## 3 Results
### MR Findings
#### 3.3.2 Extratumoral MR Findings  
The MR appearance of irradiated extratumoral ocular tissues was as follows:  
_Radiation-related intraocular inflammation (iveitis, endophthalmitis, and chronic conjunctivitis)_. In the case of _panuveitis_ (1/9 patients), MRI showed diffuse thickening of the globe wall that displayed noticeable enhancement on contrast-enhanced fat-suppressed T1-weighted images. This sequence also showed a coexisting diffuse choroidal detachment. In _endophthalmitis_ (3/9 patients), the anterior chamber and vitreous body showed increased signal intensity on precontrast T1-weighted images. Another typical finding was the high signal intensity of the vitreous body on T2-weighted fluid-attenuated inversion recovery (FLAIR) sequences performed for the brain examination executed concomitantly with the MR of the orbit (Figure 2). _Chronic conjunctivitis_ (1/9 patients). The conjunctivita appeared thickened with considerable enhancement on contrast-enhanced fat-suppressed T1-weighted sequences. _Vitreous hemorrhage_ (2/9 patients) was better visible on T1-weighted sequences in which both the anterior chamber and the vitreous body displayed high signal intensity. In 1/2 patients, on T2-weighted images, an intraocular fluid-fluid level, with relative hypointensity of the dependent portion, was identifiable within the vitreous body. On DW images vitreous hemorrhage showed restricted diffusion (Figure 3). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**MR Finding** & **T2** & **T1** & **Gd-T1** & **DWI** \\ \hline Radiation-induced necrosis & Low signal & High signal & No enhancement & Low signal \\ \hline Fibrosis & Low signal & Intermediate signal & Moderate enhancement & Low signal \\ \hline Viable tumor tissue, pigmented melanoma & Low signal & High signal & Enhancement of viable tissue & High signal \\ \hline Viable tumor tissue, poorly pigmented melanoma & Intermediate signal & Intermediate signal & Enhancement of viable tissue & High signal \\ \hline \hline low signal; internetate signal; & high signal; & no enhancement; & enhance- \\ \end{tabular}
\end{table} 
Table 5: Chart summarizing the MR imaging appearance of irradiated uveal melanomas. Figure 2: _Endophthalmitis_. A 37-year-old male patient (patient n. 5 of our series) affected by choroidal melanoma of the right eye treated with proton beam radiotherapy. Secondary enucleation was carried out 38 months after radiotherapy because of local recurrence associated with inflammatory complications and eye pain. Axial (**a**) T2-weighted FLAIR (from brain MRI scan) and (**b**) fat-suppressed T1-weighted images show increased signal intensity of the vitreous body of the right eye (white asterisks); this finding is consistent with vitreous inflammation with protein leakage. The contralateral eye shows the physiological water-like hypointense signal. (**c**) A coronal T2-weighted turbo spin-echo image displays a dome-shaped intraocular choroidal melanoma (black arrow), located along the superior aspect of the right globe, protruding into the posterior chamber. _Optic nerve degeneration_ (3/9 patients). The optic nerve of the affected eye appeared thinned and moderately hyperintense on T2-weighted images in comparison with the contralateral one (Figure 4). Figure 3: _Vitroous hemorrhage._ A 75-year-old female patient (patient n. 8 of our series) affected by choroidal melanoma of the left eye treated with proton beam radiotherapy. Secondary enucleation was carried out 14 months after radiotherapy because of local recurrence associated with treatment-related complications and eye pain. Axial (**a**) T2-weighted turbo spin-echo, (**b**) contrast-enhanced fat-suppressed T1-weighted, and (**c**) DW (b = 1000 s/mm\({}^{2}\)) images. The left globe (white asterisks) exhibits increased signal intensity on the T1-weighted image and inhomogeneous signal intensity with fluid–fluid level on the T2-weighted image. On (**c**) the DW image the left vitreous body shows restricted diffusion with high signal intensity (white asterisk).