Effect of simultaneous multislice acceleration on the quantitative measurements of diffusion-weighted imaging, intravoxel incoherent motion, and diffusion kurtosis imaging in hepatocellular carcinoma and abdominal organs.

[BACKGROUND] Although simultaneous multislice (SMS) acceleration shortens abdominal diffusion-weighted imaging (DWI) scans, its effect on quantitative hepatocellular carcinoma (HCC) measurements is unclear. This study aimed to evaluate SMS acceleration effects on DWI-derived quantitative measurements in HCC and the upper abdominal solid organs.

[METHODS] This prospective cross-sectional study initially enrolled 205 patients with clinically suspected HCC. Free-breathing conventional (CON) and SMS-accelerated monoexponential DWI, diffusion kurtosis imaging (DKI), and intravoxel incoherent motion (IVIM) were performed. Two radiologists independently measured the apparent diffusion coefficient (ADC) for monoexponential DWI, mean kurtosis, and mean diffusivity for DKI, as well as the pure diffusion coefficient and perfusion fraction () for IVIM, in HCC and the upper abdominal solid organs. Paired -tests or Wilcoxon signed-rank tests were used to compare the quantitative diffusion parameters between CON and SMS-accelerated sequences.

[RESULTS] A total of 113 patients comprising 129 HCCs were included in the study. The ADC values from SMS-DWI were significantly lower than those from CON-DWI in HCC (P=0.003). Moreover, the values from SMS-IVIM were significantly lower than those from CON-IVIM in HCC (P<0.001), liver parenchyma (P=0.005), right kidney (P=0.002), and left kidney (P=0.005). Other quantitative diffusion parameters did not differ significantly between CON and SMS-accelerated sequences (all P values >0.008).

[CONCLUSIONS] Compared with CON sequences, SMS acceleration did not affect most quantitative parameters in HCC or the upper abdominal organs. However, the monoexponential DWI-derived ADC value and IVIM-derived value on SMS-accelerated sequences should be interpreted with caution.