Photon-counting computed tomography enables low-dose, high-quality abdominal imaging: A comparative study with energy-integrating detector computed tomography

Table 1 Baseline characteristics of patients undergoing abdominal photon-counting computed tomography and energy-integrating detector computed tomography, n (%)/mean ± SD/median (interquartile range)

Variable	PCCT	EID-CT	P value
Gender			0.8222
Male	17 (42.5)	19 (47.5)
Female	23 (57.5)	21 (52.5)
Age	42.58 ± 15.49	47.68± 12.0	0.056
Height (cm)	165.85 ± 8.66	163.15 ± 7.71	0.145
Weight (kg)	61.00 (57.50-72.00)	65.00 (56.50-73.00)	0.769
BMI (kg/m2)	23.49 ± 3.43	24.39 ± 4.28	0.299

EID-CT: Energy-integrating detector computed tomography; PCCT: Photon-counting computed tomography; BMI: Body mass index.

Table 2 Comparison of radiation dose between abdominal photon-counting computed tomography and energy-integrating detector computed tomography, median (interquartile range)

Variable	PCCT	EID-CT	P value
CTDIvol (mGy)	3.78 (3.20-4.17)	7.15 (5.85-8.57)	< 0.001
DLP (mGy × cm)	103.15 (89.23-122.51)	201.60 (161.15-227.68)	< 0.001
ED (mSv)	1.55 (1.34-1.84)	3.02 (2.42-3.42)	< 0.001

EID-CT: Energy-integrating detector computed tomography; PCCT: Photon-counting computed tomography; CTDI_vol: Computed tomography dose index; DLP: Dose-length product; ED: Effective dose.

Table 3 Intraclass correlation coefficients for interobserver agreement

Variable	Intraclass correlation coefficient	95% confidence interval	P value
meanliver	0.916	0.871-0.945	< 0.001
SDliver	0.892	0.837-0.929	< 0.001
meanfat	0.899	0.851-0.936	< 0.001
SDfat	0.896	0.838-0.932	< 0.001

Table 4 Comparison of objective and subjective image quality parameters between abdominal photon-counting computed tomography and energy-integrating detector computed tomography, median (interquartile range)

Variable	PCCT	EID-CT	P value
meanliver	65.95 (62.60-68.80)	61.35 (55.77-65.08)	0.001
SDliver	11.60 (10.85-12.45)	18.60 (16.62-20.32)	< 0.001
meanfat	-108.35 (-111.72 to -103.78)	-106.15 (-110.78 to -99.08)	0.192
SDfat	11.75 (11.00-12.50)	14.30 (13.03-16.35)	< 0.001
SNR	5.57 (5.02-6.32)	3.26 (2.71-3.76)	< 0.001
CNR	10.26 (9.76-11.36)	7.14 (6.21-7.67)	< 0.001
EII	71.99 (52.96-93.39)	17.38 (12.71-20.75)	< 0.001
SNR/(CDTI)1/2	2.90 (2.46-3.53)	1.21 (0.97-1.47)	< 0.001
CNR/(CDTI)1/2	5.46 (4.77-6.36)	2.62 (2.36-2.98)	< 0.001
NR	1.00 (0.94-1.05)	1.29 (1.10-1.48)	< 0.001
Likert			< 0.001
3	1	29
4	8	7
5	31	4

EID-CT: Energy-integrating detector computed tomography; PCCT: Photon-counting computed tomography; SNR: Signal-to-noise ratio; CNR: Contrast-to-noise ratio; EII: Excellent image index; CDTI: Computed tomography dose index; NR: Noise ratio.