CT is a commonly examination method in pediatric clinical practice.Formulating and popularizing low-dose pediatric CT scanning protocols and constructing a standard image quality evaluation system are the key directions of low-dose pediatric CT imaging.In recent years,domestic CT equipment achieved technological breakthroughs in hardware performance and image reconstruction algorithms,which could provide new paths for pediatric low-dose CT imaging in children combining with artificial intelligence technology.The current status of scanning protocols,the establishment of imaging quality evaluation system and the clinical promotion,as well as challenges of domestic CT in pediatric low-dose CT imaging were reviewed in this article.

Objective:To explore the clinical application value of MRI ultra-short echo time sequence (MRI-UTE) in the diagnosis of pulmonary nodules.Methods:This study was a cross-sectional study. A total of 101 consecutive patients were recruited prospectively from January to August 2024 at Huazhong Fuwai Hospital of Zhengzhou University. All of the included patients were diagnosed with pulmonary nodules by chest CT examination and intended for treatment. All patients underwent low-dose CT examination and MRI-UTE examination. The number, classification, and lung imaging reporting and data system (lung-RADS) grading of the pulmonary nodules were analyzed. Nodules classification was determined as solid nodules or sub-solid nodules, and sub-solid nodules included part-solid nodules and pure ground-glass nodules. Taking the evaluation results of radiologists with 10 and 12 years of experience in chest imaging diagnosis as the reference standard, the Kappa test was used to analyze the agreement of CT and MRI-UTE in terms of the accurate diagnosis, classification, and lung-RADS grading of pulmonary nodules. Results:Among the 101 patients, a total of 216 pulmonary nodules were identified. MRI-UTE accurately diagnosed 180 pulmonary nodules, while 203 pulmonary nodules were detected by CT. The concordance was moderate ( Kappa=0.48, P<0.001). In terms of nodule classification, CT correctly classified 167 nodules as solid and 36 as sub-solid, whereas MRI-UTE correctly classified 153 as solid and 23 as sub-solid, with good agreement (weighted Kappa=0.73, P<0.001). For lung-RADS grading, CT correctly graded 186 nodules, with 85 graded as category 2, 46 as category 3, 33 as category 4A, 12 as category 4B, and 10 as category 4X; MRI-UTE correctly graded 155 nodules, with 74 graded as category 2, 30 as category 3, 30 as category 4A, 12 as category 4B, and 9 as category 4X. The agreement between the two modalities in determining lung-RADS grade was also good (weighted Kappa=0.74, P<0.001). Conclusion:MRI-UTE demonstrates good agreement with CT in the accurate diagnosis, classification, and lung-RADS grading of pulmonary nodules, indicating certain clinical application value.

Objective:To assess the prognostic impact of the thoracic aorta and aortic valve calcification volume (TAC, AVC) score based on CT measurementsin patients undergoing transcatheter aortic valve implantation (TAVI).Methods:We retrospectively analyzed 102 patients who underwent TAVI for severe aortic stenosis from March 2018 to April 2022 at Fuwai Central China Cardiovascular Hospital. The patients were stratified into low TAC and AVC group (TAC low, AVC low) and high TAC and AVC group (TAC high, AVC high) based on median TAC and AVC. The independent risk factors affecting the prognosis of TAVI patients were analyzed using univariate and multivariate Cox proportional risk regression, and the independent risk factors affecting the prognosis of TAVI were analyzed by survival curve. Results:A total of 102 patients were included with a median follow-up of 695 (602, 923) days, during which 9 (8.8%) all-cause deaths and 33 (32.4%) composite end-point events occurred. Univariate Cox risk regression analysis found that TAC was a risk factor for all-cause mortality events in TAVI patients ( P=0.039), TAC and AVC were risk factors for composite endpoint events in TAVI patients ( P=0.047, 0.035).TAC was an independent predictor of all-cause mortality after TAVI in multivariate analysis ( HR=8.971, 95% CI 1.121-71.790, P=0.039), and TAC and AVC were independent risk factors for composite endpoint events after TAVI ( HR=2.243, 95% CI 1.099-4.578, P=0.026; HR=2.346, 95% CI 1.146-4.804, P=0.020). Kaplan-Meier survival curves showed that high TAC and AVC scores increased the risk of end-point events ( P<0.05). Conclusion:CT-quantified TAC and AVC volume scores are independent prognostic markers in TAVI patients, with greater calcification burden portending poorer clinical outcomes.

Objective To observe the value of artificial intelligence iterative reconstruction(AIIR)for low-dose chest CT images of infants with congenital heart disease.Methods Totally 262 infants with congenital heart disease who would undergo chest CT scanning were prospectively enrolled and randomly divided into low-dose group(n=142)and conventional dose group(n=120).Chest CT scanning with tube voltage of 80 kVp and tube current of 10 mAs was performed in low-dose group,and hybrid iterative reconstruction(HIR,group A)and AIIR(group B)were used to reconstruct images,respectively.In conventional dose group,chest CT scanning with tube voltage of 80 kVp and tube current of 100 mAs was performed,and HIR was used to reconstruct images(group C).Then subjective and objective evaluation on image quality were performed,the results were compared among 3 groups,and the value of AIIR was analyzed.Results Significant differences of image quality and clarity of displaying structures were found among 3 groups(all P＜0.001).Among them,except for the clarity of interlobar fissure,no significant difference of subjective scores was found between low-dose AIIR images and conventional dose HIR images(all corrected P＞0.05),while subjective scores of low-dose HIR images were all lower than those of low-dose AIIR images and conventional dose HIR images(all corrected P＜0.05).Significant differences of standard deviation(SD),signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were found among 3 groups(all P＜0.001)and between each 2 groups(all corrected P＜0.05).The effective dose of low-dose group and conventional dose group was 0.09(0.08,0.10)and 0.85(0.75,1.03)mSv,respectively,and the former was lower than the latter(Z=-13.942,P＜0.001).Conclusion Using AIIR could obtain low-dose chest CT images of infants with quality comparable to conventional chest CT images.

Objective:To explore the clinical application value of MRI ultra-short echo time sequence (MRI-UTE) in the diagnosis of pulmonary nodules.Methods:This study was a cross-sectional study. A total of 101 consecutive patients were recruited prospectively from January to August 2024 at Huazhong Fuwai Hospital of Zhengzhou University. All of the included patients were diagnosed with pulmonary nodules by chest CT examination and intended for treatment. All patients underwent low-dose CT examination and MRI-UTE examination. The number, classification, and lung imaging reporting and data system (lung-RADS) grading of the pulmonary nodules were analyzed. Nodules classification was determined as solid nodules or sub-solid nodules, and sub-solid nodules included part-solid nodules and pure ground-glass nodules. Taking the evaluation results of radiologists with 10 and 12 years of experience in chest imaging diagnosis as the reference standard, the Kappa test was used to analyze the agreement of CT and MRI-UTE in terms of the accurate diagnosis, classification, and lung-RADS grading of pulmonary nodules. Results:Among the 101 patients, a total of 216 pulmonary nodules were identified. MRI-UTE accurately diagnosed 180 pulmonary nodules, while 203 pulmonary nodules were detected by CT. The concordance was moderate ( Kappa=0.48, P<0.001). In terms of nodule classification, CT correctly classified 167 nodules as solid and 36 as sub-solid, whereas MRI-UTE correctly classified 153 as solid and 23 as sub-solid, with good agreement (weighted Kappa=0.73, P<0.001). For lung-RADS grading, CT correctly graded 186 nodules, with 85 graded as category 2, 46 as category 3, 33 as category 4A, 12 as category 4B, and 10 as category 4X; MRI-UTE correctly graded 155 nodules, with 74 graded as category 2, 30 as category 3, 30 as category 4A, 12 as category 4B, and 9 as category 4X. The agreement between the two modalities in determining lung-RADS grade was also good (weighted Kappa=0.74, P<0.001). Conclusion:MRI-UTE demonstrates good agreement with CT in the accurate diagnosis, classification, and lung-RADS grading of pulmonary nodules, indicating certain clinical application value.

Objective:To assess the prognostic impact of the thoracic aorta and aortic valve calcification volume (TAC, AVC) score based on CT measurementsin patients undergoing transcatheter aortic valve implantation (TAVI).Methods:We retrospectively analyzed 102 patients who underwent TAVI for severe aortic stenosis from March 2018 to April 2022 at Fuwai Central China Cardiovascular Hospital. The patients were stratified into low TAC and AVC group (TAC low, AVC low) and high TAC and AVC group (TAC high, AVC high) based on median TAC and AVC. The independent risk factors affecting the prognosis of TAVI patients were analyzed using univariate and multivariate Cox proportional risk regression, and the independent risk factors affecting the prognosis of TAVI were analyzed by survival curve. Results:A total of 102 patients were included with a median follow-up of 695 (602, 923) days, during which 9 (8.8%) all-cause deaths and 33 (32.4%) composite end-point events occurred. Univariate Cox risk regression analysis found that TAC was a risk factor for all-cause mortality events in TAVI patients ( P=0.039), TAC and AVC were risk factors for composite endpoint events in TAVI patients ( P=0.047, 0.035).TAC was an independent predictor of all-cause mortality after TAVI in multivariate analysis ( HR=8.971, 95% CI 1.121-71.790, P=0.039), and TAC and AVC were independent risk factors for composite endpoint events after TAVI ( HR=2.243, 95% CI 1.099-4.578, P=0.026; HR=2.346, 95% CI 1.146-4.804, P=0.020). Kaplan-Meier survival curves showed that high TAC and AVC scores increased the risk of end-point events ( P<0.05). Conclusion:CT-quantified TAC and AVC volume scores are independent prognostic markers in TAVI patients, with greater calcification burden portending poorer clinical outcomes.

Objective To observe the value of artificial intelligence iterative reconstruction(AIIR)for low-dose chest CT images of infants with congenital heart disease.Methods Totally 262 infants with congenital heart disease who would undergo chest CT scanning were prospectively enrolled and randomly divided into low-dose group(n=142)and conventional dose group(n=120).Chest CT scanning with tube voltage of 80 kVp and tube current of 10 mAs was performed in low-dose group,and hybrid iterative reconstruction(HIR,group A)and AIIR(group B)were used to reconstruct images,respectively.In conventional dose group,chest CT scanning with tube voltage of 80 kVp and tube current of 100 mAs was performed,and HIR was used to reconstruct images(group C).Then subjective and objective evaluation on image quality were performed,the results were compared among 3 groups,and the value of AIIR was analyzed.Results Significant differences of image quality and clarity of displaying structures were found among 3 groups(all P＜0.001).Among them,except for the clarity of interlobar fissure,no significant difference of subjective scores was found between low-dose AIIR images and conventional dose HIR images(all corrected P＞0.05),while subjective scores of low-dose HIR images were all lower than those of low-dose AIIR images and conventional dose HIR images(all corrected P＜0.05).Significant differences of standard deviation(SD),signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were found among 3 groups(all P＜0.001)and between each 2 groups(all corrected P＜0.05).The effective dose of low-dose group and conventional dose group was 0.09(0.08,0.10)and 0.85(0.75,1.03)mSv,respectively,and the former was lower than the latter(Z=-13.942,P＜0.001).Conclusion Using AIIR could obtain low-dose chest CT images of infants with quality comparable to conventional chest CT images.

CT is a commonly examination method in pediatric clinical practice.Formulating and popularizing low-dose pediatric CT scanning protocols and constructing a standard image quality evaluation system are the key directions of low-dose pediatric CT imaging.In recent years,domestic CT equipment achieved technological breakthroughs in hardware performance and image reconstruction algorithms,which could provide new paths for pediatric low-dose CT imaging in children combining with artificial intelligence technology.The current status of scanning protocols,the establishment of imaging quality evaluation system and the clinical promotion,as well as challenges of domestic CT in pediatric low-dose CT imaging were reviewed in this article.

Objective:To evaluate the value of enhanced magnetic resonance imaging (MRI) on the assessment of synovial hyperplasia and International Prophylaxis Study Group (IPSG) score of hemophilic arthropathy (HA).Methods:This was a retrospective case series study. Briefly, 54 joints of 46 male patients with hemophilia type A and diagnosed with HA in Henan Provincial People′s Hospital from August 2016 to September 2017 were selected. Plain and enhanced MRI were performed at the same time. The IPSG score of synovial hyperplasia and the total joint before and after enhancement were calculated, and the enhancement rate of the synovium and muscles at the same level were also calculated. The differences in synovial hyperplasia and joint total IPSG scores before and after enhancement were compared by paired rank sum test. The correlation between enhancement joint total IPSG score, synovial IPSG score, synovial enhancement rate, total joint bleeding number, course of disease, and Hemophilia Joint Health Score (HJHS) score were analyzed by Spearman′s correlation analysis.Results:Enhanced MRI could more clearly show synovial hyperplasia and ensure better accuracy of joint total IPSG score ( Z=-2.24, P=0.025). The enhancement extent of synovial hyperplasia was higher than that of the same level muscle. There was no correlation between synovial enhancement rate and total number of joint bleeding, course of disease, and HJHS score. After enhancement, the joint total IPSG score was highly positively correlated with the total number of joint bleeding and the disease course ( r=0.96, 0.84, P<0.001) and moderately positively correlated with the HJHS score ( r=0.58, P<0.001). The enhanced synovial IPSG score showed a low positive correlation with the total number of joint bleeding and the disease course ( r=0.37, 0.36, P=0.006, 0.008), but no correlation with HJHS score. Conclusion:Enhanced MRI can provide accurate imaging of synovial hyperplasia of HA and make joint IPSG score more accurate.

Objective:To explore the characteristics, prevention and treatment strategies of lower urinary tract injury in transvaginal reconstructive pelvic surgery (vRPS).Methods:A retrospective analysis was conducted on 24 patients who suffered lower urinary tract injuries occuring in vRPS from January 2005 to June 2021, among which 4 cases were referred to our hospital from other hospitals.Results:(1) In our hospital, 1 952 patients underwent vRPS for anterior and (or) middle pelvic organ prolapse during that study period, with a 1.0% (20/1 952) incidence of lower urinary tract injuries occurring in 20 cases. (2) Ureteral injuries were observed in 14 cases who underwent transvaginal high uterosacral ligament suspension (1.4%, 14/966). The symptoms were relieved after the removal of sutures. (3) Bladder injuries occurred in 6 cases in our hospital, with 4 cases (0.7%, 4/576) in anterior transvaginal mesh surgery (aTVM), one (0.4%, 1/260) in colpocleisis, and one (0.7%, 1/150) in apical suspension for fornix prolapse. An additional 4 cases of bladder injury were referred to our hospital after aTVM. Among the 8 cases of bladder injury during aTVM, 2 cases were intraoperative incidents. Cystoscopy confirmed that the superficial branch or puncture rod of anterior vaginal mesh had penetrated into the bladder. Re-puncturing and placement of the mesh were successfully performed. No abnormalities were observed during a follow-up period of 4-5 years. Postoperative bladder injuries were identified in 6 cases, characterized by mesh erosion into the bladder and formation of calculi. These injuries were confirmed between 6 months to 2 years after vRPS. The exposed mesh and calculi in the bladder were removed through laparotomy or cystoscopy, followed up for 2-12 years. One case experienced slight re-erosion of mesh to the bladder.Conclusions:Lower urinary tract injuries are difficult to avoid in vRPS, particularly in transvaginal high uterosacral ligament suspension and aTVM. However, the incidence is low. Lower urinary tract injuries during vRPS could be easily detected and managed intraoperatively because of the use of cystoscopy. As long-term postoperative complications, erosion of transvaginal mesh to lower urinary tract postoperatively could be treated correctly, seldom with severe sequelae.