Imaging plays a significant role in diagnosis and treatment of musculoskeletal diseases.With the development of medical imaging technology,both clinical application and research depth of musculoskeletal imaging achieved remarkable progresses.The application advancements and future developing trends of musculoskeletal imaging were reviewed in this article.

Objective:To investigate the feasibility of the combination of free breathing with the high-threshold, short-delay technique in reducing radiation dose and the volumes of iodinated contrast agent in coronary computed tomography angiography (CCTA) for obese patients.Methods:The data of 73 obese patients with weights > 85 kg and body mass indices (BMIs) > 30 kg/m 2 who received CCTA in the Radiology Department of the Peking University Third Hospital from February 2023 to May 2024 were prospectively collected. These patients were divided into a control group (31 patients) and an experimental group (42 patients). Data were collected from the control group and experimental groups under breath-holding and free-breathing conditions, respectively. The bolus tracking thresholds, delay times, and ICA injection durations were set at 100 HU, 7 s, and 12 s for the control group and at 250 HU, 2 s, and 8 s for the experimental group, respectively. Other scanning and reconstruction parameters of both groups were consistent. The CT values and their standard deviations ( SD) of both groups were assessed and compared, with the CT values involving the lumens of the aorta (AO) root, left anterior descending (LAD), left circumflex artery (LCX), and right coronary artery (RCA). The signal-to-noise ratios (SNR) and contrast-to-noise ratio (CNR) were also calculated. The subjective assessment of image quality was performed for the 18 coronary artery segments using a 4-point scale. The effective radiation doses ( E) and the volumes of iodinated contrast agent of both groups were recorded and compared. The statistical differences in the aforementioned parameters between the groups were tested and analyzed using the analysis of variance (ANOVA), the Mann-Whitney U test, or the χ 2 test. With the results of the ICA as the gold standard, the diagnostic performance of the combination of free-breathing with the high-threshold, short-delay technique in CCTA for obese patients was assessed. Results:There was no statistically significant difference ( P > 0.05) in coronary artery images between both groups, specifically regarding the CT, SNR, and CNR values of the lumens of the AO roots, LAD, LCX, and RCA, as well as the SD values of the AO roots. Both groups received subjective scores of ≥ 3 for coronary artery images, meeting the diagnostic criteria, with no statistically significant differences ( P > 0.05). Compared with the results of the ICA, the analyses of the coronary artery segments of 23 patients from the experimental group, revealed that the accuracy, sensitivity, and specificity of CCTA in the diagnosis of > 50% stenosis were 89%, 86%, and 97%, respectively. Compared to that (45 ml) of the control group, the volume (30 ml) of iodinated contrast agent of the experimental group decreased by 33.3%, with no statistically significant difference in the effective radiation dose ( E) between both groups ( P > 0.05). Conclusions:The combination of free breathing with the high-threshold, short-delay technique can further reduce the volume of the ICA for obese patients while maintaining high CCTA image quality and diagnostic performance.

Objective To observe imaging manifestations of spinal chronic osteomyelitis.Methods Totally 56 patients with spinal chronic osteomyelitis were retrospectively enrolled,including 18 cases complicated with synovitis,acne,pustulosis,hyperostosis and osteomyelitis(SAPHO)syndrome while 38 cases did not.CT and MRI manifestations were observed.Results Among 56 cases,cervical spine involvement was observed in in 25 cases(25/56,44.64％).Single spine segment involvement,2 segments involvements and 3 or more segments involvements were found in 17(17/56,30.36％),18(18/56,32.14％)and 21 cases(21/56,37.50％),respectively.The ratio of 3 or more segments involvements in 18 cases with SAPHO syndrome was 61.11％(11/18),while in 38 cases without SAPHO syndrome was 26.32％(10/38),the former was higher than the latter(P＜0.05).Meanwhile,16 cases(16/56,28.57％)complicated with compression fracture,30(30/56,53.57％)with hyperosteogeny,22(22/56,39.29％)with paraspinal soft tissue swelled and 15(15/56,26.79％)with extra spinal involvements.The ratio of extra spinal involvement in patients with and without SAPHO syndrome was 72.22％(13/18)and 5.26％(2/38),respectively,the former was higher than the latter(P＜0.05).Conclusion Imaging manifestations of spinal chronic osteomyelitis had certain characteristics.In patients complicated with SAPHO syndrome,3 or more segments of spine involvements were common,with more extra spinal involvements.

Objective:To investigate the feasibility of the combination of free breathing with the high-threshold, short-delay technique in reducing radiation dose and the volumes of iodinated contrast agent in coronary computed tomography angiography (CCTA) for obese patients.Methods:The data of 73 obese patients with weights > 85 kg and body mass indices (BMIs) > 30 kg/m 2 who received CCTA in the Radiology Department of the Peking University Third Hospital from February 2023 to May 2024 were prospectively collected. These patients were divided into a control group (31 patients) and an experimental group (42 patients). Data were collected from the control group and experimental groups under breath-holding and free-breathing conditions, respectively. The bolus tracking thresholds, delay times, and ICA injection durations were set at 100 HU, 7 s, and 12 s for the control group and at 250 HU, 2 s, and 8 s for the experimental group, respectively. Other scanning and reconstruction parameters of both groups were consistent. The CT values and their standard deviations ( SD) of both groups were assessed and compared, with the CT values involving the lumens of the aorta (AO) root, left anterior descending (LAD), left circumflex artery (LCX), and right coronary artery (RCA). The signal-to-noise ratios (SNR) and contrast-to-noise ratio (CNR) were also calculated. The subjective assessment of image quality was performed for the 18 coronary artery segments using a 4-point scale. The effective radiation doses ( E) and the volumes of iodinated contrast agent of both groups were recorded and compared. The statistical differences in the aforementioned parameters between the groups were tested and analyzed using the analysis of variance (ANOVA), the Mann-Whitney U test, or the χ 2 test. With the results of the ICA as the gold standard, the diagnostic performance of the combination of free-breathing with the high-threshold, short-delay technique in CCTA for obese patients was assessed. Results:There was no statistically significant difference ( P > 0.05) in coronary artery images between both groups, specifically regarding the CT, SNR, and CNR values of the lumens of the AO roots, LAD, LCX, and RCA, as well as the SD values of the AO roots. Both groups received subjective scores of ≥ 3 for coronary artery images, meeting the diagnostic criteria, with no statistically significant differences ( P > 0.05). Compared with the results of the ICA, the analyses of the coronary artery segments of 23 patients from the experimental group, revealed that the accuracy, sensitivity, and specificity of CCTA in the diagnosis of > 50% stenosis were 89%, 86%, and 97%, respectively. Compared to that (45 ml) of the control group, the volume (30 ml) of iodinated contrast agent of the experimental group decreased by 33.3%, with no statistically significant difference in the effective radiation dose ( E) between both groups ( P > 0.05). Conclusions:The combination of free breathing with the high-threshold, short-delay technique can further reduce the volume of the ICA for obese patients while maintaining high CCTA image quality and diagnostic performance.

Objective To observe imaging manifestations of spinal chronic osteomyelitis.Methods Totally 56 patients with spinal chronic osteomyelitis were retrospectively enrolled,including 18 cases complicated with synovitis,acne,pustulosis,hyperostosis and osteomyelitis(SAPHO)syndrome while 38 cases did not.CT and MRI manifestations were observed.Results Among 56 cases,cervical spine involvement was observed in in 25 cases(25/56,44.64％).Single spine segment involvement,2 segments involvements and 3 or more segments involvements were found in 17(17/56,30.36％),18(18/56,32.14％)and 21 cases(21/56,37.50％),respectively.The ratio of 3 or more segments involvements in 18 cases with SAPHO syndrome was 61.11％(11/18),while in 38 cases without SAPHO syndrome was 26.32％(10/38),the former was higher than the latter(P＜0.05).Meanwhile,16 cases(16/56,28.57％)complicated with compression fracture,30(30/56,53.57％)with hyperosteogeny,22(22/56,39.29％)with paraspinal soft tissue swelled and 15(15/56,26.79％)with extra spinal involvements.The ratio of extra spinal involvement in patients with and without SAPHO syndrome was 72.22％(13/18)and 5.26％(2/38),respectively,the former was higher than the latter(P＜0.05).Conclusion Imaging manifestations of spinal chronic osteomyelitis had certain characteristics.In patients complicated with SAPHO syndrome,3 or more segments of spine involvements were common,with more extra spinal involvements.

Imaging plays a significant role in diagnosis and treatment of musculoskeletal diseases.With the development of medical imaging technology,both clinical application and research depth of musculoskeletal imaging achieved remarkable progresses.The application advancements and future developing trends of musculoskeletal imaging were reviewed in this article.

Objective To observe MRI manifestations of radiation myelopathy(RM).Methods Nine patients who developed RM due to radiotherapy after tumor resections were retrospectively enrolled,and clinical and imaging data were analyzed.Results Non-contrast enhanced MRI showed spinal cord swelling and thickening in all 9 cases,which could involve C1-T5 level,presented as low signals on T1WI and high signals on T2WI.The length of spinal cord edema was 30-178 mm,with a median of 90 mm.Lateral spinal cord involvements were detected in 8 cases,gray matter involvements were found in 9 cases,while posterior spinal cord involvements were noticed in 7 cases.Enhanced scanning was performed in 4 cases,and RM lesions presented as moderate"nodule"or"strip"like enhancements with length of 19-53 mm,and their distribution consistent with tumor resection areas.Four patients underwent MRI follow-up,the ranges of spinal cord edema gradually decreased or expanded at first and then decreased.Conclusion RM mainly presented as spinal cord thickening and edema on MRI,with low signals on T1WI and high signals on T2WI.Moderately"nodule"or"strip"like enhancements could occur in some lesions,with distribution consistent with surgical resection areas.

Objective:To investigate the application status of emergency radiology in China, and to provide data support for the standardized development, scientific management and big data research of emergency radiology.Methods:From August 12th to October 19th, 2022, a questionnaire survey was conducted through WeChat"Questionnaire Star"to send targeted questionnaires to investigate the relevant data of the current status of emergency radiology in China, mainly including digital radiography (DR) and computed tomography (CT). This study was initiated by the Chinese Emergency Radiology Database Collaboration Group, and comprehensively investigated emergency imaging personnel, equipment, workload, critical value reporting process, and artificial intelligence (AI) application status.Results:There were 123 hospitals in the study. The survey showed that emergency DR/CT reports were mainly completed by residents and above (69.1%). There were 21 DR brands, 10 CT brands and 8 MR brands used for emergency imaging examinations. The median number of DR examinations in tertiary hospitals and secondary hospitals investigated from January to June 2022 was 4 642 and 2 015 cases respectively, and the median number of CT examinations was 16 512 and 3 762 cases respectively. The average single-shift workload of DR in the emergency radiology department during the day and night shift in tertiary hospitals was mainly ≤20 copies and 21-50 copies, and the average single-shift workload of CT in the emergency radiology department during the day and night shift was mainly 21-50 copies and 51-100 copies, while the average single-shift workload of DR/CT in the emergency radiology department during the day/night shift in secondary hospitals was mainly ≤20 copies. In terms of critical value reporting process, 74.8% of emergency imaging doctors and 84.6% of emergency imaging technicians took the way of phone/text message to notify the clinical doctor or the patients′ family. The overall deployment rate of AI in emergency imaging was about 60.2%. 75% of the respondents believed that in the future, AI can improve emergency radiology work from aspects such as emergency screening, aided diagnosis and process optimization.Conclusions:The emergency medical imaging mainly based on DR and CT has the current situations such as generally low seniority of doctors, diverse brands of imaging equipments, large volume of examinations and intense workload per doctor, especially in tertiary hospitals, and dependence on traditional means for critical value reporting. At present, AI is emerging in the field of emergency imaging, and there is still a long way to go to play the huge potential of AI in the intelligent whole process of emergency imaging in the future.

Objective To explore the predicting value of quantitative CT features of peritumoral nodules for the risk of thymic epi-thelial tumors(TETs).Methods A total of 108 patients with TETs confirmed by pathology were analyzed retrospectively.Accord-ing to the WHO classification of thymic tumors,the patients were divided into high-risk group and low-risk group.The quantitative CT features included the long diameter,volume,mass,and distance between peritumoral nodules and main tumor.The values of these features were assessed using the Mann-Whitney U test,and the thresholds were determined using the receiver operating characteristic(ROC)curve.Results Among 108 TETs patients,there were 45 patients with peritumoral nodules on chest CT,including 30 high-risk group and 15 low-risk group,respectively.Interobserver consistencies were well with intraclass correlation coefficient(ICC)between 0.886 and 0.907.The long diameter,volume,and mass of peritumoral nodules were greater in the high-risk group than in the low-risk group(P＜0.05),and there was no significant difference in the distance to the main tumor(P＞0.05).The mass of peritumoral nodules had the best diagnostic performance in predicting TETs risk,and the thresholds was 27.84 mg with the area under the curve(AUC)of 0.889,sensitivity of 83.3％,specificity of 87.5％,and accuracy of 85.3％,respectively.Conclusion The quantitative CT features of peritumoral nodules especially mass can be useful in predicting the risk of TETs.

Objective To observe MRI manifestations of radiation myelopathy(RM).Methods Nine patients who developed RM due to radiotherapy after tumor resections were retrospectively enrolled,and clinical and imaging data were analyzed.Results Non-contrast enhanced MRI showed spinal cord swelling and thickening in all 9 cases,which could involve C1-T5 level,presented as low signals on T1WI and high signals on T2WI.The length of spinal cord edema was 30-178 mm,with a median of 90 mm.Lateral spinal cord involvements were detected in 8 cases,gray matter involvements were found in 9 cases,while posterior spinal cord involvements were noticed in 7 cases.Enhanced scanning was performed in 4 cases,and RM lesions presented as moderate"nodule"or"strip"like enhancements with length of 19-53 mm,and their distribution consistent with tumor resection areas.Four patients underwent MRI follow-up,the ranges of spinal cord edema gradually decreased or expanded at first and then decreased.Conclusion RM mainly presented as spinal cord thickening and edema on MRI,with low signals on T1WI and high signals on T2WI.Moderately"nodule"or"strip"like enhancements could occur in some lesions,with distribution consistent with surgical resection areas.