The Spatial Relationship between Apparent Diffusion Coefficient and Standardized Uptake Value of ¹⁸F-Fluorodeoxyglucose Has a Crucial Influence on the Numeric Correlation of Both Parameters in PET/MRI of Lung Tumors

Table 2

Correlation coefficients and values for sequential PET/CT and DW-MRI. Statistically significant correlations () are indicated in bold. Maximum standardized uptake value (), mean standardized uptake value (), minimum apparent diffusion coefficient (), and mean apparent diffusion coefficient ().

	Reader 1			Reader 3
All tumors	n = 25			n = 25
Vol/Vol	0.99	<0.001	0.97	0.98	<0.001	0.92
/	0.99	<0.001	0.98	—	—	—
/	0.74	<0.001	0.69	0.61	0.001	0.62
	−0.25	0.24	−0.12	−0.38	0.06	−0.32
	−0.11	0.61	−0.02	−0.19	0.37	−0.03
@	−0.15	0.49	−0.13	—	—	—
@	−0.26	0.21	−0.12	−0.32	0.12	−0.27
Spatial match	n = 17			n = 15
	−0.52	0.03	−0.39	−0.48	0.07	−0.36
	−0.26	0.31	−0.18	−0.19	0.49	−0.05
@	−0.26	0.30	−0.31	−0.22	0.42	−0.25
@	−0.39	0.12	−0.18	−0.54	0.04	−0.26
Spatial mismatch	n = 8			n = 10
	0.76	0.02	0.88	0.27	0.45	0.32
	0.75	0.02	0.71	0.32	0.36	0.45
@	0.56	0.14	0.67	0.35	0.32	0.34
@	0.60	0.10	0.55	0.29	0.40	0.05
Diameter ≤ 3 cm	n = 10			n = 10
	−0.01	0.97	0.10	−0.31	0.37	−0.13
	0.20	0.57	0.26	−0.03	0.94	0.09
@	0.06	0.87	0.02	—	—	—
@	0.11	0.77	0.30	0.07	0.85	0.04
Diameter > 3 cm & spatial match	n = 7			n = 6
	−0.96	<0.001	−0.93	−0.76	0.06	−0.60
	−0.87	0.006	−0.75	−0.81	0.03	−0.54
@	−0.75	0.04	−0.5	−0.75	0.06	−0.60
@	−0.76	0.04	−0.71	−0.85	0.02	−0.89
Diameter > 3 cm & spatial mismatch	n = 8			n = 9
	0.76	0.02	0.88	0.39	0.29	0.41
	0.75	0.02	0.71	0.59	0.09	0.67
@	0.56	0.14	0.67	0.53	0.14	0.61
@	0.60	0.10	0.55	0.33	0.39	0.13