Table 1 Parameters of MR imaging
Sequence type | Breathing position | Coverage | Orientation | TR [ms] | TE [ms] | Acquisition matrix | Slice thickness/ gap [mm] | Pixel bandwidth [Hz] | |
|---|---|---|---|---|---|---|---|---|---|
1) Anatomic MR imaging (performed in every patient) | |||||||||
T1-weighted in/opposed phase | Inspiratory breath-hold | Upper abdomen | Transverse | 115 | 2.27 and 4.78 | 320 × 272 | 5 / 1 | 445 | |
HASTE-IR T2-weighted | Inspiratory breath-hold | Upper abdomen | Coronal | 1000 | 80 | 256 × 230 | 6 / 0.6 | 545 | |
HASTE T2-weighted | Expiratory breath-hold | Upper abdomen | Transverse | 680 | 95 | 320 × 320 | 4 / 0.4 | 505 | |
2) Diffusion weighted MR imaging (performed in every patient) | |||||||||
ss-EPI | Expiratory breath-hold | Pancreas | Transverse | 2200 | 58 | 130 × 92 | 5 / 0.25 | 2260 | Pixel spacing: 2.7 mm/ 2.7 mm; Number of acquired slices per b-value: 14; b-values [s/mm2]: 0, 50, 100, 150, 200, 300, 400, 600, and 800; Number of excitations: 1 for b = 0 s/mm2, 2 for every other b-value; Number of diffusion-encoding gradient directions: 3; K-space based parallel imaging technique (GRAPPA); acceleration factor: 2; Fat saturation technique: spectral fat saturation. |
The acquisition was separated into blocks (b0, b50), (b0, b100) … (b0, b800). Each block was acquired in a single breath-hold in expiration (TA = 22 s) to avoid motion artifacts. No registration for correction of patient breathing-motion was applied. | |||||||||