In this study, we propose an automatic contour outlining method to measure the spatial resolution of homemade automatic tube current modulation (ATCM) phantom by outlining the edge contour of the phantom image, selecting the region of interest (ROI), and measuring the spatial resolution characteristics of computer tomography (CT) phantom image. Specifically, the method obtains a binarized image of the phantom outlined by an automated fast region convolutional neural network (AFRCNN) model, measures the edge spread function (ESF) of the CT phantom with different tube currents and layer thicknesses, and differentiates the ESF to obtain the line spread function (LSF). Finally, the values passing through the zeros are normalized by the Fourier transform to obtain the CT spatial resolution index (RI) for the automatic measurement of the modulation transfer function (MTF). In this study, this algorithm is compared with the algorithm that uses polymethylmethacrylate (PMMA) to measure the MTF of the phantom edges to verify the feasibility of this method, and the results show that the AFRCNN model not only improves the efficiency and accuracy of the phantom contour outlining, but also is able to obtain a more accurate spatial resolution value through automated segmentation. In summary, the algorithm proposed in this study is accurate in spatial resolution measurement of phantom images and has the potential to be widely used in real clinical CT images.
Phantoms, Imaging ; Tomography, X-Ray Computed/instrumentation* ; Algorithms ; Neural Networks, Computer ; Image Processing, Computer-Assisted/methods* ; Humans ; Polymethyl Methacrylate

Objective To analyze the lumbar/hip imaging and surface electromyography data of professional equestrian riders,to understand the incidence of chronic diseases in the hip and lower back of the rider,and to explore the causes of chronic pain in riders.Methods Twenty-five equestrian riders from the Shanghai Equestrian Sports Management Center were divided into chronic lower-back pain and chronic hip pain groups.Twelve healthy subjects without hip or lower-back pain were included in the control group.Medical history,X-ray,and magnetic resonance imaging of the hip and lower back,and surface electromyography data of the core muscle were collected.Results The JOA score of the lumbar spine in patients with chronic lower-back pain was significantly lower than that in the control group(P<0.05).The riders had relatively mild chronic hip pain,but the Harris score was significantly lower than that of the control group(P<0.05).The JOA score of the equestrian rider's waist significantly correlated with the Pfirrmann grading.However,the visual analog scale and Harris hip pain scores were not significantly correlated with imaging parameters.The root mean square amplitudes of the rectus abdominis,erector spinalis,rectus femoris,gluteus medius,and multifidus were greater in the riding position than in the normal sitting position(P<0.05).Conclusions The cause of chronic lower-back pain in riders may be related to soft tissue overwork and lumbar degeneration.Changes in the lumbar-hip sagittal sequence pelvic and sacral inclination angles can reflect the degree of lumbar stiffness of the riders.

Objective:To explore the changes of dynamic cerebral autoregulation ability in pilots exposed to acute positive acceleration(+ Gz) by transcranial Doppler combined with beat-to-beat blood pressure.Methods:A total of 26 pilots enrolled in the + 8Gz manned centrifuge trial at the Air Force Medical Center, Air Force Medical University from June to October 2022 were prospectively included. Blood pressure and heart rate were monitored in the resting state before the trial and within 5 min after centrifugation. Transcranial Doppler combined with noninvasive continuous beat-to-beat blood pressure monitor were used to detect bilateral middle cerebral artery blood flow velocity and beat-to-beat pulse pressure respectively. The transfer function analysis was applied to derive the parameters of cerebral blood flow autoregulation in each frequency band from 0.02 to 0.50 Hz, and the phase, gain and coherence were calculated. The above parameters were compared between resting state and after acute + 8Gz positive acceleration exposure.Results:Compared with the resting state, in all of the 26 pilots after acute + 8Gz positive acceleration exposure, the systolic and diastolic blood pressure and heart rate increased significantly ( P<0.001), the phase significantly increased and the gain significantly decreased in the ultra-low frequency band (0.02-0.07 Hz) ( P<0.05); whereas there were no statistical differences of gain and phase in the low frequency band (0.07-0.20 Hz) and the high frequency band (0.20-0.50 Hz) (all P>0.05). Conclusions:Transcranial Doppler combined with beat-to-beat pulse pressure can be used for the assessment of changes in immediate dynamic cerebral autoregulation after acute + Gz exposure, and transfer function analysis of ultra-low frequency band parameters is suitable for this type of evaluation.

Objective:To construct a new thrombus risk assessment model and evaluate its predictive ability for venous thromboembolism(VTE)in the patients with malignant tumors,and to provide the basis for the early predition of the malignant tumor patients with high risk for VTE.Methods:A total of 128 untreated malignant tumor patients were included,of which 40 were diagnosed with VTE within 2 months of malignant tumor diagnosis and categorized as VTE group.A total of 88 patients who did not develop VTE were categorized as non-VTE group.The clinical risk factors and laboratory indicators of the patients in two groups were compared and analyzed;the types of thrombotic events of the patients were analyzed;the diagnostic values of thrombin-antithrombin-complex(TAT),α2-plasmin inhibitor-plasmin complex(PIC),D-dimer(D-dimer),and fibrin degradation products(FDP)in malignant tumors complicated by VTE were assessed using receiver operating characteristic(ROC)curve analysis;Multivariate Logistic regression analysis was used to analyze the correlations of the clinical risk factors and biomarkers with the malignant tumors complicated with VTE.A new thrombus risk assessment model was constructed,consisting of TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors.The predictive probability of the model for malignant tumors complicated by VTE was evaluated based on the significance,goodness of fit,calibration curve,and C value of the model.The clinical application value of the new thrombus risk assessment model,COMPASS-CAT risk score(CRS),and Khorana risk score(KRS)in assessing malignant tumor patients complicated by VTE was compared using the C value and decision curve analysis(DCA).Results:The plasma levels of TAT(P＜0.001),PIC(P＜0.001),D-dimer(P＜0.05),and FDP(P＜0.01)of the patients in VTE group were higher than those in non-VTE group.Compared with the patients without cardiovascular risk factors,poor differentiation,and lymphatic metastasis,the malignant tumor patients with cardiovascular risk factors(P＜0.001),poor differentiation(P＜0.001),and lymphatic metastasis(P＜0.05)were more likely to develop VTE.Most VTE events(65％)were isolated deep vein thromboembolism(DVT).The ROC curve analysis showed that the area under the curve(AUC),sensitivity,and specificity of TAT and PIC were higher than those of D-dimer and FDP.TAT≥0.70 μg·L-1(P＜0.05),poor differentiation(P＜0.01),and cardiovascular risk factors(P＜0.01)were the independent risk factors for VTE in the malignant tumor patients.A new thrombus risk assessment model consisting of TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors was constructed.The new risk assessment model had a high goodness of fit(P=0.805)and good predictive ability during internal validation(x2=75.266,P＜0.001).The ROC curve analysis results showed that the C values for the new thrombus risk prediction model,CRS,and KRS were 0.908,0.676,and 0.541,respectively.The DCA curve analysis results showed that the new thrombus risk assessment model had a higher net benefit rate compared with CRS and KRS.Conclusion:TAT and PIC have greater diagnostic efficiency than D-dimer in the early prediction of the malignant tumor patients with high-risk VTE.For the patients included in this study,the new thrombus risk assessment model,constructed from TAT≥0.70 μg·L-1,poor differentiation,and cardiovascular risk factors,has superior diagnostic efficiency and clinical predictive value compared with CRS and KRS.

Dinitrogen tetroxide is often used as an oxidant in rocket propellant and has strong irritant and corrosive properties. This paper analyzes the clinical data of a patient with dinitrogen tetroxide poisoning admitted in the 63710 Army Hospital of Chinese People's Liberation Army, so as to further explore the poisoning mechanism, clinical characteristics and key points of acute inhaled dinitrogen tetroxide poisoning.

Objective:To propose a method for obtaining noise from thoracic CT images based on the Canny edge detection algorithm.Methods:A total of 250 pieces of thoracic CT images of male volunteers collected in 2021 were selected. The contours of thoracic CT images were extracted by the Canny adaptive threshold method. The similarity of the Sobel algorithm, the Canny double threshold method, and the Canny adaptive threshold method was compared. The Hoff transform was used to determine the regions of interest. The effects of the selection size of the regions of interest, the reconstructed convolution kernel, and tube current on the noise of thoracic CT images were investigated.Results:The Canny adaptive threshold method preserved more detail, and the continuity and integrity of the edges were improved, indicating that it was more flexible and robust for edge detection and image segmentation. The Canny adaptive threshold method had the highest structural similarity index (0.644) and the lowest root mean square error (0.371). It had the highest similarity in edge contour detection, and the effect was more significant. As the size of the square area of interest increased, the average noise decreased. The noise standard deviation increased in some intervals, especially in larger square regions. In the case of the same reconstructed convolution kernel, the mean noise of the ascending aorta in thoracic CT images was higher than that of the thoracic aorta. The noise standard deviation of the ascending aorta was lower than that of the thoracic aorta. For ascending aorta, the mean ascending aorta noise (41.97 dB) of reconstructed convolutional nucleus E was the lowest, with the highest noise standard deviation (20.64 dB). For the thoracic aorta, the mean noise (30.78 dB) of the reconstructed convolutional nucleus E was the lowest. The mean noise and standard deviation of the thoracic aorta decreased with the increase in tube current.Conclusions:A method based on the Canny edge detection algorithm to obtain noise from thoracic CT images is proposed, which is suitable for detecting thoracic CT images.

Dinitrogen tetroxide is often used as an oxidant in rocket propellant and has strong irritant and corrosive properties. This paper analyzes the clinical data of a patient with dinitrogen tetroxide poisoning admitted in the 63710 Army Hospital of Chinese People's Liberation Army, so as to further explore the poisoning mechanism, clinical characteristics and key points of acute inhaled dinitrogen tetroxide poisoning.

Light adaptation enables the vertebrate visual system to operate over a wide range of ambient illumination. Regulation of phototransduction in photoreceptors is considered a major mechanism underlying light adaptation. However, various types of neurons and glial cells exist in the retina, and whether and how all retinal cells interact to adapt to light/dark conditions at the cellular and molecular levels requires systematic investigation. Therefore, we utilized single-cell RNA sequencing to dissect retinal cell-type-specific transcriptomes during light/dark adaptation in mice. The results demonstrated that, in addition to photoreceptors, other retinal cell types also showed dynamic molecular changes and specifically enriched signaling pathways under light/dark adaptation. Importantly, Müller glial cells (MGs) were identified as hub cells for intercellular interactions, displaying complex cell‒cell communication with other retinal cells. Furthermore, light increased the transcription of the deiodinase Dio2 in MGs, which converted thyroxine (T4) to active triiodothyronine (T3). Subsequently, light increased T3 levels and regulated mitochondrial respiration in retinal cells in response to light conditions. As cones specifically express the thyroid hormone receptor Thrb, they responded to the increase in T3 by adjusting light responsiveness. Loss of the expression of Dio2 specifically in MGs decreased the light responsive ability of cones. These results suggest that retinal cells display global transcriptional changes under light/dark adaptation and that MGs coordinate intercellular communication during light/dark adaptation via thyroid hormone signaling.
Animals ; Mice ; Dark Adaptation ; Light ; Retina ; Retinal Cone Photoreceptor Cells/metabolism* ; Adaptation, Ocular ; Neuroglia/physiology* ; Cell Communication ; Thyroid Hormones

Objective:To investigate the effects of different intensity of lighting on normal refractive development and form deprivation myopia (FDM) in guinea pigs.Methods:A total of 108 healthy 3-week-old guinea pigs were divided into normal refractive development guinea pigs ( n=54) and FDM guinea pigs ( n=54). FDM models were prepared in FDM animals by occlusion of the left eyes using an opaque mask, and the bilateral eyes were open in the normal refractive development guinea pigs.The guinea pigs were randomized to low (20 lx), normal(300 lx), and high intensity-lighting (5 000 lx) groups with a 12-hour light/12-hour dark cycle for 6 consecutive weeks under LED light.The ocular biometry was performed in a two-week interval.Axial length (AL) and dilated diopter were measured by A-scan ultrasonography and retinoscopy, respectively, and were compared after different lighting durations, and the change trends of them in normal refractive development and FDM guinea pigs were evaluated. Results:The AL values were not significantly different among low, normal and high intensity-lighting groups ( Fgroup=0.365, P=0.697), and the AL was gradually prolonged over the lighting duration ( Ftime=353.750, P<0.001). The diopters showed a statistically significant difference among different intensity-lighting groups ( Fgroup=3.576, P=0.034). The diopter in high intensity-lighting for 4 weeks was (+ 2.75±2.15) D, which was significantly higher than (0.41±3.07) D in the normal refrective development guinea pigs ( P<0.001). In the FDM guinea pigs, both AL and diopter were not significantly different among low, normal and high intensity-lighting groups ( Fgroup=0.105, P=0.900; Fgroup=0.973, P=0.387), and significant differences were seen in AL and diopter among three groups ( Ftime=408.302, 27.407; both at P<0.001). The diopter in FDM eyes of low intensity-lighting for 2 weeks was (+ 2.35±1.95) D, which was higher than (+ 1.90±0.97) D before lighting, with no statistically significant difference between them ( P>0.05). The AL was shortest and the AL change was smallest in normal refractive development guinea pigs of high intensity-lighting group.The diopter change in FDM guinea pigs of the low intensity-lighting group was significantly smaller than that in the normal intensity-lighting group ( P<0.001), with a transient hyperopia drift. Conclusions:The 5 000 lx lighting can slow down the development toward myopia in the normal refractive development eyes, and 20 lx lighting tends to delay the progression FDM eyes with a hyperopic shift after lighting for 2 weeks.

Objective To investigate the diagnosis and treatment of adult Hirschsprung disease. Methods The clinical data of 10 patients with adult Hirschsprung disease from August 2011 to August 2017 in the Department of General Surgery of the First Affiliated Hospital of Soochow University were retrospectively analyzed. Results Among the 10 patients, 4 cases were male, and 6 cases were female, with age 21 to 65 years old, and body mass index 16.77 to 25.73 kg/m2. The patients were diagnosed with Hirschsprung disease by postoperative pathological examination. All patients had difficult defecation medical history. Barium enema examination in 3 patients before operation showed obvious narrow segment, migrating segment and dilatation segment. Four cases received emergency surgical operation, and 6 cases received selective surgical operation. Complications included intestinal obstruction in 3 cases, incisions infection in 2 cases, and incision rupture in 1 case. Conclusions Adult Hirschsprung disease is difficult to be diagnosed, and the aspect of medical history, barium enema examination, surgical findings and pathological examination has to be combined. The surgery way of AHD is diverse and ought to be individual. Laparoscopic surgery with small trauma and quick recovery has great development space.