Various Ocular MR Imagings in a Mouse Implanted with a New Cell Line of Retinoblastoma and the Correlation with the Pathology: Preliminary Study

PURPOSE: We wanted to show various MR and correlated pathologic images of retinoblastoma in nude mousewith a new human retinoblastom cell line (SNUOT-Rb1), which was inoculated into the intravitreous cavity. MATERIALS AND METHODS: The established cell line was inoculated into the intravitreous cavity of 36 eyeballs of 18 mice and the transplanted retinoblastoma was examined for 3 months. The T1-weighted (T1WI), T2-weighted (T2WI), and contrast enhanced (Gd-DTPA) T1-weighted images were obtained with using a small loop coil. After scanning, the mice's eyeballs were extracted and the hematoxylin & eosin stained specimens were examined with a microscope. We compared the MR imagings with pathologic findings and evaluated the character of the tumors. RESULTS: The innoculated cells in the eyeballs of the mice grew into retinoblastoma (23/36, 64%). The eyeballs with retinoblastoma protruded externally and showed focal hemorrhage. Most tumors showed iso-signal intensity on TIWI (13/23, 57%), high signal intensity on T2WI (17/23, 74%), and good enhancement (21/23, 91%) with contrast. Almost all of the tumors (n=21) were located in the retina and three extraretinal tumors were confirmed by pathology. Involvement of the optic nerve was suspected on MRI and this was confirmed by pathology in 6 cases and 5 cases, respectively. CONCLUSION: We could demonstrate various MR imagings of transplanted retinoblastoma by using the new tumor cell line in vivo.

MR Imaging of the Eyeball: Anatomy and Pathology

The eyeball can be divided into the anterior and posterior compartment bordering on the lens. The ocular wallis composed of three layers, namely the sclera, choroid and retina. Different pathologic conditions can occur,depending on the anatomic location. This paper illustrates the anatomical features of normal eyeball, as seen onMRI, and a variety of pathologic conditions of the compartments. An understanding of the MR features of variousintraocular lesions is thus facilitated