Fig. 2

Successful tissue differentiation on micro-CT scanning demonstrate iodine diffusion staining technique is practical for both large (age of 25 days) and small (age of 36 h) postnatal encapsulated rat brain, Figure (a–g). (a) demonstrates unsuccessful neural-tissue scanning using 1.0% iodine perfusion staining for adult rat, whereas (b) and (c) show 1.5% iodine diffusion staining yielded good neural tissue contrast with adult and neonatal rat brains after 44 and 16 days, respectively. However, the same staining techniques using 0.5 and 1.0% PTA yielded little success on adult rat brains, (d) and (e), even after 2.5 years. Similarly, (f) and (g) show incomplete tissue differentiation of neonatal rat brains despite prolonged staining of 148 days using 0.5 and 1.0% PTA staining, respectively. Because PTA staining was non-uniform, selected coronal views were chosen to illustrate regions of incomplete tissue differentiation: (a–d) are anterior coronal views while (e–g) are posterior coronal views. Figure (h–n) illustrate iodine diffusion staining is equally effective but more efficient temporally to PTA staining for micro-CT scanning of small and isolated neural tissues. (h) shows lack of tissue contrast with no staining. (i–k) illustrate progressive improvement of tissue details on micro-CT scans with 1.5% iodine staining over time: 3, 6 h, and 6 days, respectively. Similarly, (l–n) show the same with 1.5% PTA staining over the same respective durations. Iodine staining was significantly faster