Table 2. Comparison of Grid Images with Grid-Like Images for 11 Anatomic Region.

Anatomic Regions	1	2	3	4	5	Mean	P
Unobscured lung
Reader 1	0	1	37	0	0	3.0	0.317
Reader 2	0	7	28	3	0	2.9	0.206
Hilum
Reader 1	0	0	38	0	0	3.0	1.000
Reader 2	0	0	37	1	0	3.0	0.317
Minor fissure
Reader 1	0	8	26	4	0	2.9	0.248
Reader 2	0	2	36	0	0	2.9	0.157
Rib
Reader 1	0	1	37	0	0	3.0	0.317
Reader 2	0	0	38	0	0	3.0	1.000
Heart border
Reader 1	0	1	37	0	0	3.0	0.317
Reader 2	0	0	38	0	0	3.0	1.000
Retrocardiac lung
Reader 1	0	19	18	1	0	2.5	< 0.001
Reader 2	1	2	35	0	0	2.9	0.102
Subdiaphragmatic lung
Reader 1	0	15	17	6	0	2.8	0.050
Reader 2	1	3	34	0	0	2.9	0.059
Azygoesophageal recess
Reader 1	0	1	37	0	0	3.0	0.317
Reader 2	2	2	33	1	0	2.9	0.129
Proximal airway
Reader 1	0	10	28	0	0	2.7	0.002
Reader 2	0	11	27	0	0	2.7	0.001
Thoracic spine
Reader 1	0	6	32	0	0	2.8	0.014
Reader 2	0	1	37	0	0	3.0	0.317
Overall appearance
Reader 1	0	1	37	0	0	3.0	0.317
Reader 2	0	7	30	1	0	2.8	0.034