Predictive value of extracellular volume fraction determined using enhanced computed tomography for pathological grading of clear cell renal cell carcinoma: a preliminary study

Table 2 Comparison of CT parameter values between four ISUP grades

Parameters	ISUP grade 1	ISUP grade 2	ISUP grade 3	ISUP grade 4	F	p
CT value in plain scan (HU)	29.17 ± 6.48	33.78 ± 6.80	38.58 ± 6.69^ab	31.25 ± 8.36^c	3.893	0.013*
CT value of MP (HU)	110.26 ± 49.25	124.70 ± 34.64	147.71 ± 42.15	139.71 ± 15.48	2.330	0.083
CT value of NP (HU)	105.49 ± 23.89	125.06 ± 28.72	162.35 ± 21.31^ab	177.32 ± 13.78^ab	18.504	< 0.001*
CT value of DP (HU)	84.62 ± 18.99	94.76 ± 24.55	112.14 ± 16.07^ab	112.24 ± 17.05^ab	4.513	0.006*
CT value of aorta in plain scan (HU)	325.85 ± 54.35	323.73 ± 54.35	324.85 ± 44.36	329.08 ± 59.91	0.023	0.995
CT value of aorta in balance phase (HU)	171.40 ± 21.28	155.35 ± 29.42	157.52 ± 16.02	141.65 ± 15.08	1.979	0.127
ΔS1 (HU)	77.01 ± 49.41	93.19 ± 34.91	116.39 ± 39.95^ab	108.92 ± 18.51	2.558	0.063
ΔS2 (HU)	72.24 ± 24.46	93.55 ± 28.55^a	131.03 ± 18.39^ab	146.53 ± 19.37^ab	19.525	< 0.001*
ΔS3 (HU)	55.45 ± 16.31	60.98 ± 21.66	73.57 ± 15.76^ab	80.99 ± 11.59^ab	4.107	0.010*
ECV (%)	28.31 ± 3.34	35.06 ± 4.73^a	46.69 ± 4.77^ab	56.41 ± 6.36^abc	67.979	< 0.001*
AEF (%)	0.98 ± 0.38	1.03 ± 0.38	0.90 ± 0.33	0.75 ± 0.11	1.677	0.181

Notes: Data are presented as the number, mean ± standard deviation. ^a significant difference with ISUP grade 1 (p < 0.05), ^b significant difference with ISUP grade 2 (p < 0.05), ^C significant difference with ISUP grade 3 (p < 0.05). * p < 0.05. CT, computed tomography; HU, Hounsfield unit; MP, corticomedullary phase, NP, nephrographic phase; DP, delay phase; ECV, extracellular volume; AEF, arterial enhancement fraction

ISSN: 1470-7330