Table 2. Intra- andinter-observer agreements for the H/CL ratio at 3 hours after PYP injection.

	ROI size	ICC (1,1) for intra-observer agreement	ICC (2,1) for inter-observer agreement
Overall (n=90)	4.5 cm	0.949	0.906
	3 cm	0.934	0.848
	2 cm	0.901	0.773
Positive SPECT (n= 41)	4.5 cm	0.979	0.920
	3 cm	0.977	0.865
	2 cm	0.957	0.784
Negative SPECT (n= 49)*	4.5 cm	0.810	0.787
	3 cm	0.764	0.715
	2 cm	0.713	0.634

^*Patients with Grade 0 uptake on 3-hour planar images (n=20) were excluded because the heart ROI could not be determined.

ICC, intraclass correlation coefficients; H/CL, heart-to-contralateral lung uptake; ROI, region of interest