Table 1.

Contrast-to-noise ratios (CNR) between tissue and embedding material for the reconstructed raw data set (RAW) and the reconstructed phase retrieved data set (PHR) for the PTA stained lungs embedded in resin and paraffin.

	Paraffin	Resin
CNR RAW	1.90 ± 0.45	0.51 ± 0.05
CNR PHR	9.98 ± 1.65	5.94 ± 1.33
CNR PHR/CNR RAW	5.3 ± 1.73	11.6 ± 3.06

The ratio (CNR PHR/CNR RAW) reveals that phase retrieval was more beneficial for the resin embedded sample than for the paraffin embedded sample, but in both cases significantly improved the CNR.