ABSTRACT
Objective: To explore the feasibility of intravoxel incoherent motion DWI (IVIM-DWI) in assessment of hypoxic status of tumor microenvironment of C6 glioma in SD rat models. Methods C6 glioma models were established in 48 SD rats. IVIM-DWI scanning were performed on 16 rats on the 14th day, 21st day and 28th day after modeling, respectively, and parameters of ADC, slow diffusion coefficient (D), fast diffusion coefficient (D*) and fractional perfusion-related volume (f) were obtained. The rats were scarified after each scanning, and the tumors were removed for hypoxia-inducible factor (HIF-1α) immunohistochemical staining and scoring. Differences of IVIM-DWI parameters and HIF-1α score at different time points were compared, and correlation between parameters of IVIM-DWI and HIF-1α score were analyzed. Results: There were statistical differences of IVIM-DWI parameters and HIF-1α score on the 14th day, 21st day and 28th day after modeling (all P<0.01). On the 21st day after modeling, HIF-1α score was negatively correlated with D, D* and f (r=-0.73, -0.58, -0.67, all P<0.05), while on the 28th day after modeling, HIF-1α score were negatively correlated with D and f (r=-0.60, -0.65, both P<0.05). Conclusion: IVIM-DWI can be used to assess hypoxic status of tumor microenvironment of C6 glioma SD rat models.
ABSTRACT
Intravoxel incoherent motion (IVIM) imaging can be used to evaluate the diffusion of water molecules and microcirculation perfusion in vivo by using a biexponential model with multiple b-values. IVIM has been used to differential diagnose breast benign and malignant lesions, evaluate the effect of neoadjuvant chemotherapy, and IVIM parameters maybe relate to molecular subtypes and prognostic factors of breast cancer. The research progresses of IVIM in breast cancer were reviewed in this article.
ABSTRACT
Objective To investigate the relationships between the parameters of intravoxel incoherent motion (IVIM)DWI at 3.0 Tesla and T staging of moderately differentiated adenocarcinoma of rectum.Methods Clinical data and MRI findings including con-ventional imaging and IVIM-DWI were collected in a total of 37 patients with moderately differentiated adenocarcinoma of rectum proven by pathology.The patients were divided into two groups without (staging T1 and T2)or with myometrial invasion (T3 and T4).The D,D? ,f and ADC values of rectal cancer and normal rectal wall were measured and were compared between the lesion and normal rectal wall,between both groups and among different T stages.The relationships of the parameters of IVIM-DWI and ADC values with the T staging of moderately differentiated adenocarcinoma of rectum were analyzed.Results The D,D? ,f and ADC val-ues of rectal cancer were lower than those of normal rectal wall with statistical differences in D,f and ADC values (P <0.05).The differences in D and D? values among different T stages were statistically significant,and LSD Duncan test showed that the differ-ence in D? value between T1 and T4 (P =0.01 7)and between T3 and T4 (P =0.003)and in D value between T2 and T3 (P =0.005) were statistically significant.The D,f,D? and ADC values of noninvasion group and invasion one were (0.93±0.1 6)×10 -3 mm2/s versus (0.77±0.1 9)×10 -3 mm2/s,(27.1±2.94)% versus (24.6 ±4.13)%,(12.6±2.44)×10 -3 mm2/s versus (12.3±3.49)× 10 -3 mm2/s,and (0.95±0.09)×10 -3 mm2/s versus (0.87 ±0.12)×10 -3 mm2/s respectively,and the difference in D value was statistically significant (t=2.5 12,P =0.01 7).Conclusion The parameters of IVIM-DWI and the ADC values are different in rectal cancer and normal rectal wall,and the D value may help to identify the tumor invasion into the muscularis propria.