Dynamic contrast-enhanced magnetic resonance imaging and diffusion-weighted imaging in the activity staging of terminal ileum Crohn's disease

Table 1 Magnetic resonance enterography acquisition parameters

Parameter	HASTE	Trufi	DWI	Dixon	Twist	Dixon
Imaging plane (s)	Coronal/axial	Axial	Axial	Axial	Axial	Axial/coronal
TR (ms)	1800/1600	382.48/398.94	8300	3.93	4.5	3.93/4.21
TE (ms)	88/95	1.68/1.72	54	1.26 2.49	1.23 2.46	1.26 2.49/1.34 2.57
Flip angle (°)	180/160	50/52	-	9	6.1	9
FOV (mm2)	360 × 360/380 × 380	380 × 380	400 × 400	400 × 400	380 × 380	400 × 400/450 × 450
Slices	30/50	55	48	96	96	96/72
Slice thickness (mm)	5	5	5	3	3	3/1.5
Slice gap (%)	20	20	20	20	20	20
Fat saturation	Yes	No/Yes	-	-	-	-
TA (min : s)	0:54/1:32	0:21/0:22	3:03	0:16	2:05	0:16/0:12

HASTE: Half-Fourier acquisition single-shot turbo spin echo; DWI: Diffusion-weighted imaging; TR: Repetition time; TE: Echo time; TA: Acquisition time; FOV: Field of view.

Table 2 Parameters in the normal ileal loop and the inflamed terminal ileum in different staging of Crohn’s disease

Parameter	Total				Remission CD			Mild CD			Moderate-severe CD
	NIL	ITI	P value		NIL	ITI	P value	NIL	ITI	P value	NIL	ITI	P value
Ktrans (min -1)	0.01 ± 0.01	0.07 ± 0.04	< 0.001		0.01 ± 0.01	0.03 ± 0.01	< 0.001	0.01 ± 0.00	0.05 ± 0.01	< 0.001	0.01 ± 0.00	0.12 ± 0.04	< 0.001
Kep (min -1)	0.15 ± 0.05	0.24 ± 0.11	< 0.001		0.11 ± 0.03	0.16 ± 0.05	< 0.001	0.18 ± 0.05	0.21 ± 0.05	< 0.001	0.15 ± 0.05	0.35 ± 0.11	< 0.001
Ve	0.08 ± 0.03	0.27 ± 0.07	< 0.001		0.10 ± 0.04	0.18 ± 0.03	< 0.001	0.07 ± 0.02	0.26 ± 0.03	< 0.001	0.08 ± 0.03	0.35 ± 0.05	< 0.001
ADC (×10-3 mm2/s)	2.41 ± 0.30	1.41 ± 0.26	< 0.001		2.33 ± 0.26	1.72 ± 0.12	< 0.001	2.45 ± 0.31	1.42 ± 0.12	< 0.001	2.42 ± 0.30	1.12 ± 1.12	< 0.001
MaRIA		14.10 ± 10.09				6.39 ± 1.07			9.34 ± 1.30			27.12 ± 8.23

NIL: Normal ileal loop; ITI: Inflamed terminal ileum; CD: Crohn’s disease; ADC: Apparent diffusion coefficient; MaRIA: Magnetic Resonance Index of Activity.

Table 3 Correlations of parameters of inflamed terminal ileum with Crohn’s Disease Activity Index and Crohn’s Disease Endoscopic Index of Severity in different staging of Crohn’s disease

Parameter	CDAI		CDEIS
	r	P value	r	P value
Ktrans (min -1)	0.866	< 0.001	0.563	< 0.001
Kep (min -1)	0.870	< 0.001	0.567	< 0.001
Ve	0.858	< 0.001	0.571	< 0.001
ADC (× 10-3 mm2/s)	-0.857	< 0.001	-0.536	< 0.001
MaRIA	0.890	< 0.001	0.842	< 0.001

CDAI: Crohn’s Disease Activity Index; CDEIS: Crohn’s Disease Endoscopic Index of Severity; ADC: Apparent diffusion coefficient; MaRIA: Magnetic Resonance Index of Activity.

Table 4 Receiver operating characteristic analysis results for the parameters for differentiating inactive Crohn’s disease from active Crohn’s disease

Parameter	AUC (CI)	Threshold	Sensitivity (CI)	Specificity (CI)	PPV (CI)	NPV (CI)	LR+ (CI)	LR- (CI)
Ktrans (min -1)	0.76 (0.61-0.91)	0.03	0.83 (0.66-0.93)	0.69 (0.39-0.90)	0.88 (0.71-0.96)	0.6 (0.33-0.83)	2.69 (1.18-6.17)	0.25 (0.11-0.55)
Kep (min -1)	0.68 (0.50-0.85)	0.19	0.69 (0.51-0.83)	0.69 (0.39-0.90)	0.86 (0.66-0.95)	0.45 (0.24-0.68)	2.23 (0.96-5.19)	0.45 (0.26-0.79)
Ve	0.78 (0.60-0.96)	0.29	0.83 (0.66-0.93)	0.85 (0.54-0.97)	0.94 (0.77-0.99)	0.65 (0.39-0.85)	5.39 (1.49-19.44)	0.20 (0.10-0.43)
ADC (× 10-3 mm2/s)	0.89 (0.78-1.00)	1.6	0.91 (0.76-0.98)	0.77 (0.46-0.94)	0.91 (0.76-0.98)	0.77 (0.46-0.94)	3.96 (1.46-10.74)	0.11 (0.04-0.34)
MaRIA	0.91 (0.82-1.00)	7.2	0.89 (0.72-0.96)	0.85 (0.54-0.97)	0.94 (0.78-0.99)	0.73 (0.45-0.91)	5.76 (1.60-20.71)	0.14 (0.05-0.35)
Ktrans + Kep + Ve	0.80 (0.62-0.98)	-	0.89 (0.72-0.96)	0.85 (0.54-0.97)	0.94 (0.78-0.99)	0.73 (0.45-0.91)	5.76 (1.60-20.71)	0.14 (0.05-0.35)
Ktrans + Kep + Ve + ADC	0.95 (0.85-1.00)	-	0.97 (0.83-1.00)	0.92 (0.62-1.00)	0.97 (0.83-1.00)	0.92 (0.62-1.00)	12.63 (1.92-83.09)	0.03 (0.00-0.22)

AUC: Area under the curve; CI: 95% confidence interval; NPV: Negative predictive value; PPV: Positive predictive value; LR+: Positive likelihood ratios; LR-: Negative likelihood ratios; ADC: Apparent diffusion coefficient; MaRIA: Magnetic Resonance Index of Activity.