Role of diffusion-weighted magnetic resonance imaging in the diagnosis of extrahepatic cholangiocarcinoma

Table 1 ADC value and SNR for EHCC with different b value

B value (s/mm2)	ADC (× 10-3 mm2/s)	SNR
100	2.73 ± 0.55	135.81 ± 33.27
300	1.84 ± 0.42	99.17 ± 22.63
500	1.31 ± 0.29	69.31 ± 16.36
800	1.22 ± 0.29	47.90 ± 12.35
1000	0.89 ± 0.23	29.48 ± 9.72
M	136.23	142.79
P	< 0.01	< 0.01

All P values are less than 0.05 for each two b values exhibited above. ADC: Apparent diffusion coefficient; SNR: Signal-noise ratio; EHCC: Extrahepatic cholangiocarcinoma.

Table 2 Evaluation of diagnostic accuracy of DWI and MRCP for EHCC

	Confirmed pathological diagnosis		Total
	EHCC	Non-EHCC
DWI
EHCC	33	0	33
Non-EHCC	2	21	23
MRCP
EHCC	26	6	32
Non-EHCC	9	15	24
Total	35	21	56

DWI: Diffusion-weighted imaging; MRCP: Magnetic resonance cholangiopancreatography.