Objective      To compare the sequences of iterative decomposition of water and fat with echo asymmetric and least-squares estimation (IDEAL) and 3D FSE-Cube imaging of

brachial plexus.       Methods      Brachial plexus of 30 health volunteers were imaged on 3.0T MR system with sequences of 3D FSE-Cube and IDEAL respectively. All of the volunteers underwent the same MR scanning for 2 times with 3D FSE-Cube sequence with the assistive device was used in the second time. Images were post-processed with MIP and CPR

and then the display rate was calculated

and image quality was assessed

signal noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.       Results      The display rates of the ganglion

supra clavicular nerve

and infra clavicular nerve on 3D FSE-Cube sequence were 73.33%

56.67% and 40.00% respectively

while the rates were 100.00%

97.67% and 93.33% respectively after use of the assistive device

with statistically difference between them (

P

<

0.05). The display rate of ganglion were 96.67% and 100.00% on IDEAL and 3D FSE-Cube respectively

and that of supra clavicular nerve was 86.67% and 96.67%

respectively

but there was no significantly difference in both of them (

P

>0.05). The infra clavicular nerve was shown better on 3D FSE-Cube than IDEAL (93.33%

vs

70.00%

P

<

0.05）. In levels of ganglion

the imaging quality on IDEAL and 3D FSE-Cube had no significant difference（

P

>0.05）. In the levels of interscalene area

costoclavicular space

and axillary

the quality of 3D FSE-Cube was better than IDEAL (

P

<

0.05). In the level of ganglion

the signals of IDEAL were higher than those of 3D FSE-Cube (

P

<

0.05). There was no significant difference in other level of brachial plexus between the 2 sequences (

P

>0.05). SNR and CNR were both higher in IDEAL than in 3D FSE-Cube (

P

<

0.01).       Conclusion      The sequences of IDEAL and 3D FSE-Cube both have the capacity of clearly displaying postganglionic brachial plexus

But the imaging quality of 3D FSE-Cube is better when combined with assistive device.