Sensitivity of genotypically diverse rice varieties to radiation and the related changes to antioxidant enzyme activities.

PURPOSE: Radiation mutagenesis, which typically involves gamma rays, is important for generating new rice germplasm resources. Determining the appropriate radiation dose range is critical for the success of radiation mutagenesis. Clarifying the sensitivity and tolerance of genotypically diverse rice varieties to gamma irradiation as well as the radiation-induced changes to reactive oxygen species (ROS) generation and antioxidant enzyme activities is crucial for increasing the utility of radiation mutagenesis in rice breeding programs. MATERIALS AND METHODS: The seeds of the following four rice varieties with different genotypes were used as test materials: indica Zhe 1613, glutinous indica Zhe 1708, japonica Zhejing 100, and glutinous japonica Zhenuo 65. Additionally,60Co was used as the source of gamma rays. The rice seeds were irradiated with 14 doses (0, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, and 750 Gy). Non-irradiated seeds were used as the control. The seedling survival rate for each variety was recorded at 3, 7, 14, and 28 days after sowing. Moreover, the median lethal dose (LD50) and critical dose (LD40) were calculated according to the seedling survival rates at 28 days after sowing. The seedling superoxide anion (O2•-), hydrogen peroxide (H2O2), and malondialdehyde (MDA) contents and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) activities were analyzed at 7 days after sowing. RESULTS: As the radiation dose increased, the seedling survival rate decreased. The seedling survival rate also decreased significantly as the number of days after sowing increased. Among the rice genotypes, the rank-order of the radiation tolerance was as follows: indica Zhe 1613 > glutinous indica Zhe 1708 > japonica Zhejing 100 > glutinous japonica Zhenuo 65. The LD50 values were 426.7 Gy for Zhe 1613, 329.2 Gy for Zhe 1708, 318.3 Gy for Zhejing 100, and 316.6 Gy for Zhenuo 65. Increases in the radiation dose resulted in significant increases in the seedling O2•- and H2O2 contents, but only up to a certain point. Further increases in the radiation dose caused the seedling O2•- and H2O2 contents to decrease. The H2O2 content for each variety peaked when the radiation dose was very close to the LD50. We propose that the radiation dose associated with the highest H2O2 content (±50 Gy) should be used as the recommended dose for the gamma irradiation of rice. The radiation dose that resulted in peak seedling O2•- contents in the analyzed rice varieties was very close to the LD40. In all rice varieties, the MDA content increased as the radiation dose increased. The SOD, CAT, POD, and APX activities increased as the radiation dose increased within a certain range (less than 600 Gy for Zhe 1613 and 400 Gy for the other varieties), but there were slight differences among the rice varieties. CONCLUSIONS: Genotypically diverse rice varieties vary regarding their sensitivity to gamma irradiation. Our findings suggest that ROS generation and antioxidant enzyme activities are important factors associated with the radiation mutagenesis of rice. The close relationship between the activities of key antioxidant enzymes, such as SOD, POD, APX, and CAT, and the LD50 and LD40 may be exploited to enhance radiation mutagenesis through the use of plant growth regulators.

COVID-19 lesion detection and segmentation-A deep learning method.

PURPOSE: In this paper, we utilized deep learning methods to screen the positive COVID-19 cases in chest CT. Our primary goal is to supply rapid and precise assistance for disease surveillance on the medical imaging aspect. MATERIALS AND METHODS: Basing on deep learning, we combined semantic segmentation and object detection methods to study the lesion performance of COVID-19. We put forward a novel end-to-end model which takes advantage of the Spatio-temporal features. Furthermore, a segmentation model attached with a fully connected CRF was designed for a more effective ROI input. RESULTS: Our method showed a better performance across different metrics against the comparison models. Moreover, our strategy highlighted strong robustness for the processed augmented testing samples. CONCLUSION: The comprehensive fusion of Spatio-temporal correlations can exploit more valuable features for locating target regions, and this mechanism is friendly to detect tiny lesions. Although it remains in discrete form, the feature extracting in temporal dimension improves the precision of final prediction.

CT-Based Radiomics Signature for Preoperative Prediction of Coagulative Necrosis in Clear Cell Renal Cell Carcinoma

Objective@#The presence of coagulative necrosis (CN) in clear cell renal cell carcinoma (ccRCC) indicates a poor prognosis, while the absence of CN indicates a good prognosis. The purpose of this study was to build and validate a radiomics signature based on preoperative CT imaging data to estimate CN status in ccRCC. @*Materials and Methods@#Altogether, 105 patients with pathologically confirmed ccRCC were retrospectively enrolled in this study and then divided into training (n = 72) and validation (n = 33) sets. Thereafter, 385 radiomics features were extracted from the three-dimensional volumes of interest of each tumor, and 10 traditional features were assessed by two experienced radiologists using triple-phase CT-enhanced images. A multivariate logistic regression algorithm was used to build the radiomics score and traditional predictors in the training set, and their performance was assessed and then tested in the validation set. The radiomics signature to distinguish CN status was then developed by incorporating the radiomics score and the selected traditional predictors. The receiver operating characteristic (ROC) curve was plotted to evaluate the predictive performance. @*Results@#The area under the ROC curve (AUC) of the radiomics score, which consisted of 7 radiomics features, was 0.855 in the training set and 0.885 in the validation set. The AUC of the traditional predictor, which consisted of 2 traditional features, was 0.843 in the training set and 0.858 in the validation set. The radiomics signature showed the best performance with an AUC of 0.942 in the training set, which was then confirmed with an AUC of 0.969 in the validation set. @*Conclusion@#The CT-based radiomics signature that incorporated radiomics and traditional features has the potential to be used as a non-invasive tool for preoperative prediction of CN in ccRCC.

Diagnostic imaging of primary hepatic neuroendocrine tumors and treatment with transarterial chemoembolization: analysis of 6 cases / 中华肝脏病杂志

Objective@#To investigate the imaging diagnosis, treatment and prognosis of primary hepatic neuroendocrine tumors.@*Methods@#The clinical features, imaging manifestations, histopathological and immunohistochemical findings and interventional therapy of 6 patients identified with pathologically confirmed primary hepatic neuroendocrine tumors were retrospectively analyzed, and the related literatures were reviewed.@*Results@#All 6 patients presented with symptoms of abdominal pain. 4 patients had solitary hepatic mass and 2 patients had multiple hepatic masses. Magnetic resonance imaging showed low signal intensity on T1 weighted imaging, high signal intensity on T2 weighted imaging and clear boundary; the arterial phase of enhancement scan was uneven and enhanced, and portal venous phase or delayed phase showed continuous enhancement, surrounded by ring enhanced capsule. A pathological diagnosis was primary neuroendocrine tumor of the liver. After interventional treatment, 6 patients had some therapeutic effects. Among them, 4 patients underwent multiple interventional therapies, followed by 4 years of follow-up has shown satisfactory results.@*Conclusion@#Primary hepatic neuroendocrine tumors are very rare and their imaging manifestations are specific. Eventually, relies on pathological and immunohistochemical diagnosis. Transarterial chemoembolization therapy can bring satisfactory results in the treatment of primary hepatic neuroendocrine tumor.

Clinical assessment of spectrum CT with material decomposition technique in overcoming renal cyst pseudoenhancement / 中国医学影像技术

Objective To evaluate the value of material decomposition imaging of spectrum CT in overcoming renal cyst pseudoenhaneement.Methods Totally 80 patients with renal cysts (total 75 cysts) who underwent CT imaging with GSI mode were collected.The renal cysts were divided into 3 groups according to diameters,group A (diameters 0.5-＜1.5 cm,n=25),B (1.5-＜2.5 cm,n=25) and C (2.5-＜3.5 cm,n=25) respectively.The iodine-water density imaging was reconstructed by using the GSI Viewer analysis software.The CT value and iodine-water concentration of the cysts were recorded.The difference of CT value,iodine-water concentration in unenhanced and enhanced dual phases in each group was compared.Results The difference of CT value between plain scan and parenchyma phase among the 3 groups had statistically significant difference (F=204.128,P＜0.001),and the differences comparing any two were statistically significant (all P＜0.05).The postcontrast attenuation increased more than 10 HU in group A and B,indicating renal cyst pseudoenhancement,and less than 10 HU in group C,which had no pseudoenhancement.There were statistical difference in iodine concentration of the cysts of the 3 groups in unenhance,cortical and parenchyma phases (all P＜0.001),but the difference value in unenhance,cortical and parenchyma phases were less than 10 (100 μg/cm3),and the difference value of the 3 group was group A＞group B＞group C (all P＜0.05).The water concentration of the cysts in group A descend in renal cortical and parenchyma phase with statistical difference (P＜0.001),but the difference value was less than 10 mg/cms.Conclusion The measurements of iodine-water concentration appear to drift as well,the smaller the greater,The degree of the iodine concentration shifting is more obvious than water concentration.

Application of MR-cine in evaluation on functional dyspepsia / 吉林大学学报(医学版)

Objective:To explore the value of MR-cine for assessment of the duodenum peristalsis in the patients with functional dyspepsia.Methods:25 patients with functional dyspepsia were selected according to the diagnostic criteria of RomeⅢ of functional gastrointestinal disorders (FGIDs)as case group and 25 cases of healthy volunteers who had been screened out in clinic were used as normal control group. After fasting for 8 h,supine position was performed.1.5TGEHDxMR was used to scan the coronal,axial and oblique coronal fast steady state precession (FIESTA)sequence of gastric and duodenal descending part.The images of 5 and 15 min after drinking 600 mL mannitol solution (concentration 2.5%)were collected and sent to MR AW4.4 workstation.The duodenal motility in the patients with functional dyspepsia was measured by recording the times of duodenum and measuring and calculating the percentage occlusion of duodenum contractions (PDC). Results:After drinking mannitol, the oblique coronal scan of all subj ects clearly displayed the anatomical structure and peristaltic wave of descending part of duodenum. After drinking 5 and 1 5 min of mannitol,the peristaltic wave frequencies in case group were lower than those in normal control group. The descending duodenum PDC of the patients in case group was significantly lower than that in normal control group (P0.05).Conclusion:MR-cine can evaluate preliminarly the duodenum peristalsis of the patients with functional dyspepsia. The diagnosis of FGIDs can be further studied by using the noninvasive MR-cine examination technique.

Application value of split-bolus spectral computed tomography in the portal venography / 中华消化外科杂志

Objective To investigate the effect of split-bolus spectral computed tomography(CT) on the portal venography and radiation dose.Methods The prospective study was adopted.The clinical data of 119 patients who underwent spectral CT at China-Japan Union Hopital from September 2014 to March 2015 were collected.Patients were randomly divided into the portal venography with split-bolus spectral CT single-phase enhanced scan group and portal vein multi-phase scan group by random sequence method.In the portal venography with split-bolus spectral CT single-phase enhanced scan group,the spectral CT was used with the method of split-bolus single phase imaging,and in the portal vein multi-phase scan group,standard spiral CT was used to perform three-phase scan.Two observers evaluated CT portal venography subjectively and objectively,measured CT values,contrast to noise ratio (CNR),signal noise ratio (SNR),and calculated radiation dose.Observed indices included (1) choice of optimal monochromatic images.(2) CT values of portal veins,measurement of CNR and SNR.(3) Subjective scoring of portal venography quality.(4) Comparison of radiation dose.Measurement data with normal distribution were presented as x ± s,comparison between groups was analyzed by independent sample t test.Comparison of count data was analyzed by chi-square test.Results The 113 patients were screened for eligibility,including 59 in the portal venography with split-bolus spectral CT single-phase enhanced scan group and 54 in the portal vein multi-phase scan group.(1) Choice of optimal monochromatic images:optimal monochromatic images were abstracted at 60 keV from spectral CT portal venography.(2) CT values of portal veins and measurement of CNR and SNR:the CT values of intrahepatic portal vein,extrahepatic portal vein and branches of portal vein were (319 ± 44) HU,(328 ± 53) HU,(294 ± 45) HU in the reconstructed images at the energy level of 60 keV in the portal venography with split-bolus spectral CT single-phase enhanced scan group and (213 ±41)HU,(228 ±49)HU,(210 ±41)HU in the portal vein multi-phase scan group,with significant differences between the 2 groups(t =8.04,6.34,6.82,P ＜ 0.05).The CNR of intrahepatic portal vein,extrahepatic portal vein and branches of portal vein were 15 ± 5,24 ± 8,22 ± 7 in the portal venography with split-bolus spectral CT single-phase enhanced scan group and 13 ± 4,20 ± 6,19 ± 6 in the portal vein multi-phase scan group,respectively,with no significant difference (t =-1.13,-1.89,-1.51,P ＞ 0.05).The SNR of intrahepatic portal vein,extrahepatic portal vein and branches of portal vein were 31 ± 6,29 ± 6,27 ± 6 in the portal venography with split-bolus spectral CT single-phase enhanced scan group and 29 ± 7,28 ± 9,26 ± 6 in the portal vein multi-phase scan group,respectively,with no significant differences (t =-0.688,0.615,0.600,P ＞ 0.05).(3) Subjective scoring of portal venography quality:the subjective score of image quality of portal venography was 14.3 ± 1.0 in the portal venography with split-bolus spectral CT single-phase enhanced scan group and 12.5 ± 1.8 in the portal vein multi-phase scan group,with a significant difference (t =12.43,P ＜ 0.05).(4) Comparison of radiation dose:the radiation dose was (8.1 ± 1.1)mSv of patients in the portal venography with split-bolus spectral CT single-phase enhanced scan group and (17.4 ± 7.5) mSv in the portal vein multiphase scan group,with a significant difference (t =24.14,P ＜ 0.05).Conclusion Spectral CT portal vein imaging combined with split-bolus protocol can achieve better manifestations of portal vein and its branches,and reduce radiation dose in the scanning process.

Preliminary clinical study of sacroiliac activity in ankylosing spondylitis patients using quantitative dynamic contrast enhanced MRI / 中华放射学杂志

Objective To investigate the diagnostic values of DCE-MRI quantitative evaluation of the activity of sacroiliac joints in ankylosing spondylitis.Methods Forty two patients (36 male and 6 female) with ankylosing spondylitis in our hospital were enrolled prospectively according to the standard of diagnostic criteria for ankylosing spondylitis revised in 1984.All of them were evaluated with the blood sedimentation,C-reactive protein and ankylosing spondylitis activity index (BASDAI).We divided the patients with ankylosing spondylitis into stationary phase group and active phase group.We analyzed each of the MRI images of the two patients groups using the extended Tofts model to determine the quantitative parameters of DCE-MRI,such as contrast transfer coefficient (Ktrans),reflux constant (Kep),extravascular extracellular volume fraction (Ve),plasma volume fraction (Vp).And then the differences of quantitative data between the two groups were compared.Spearman correlation analysis was performed between the parameters with statistically significant difference and BASDAI scores.Results Among the 42 patients,22 patients (18 male and 4 female) were in active phase group and the other 20 patients (18 male and 2 female) were in stationary phase group.Ktrans,Kep,Ve were (0.750± 1.130)/min,(1.008±0.732)/min,0.460± 1.735;(0.163±0.401)/min,(0.505 ± 0.902)/min,0.345 ±3.460 for active phase group and the stationary phase group,respectively.The results of the active phase group was significantly higher than the stationary phase group (Z=3.727,2.317,3.696,respectively;all P＜0.05).The Vp had no statistically significance for the active phase group (0.125 ± 0.310) and the stationary phase group (0.160 ± 0.329) (Z=1.209,P＞0.05).Strong correlations existed between Ktrans,Kep,Ve and BASDAI score,the correlation coefficients were 0.714,0.430,and 0.676 (P＜0.05).Conclusions Quantitative DCE-MRI parameters can evaluate the activity of the ankylosing spondylitis.Strong correlations exist between Ktrans,Kep,Ve and BASDAI score.

Value of Diffusion-weighted Imaging in Distinguishing Prostate Cancer from Benign Prostatic Hyperplasia:a Meta-analysis / 中国医学影像学杂志

Purpose To explore the ADC value in distinguishing prostate cancer (PCa) and benign prostatic hyperplasia (BPH) by reviewing related articles. Materials and Methods The studies about the diffusion-weighted images in distinguishing the prostate cancer and benign prostatic hyperplasia were enrolled from the websites of Elsevier Science, PubMed, Springer-Link, Wiley Online Library, Medline and CNKI from 2000 to 2011, with DWI, prostate, cancer, carcinoma and hyperplasia as search terms. According to the uniform inclusion and exclusion criteria, the correct studies were chosen and the parameters including the mean values and standard deviations of ADC value were extracted. Meta-analysis was done by using Stata 11 software. Results A total of 7 studies met the inclusion criteria, including 4 English articles and 3 Chinese articles. The fixed-effect model was used due to no heterogeneity. The standardized mean difference (SMD) was-1.357 and 95%confidence interval (95%CI) was (-1.604,-1.109, P=0.000). Conclusion DWI can be helpful in distinguishing the prostate cancer from the benign prostatic hyperplasia, and the ADC value of PCa is lower than that of BPH.

Clinical application of proton magnetic resonance spectroscopy in differential diagnosis of intracranial lesions with ring-like enhancement / 吉林大学学报(医学版)

0.05). The peak of NAA was significantly different between high grade glioma and metastatic carcinoma(P0.05). The peak of AA was characteristic of brain abscess. The ratio of Cho/Cr0 in brain abscess was significantly lower than those in high grade glioma and metastatic carcinoma(P