The present study describes systematically the ultrastructural changes of blood and some organs of rabbits, goats and rats with severe decompression sickness. In our experiment, the animals were exposed to pressure of 0.6 MPa and 1.0 MPa for 60 minutes respectively, to induce severe decompression sickness. The results are as follows: 1. Abnormality of platelets. The granules of platelets decreased and the platelet pseudopods were formed with adhesion and aggregation of platelets. 2. Deformation of erythrocytes. Triangle-like or shell-like cells, dacryocytes, twisted cells, and Ⅰ—Ⅲ type echinocytes were found. 3. Changes of endotheliocytes of the vascular wall became flattened. The space between these cells significantly widened (up to 4-18?m), and blood cells could be found to have wedged into it. 4. Formation of air-blood surface by the intravascular blood. 5. Alteration of organelies. There occured the expansion of rough endoplasmic reticulum, the degranulation and rupture of membranes, as well as the swelling and dissolution of mitochondria.

In this paper, a new method was presented which can generate dental panoramic radiographs from the 3D CT sectional data. The dental panoramic radiograph was generated by casting ray into the 3D sectional data from a curved surface close to the dental arch. With this method, the relationship between the 3D CT sectional data and the dental panoramic radiographs was built, which helped to overcome the defects in the real X-ray panoramic radiographs, such as structure overlap and unselectable content for displaying. The technology is of certain significance in computer aided technique and surgical planning related to dentistry.
Humans ; Image Processing, Computer-Assisted ; Imaging, Three-Dimensional ; methods ; Radiography, Panoramic ; methods ; Tomography, X-Ray Computed ; methods

Objective To explore the values of metrics on intravoxel incoherent motion (IVIM) and gadoxetic acid enhanced T1ρ imaging for staging of non?alcoholic fatty liver disease activity scores (NAS) and inflammation in nonalcoholic steatohepatitis (NASH) rabbits model. Methods NASH rabbits model was established by feeding with a varied duration (4, 8, 12 weeks) of high?fat, high?cholesterol diet. IVIM and gadolinium?ethoxybenzyl?diethylenetriamine pentaacetic acid (Gd?EOB?DTPA) enhanced T1ρ images were performed by a 3.0 T MR scanner. The inter?class correlation coefficients (ICC) and Bland?Altman analysis were applied to evaluate the reproducibility of the IVIM and Gd?EOB?DTPA enhanced T1ρ mapping measurers. Spearman correlation analysis were used to assess the correlation between MR metrics, including ADC, D, D*, f, T1ρ, T1ρ (hepatobiliary phase, HBP), and NAS score and inflammation grades respectively with reference to histopathology. ROC curve analysis was used to evaluate the diagnostic performance of T1ρ and IVIM parameters for NASH, inflammation grade, and hepatic fibrosis. Multiple linear regression equations were used to analyze the independent influence factors of T1ρ (HBP). Results The f value was negatively correlated with the NAS score (r=-0.530, P<0.01). The f value of the fibrosis S1?2 was significantly lower than that of the S0 (P<0.01). There was no statistical difference in D, D*, ADC among NASH score, inflammation, and fibrosis stage. T1ρ and T1ρ (HBP) values were positively correlated with NAS scores and inflammation grades. The area under curve (AUC) for the diagnosis of NASH for T1ρ, T1ρ(HBP), ADC, D, D*, and f values were 0.849, 0.949, 0.728, 0.596, 0.522, and 0.871, respectively. The AUCs of T1ρ (HBP)+f in the diagnosis of NASH, G2?3 inflammation, and F1?2 fibrosis were 0.971, 0.935, and 0.903, respectively. Fibrosis (R2=0.624, P=0.002) and inflammation (R2=0.746, P=0.002) were major independent factors of T1ρ (HBP). Conclusion Gd?EOB?DTPA enhanced T1ρ imaging can reflect the severity of NASH and degree of inflammation. IVIM measurements are not accurate enough to stage liver inflammatory activity of NASH. T1ρ (HBP)+f might be a superior noninvasive imaging biomarker than either non?enhanced T1ρ or IVIM for NASH activity and inflammation assessments.

Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.

Objective: To explore the values of metrics on intravoxel incoherent motion (IVIM) and gadoxetic acid enhanced T₁ρ imaging for staging of non-alcoholic fatty liver disease activity scores (NAS) and inflammation in nonalcoholic steatohepatitis (NASH) rabbits model. Methods: NASH rabbits model was established by feeding with a varied duration (4, 8, 12 weeks) of high-fat, high-cholesterol diet. IVIM and gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced T₁ρ images were performed by a 3.0 T MR scanner. The inter-class correlation coefficients (ICC) and Bland-Altman analysis were applied to evaluate the reproducibility of the IVIM and Gd-EOB-DTPA enhanced T₁ρ mapping measurers. Spearman correlation analysis were used to assess the correlation between MR metrics, including ADC, D, D^*, f, T₁ρ, T₁ρ (hepatobiliary phase, HBP), and NAS score and inflammation grades respectively with reference to histopathology. ROC curve analysis was used to evaluate the diagnostic performance of T₁ρ and IVIM parameters for NASH, inflammation grade, and hepatic fibrosis. Multiple linear regression equations were used to analyze the independent influence factors of T₁ρ (HBP). Results: The f value was negatively correlated with the NAS score (r=-0.530, P<0.01). The f value of the fibrosis S1-2 was significantly lower than that of the S0 (P<0.01). There was no statistical difference in D, D^*, ADC among NASH score, inflammation, and fibrosis stage. T₁ρ and T₁ρ (HBP) values were positively correlated with NAS scores and inflammation grades. The area under curve (AUC) for the diagnosis of NASH for T₁ρ, T₁ρ(HBP), ADC, D, D^*, and f values were 0.849, 0.949, 0.728, 0.596, 0.522, and 0.871, respectively. The AUCs of T₁ρ (HBP)+f in the diagnosis of NASH, G2-3 inflammation, and F1-2 fibrosis were 0.971, 0.935, and 0.903, respectively. Fibrosis (R²=0.624, P=0.002) and inflammation (R²=0.746, P=0.002) were major independent factors of T₁ρ (HBP). Conclusion Gd-EOB-DTPA enhanced T₁ρ imaging can reflect the severity of NASH and degree of inflammation. IVIM measurements are not accurate enough to stage liver inflammatory activity of NASH. T₁ρ (HBP)+f might be a superior noninvasive imaging biomarker than either non-enhanced T₁ρ or IVIM for NASH activity and inflammation assessments.