FEASIBILITY STUDY OF MAGNETIC RESONANCE IMAGINING APPLICATION IN EXPERIMENTAL RADIOLOGY FOR INTRAVITAL VERIFICATION OF LUNGS METASTASES IN MICE

Background. For preclinical studies of radiopharmaceuticals there is a high need for development new methods of in vivo metastasis diagnosis in mice after tumor cells transplantation. The study was carried out to assess feasibility of lung metastasis diagnosis with magnetic resonance imaging (MRI) visualization in mice C57Bl6. The aim of this study was to assess feasibility of MRI for verification of distant metastases of the solid B16-F10 melanoma with validation by anatomic dissection. Methods. Metastatic lesions were caused by injection of B16-F10 murine melanoma cells into cavum medullare of the tibia. Imaging studies were performed on the 21th day after transplantation using 7T magnetic resonance tomograph, coronal and axial images were acquired. Validation of metastasis was made by anatomic dissection and histological examination. Results . MRI method enables visualization of lung nodules with diameter at least 0.8 mm, because smaller nodules cannot be distinguished from heartbeat artifacts. Histological examination revealed that macroscopic anatomic dissection can precisely detect subpleural lung nodules. Conclusion . This study demonstrated feasibility of in vivo lung metastasis verification with MRI method in mice: metastases comparable in diameter to the size of large bronchi can be detected by MRI as well as by ex vivo dissection. For centrally located lung metastasis MRI method is preferable because macroscopic dissection enables to visualize only nodules which are located subpleurally.