Low contrast medium and radiation dose for hepatic computed tomography perfusion of rabbit VX2 tumor

Table 1 Perfusion parameters for normal parenchyma, viable tumor component and whole tumor (n = 11) obtained using protocols A, B and C

	HAP (mL/min per 100 mg)	HPP (mL/min per 100 mg)	HBF (mL/min per 100 mg)	HPI (%)
Normal liver 120 kVp	31.27 ± 9.22	99.44 ± 22.99	130.71 ± 31.08	23.60 ± 3.99
80 kVp IR	28.38 ± 9.45	97.5 ± 22.11	125.93 ± 29.19	22.24 ± 4.55
80 kVp	28.5 ± 9.56	97.56 ± 22.02	125.96 ± 29.35	22.20 ± 4.34
P value	0.721	0.974	0.912	0.699
Viable tumor
120 kVp	112.68 ± 50.22	82.67 ± 25.21	195.36 ± 72.38	56.65 ± 6.42
80kVp IR	108.94 ± 43.35	83.83 ± 25.04	192.77 ± 63.56	55.66 ± 6.90
80 kVp	106.76 ± 42.99	83.91 ± 25.36	192.49 ± 64.08	55.46 ± 7.23
P value	0.954	0.992	0.994	0.909
Whole tumor
120 kVp	102.06 ± 45.53	81.65 ± 25.55	183.71 ± 68.66	54.60 ± 6.01
80 kVp IR	96.71 ± 38.69	81.99 ± 22.79	178.70 ± 57.81	53.10 ± 6.71
80 kVp	99.48 ± 40.32	83.37 ± 23.11	182.85 ± 59.63	53.22 ± 7.03
P value	0.956	0.984	0.980	0.842

Data are expressed as mean ± SD. HAP: Hepatic arterial perfusion; HPP: Hepatic portal perfusion; HBF: Hepatic blood flow; HPI: Hepatic perfusion index; IR: Iterative reconstruction.

Table 2 Quantitative image analysis (n = 11)

				P value
	80 kVp with IR	80 kVp	120 kVp	80 IR vs 120	80 vs 120
Normal liver
Arterial phase (HU)	78.88 ± 7.1	78.61 ± 7.27	71.57 ± 6.93	0.041	0.049
Portal venous phase (HU)	129.00 ± 5.70	129.5 ± 5.67	120.34 ± 5.26	0.002	0.001
Viable tumor
Arterial phase (HU)	131.68 ± 24.24	131.74 ± 24.29	122.15 ± 23.25	0.552	0.549
Portal venous phase (HU)	86.05 ± 12.82	87.77 ± 13.39	79.43 ± 10.59	0.357	0.211
Noise
NoiseHAP (HU)	9.31 ± 0.94	13.85 ± 1.05	8.16 ± 0.95	0.019	< 0.001
NoisePVP (HU)	9.50 ± 0.93	13.47 ± 1.27	8.27 ± 1.17	0.031	< 0.001
CNR
CNRHAP	5.63 ± 2.38	3.88 ± 1.82	6.16 ± 2.60	0.814	0.048
CNRPVP	4.60 ± 1.27	3.16 ± 1.04	5.11 ± 1.74	0.587	0.004

Data are expressed as mean ± SD. CNR: Tumor-to-liver contrast-to-noise ratio; IR: Iterative reconstruction.

Table 3 Contrast medium consumption (n = 11)

	80 kVp	120 kVp	P value
Body weight (kg)	3.0 ± 0.11	3.0 ± 0.11
Concentration of contrast medium (mgI/mL)	270	350
Volume of contrast medium (mL)	4	5
Contrast medium dose (mgI/kg)	360.1 ± 13.3	583.5 ± 21.5	< 0.001

Data are expressed as mean ± SD.