Magnetom trio 3t mr system

All MR images were obtained with a Magnetom Trio 3T MR system (Siemens Healthcare, Erlangen, Germany) using a six-channel body array coil and a six-channel spine matrix coil.
T2*WIs were obtained as part of the routine liver protocol in our institution. The sequence and scan parameters of the T2*WIs are shown in Table 1. We also obtained T1W1s (in-phase and opposed-phase), fat-suppressed T2WIs, diffusion-weighted images, and DCE-MR images routinely, and diagnosed the target nodule as HCC.
Table 1

Magnetic resonance sequence and scan parameters

	T2*WI
Pulse sequence	2D-GRE
TR (ms)	202–236
TE (ms)	7.38
Flip angle (°)	20
Matrix size	512 × 330–400
Acquisition time (s)	20–22
Field of view (mm)	340–420 × 223–315
Section thickness (mm)	4–5
Interslice gap (mm)	1

2D-GRE two-dimensional gradient-recalled echo, T2*WI T2*-weighted image, TE echo time, TR repetition time, TSE turbo spin echo

MR examination involved imaging and spectroscopy, each part taking approximately 60 min to complete. Subjects were examined in a supine position using the Siemens MAGNETOM Trio 3T MR system equipped with an eight-channel surface body array coil.
In addition to standard localizer sequences, T2-weighted HASTE sequences (half-Fourier acquisition single-shot turbo spin-echo sequence) in transversal and coronal anatomic directions (echo time/repetition time TR/TE = 1800/96 ms; 20 slices 10 mm in width) were used to position the volume of interest (VOI) for MRS.
A standard PRESS (point-resolved spectroscopy sequence) was used (TR/TE = 4500/30 ms) to measure HFC. MR images in three basic anatomical orientations were used to set the VOI at 40 × 30 × 25 mm in biopsy position (Figure 1a).
Single breath-holding spectra acquired with water signal suppression were measured twice; spectra without water suppression were repeated three times. To estimate T2 relaxation times, a set of PRESS spectra with echo times of 30, 50, 68, 135, 180 and 270 ms was acquired without water suppression; T1 values were not calculated.