Short-term reproducibility and impact factors of intravoxel incoherent motion parameters for lung cancer / 中国医学影像技术

ABSTRACT

Objective To prospectively evaluate the short-term test-retest reproducibility of intravoxel incoherent motion (IVIM) parameters for lung cancer,and to investigate its impact factors.Methods Thirty-eight lung cancer patients underwent twice free breathing IVIM scanning (0.5-1.0 h interval).Two radiologists independently analyzed IVIM images to obtain true diffusion coefficient (D),pseudo-diffusion coefficient (D*) and perfusion fraction (f).All the parameters were compared between repeated measurements and scans.Intra-and inter-observer,test-retest reproducibility was assessed with interclass correlation coefficients (ICCs).The impact of lung cancer type (peripheral and central),size (the largest diameter ≥2 cm and ＜2 cm) and location (upper,mid,and lower lung field) on short-term reproducibility were compared by using coefficient of variations (WCVs).Results There was no significant difference between repeated measurements for all parameters (all P＞ 0.05).All the parameters showed good intra-and inter-observer agreement.WCVsof D* and f (19.88％-36.83％) were higher than those of D (2.97％-4.62％).WCVs of D were higher for central lung cancer and the largest diameter ＜2 cm,and increasing from apical to lower zone.WCV of f was larger in the central lung cancer and the largest diameter ≥2 cm,while D* was greatly influenced by type,size and location of lung cancer.Conclusion The test retest reproducibility of D is good,while of D* and f are poor in lung cancer.The type,size and location of lung cancers are the impact factors of IVIM parameters.