<p>SUPPLEMENTARY MATERIAL</p><p>Impact of hepatobiliary phase liver MRI versus Contrast Enhanced Ultrasound after an</p><p> inconclusive extracellular based gadolinium-contrast enhanced MRI for the diagnosis of</p><p> benign hepatocellular tumors</p><p>1 TABLE OF CONTENTS</p><p>Page 3: Supplementary Table 1: Typical FNH diagnostic criteria on CE-MRI</p><p>Page 4: Supplementary Table 2: Atypical features for FNH identified on CE-MRI </p><p>Page 5: Supplementary Table 3: MRI sequence parameters</p><p>Page 6: Supplementary Table 4: FNH diagnostic criteria on HBP-MRI and CEUS </p><p>Page 7: Supplementary Table 5: Inter observer concordance of SET-1 and SET-2.</p><p>2 Supplementary Table 1: Typical FNH diagnostic criteria on CE-MRI</p><p>General aspect Lobulated No capsule</p><p>Signal Homogeneous (except the central scar)</p><p>Iso or faint hypo T1 and hyper T2</p><p>Central scar Hyper T2 </p><p>Hypo T1</p><p>Enhancing on venous phase</p><p>Enhancement Early (arterial phase), Intense</p><p>No wash-out</p><p>3 Supplementary Table 2. Atypical features for FNH identified on CE-MRI</p><p>All lesions FNH HCA N = 83 N = 46 N = 37</p><p>Atypical or absence of central scar including low T2 SI or absent 74 (89.1%) 41 (89.1%) 33 (89.2%) enhancement on delayed phase</p><p>Other atypical features including at least heterogeneous SI or High 27 (32.5%) 8 (17.4%) 19 (51.4%) T2 SI or High T1 SI (fat or hemorrhage) or capsule </p><p>Absent or faint arterial 31 (37.3%) 8 (17.4%) 23 (62.2%) enhancement </p><p>Results are expressed as number of lesions and percentages (%) SI is for signal intensity</p><p>4 Supplementary Table 3. MRI sequence parameters</p><p>Identical T1 IP, T1 OP, VIBE and FS T1-WI were performed before Gd-BOPTA and</p><p> repeated on delayed HBP imaging. </p><p>Slice Echo TR TE Flip Sequences thickness train (ms) (ms) angle (α) (mm) length GRE IP and OP T1-WI 121 2.38-4.76 70° 5 NA</p><p>Breath-hold FS TSE T2-WI 2400 86 150° 5 23</p><p>Additional TSE T2-WI 2400 138 150° 5 23</p><p>Breath-hold HASTE T2-WI 600 74 150° 3 156</p><p>Dynamic breath-hold 3D VIBE T1-WI 3.31 1.25 15° 3 NA</p><p>FS T1-WI 117 2.78 70° 5 NA</p><p>TR = repetition time, TE = echo time, α = flip angle, T1 or T2-WI = T1 or T2-weighted imaging, GRE = gradient recalled echo, IP = in phase, OP = out-of-phase, FS = fat- suppressed, TSE = turbo spin echo, HASTE = half-Fourier acquisition single-shot turbo spin- echo, VIBE = volumetric interpolated breath-hold examination, 3D = three-dimensional, NA = Not Applicable</p><p>5 Supplementary Table 4: FNH diagnostic criteria on HBP-MRI and CEUS</p><p>HBP-MRI CEUS (Using hepatospecific contrast agents)</p><p>Contrast uptake of the tumor on delayed phase Early intense, centrifugal enhancement</p><p>(in comparison with pre-injection images) Central artery</p><p>- Homogeneous uptake Spoked-wheel pattern</p><p>- Heterogeneous uptake No wash-out</p><p>- Peripheral rim (“Hypointense with ring type Homogenous on delayed phase (except the </p><p> enhancement”) [1] central scar)</p><p>1 van Kessel CS, de Boer E, ten Kate FJ, Brosens LA, Veldhuis WB, van Leeuwen MS (2013) Focal nodular hyperplasia: hepatobiliary enhancement patterns on gadoxetic-acid contrast-enhanced MRI. Abdom Imaging 38:490-501</p><p>6 Supplementary Table 5: Inter observer concordance of SET-1 and SET-2.</p><p>SET-1 SET-2 CE-MRI + HBP-MRI CE-MRI + CEUS</p><p>All lesions n = 83 (46 FNH + 37 HCA)</p><p> wκ (95%CI) 0.83 (0.77-0.90) 0.72 (0.65-0.80)</p><p>Lesions ≤ 35 mm n = 58 (36 FNH + 22 HCA)</p><p> wκ (95%CI) 0.80 (0.71-0.89) 0.73 (0.64-0.82)</p><p>Lesions > 35 mm n = 25 (10 FNH + 15 HCA)</p><p> wκ (95%CI) 0.9 (0.82-0.98) 0.64 (0.47-0.81)</p><p> wκ for Cohen’s quadratic weighted kappa coefficient and 95% confidence intervals are in parenthesis</p><p>7 8</p>