Table 6.

IVIM-DWI quantitative parameter histogram analysis and SPARCC scoring results to identify the activity group, efficacy of inactive group and control group

	Parameter	Cut-off	AUC	AUC 95% confidence interval (%)	Sensitivity (%)	Specificity (%)	p-value
Active vs inactive group	Dslow kurtosis	1.512*	0.735	60.0 ~ 84.4	84.62	58.82	0.001
	Dslow entropy	3.782*	0.680	54.1 ~ 79.9	66.67	70.59	0.012
	f 10th	0.016*	0.708	57.1 ~ 82.2	51.28	94.12	<.001
	f 25th	0.053*	0.673	53.4 ~ 79.2	61.54	76.47	0.019
	ADC kurtosis	1.253*	0.685	54.7 ~ 80.2	71.79	70.59	0.012
	ADC 75th	0.787	0.676	51.9 ~ 82.3	74.40	70.60	0.038
	ADC 90th	0.993	0.677	52.5 ~ 82.9	74.40	64.70	0.036
	SPARCC	12*	0.799	67.1 ~ 89.5	69.23	82.35	<.001
Active vs control group	Dslow mean	0.338	0.910	81.1 ~ 96.8	79.49	100.00	<.001
	Dslow skewness	0.896*	0.832	71.7 ~ 91.5	76.92	87.50	<.001
	Dslow kurtosis	2.699*	0.895	79.2 ~ 95.8	87.18	83.88	<.001
	Dslow entropy	3.800*	0.697	56.8 ~ 80.6	64.10	79.17	0.003
	Dslow 10th	0.244	0.867	75.8 ~ 93.9	74.36	100.00	<.001
	Dslow 25th	0.288	0.893	79.0 ~ 95.7	79.49	100.00	<.001
	Dslow 50th	0.332	0.910	81.1 ~ 96.8	79.49	100.00	<.001
	Dslow 75th	0.374	0.926	83.2 ~ 97.7	82.05	100.00	<.001
	Dslow 90th	0.476	0.925	83.0 ~ 97.6	82.50	100.00	<.001
	Dfast mean	106.882	0.851	73.9 ~ 92.9	82.05	87.50	<.001
	Dfast skewness	3.066	0.752	62.7 ~ 85.2	66.67	87.50	<.001
	Dfas kurtosis	12.445	0.717	58.9 ~ 82.3	61.54	95.83	0.001
	Dfast entropy	1.359	0.670	54.0 ~ 78.3	43.59	100.00	0.013
	Dfast 10th	2.290	0.647	54.4 ~ 78.1	61.54	87.50	0.012
	Dfast 50th	11.810	0.803	68.4 ~ 89.3	66.67	91.67	<.001
	Dfast 75th	250.000	0.807	68.8 ~ 89.6	71.79	91.67	<.001
	f Entropy	3.032*	0.670	54.0 ~ 78.3	38.46	91.67	0.013
	f 10th	0*	0.782	66.0 ~ 87.6	56.41	100.00	<.001
	f 25th	0.021*	0.864	75.5 ~ 93.8	74.36	91.67	<.001
	f 50th	0.090*	0.822	70.5 ~ 90.7	64.10	91.67	<.001
	ADC mean	0.427	0.874	76.6 ~ 94.4	79.49	95.83	<.001
	ADC skewness	0.978*	0.747	62.1 ~ 84.8	69.23	91.67	<.001
	ADC kurtosis	1.253*	0.784	66.2 ~ 87.8	71.79	91.67	<.001
	ADC 10th	0.298	0.874	76.6 ~ 94.4	76.92	100.00	<.001
	ADC 25th	0.347	0.896	79.4 ~ 95.9	76.92	100.00	<.001
	ADC 50th	0.395	0.907	80.7 ~ 96.6	79.49	100.00	<.001
	ADC 75th	0.462	0.874	76.7 ~ 94.5	82.05	95.83	<.001
	ADC 90th	0.645	0.873	76.5 ~ 94.3	82.05	95.83	<.001
	SPARCC	0*	0.936	84.5 ~ 98.2	87.18	100.00	<.001
Inactive vs control group	Dslow mean	0.338	0.863	71.9 ~ 95.0	64.71	100.00	<.001
	Dslow kurtosis	2.434*	0.738	57.7 ~ 86.2	64.71	83.33	0.006
	Dslow 10th	0.244	0.778	62.1 ~ 89.3	64.71	100.00	0.003
	Dslow 25th	0.288	0.819	66.7 ~ 92.1	64.71	100.00	<.001
	Dslow 50th	0.332	0.858	71.3 ~ 94.7	64.71	100.00	<.001
	Dslow 75th	0.368	0.885	74.6 ~ 96.3	76.47	95.83	<.001
	Dslow 90th	0.476	0.912	78.1 ~ 97.8	82.35	100.00	<.001
	Dfast mean	84.273	0.775	61.7 ~ 89.0	64.71	95.83	0.001
	Dfast skewness	3.466*	0.757	59.8 ~ 87.7	58.82	95.83	0.002
	Dfast kurtosis	12.445*	0.760	60.1 ~ 87.9	58.82	95.83	0.002
	Dfast entropy	1.363*	0.804	65.0 ~ 91.1	58.82	100.00	<.001
	Dfast 50th	12.489	0.770	61.2 ~ 88.6	70.59	91.67	0.001
	Dfast 75th	21.439	0.828	67.8 ~ 92.8	64.71	100.00	<.001
	f Skewness	3.451*	0.772	61.5 ~ 88.8	76.47	79.17	0.001
	f Kurtosis	12.888*	0.762	60.4 ~ 88.1	76.47	79.17	0.002
	f 25th	0.021*	0.743	58.2 ~ 86.6	58.82	91.67	0.001
	f 90th	0.195*	0.733	57.2 ~ 85.9	70.59	79.17	0.008
	ADC mean	0.427	0.784	62.8 ~ 89.7	64.71	95.83	<.001
	ADC 10th	0.239	0.773	61.6 ~ 88.9	76.47	83.33	0.003
	ADC 25th	0.347	0.806	65.3 ~ 91.3	64.71	100.00	<.001
	ADC 50th	0.394	0.838	69.0 ~ 93.4	64.71	100.00	<.001
	ADC 75th	0.462	0.814	66.1 ~ 91.8	76.47	95.83	<.001
	ADC 90th	0.604	0.843	69.6 ~ 93.8	82.35	91.67	<.001
	SPARCC	0*	0.735	57.4 ~ 86.1	47.06	100.00	<.001

ADC, apparent diffusion coefficient; AUC, area under the curve; IVIM-DWI, intravoxel incoherent motion diffusion-weighted imaging; SPARCC, Spondyloarthritis Research Consortium of Canada.