ABSTRACT
Objective To evaluate the feasibility of diffusion kurtosis imaging (DKI)in the diagnosis and aggressiveness assessment of prostate cancer.Methods The MR data with multi-b-value diffusion-weighted imaging (DWI)of 30 male patients with prostate cancer were retrospectively analyzed.D maps and K maps were generated from the DKI model and ADC maps were obtained using the conventional monoexponential model.Differences in the D,K and ADC values between prostate cancer and benign peripheral zone (PZ)tissues,among tumors with different Gleason scores were analyzed.P<0.05 was considered statistical significance.Results ADC and D values were significantly lower in the prostate cancers than in the benign PZs (P <0.001).K values were significantly greater in the prostate cancers than in the benign PZs (P <0.001).ADC,D and K values were different significantly among the tumors with Glea-son scores of 6,7 and ≥8 (P <0.001,P =0.01 5 and P <0.001,respectively).Conclusion The DKI model can better describe the signal intensity attenuation with b values increasing,which is helpful for diagnosing and grading prostate cancer.K value may be used to quantitatively evaluate the complicated microstructure of prostate cancer.
ABSTRACT
Objective To analyze and explore the value of 3 T high resolution magnetic resonance vessel wall imaging for identifying the activity of Takayasu arteritis. Methods Twenty-six consecutive patients with Takayasu arteritis underwent 3.0 T high resolution MR vessel wall imaging on supraortic vessels (according to the classification of Lupi-Herrea , type Ⅰ and Ⅲ were included). Sixteen patients were in active phase and 10 in inactive phase based on the Kerr criteria. The MR vessel wall imaging appearances of Takayasu arteritis were compared between the active phase and inactive phase cases. Results Wall thickening was demonstrated in all involved arteries. There were statistically significant differences between active phase and inactive phase cases in MR appearances including multi-ring thickening of vessel wall (75/80 and 18/50), arterial inner wail enhancement (50/80 and 19/50), obscurity of perivascular fat (55/80 and 18/50,X<'2>=50.39,7.41,13.40,P<0.01). There was also a statistically significant difference in the thickness of carotid artery wall between the two groups [ (3.8±0.2) mm vs (2.5±0.8) mm]. Conclusion 3 T high resolution MR vessel wall imaging is valuable for identifying the activity of Takayasu arteritis.