Magnetom verio 3.0t

Because there can be discrepancies in the liver and kidney echo intensity, fatty liver was assessed in all subjects by abdominal ultrasonography based on the following criteria: the presence of posterior attenuation of the ultrasound beam, vessel blurring, difficult visualization of the gallbladder wall, and difficult visualization of the diaphragm [17 (link)]. A total of 979 subjects also underwent liver and pancreatic fat content (PFC) quantification via magnetic resonance imaging (MRI) of the upper abdomen with a 3.0-Tesla MRI scanner (Siemens 3.0T MAGNETOM Verio; Siemens, Munchen, Germany), which was performed within 2 weeks after the patient’s biochemical measurements were taken. The scanning protocol and imaging parameters, described in detail in our previous study [18 (link)], were as follows: TE1, 2.5 ms; TE2, 3.7 ms; repetition time, 5.47 ms; flip angle, 5°; receiver bandwidth, ±504.0 kHz per pixel; and slice thickness, 3.0 mm. The fat content was calculated for each patient using an irregularly shaped region of interest that covered the entire liver in 21 consecutive slices (maximum area centered). Based on the MRI proton density fat fraction (MRI-PDFF), the liver fat content (LFC) was classified as absent (<5%), mild (5% to 10%), moderate (10% to 25%), and severe (>25%) steatosis [19 (link)-21 (link)]. Pancreatic fat infiltration was defined as an average PFC ≥5%.

MRI-PDFF was utilized to quantify the LFC with an irregularly shaped region of interest (ROI) covering the entire liver in twenty-one consecutive slices (max-area centered) from patients placed by two radiologists. The radiologists reported the MRI-PDFF independently of each other and were blinded to all the clinical data.²⁵ Upper-abdominal MRI with a 3.0-Tesla MRI scanner (Siemens 3.0T MAGNETOM Verio) was performed at baseline and at the sixth month. MRI-PDFF maps were also attained by placing circular ROIs with diameter of 20 mm centrally in each of the eight liver segments. The liver fat-water separation images were obtained via a T1 volumetric interpolated breath-hold examination IDEAL-IQ/Dixon sequence with the same scanning protocol and imaging parameter settings as presented in our previous study.²⁵ Briefly, TE1 2.5 ms, TE2 3.7 ms, 5.47 ms for repetition, 5° flip angle, ±504.0 kHz per pixel receiver bandwidth, and a slice thickness of 3.0 mm. While the fat-water separation images were acquired, data for LFC were further analyzed [Supplemental Figure 1(b), (e), (h), (k)].

Each subject underwent an upper-abdominal MRI examination while supine with a 3-Tesla whole-body human MRI scanner (SIEMENS 3.0T MAGNETOM Verio). The scanning protocol involved an initial set of localizer images and then a T1 volumetric interpolated breath-hold examination (VIBE) Dixon sequence, and covered all upper abdominal organs, including the liver and pancreas. The imaging parameters were: TE₁ 2.5 ms; TE₂ 3.7 ms; repetition time 5.47 ms; 5° flip angle; ± 504.0 kHz per pixel receiver bandwidth; and a slice thickness of 3.0 mm. All the subjects were carefully instructed to hold their breath during end inspiration to ensure consistency among subjects.

Data were collected on a 3T Siemens scanner (3.0T MAGNETOM Verio) at Kokoro Research Center, Kyoto University. Functional data were acquired with a T2*-weighted gradient-echo, echo-planar imaging (EPI) sequence (echo time [TE] = 25 ms; repetition time [TR] = 2,000 ms; flip angle = 75°; matrix = 64 × 64; field of view = 224 mm; 3.5 × 3.5 × 3.5 mm voxel size) with 34 axial slices. We acquired 180 volumes for each test run, 180 volumes for each color-localizer run, and 240 volumes for the additional localizer run. Structural images were acquired using a T1-weighted anatomical sequence (three-dimensional [3-D] magnetization-prepared rapid acquisition with gradient echo; TE = 3.51 ms; TR = 2250 ms; flip angle = 9°; matrix = 256 × 256; 1.0 × 1.0 × 1.0 mm voxel size).