Objective:To investigate the feasibility of the application of low tube potential scanning in dacryocystography CT.Methods:The mixture of iohexol and saline with the ration of 1∶3 as the dacryocyst was set on the nose wing of the head-neck phantom. The phantom was scanned at 80, 100, 120, 140 kV with appropriate mAs to set the volume CT dose index(CTDI vol)at 10, 15, 20, 25, 30, 35 or 40 mGy. All the images were objectively evaluated to find out the optimal scanning parameters of 80 kV/240 mAs with the same contrast-to-noise ratio(CNR)of conventional scanning condition of 120 kV/180 mAs. A total of 62 patients who conducted dacryocystography CT in Beijing Tongren Hospital from November 2019 to July 2020 were prospectively selected. They were randomly divided equally into conventional scanning group with 120 kV/180 mAs and low tube potential group with 80 kV/240 mAs. The CT number, noise (SD) and contrast-to-noise ratio (CNR) of the two groups were measured as the objective evaluation indicators of image quality. The subjective evaluation was performed by two senior radiologists using a double-blind method and a 5-scale system evaluation. Results:For the phantom study, the CNR was positively correlated with CTDI vol under the same tube potential ( r=0.985, 0.965, 0.971, 0.972, P < 0.05). With the same CNR, the radiation dose decreased with lower tube potential. Under the conventional scanning parameters of 120 kV/180 mAs, the CNR was 27.8. At the same CNR, the optimal scanning parameters were 80 kV/240 mAs. For the clinical study, the CTDI vol of conventional scanning group and low tube potential group were 31.2 and 12.8 mGy respectively, 59% decreased in low tube potential group. There were statistically significant differences in CT number of dacryocyst area, CT number of orbital fat area and noise between the two groups ( t=-3.476, 2.601, -5.704, P < 0.05). There was no statistically significante difference in CNR between 2 groups( P>0.05). Two observers had a good consistency ( Kappa >0.75). There was no statistically significante difference in subjective rating between 2 groups( P>0.05). Conclusions:Low tube potential scanning could obtain satisfactory image quality in dacryocystography CT at much lower radiation dose.

This paper is mainly devoted to the relationship between the correlation dimension (CD) of exercise heart rate variability (EHRV) and the status of cardiovascular function. Hypertensive patients and healthy people were enrolled in two contrast groups. Dynamic electrocardiograph (ECG) in step exercise was recorded. EHRV was extracted by wavelet transform. The CDs in the whole course of exercise and in three stages of exercise were calculated, the three stages being named rest-before-exercise, during-exercise, and after-exercise. SPSS software was used for statistical analysis. The results revealed all the CDs showed significant difference between two groups except that in the stage of during exercise. By discrimination analysis, the average correct rate was 92.2%. It indicated that the CD in stress status probably could be an effective non-linear parameter for assessing cardiovascular function status.
Adult ; Aged ; Case-Control Studies ; Electrocardiography ; methods ; Exercise ; physiology ; Exercise Test ; Female ; Heart Rate ; physiology ; Humans ; Hypertension ; physiopathology ; Male ; Middle Aged ; Nonlinear Dynamics ; Signal Processing, Computer-Assisted ; Young Adult

Objective: To observe and study clinical efficacy of restruction of finger pulp using tibial flap. Methods: From January 2009 to October 2013, we reconstructed the 20 finger pulps with free tibial flap of the second toe. Results: 20 flaps survived completely and were followed up for 6 months to 2 years, with an average of 1 year. There were no obvious scars in the reconstructive finger pulps. And the reconstructed finger pulps all had good appearance, texture, a fingerprint point discrimination at 6-8 mm, and finger function recovered well. Conclusions The shape of finger pulp after reconstuction with the free tibial flap of the second toe has the similar appearance to the normal finger pulp and a good sensory function, which is one of the best ways to reconstruct the finger pulp defects.

OBJECTIVEIn order to study the relation between polymorphisms of methylenetetrahydrofolate reductase C677T (MTHFR) and susceptibility of stomach cancer (SC).

METHODSWe conducted a case-control study with 107 cases of SC and 200 population-based controls in Huaian city of Jiangsu province, China. The epidemiological data were collected, and DNA of peripheral blood leukocytes was obtained from all of the subjects. MTHFR genotypes were detected by PCR-RFLP method.

RESULTS(1) The frequency of MTHFR variant genotypes (C/T + T/T) among the cases (79.4%) was significantly higher than the controls (68.5%) (P = 0.041 6); the crude OR for SC was 1.78 (95% CI: 0.99 - 3.22). After adjustment for sex and age, the OR for SC was 1.89 (95% CI: 1.08 - 3.32). (2) Subjects who had MTHFR variant genotypes and having smoking habit were at a significantly higher risk of developing SC (OR = 7.72, 95% CI: 2.23 - 26.79) compared with those who had wild-type homozygotes (C/C) genotype and no smoking habit. Individuals who had variant genotypes and who had habit of frequent alcohol drinking were at an increased risk of developing SC (OR = 3.08, 95% CI: 1.30 - 7.23) compared with those with C/C genotype and low consumption of alcohol. As compared with subjects with C/C genotype and low consumption of alcohol and no smoking habit, individuals who had variant genotypes and who had habits of frequent alcohol drinking and smoking had 12.96 (95% CI: 2.76 - 70.46) folds risk developing SC.

CONCLUSIONSThese results in the present study suggested that the polymorphisms of MTHFR C677T was associated with risk of developing SC, and there was a coordinated effect between MTHFR genotypes and habits of smoking and alcohol drinking in the development of SC.

Alcohol Drinking ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2) ; Middle Aged ; Oxidoreductases Acting on CH-NH Group Donors ; genetics ; Point Mutation ; Polymorphism, Genetic ; Risk Factors ; Smoking ; Stomach Neoplasms ; epidemiology ; genetics

Objective:To investigate the trend of radiological diagnostic examination frequency and the related influencing factors in a general hospital in recent four years.Methods:The hospital information system and the radiology information system were used to collect the information on the numbers of the outpatients, the emergency patients, and the inpatients and the radiology examination information from 2019 to 2022. The examination frequency and proportion of various imaging equipment were counted by using the perspective table of data, and the examination items and the proportion of the radiological diagnostic examinations were calculated. The positive rates of the radiological examinations were measured from 2019 to 2022. The gender and age distribution of the patients were analyzed. Spearman correlation analysis was used to analyze the relationships between the numbers of the patients undergoing radiological examinations and the numbers of the outpatients, emergency patients and the inpatients.Results:The annual frequency of radiological diagnostic examinations from 2019 to 2022 were 307 306, 245 418, 317 250 and 325 625, respectively, with a total of 1 195 599. Among them, the proportions of CT, X-rays, bedside X-rays, bone density, gastrointestinal imaging and mammography were 59.74%, 38.04%, 1.39%, 0.42%, 0.21% and 0.19%, respectively. In each year, the proportion of CT in all radiological diagnostic examinations was 49.58%, 63.40%, 60.40% and 65.20%, respectively. The frequency of emergency CT and emergency chest CT was correlated with the number of emergency patients( r =0.63, 0.61, P<0.05), and the frequency of non-emergency CT was correlated with the number of outpatients and inpatients ( r =0.61, 0.66, P<0.05). The positive rates of the CT examinations were higher than 80% except the lowest of 79.95% in 2021. Conclusions:Radiological examinations especially CT examinations have increased significantly, and played an important role in the diagnosis of diseases. However, attention should be paid to the Justification of the CT examinations. Timely statistical analysis of radiological examination information can provide data supports and references for scientific management of radiological examinations.

Objective:To investigate the feasibility of simultaneous arteriovenous enhancement of neck CT with two-stage injection of contrast agent and its effect on image quality and radiation dose.Methods:A total of 30 patients undergoing neck CT enhancement scan due to space-occupying lesions in Beijing Tongren Hospital, Capital Medical University from February to April 2022 were prospectively included as the experimental group. The neck CT enhancement scan was performed with two-stage injection of contrast agent and arteriovenous simultaneous enhancement. The dosage of contrast agent was calculated according to the patient′s body weight, and the method of two-stage injection was adopted. The dosage of contrast agent in the first stage was 0.7 ml/kg, with normal saline in the middle stage, and the second stage (began at 35 s) was 0.3 ml/kg. A total of 30 patients with gender and age matching with the experimental group from December 2021 to January 2022 were retrospectively collected as the control group. The control group was treated with the traditional arterial phase and venous phase scanning method with the dosage of 1.0 ml/kg contrast agent. The arterial phase was scanned at the 30 s and the venous phase was scanned at the 60 s. The CT values of bilateral carotid arteries and jugular veins in the experimental group were measured, the CT values of bilateral carotid arteries in the arterial phase were measured in the control group, and the CT values of bilateral carotid arteries and jugular veins in the venous phase were measured. Carotid artery enhancement score was performed for images of experimental group and control group in arterial and venous phase, and jugular vein and lesion enhancement score was performed for images of experimental group and control group in venous phase. The effective dose was calculated for both groups. The difference of carotid artery CT values between images was compared by one-way analysis of variance, and LSD method was used for pairwise comparison. The CT values of jugular vein were compared using independent sample t test. Kruskal-Wallis test was used to compare carotid artery enhancement scores, and Nemenyi method was used for pairwise comparison. Jugular vein and lesion enhancement scores and effective dose were compared by Mann-Whitney U test. Results:The CT value of carotid artery of experimental group [left (276±24) HU, right (273±25) HU] was lower than that of control group in arterial phase [left (329±33) HU, right (327±32) HU], and higher than that in the venous phase [left (147±15) HU, right (148±16) HU]. All the differences were statistically significant ( P<0.001). The CT value of jugular vein of experimental group [left (206±18) HU, right (203±19)] was higher than that of control group in the venous phase [left (154±15) HU, right (151±15)], the difference was statistically significant ( t=11.88, 11.76, both P<0.001). There was no significant difference in carotid artery enhancement score between experimental group and control group in arterial phase ( P=0.624), but the carotid artery enhancement score of the experimental group was higher than that of the control group in the venous phase, and the difference was statistically significant ( P<0.001). The scores of jugular vein and lesion enhancement in experimental group were higher than those of control group in venous phase, and the difference was statistically significant ( Z=5.01, P<0.001). The effective dose of the experimental group [2.41(2.04, 2.72) mSv] was decreased by 52.2% compared with the control group [5.04(4.18, 5.44) mSv], and the difference was statistically significant ( Z=-6.24, P<0.001). Conclusions:The neck CT enhanced scan with two-stage injection of contrast agent and arteriovenous simultaneous enhancement method can obtain comprehensive images of arterial and venous phases, and realize simultaneous enhancement of carotid artery, jugular vein and lesions, and reduce radiation dose.

Objective:To construct a spatial radiomics model based on the spatial distribution characteristics of supratentorial pilocytic astrocytoma (PA) and ganglioglioma (GG) and to evaluate its differential diagnosis efficiency.Methods:The study was a cross-sectional study. A retrospective collection of 244 patients with episodic PA and GG who attended Beijing Tiantan Hospital of Capital Medical University (Center 1) from June 2016 to June 2022 and 116 patients with episodic PA and GG who attended General Hospital of Eastern Theater Command (Center 2) from March 2019 to October 2022 was performed. The patients in Center 1 were divided into a training set (171 patients) and a validation set (73 patients) in a 7∶3 ratio according to the random number table method, and the patients in Center 2 as a whole were regarded as test sets. All patients underwent MRI. Segmentation of tumor based on enhanced T 1WI and T 2WI images, alignment to standard space to generate a statistical parametric mapping of tumor locations and intergroup comparison was conducted. The Johns Hopkins University template was used to extract 189 tumor location features to construct a spatial model of tumor location; PyRadiomic 3.0.1 software was used to extract tumor radiomics features to construct a radiomics model; and the two models were fused to construct a spatial radiomics model. The efficacy of spatial radiomics model, spatial model, and radiomics model to discriminate PA from GG was analyzed using receiver operating characteristic curves and area under the curve (AUC). The generalization ability of the model was assessed by the difference in accuracy between the test sets and the validation sets (ΔACC). The clinical utility of the model was compared using clinical decision curves and calibration curves. Results:The statistical parametric mapping of lesions showed that supratentorial PA was vulnerable to medial structure areas such as suprasellar region, thalamus, basal ganglia and frontal lobe, temporal lobe, parietal lobe. GG was mainly distributed in bilateral temporal lobes, as well as frontal lobe, occipital lobe and parietal lobe. The AUCs of spatial radiomics model, radiomics model and spatial model to identify PA and GG in the test set were 0.876, 0.785, and 0.819, with accuracies of 77.59%, 72.41%, and 77.14%, respectively, and ΔACCs in the test set and validation set were 11.6%, 15.43%, and 6.94%, respectively. The clinical decision curves showed an overall greater clinical benefit of the spatial radiomics model compared with the conventional radiomics model and spatial model.Conclusion:Spatial radiomics model containing spatial information on lesion location can improve the diagnostic efficacy of supratentorial PA and GG, and enhance the generalization of the prediction model.

Objective:To explore and compare the impacts of different scanning protocols on image quality and radiation dose in chest computed tomography (CT) scans.Methods:A retrospective analysis was conducted for the data of 65 randomly selected patients who underwent chest CT scans using a tube voltage of 120 kV, the automatic modulation technique for tube current, and z-axis radiation dose modulation at the Emergency Department of our hospital from June to July 2023. The enrolled cases were divided into two groups: the high-resolution group ( n = 34) and the conventional group ( n = 31), with the settings for scanning protocols identical to those for phantom scans. For patients in both groups, thin-layer images of the cross-sections in the lung and mediastinal windows were reconstructed using thickness/intervals of 1 mm/1 mm and 2 mm/1 mm, respectively. Meanwhile, high-resolution and conventional CT scans were conducted using a Catphan500 phantom under a tube voltage of 120 kV and a tube current of 150 mAs. Of both scanning protocols, the high-resolution CT scan utilized the lung nodule-orientated scanning mode, pitch of 1.5, and a detector combination providing a collimation of 16 × 0.75 mm. In contrast, the conventional CT scan was performed using the body-orientated scanning mode, pitch of 0.813, and a detector combination providing a collimation of 16 × 1.5 mm. Then, the high-contrast resolutions of the phantom images obtained using the two scanning protocols were objectively evaluated. Both coronal chest images in the lung window and cross-sectional images in the mediastinal window were reconstructed with a thickness/interval of 5 mm/5 mm for both groups. Then, the obtained images were imported into the Radimetrics system to compare the body size-specific dose estimation (SSDE), doses to sensitive organs on the body surface, and scanning time of both groups. For the cross-sectional images in the mediastinal window, the contrast-noise-ratio (CNR), signal-to-noise ratio (SNR), and figure-of-merit (FOM) were measured and calculated at the fixed anatomical parts. For the cross-sectional images in the lung window, their quality was subjectively evaluated by two senior diagnostic radiologists. Results:The result of phantom scans indicated that high-resolution CT scans yielded images with an approximately 5% increase in the spatial resolution in the xy-plane and a nearly 20% increase in the spatial resolution along the z-axis compared to conventional CT scans. The result of clinical data demonstrated that the conventional group exhibited significantly higher doses to the thyroid and the female breast ( t = 2.8, 2.3, P < 0.05), along with notably elevated SNR, CNR, and FOM values of the right trapezius, compared to the high-resolution group ( t = 4.1, 5.8, z=4.4, P < 0.001). However, the high-resolution group manifested significantly higher SNR, CNR, and FOM values of the thoracic aorta compared to the conventional group ( t = 3.4, 4.4, z=3.4, P < 0.001). In addition, the cross-sectional and coronal images in the lung window of the clinical cases in the high-resolution group exhibited more stable quality, with subjective scores exceeding 4 and the average scores of both groups not statistically significantly different. Conclusions:For chest CT examination, high-resolution CT scans are more suitable for observations focusing on the details of the lungs and mediastinum, while conventional CT is more suitable for those centering on soft tissues on the body surface.

Cancer immunotherapy is impaired by the intrinsic and adaptive immune resistance. Herein, a bispecific prodrug nanoparticle was engineered for circumventing immune evasion of the tumor cells by targeting multiple immune resistance mechanisms. A disulfide bond-linked bispecific prodrug of NLG919 and JQ1 (namely NJ) was synthesized and self-assembled into a prodrug nanoparticle, which was subsequently coated with a photosensitizer-modified and tumor acidity-activatable diblock copolymer PHP for tumor-specific delivery of NJ. Upon tumor accumulation via passive tumor targeting, the polymeric shell was detached for facilitating intracellular uptake of the bispecific prodrug. NJ was then activated inside the tumor cells for releasing JQ1 and NLG919 via glutathione-mediated cleavage of the disulfide bond. JQ1 is a bromodomain-containing protein 4 inhibitor for abolishing interferon gamma-triggered expression of programmed death ligand 1. In contrast, NLG919 suppresses indoleamine-2,3-dioxygenase 1-mediated tryptophan consumption in the tumor microenvironment, which thus restores robust antitumor immune responses. Photodynamic therapy (PDT) was performed to elicit antitumor immunogenicity by triggering immunogenic cell death of the tumor cells. The combination of PDT and the bispecific prodrug nanoparticle might represent a novel strategy for blockading multiple immune evasion pathways and improving cancer immunotherapy.