The Study Of3D Non-rigid Registration In The Quantitative Analysis Of Dynamic Contrast-enhanced(DCE) Magnetic Resonance Imaging(MRI) Data

Objective To evaluate the value of3D non-rigid registration in the quantitative analysis of dynamic contrast-enhanced (DCE) magnetic resonance imaging(MRI) data.Materials and Methods27patients and10patients were suffered from HCC and colorectal liver metastases respectively, and all these patients were performed the whole-liver perfusion MR imaging.. We used the time-concentration curve of the abdominal aorta and the portal vein as a vascular input function to investigate image results of HCC and metastases before and after correction with3D non-rigid registration. Two radiologists measured and estimated the size and perfusion parameters of all lesions including volume transfer constant(Ktrans), flux rate constant between EES and plasma(KeP), volume of extravascular extracellular space(EES)per volume unit of tissue(Ve), plasma volume fraction (Vp), and hepatic artery index (HPI) by using GE software(Omni.Kinetics). We compared the area diversify of lesions in the slice showing the largest area of lesion and the time-concentration curve, and quantitative parameter before and after correction. We also analyzed the sensitivity, specificity of the quantitative parameter by using receiver operating characteristic curve (ROC).Results Before registration, three was a significant difference between HCC and liver metastases in Ktrans(P<0.05). After registration, both Ktrans and Vp value of HCC were significantly greater than that of metastases group (P<0.05, P<0.05) and the area of lesion was smaller than that before registration, but there was no significant difference (P>0.05). The time-concentration curve was more smooth than that before registration. By analysis of ROC curve, the best threshold of Ktrans before registration was0.18min-1, with the sensitivity of81%and specificity78%. After registration,the best threshold of Ktrans was0.20min-1, with the sensitivity of87%and specificity68%; The best threshold of Vp was0.16, with the sensitivity of72%and specificity89%.Conclusion3D non-rigid registration of DCE-MRI may be useful to differentiate HCC from colorectal liver metastases and improve sensitivity and specificity in diagnosing these tumors.