Table 3.

Porcine study: RE and UQI values of different reconstruction techniques with different levels of angular sampling sparseness (varied by numbers of projections). The “Initial Prior” column shows the RE and UQIs between the “gold‐standard” new CT volume and the initial prior CT volume. Other columns show the RE and UQI values between the “gold‐standard” new CT volume and the CT volumes reconstructed by different techniques. The UQI values were calculated based on the three 2D ROIs enclosed in the boxes of Fig. 9(a), evaluating axial, coronal, and sagittal views, respectively

No. of projections	Initial prior	ART‐dTV	2D‐3D Deformation	ADRIC
RE
10	15.66%	10.70%	14.91%	8.98%
20		8.78%	13.61%	6.80%
40		7.97%	12.58%	5.82%
60		6.91%	12.14%	5.29%
UQI (axial ROI/coronal ROI/sagittal ROI)
10	0.37/ 0.65/ 0.69	0.65/ 0.78/ 0.78	0.13/ 0.39/ 0.69	0.68/ 0.82/ 0.84
20		0.82/ 0.90/ 0.86	0.19/ 0.47/ 0.78	0.84/ 0.91/ 0.91
40		0.88/ 0.92/ 0.90	0.24/ 0.49/ 0.85	0.90/ 0.94/ 0.95
60		0.91/ 0.95/ 0.94	0.25/ 0.50/ 0.85	0.93/ 0.96/ 0.96