Table 1.

Experiment 1—Detailed DSC and SMBD performances at several compression ratios for 2D and 3D U-Net segmentation of the bladder on CT and CBCT images.

Bladder		Compression ratio
		1:1	24:1	32:1	48:1	64:1	96:1	128:1
DSC	2D CT	$0.918\pm 0.039$	$0.914\pm 0.038$	$0.902\pm 0.042$	$0.872\pm 0.067$	$0.809\pm 0.088$	$0.578\pm 0.182$	$0.301\pm 0.260$
	3D CT	$0.916\pm 0.033$	$0.912\pm 0.034$	$0.902\pm 0.043$	$0.885\pm 0.060$	$0.859\pm 0.076$	$0.758\pm 0.122$	$0.409\pm 0.291$
	2D CBCT	$0.855\pm 0.068$	$0.842\pm 0.071$	$0.805\pm 0.074$	$0.748\pm 0.073$	$0.651\pm 0.078$	$0.347\pm 0.077$	$0.175\pm 0.096$
	3D CBCT	$0.832\pm 0.118$	$0.825\pm 0.123$	$0.808\pm 0.129$	$0.780\pm 0.138$	$0.741\pm 0.141$	$0.651\pm 0.118$	$0.450\pm 0.133$
SMBD	2D CT	$2.040\pm 1.404$	$2.251\pm 1.280$	$2.407\pm 1.170$	$3.157\pm 1.455$	$4.663\pm 2.546$	$7.204\pm 3.598$	$10.08\pm 2.741$
	3D CT	$1.445\pm 0.579$	$1.546\pm 0.615$	$1.831\pm 0.806$	$2.083\pm 1.123$	$2.458\pm 1.356$	$3.901\pm 1.995$	$8.205\pm 4.186$
	2D CBCT	$2.883\pm 1.827$	$3.015\pm 1.702$	$3.490\pm 1.699$	$4.121\pm 1.662$	$4.912\pm 1.336$	$7.989\pm 2.466$	$13.20\pm 4.251$
	3D CBCT	$2.582\pm 1.963$	$2.695\pm 2.033$	$2.955\pm 2.167$	$3.361\pm 2.364$	$3.857\pm 2.371$	$4.902\pm 1.920$	$7.811\pm 2.151$