Intravoxel incoherent motion diffusion-weighted imaging in head and neck squamous cell carcinoma: assessment of perfusion-related parameters compared to dynamic contrast-enhanced MRI.

To investigate the correlation between perfusion-related parameters obtained with intravoxel incoherent motion (IVIM) and classical perfusion parameters obtained with dynamic contrast-enhanced (DCE) magnetic resonance imaging in patients with head and neck squamous cell carcinoma (HNSCC), and to compare direct and asymptotic fitting, the pixel-by-pixel approach, and a region of interest (ROI)-based approach respectively for IVIM parameter calculation. Seventeen patients with HNSCC were included in this retrospective study. All magnetic resonance (MR) scanning was performed using a 3T MR unit. Acquisition of IVIM was performed using single-shot spin-echo echo-planar imaging with three orthogonal gradients with 12 b-values (0, 10, 20, 30, 50, 80, 100, 200, 400, 800, 1000, and 2000). Perfusion-related parameters of perfusion fraction 'f' and the pseudo-diffusion coefficient 'D*' were calculated from IVIM data by using least square fitting with the two fitting methods of direct and asymptotic fitting, respectively. DCE perfusion was performed in a total of 64 dynamic phases with a 3.2-s phase interval. The two-compartment exchange model was used for the quantification of tumor blood volume (TBV) and tumor blood flow (TBF). Each tumor was delineated with a polygonal ROI for the calculation of f, f∙D* performed using both the pixel-by-pixel approach and the ROI-based approach. In the pixel-by-pixel approach, after fitting each pixel to obtain f, f∙D* maps, the mean value in the delineated ROI on these maps was calculated. In the ROI-based approach, the mean value of signal intensity was calculated within the ROI for each b-value in IVIM images, and then fitting was performed using these values. Correlations between f in a total of four combinations (direct or asymptotic fitting and pixel-by-pixel or ROI-based approach) and TBV were respectively analyzed using Pearson's correlation coefficients. Correlations between f∙D* and TBF were also similarly analyzed. In all combinations of f and TBV, f∙D* and TBF, there was a significant correlation. In the comparison of f and TBV, a moderate correlation was observed only between f obtained by direct fitting with the pixel-by-pixel approach, whereas a good correlation was observed in the comparisons using the other three combinations. In the comparison of f∙D* and TBF, a good correlation was observed only with f∙D* obtained by asymptotic fitting with the ROI-based approach. In contrast, moderate correlations were observed in the comparisons using the other three combinations. IVIM was found to be feasible for the analysis of perfusion-related parameters in patients with HNSCC. Especially, the combination of asymptotic fitting with the ROI-based approach was better correlated with DCE perfusion.

Fujima N ，Yoshida D ，Sakashita T ，Homma A ，Tsukahara A ，Tha KK ，Kudo K ，Shirato H ... -  《-》

Intravoxel Incoherent Motion MR Imaging in the Head and Neck: Correlation with Dynamic Contrast-Enhanced MR Imaging and Diffusion-Weighted Imaging.

Xu XQ ，Choi YJ ，Sung YS ，Yoon RG ，Jang SW ，Park JE ，Heo YJ ，Baek JH ，Lee JH ... -  《-》

Perfusion parameters of intravoxel incoherent motion based on tumor edge region of interest in cervical cancer: evaluation of differentiation and correlation with dynamic contrast-enhanced MRI.

Wang H ，Zhu L ，Li G ，Zuo M ，Ma X ，Wang J ... -  《-》

Relationship between intravoxel incoherent motion diffusion-weighted MRI and dynamic contrast-enhanced MRI in tissue perfusion of cervical cancers.

To investigate the relationship between intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) and dynamic contrast-enhanced MRI (DCE-MRI) in cervical cancer perfusion. Prospective newly diagnosed cervical cancer patients underwent diffusion-weighted MRI (13 b-values: 1-1000 s/mm(2) ) and DCE-MRI. The IVIM perfusion parameters, perfusion fraction (f), pseudodiffusion coefficient (D*), and flow-related parameter (fD*), were derived from a biexponential decay model. DCE-MRI was analyzed with a pharmacokinetic model and signal-time curve to derive the amplitude factor (A), estimated volume transfer constant between blood plasma, and the extravascular extracellular space (est K(trans) ), maximum relative enhancement (MaxRE), and area under the signal-time curve (AUC). Spearman's rank correlation coefficient (r) evaluated the correlative relationships. The f = 13.51% ± 1.76%, D* = 71.72 ± 7.55 × 10(-3) mm(2) /s, fD* = 9.64 ± 1.28 × 10(-3) mm(2) /s, A = 1.41 ± 0.43, est K(trans) = 0.19 ± 0.06 s(-1) , MaxRE of 120.02 ± 21.07%, and AUC 212,393 ± 54,423 was found in 25 cervical cancer patients. Statistically significant positive correlations were found between fD* and est K(trans) (r = 0.42, P = 0.038), fD* and A (r = 0.50, P = 0.011), fD* and MaxRE (r = 0.52, P = 0.008), f and AUC (r = 0.58, P = 0.003). The IVIM perfusion parameters showed moderate to good correlations with quantitative and semiquantitative perfusion parameters derived from DCE-MRI in cervical cancer.

Lee EY ，Hui ES ，Chan KK ，Tse KY ，Kwong WK ，Chang TY ，Chan Q ，Khong PL ... -  《-》

Correlative assessment of tumor microcirculation using contrast-enhanced perfusion MRI and intravoxel incoherent motion diffusion-weighted MRI: is there a link between them?

The purpose of this study was to correlate intravoxel incoherent motion (IVIM) imaging with classical perfusion-weighted MRI metrics in human gliomas. Parametric images for slow diffusion coefficient (D), fast diffusion coefficient (D*), and fractional perfusion-related volume (f) in patients with high-grade gliomas were generated. Maps of Fp (plasma flow), vp (vascular plasma volume), PS (permeability surface-area product), ve (extravascular, extracellular volume), E (extraction ratio), ke (influx ratio into the interstitium), and tc (vascular transit time) from dynamic contrast-enhanced (DCE) and dynamic susceptibility contrast-enhanced (DSC) MRI were also generated. A region-of-interest analysis on the contralateral healthy white matter and on the tumor areas was performed and the extracted parameter values were tested for any significant differences among tumor grades or any correlations. Only f could be significantly correlated to DSC-derived vp and tc in healthy brain tissue. Concerning the tumor regions, Fp was significantly positively correlated with D* and inversely correlated with f in DSC measurements. The D*, f, and f × D* values in the WHO grade III gliomas were non-significantly different from those in the grade IV gliomas. There was a trend to significant negative correlations between f and PS as well as between f × D* and ke in DCE experiments. Presumably due to different theoretical background, tracer properties and modeling of the tumor vasculature in the IVIM theory, there is no clearly evident link between D*, f and DSC- and DCE-derived metrics.

Bisdas S ，Braun C ，Skardelly M ，Schittenhelm J ，Teo TH ，Thng CH ，Klose U ，Koh TS ... -  《-》