In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.

Objective:To explore the capability of deep learning image reconstruction (DLIR) compared to adaptive statistical iterative reconstruction (ASiR-V) in improving the image quality and myocardial edge sharpness of dynamic stress myocardial CT perfusion imaging (CTP).Methods:Thirty subjects who underwent dynamic stress myocardial CTP at Guangdong Provincial People′s Hospital from September 2023 to February 2024 were recruited. Image data of all enrolled patients were reconstructed using ASiR-V 50%, ASiR-V 80%, medium-intensity DLIR(DLIR-M), and high-intensity DLIR(DLIR-H), respectively. Regions of interest were selected in the left ventricular cavity, interventricular septum, and left ventricular lateral wall for measurement of CT values and standard deviations (SD), and calculation of signal to noise ratio (SNR) and contrast to noise ratio (CNR). Matlab was utilized to obtain the differences (d) and slopes (s) of CT value changes at four left ventricular myocardial edges for objective edge sharpness evaluation. Two radiologists subjectively scored the images for noise, natural appearance, and edge sharpness. In case of disagreement between the two radiologists, a third senior radiologist′s score was decisive. Left ventricular myocardial blood flow (MBF) of ASiR-V and DLIR images with lower SD, higher SNR and CNR were calculated, respectively. When the normal distribution was satisfied, the independent sample t test was used for comparison between two groups, and the random block design ANOVA was used for comparison between multiple groups. And analysis was conducted using Friedman test for non-normally distributed data, and Bonferroni correction for pairwise comparisons. Results:There were statistically significant differences in SD, SNR, and CNR among the four images in the interventricular septum and left ventricular lateral wall (all P<0.05), with ASiR-V 80% and DLIR-H demonstrating the lowest SD, highest SNR and CNR, and the subjective image noise score. Statistically significant differences were observed in d and s for the four left ventricular myocardial edges (all P<0.05), with DLIR-M and DLIR-H exhibiting the best objective edge sharpness [5 (5, 5)], and ASiR-V 80% the worst [3.5 (3, 4)]. In the subjective scores for natural appearance, DLIR-M and DLIR-H received the highest scores [5 (5, 5)], while ASiR-V 80% received the lowest scores [3 (3, 4)], with statistically significant differences (all P<0.05). There was no statistically significant difference in MBF values calculated from ASiR-V 80% and DLIR-H images (all P>0.05). Conclusions:The SD value, SNR and CNR of dynamic stress myocardial CTP images reconstructed by DLIR-H are equivalent to ASiR-V 80%, and using DLIR-H can improve the edge sharpness of left ventricular myocardium without affecting the calculation of MBF.

In proton therapy,prompt gamma-ray imaging is considered as one of the most promising methods for assessing proton beam range.Prompt gamma-ray imaging detector evaluates the proton beam range based on the prompt gamma-ray distribution obtained by the prompt gamma-ray imaging system,which enables high-precision measurement of the proton beam range.Herein a proton beam range verification algorithm is designed for the newly developed prototype of the range verification detector(pixelated prompt gamma-ray imaging detector),which verifies the range estimation accuracy of the prototype for different phantoms and different energies of homogeneous media through Monte Carlo simulation.The results show that the accuracy of the proton beam range verification algorithm is within 0.5 mm of the safety margin error of the Bragg peak,and the measurement accuracy is significantly improved with the increase of the number of protons,indicating that the prototype algorithm is feasible for proton beam range verification.

Objective:To explore the capability of deep learning image reconstruction (DLIR) compared to adaptive statistical iterative reconstruction (ASiR-V) in improving the image quality and myocardial edge sharpness of dynamic stress myocardial CT perfusion imaging (CTP).Methods:Thirty subjects who underwent dynamic stress myocardial CTP at Guangdong Provincial People′s Hospital from September 2023 to February 2024 were recruited. Image data of all enrolled patients were reconstructed using ASiR-V 50%, ASiR-V 80%, medium-intensity DLIR(DLIR-M), and high-intensity DLIR(DLIR-H), respectively. Regions of interest were selected in the left ventricular cavity, interventricular septum, and left ventricular lateral wall for measurement of CT values and standard deviations (SD), and calculation of signal to noise ratio (SNR) and contrast to noise ratio (CNR). Matlab was utilized to obtain the differences (d) and slopes (s) of CT value changes at four left ventricular myocardial edges for objective edge sharpness evaluation. Two radiologists subjectively scored the images for noise, natural appearance, and edge sharpness. In case of disagreement between the two radiologists, a third senior radiologist′s score was decisive. Left ventricular myocardial blood flow (MBF) of ASiR-V and DLIR images with lower SD, higher SNR and CNR were calculated, respectively. When the normal distribution was satisfied, the independent sample t test was used for comparison between two groups, and the random block design ANOVA was used for comparison between multiple groups. And analysis was conducted using Friedman test for non-normally distributed data, and Bonferroni correction for pairwise comparisons. Results:There were statistically significant differences in SD, SNR, and CNR among the four images in the interventricular septum and left ventricular lateral wall (all P<0.05), with ASiR-V 80% and DLIR-H demonstrating the lowest SD, highest SNR and CNR, and the subjective image noise score. Statistically significant differences were observed in d and s for the four left ventricular myocardial edges (all P<0.05), with DLIR-M and DLIR-H exhibiting the best objective edge sharpness [5 (5, 5)], and ASiR-V 80% the worst [3.5 (3, 4)]. In the subjective scores for natural appearance, DLIR-M and DLIR-H received the highest scores [5 (5, 5)], while ASiR-V 80% received the lowest scores [3 (3, 4)], with statistically significant differences (all P<0.05). There was no statistically significant difference in MBF values calculated from ASiR-V 80% and DLIR-H images (all P>0.05). Conclusions:The SD value, SNR and CNR of dynamic stress myocardial CTP images reconstructed by DLIR-H are equivalent to ASiR-V 80%, and using DLIR-H can improve the edge sharpness of left ventricular myocardium without affecting the calculation of MBF.

Cardiovascular disease is the leading cause of death among Chinese residents, and non-invasive imaging technology has important value in the diagnosis and treatment of cardiovascular disease. Cardiac magnetic resonance (CMR) can characterize cardiac pathophysiological information from multiple dimensions, including cardiac structure, function, tissue characteristics, and microstructure, through multi parameter and multi sequence " one-stop" imaging. This article will focus on new technologies such as CMRT1 mapping, feature tracking, and diffusion tensor imaging, and explain their applications and progress in the diagnosis, efficacy monitoring, and prognosis prediction of various myocardial lesions such as non ischemic heart disease and ischemic heart disease.

Objective:To analyze the risk factors of bronchopulmonary dysplasia(BPD)in very preterm infants(VPI), and to provide scientific basis for the prevention and treatment of BPD in VPI.Methods:A prospective multicenter study was designed to collect the clinical data of VPI in department of neonatology of 28 hospitals in 7 regions from September 2019 to December 2020.According to the continuous oxygen dependence at 28 days after birth, VPI were divided into non BPD group and BPD group, and the risk factors of BPD in VPI were analyzed.Results:A total of 2 514 cases of VPI including 1 364 cases without BPD and 1 150 cases with BPD were enrolled.The incidence of BPD was 45.7%.The smaller the gestational age and weight, the higher the incidence of BPD( P<0.001). Compared with non BPD group, the average birth age, weight and cesarean section rate in BPD group were lower, and the incidence of male infants, small for gestational age and 5-minute apgar score≤7 were higher( P<0.01). In BPD group, the incidences of neonatal respiratory distress syndrome(NRDS), hemodynamically significant patent ductus arteriosus, retinopathy of prematurity, feeding intolerance, extrauterine growth restriction, grade Ⅲ~Ⅳ intracranial hemorrhage, anemia, early-onset and late-onset sepsis, nosocomial infection, parenteral nutrition-associated cholestasis were higher( P<0.05), the use of pulmonary surfactant(PS), postnatal hormone exposure, anemia and blood transfusion were also higher, and the time of invasive and non-invasive mechanical ventilation, oxygen use and total hospital stay were longer( P<0.001). The time of starting enteral nutrition, cumulative fasting days, days of reaching total enteral nutrition, days of continuous parenteral nutrition, days of reaching 110 kcal/(kg·d) total calorie, days of reaching 110 kcal/(kg·d) oral calorie were longer and the breastfeeding rate was lower in BPD group than those in non BPD group( P<0.001). The cumulative doses of amino acid and fat emulsion during the first week of hospitalization were higher in BPD group( P<0.001). Multivariate Logistic regression analysis showed that NRDS, invasive mechanical ventilation, age of reaching total enteral nutrition, anemia and blood transfusion were the independent risk factors for BPD in VPI, and older gestational age was the protective factor for BPD. Conclusion:Strengthening perinatal management, avoiding premature delivery and severe NRDS, shortening the time of invasive mechanical ventilation, paying attention to enteral nutrition management, reaching whole intestinal feeding as soon as possible, and strictly mastering the indications of blood transfusion are very important to reduce the incidence of BPD in VPI.

OBJECTIVE: To explore the MRI findings of os acromiale and to analyze the relationship between os acromiale and the supraspinatus and infraspinatus injury. METHODS: From January 2010 to August 2020, 21 patients with os acromiale (os arcomiale group) were compared with 21 subjects with no evidence of os acromiale (no os arcomiale group). There were 14 males and 7 females in the os arcomiate group, aged from 29 to 77 years old, mean aged (55.5±11.5) years old. While in the control group, there were 10 males and 11 females in no os arcomiale group, aged from 31 to 70 years old, mean aged (51.1±10.0) years old. The os acromiales were classified as edematous os acromiale or non-edematous os acromiale based on whether the presence of marrow edema, and as displaced os acromiale or non-displaced os acromiale based on whether the presence of displacement of the os acromiale. The MRI features of os acromiale were analyzed. Statistical analyses were performed to identify the differences between the os arcomiale group and no os arcomiale group regarding rotator cuff tear, supraspinatus and infraspinatus injury. Differences in the supraspinatus and infraspinatus tear between the edematous and non-edematous os acromiale group, the displaced and non-displaced os acromiale group, the displaced os acromiale and no os arcomiale group were also assessed. RESULTS: On MRI, all the 21 os acromiales appeared as a triangular or irregular bone fragment of the distal acromion, and forms a pseudo-acromioclavicular joint with the acromion. Eleven cases were edematous os acromiale, 11 cases were displaced os acromiale. In the os arcomiale group, 17 had supraspinatus tear, 1 had supraspinatus tendinitis, 11 had infraspinatus tear, and 4 had infraspinatus tendinitis. In the no os arcomiale group, 11 had supraspinatus tear, 2 had supraspinatus tendinitis, 5 had infraspinatus tear, and 1 had infraspinatus tendinitis. No statistically significant difference between the os arcomiale group and no os arcomiale group regarding the rotator cuff tear, supraspinatus and infraspinatus injury (P>0.05). In the 11 cases of edematous os arcomiale, 10 had supraspinatus tear and 7 had infraspinatus tear. In the 10 cases of non-edematous os acromiale, 7 had supraspinatus tear and 4 had infraspinatus tear. No statistically significant difference was noted between the edematous os acromiale and non-edematous os acromiale in terms of supraspinatus and infraspinatus tear (P>0.05). In the 11 cases of displaced os acromiale, 11 had supraspinatus tear and 9 had infraspinatus tear. In the 10 cases of non-displaced os acromiale, 6 had supraspinatus tear and 2 had infraspinatus tear. In the no os arcomiale group, 11 had supraspinatus tear and 5 had infraspinatus tear. There was a statistically significant increases in the prevalence of supraspinatus and infraspinatus tear in the displaced os acromiale group compared with non-displaced os acromiale group, the displaced os acromiale group and no os arcomiale group(P<0.05). CONCLUSION Shoulder MRI can very well depict os acromiale and can reveal associated abnormalities such as adjacent bone marrow edema, displaced deformity, and rotator cuff tear, and it can be used to assess the stability of the os acromiale. The presence of os acromiale may not increase the risk of supraspinatus and infraspinatus tear significantly. However, the presence of displaced os acromiale is at greater risk of supraspinatus and infraspinatus tear.
Acromion/diagnostic imaging* ; Adult ; Aged ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Rotator Cuff ; Rotator Cuff Injuries/diagnostic imaging* ; Shoulder

OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.
Female ; Fetal Growth Retardation ; Gestational Age ; Hospitalization ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Prospective Studies ; Risk Factors

OBJECTIVE: To investigate the short-term clinical effect of double channel decompression and bone grafting through the greater trochanter combined with allograft fibula propping in the treatment of osteonecrosis of femoral head (ONFH). METHODS: Twenty two patients (23 hips) with osteonecrosis of the femoral head were included from November 2017 to February 2019. According to Association Research Cirulation Osseous(ARCO) staging, there were 13 hips at stageⅡgroup, aged from 20 to 48 years old with an average of(32.5±8.5)years old;10 hips at stageⅢgroup, aged from 18 to 45 years old with an average of(32.7±8.6) years old. A single approach through the greater trochanterwas used for decompression, bone grafting and fibula support. Harris scoring system was used to evaluate the function of hip joint before and after implantation, and the anteroposterior and lateral X-ray films of hip joint were taken at 3, 6, 12 and 18 months after implantation to observe and analyze the progress of femoral head necrosis and regeneration. RESULTS: All patients were followed up, and the duration ranged from 12 to 18 months with an average of (14.6±2.1) months. Harris score of stageⅡand stageⅢpatients increased from 73.2± 5.5 and 66.5±3.4 to 87.6±8.7( CONCLUSION The effect of double trochanteric decompression and bone grafting combined with fibular allograft propping in the treatment of early and middle stage avascular necrosis of the femoral head is good, especially suitable for young and middle aged patients with ARCOⅡstage avascular necrosis of the femoral head.
Adolescent ; Adult ; Allografts ; Bone Transplantation ; Decompression ; Femur Head ; Femur Head Necrosis ; Fibula ; Follow-Up Studies ; Humans ; Middle Aged ; Treatment Outcome ; Young Adult

OBJECTIVE: To investigate the incidence rate and risk factors for metabolic bone disease of prematurity (MBDP) in very low birth weight/extremely low birth weight (VLBW/ELBW) infants. METHODS: The medical data of 61 786 neonates from multiple centers of China between September 1, 2013 and August 31, 2016 were retrospectively investigated, including 504 VLBW/ELBW preterm infants who met the inclusion criteria. Among the 504 infants, 108 infants diagnosed with MBDP were enrolled as the MBDP group and the remaining 396 infants were enrolled as the non-MBDP group. The two groups were compared in terms of general information of mothers and preterm infants, major diseases during hospitalization, nutritional support strategies, and other treatment conditions. The multivariate logistic regression analysis was used to investigate the risk factors for MBDP. RESULTS: The incidence rate of MBDP was 19.4% (88/452) in VLBW preterm infants and 38.5% (20/52) in ELBW preterm infants. The incidence rate of MBDP was 21.7% in preterm infants with a gestational age of < 32 weeks and 45.5% in those with a gestational age of < 28 weeks. The univariate analysis showed that compared with the non-MBDP group, the MBDP group had significantly lower gestational age and birth weight, a significantly longer length of hospital stay, and a significantly higher incidence rate of extrauterine growth retardation ( CONCLUSIONS A lower gestational age, hypocalcemia, extrauterine growth retardation at discharge, and neonatal sepsis may be associated an increased risk of MBDP in VLBW/ELBW preterm infants. It is necessary to strengthen perinatal healthcare, avoid premature delivery, improve the awareness of the prevention and treatment of MBDP among neonatal pediatricians, and adopt positive and reasonable nutrition strategies and comprehensive management measures for preterm infants.
Birth Weight ; Bone Diseases, Metabolic/etiology* ; China/epidemiology* ; Female ; Humans ; Infant ; Infant, Extremely Low Birth Weight ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Pregnancy ; Retrospective Studies ; Risk Factors