Objective To evaluate the ability of ultra-high-b-value diffusion weighted imaging (DWI) in diagnosis of the prostate cancer (PCa) at 1.5T MR.Methods 12 patients with PCa and 17 patients with benign prostate hyperplasia (BPH) proved by histopathology underwent MRI and DWI examinations (b=400, 800,1 400 s/mm2).The signal intensity and visual degree of region of interest (ROI) in all DWI with different b values were respectively measured.The signal intensity and visual degree of ROI between high-b-value DWI and ultra-high-b-value DWI were compared,respectively.Results The difference of signal intensity of PCa between high-b-value DWI and ultra-high-b-value DWI was statistically significant (χ2=220.957,P=0.000<0.05).The signal intensity of PCa was getting brighter in DWI with higher b value.The difference of visual degree between these two groups was also statistically significant (χ2=11.378,P=0.003<0.05).The difference among PCa, BPH and normal prostate peripheral zone was statistically significant in ultra-high-b-value DWI (χ2=25.913, P=0.000<0.05).The brightness of PCa in ultra-high-b-value DWI mainly was bright or grey-bright (71.4%), while the brightness of BPH and normal prostate peripheral zone were mainly dark or grey-dark (BPH 63.0%, normal prostate peripheral zone 73.3%).The difference of visual degree among PCa, BPH and normal prostate peripheral zone was statistically significant difference as well (Z=-6.908,-6.110,P=0.000<0.017).The diagnostic efficiency of the signal intensity and visual degree were highest with b=1 400 s/mm2.Conclusion DWI with ultra-high-b-value can improve the display rate of the PCa at 1.5T MR, making easier the detection and diagnosis of PCa.

Objective To explore the value of whole-lesion method measuring hepatic abscess lesions in ADC map.Methods 13 cases with hepatic abscess were measured by using three methods,drawing the outline of the lesion by manual operation,and placing the round ROI in the central area and the peripheral area in ADC map,respectively.The differences of the ADC values measured by the three methods were compared.The Friedman test was used for the mean of ADC values.The value differences of the groups were compared by the Bonferroni test.Results Among the 17 lesions,6 lesions located in the anterior segment of right lobe of liver,7 lesions in the posterior segment of right lobe of liver,1 lesion in the caudate lobe,1 lesion in the junction zone between the anterior segment of right lobe and the medial segment of left lobe,1 lesion in the medial segment of left lobe and 1 lesion in the lateral segment of left lobe of liver.The mean values from the three methods(×10-3 mm2/s) and the 95％ confidence intervalwere:1.27±0.33,1.23± 0.84,1.29±0.44 and (1.21,1.34),(1.06,1.40),(1.20,1.38),respectively.The results of the Friedman test were x2=2.176,P=0.337,and there was no statistical significance between the differences.There were also no statistical significance by the Bonferroni test (P values ＞0.05/3=0.017).The 95 ％ confidence interval of the whole-lesion method was the narrowest,and the accuracy was the highest.The 95％ confidence interval of the central method was the widest,and the accuracy was the lowest.Conclusion The whole-lesion measurement may be used as an analytical method for hepatic abscess in ADC map.

Objective:To explore the application value of the method of judging the density of small shadows in the lung area by using CT and CT reference films for pneumoconiosis.Methods:The chest imaging data of 244 employees of a large copper company in Tongling City, Anhui Province who underwent occupational physical examination at Tongling Municipal Hospital in Anhui Province from January 2016 to December 2019 were retrospectively analyzed. Totally 244 cases underwent chest CT scan and chest DR radiography at the same time. The shape and size of the small shadows (the size of the circular and quasi-circular nodules in the lung area were represented by p, q, r, and the size of the irregular small shadows were represented by s, t, u), the overall density, the density of small shadows in each lung area, the large shadows, and the diagnosis stage were observed and compared. The small shadow density of each lung area was judged by the method of judging the small shadow density of CT lung area and the reference film, and other observation indicators were judged according to GBZ70-2015 Diagnosis of Occupational Pneumoconiosis. Results:There was a significant difference between CT and DR in judging s-shaped small shadows and no small shadows ( P<0.05), and there was no statistically significant difference in judging p, q, r, t, and u-shaped small shadows ( P>0.05). CT and DR had medium to high consistency in the judgment of the overall density of small shadows (Kappa=0.692, P=0.001), and the diagnostic coincidence rate was 82.38% (201/244). There was moderate to high agreement between CT and DR in the density of small shadows shown in the right upper, right lower, left upper, left middle, and left lower lung regions (Kappa ranged from 0.40 to 0.75, P<0.05), and the consistency in the right middle lung region was poor (Kappa=0.381, P=0.001). Eleven large shadows were detected in 8 cases by DR, 31 large shadows were detected in 23 cases by CT, and 20 (8.20%) large shadows were detected more frequently by CT than DR. The agreement between CT and DR for the diagnosis and staging of silicosis was excellent (Kappa=0.843, P=0.001), and the diagnostic coincidence rate was 91.80% (224/244). Conclusion:Applying the method of determining the density of small shadows in the lung area of pneumoconiosis and reference films, combined with GBZ70-2015 Diagnosis of Occupational Pneumoconiosis, can make a more accurate diagnosis of silicosis.