Purpose To investigate the correlation between intervertebral disc degeneration and paraspinal muscle fatty infiltration in chronic low back pain(CLBP)using quantitative MRI techniques.Materials and Methods A total of 63 CLBP patients and 42 volunteers in Zigong Fourth People's Hospital from September 2023 to March 2024 were retrospectively collected.Magnetic resonance scans were performed using multi-echo water-fat separation technique and T2 mapping technique.Intervertebral disc degeneration was assessed using the Pfirrmann grading,while paraspinal muscle fatty infiltration was evaluated using the Goutallier grading.Proton density fat fraction(PDFF)of the multifidus and erector spinae muscles,and T2 values of the nucleus pulposus were quantitatively measured.The relationships between these parameters and their associations with age and gender were analyzed.Results Compared with healthy volunteers,CLBP patients showed significantly reduced T2 values of the nucleus pulposusand significantly increased PDFF of the paraspinal muscles(Z=-5.54-4.65,all P<0.001).The Pfirrmann grading of intervertebral discs and the Goutallier grading of paraspinal muscles were significantly correlated with the T2 value of the nucleus pulposus and the PDFF of the paraspinal muscles(|r|>0.4,P<0.05).Age and Pfirrmann grading were independent predictors of paraspinal muscle fat infiltration(β=0.228-5.682,all P<0.001),and gender was also an independent predictor at the L4/5 intervertebral disc level(β=-2.834,-3.352,both P<0.05).Conclusion Intervertebral disc degeneration and paraspinal muscle fat infiltration are closely related in CLBP,age and gender also have an impact.

Objective To explore the value of time-dependent diffusion MRI(td-dMRI)parameters for differentiating invasive breast cancer(IBC)with ductal carcinoma in situ(DCIS)(IBC-DCIS)from simple IBC.Methods A total of 19 patients with IBC-DCIS(IBC-DCIS group)and 53 patients with simple IBC(IBC group)confirmed by surgery and postoperation pathology were retrospectively enrolled.Breast td-dMRI acquired with oscillating gradient spin-echo(OGSE)and pulsed gradient spin-echo(PGSE)sequences before operation were interpreted,and apparent diffusion coefficient(ADC)and microstructure parameters,including OGSE-ADC value,PGSE-ADC value,cellularity,cell diameter,intracellular volume fraction and extracellular diffusion coefficient were obtained and compared between groups.Receiver operating characteristic(ROC)curves of parameters being significantly different between groups were plotted,and the area under the curve(AUC)was calculated to evaluate the efficacy of these parameters for differentiating IBC-DCIS from IBC.Results Significant differences of OGSE-ADC value,PGSE-ADC value,cellularity,cell diameter,intracellular volume fraction and extracellular diffusion coefficient were found between groups(all P＜0.05).The AUC of the above parameters for differentiating IBC-DCIS from IBC was 0.81,0.79,0.78,0.68,0.77 and 0.81,respectively.Conclusion td-dMRI parameters could be used to noninvasively and effectively differentiate IBC-DCIS from simple IBC.

Purpose To investigate the correlation between intervertebral disc degeneration and paraspinal muscle fatty infiltration in chronic low back pain(CLBP)using quantitative MRI techniques.Materials and Methods A total of 63 CLBP patients and 42 volunteers in Zigong Fourth People's Hospital from September 2023 to March 2024 were retrospectively collected.Magnetic resonance scans were performed using multi-echo water-fat separation technique and T2 mapping technique.Intervertebral disc degeneration was assessed using the Pfirrmann grading,while paraspinal muscle fatty infiltration was evaluated using the Goutallier grading.Proton density fat fraction(PDFF)of the multifidus and erector spinae muscles,and T2 values of the nucleus pulposus were quantitatively measured.The relationships between these parameters and their associations with age and gender were analyzed.Results Compared with healthy volunteers,CLBP patients showed significantly reduced T2 values of the nucleus pulposusand significantly increased PDFF of the paraspinal muscles(Z=-5.54-4.65,all P<0.001).The Pfirrmann grading of intervertebral discs and the Goutallier grading of paraspinal muscles were significantly correlated with the T2 value of the nucleus pulposus and the PDFF of the paraspinal muscles(|r|>0.4,P<0.05).Age and Pfirrmann grading were independent predictors of paraspinal muscle fat infiltration(β=0.228-5.682,all P<0.001),and gender was also an independent predictor at the L4/5 intervertebral disc level(β=-2.834,-3.352,both P<0.05).Conclusion Intervertebral disc degeneration and paraspinal muscle fat infiltration are closely related in CLBP,age and gender also have an impact.

Objective To explore the value of time-dependent diffusion MRI(td-dMRI)parameters for differentiating invasive breast cancer(IBC)with ductal carcinoma in situ(DCIS)(IBC-DCIS)from simple IBC.Methods A total of 19 patients with IBC-DCIS(IBC-DCIS group)and 53 patients with simple IBC(IBC group)confirmed by surgery and postoperation pathology were retrospectively enrolled.Breast td-dMRI acquired with oscillating gradient spin-echo(OGSE)and pulsed gradient spin-echo(PGSE)sequences before operation were interpreted,and apparent diffusion coefficient(ADC)and microstructure parameters,including OGSE-ADC value,PGSE-ADC value,cellularity,cell diameter,intracellular volume fraction and extracellular diffusion coefficient were obtained and compared between groups.Receiver operating characteristic(ROC)curves of parameters being significantly different between groups were plotted,and the area under the curve(AUC)was calculated to evaluate the efficacy of these parameters for differentiating IBC-DCIS from IBC.Results Significant differences of OGSE-ADC value,PGSE-ADC value,cellularity,cell diameter,intracellular volume fraction and extracellular diffusion coefficient were found between groups(all P＜0.05).The AUC of the above parameters for differentiating IBC-DCIS from IBC was 0.81,0.79,0.78,0.68,0.77 and 0.81,respectively.Conclusion td-dMRI parameters could be used to noninvasively and effectively differentiate IBC-DCIS from simple IBC.

Video-based intelligent action recognition remains challenging in the field of computer vision.The review analyzes the state-of-the-art methods of video-based intelligent action recognition,including machine learning methods with handcrafted features,deep learning methods with automatically extracted features,and multi-information fusion methods.In addition,the important medical applications and limitations of these technologies in the past decade are introduced,and the interdisciplinary views on the future application to improve human health are also shared.

Objective To evaluate the quality of treatment planning(TP)and re-optimization planning(RP)of radiotherapy for rectal cancer using PlanIQ software,thereby providing methods and tools for the screening and optimization of radiotherapy plans.Methods Twenty patients with rectal cancer who received radiotherapy were selected retrospectively,with 10 cases of intensity-modulated radiotherapy(IMRT)and 10 of volumetric modulated arc therapy(VMAT).(1)TP:IMRT plan involved 5-field irradiation,and VMAT plan involved two 360°arcs.The prescription doses were 50 Gy/25 f for PTV1 and 45 Gy/25 f for PTV2.All plans underwent direct machine parameter optimization and required 95%isodose lines to cover 100%of the target volume.Organs-at-risk(OAR)were limited by reference to tolerated dose standards.After the planning was completed,the plans were reviewed and confirmed by a physician,and the treatment was implemented after dose verification.(2)RP:a physicist with 10 years of experience re-optimized the 20 TP plans,with the irradiation technique and field setting unchanged.The re-optimization involved adjusting planning conditions and parameters based on individual experience until the dose to OAR was minimized while without affecting PTV coverage.The quality of TP plans and RP plans were quantitatively evaluated using PlanIQ software.Non-parametric Wilcoxon signed rank test was performed for dose-volume histogram parameters and plan quality index between two groups.Results The dose-volume histogram parameters in RP plans were superior to those in TP plans,and the differences in the Dmax of PTV1,the V45 Gy and Dmax of small intestine,and the V45 Gy of colon were statistically significant(P<0.05).The quality scores of RP plans for IMRT group,VMAT group and all patients were significantly higher than those of TP plans(P<0.05),with plan quality index of 88.55±3.35 vs 86.61±4.63(P=0.005),89.72±3.15 vs 87.21±3.04(P=0.028),and 89.14±3.22 vs 86.91±3.22(P=0.001),respectively.Conclusion RP can further improve the quality of radiotherapy plan for rectal cancer.PlanIQ software serves as an effective tool for quality control and screening of radiotherapy planning.

Objective To assess inter-observer variations(IOV)in the delineation of target volumes and organs-at-risk(OAR)for intensity-modulated radiotherapy(IMRT)of nasopharyngeal carcinoma(NPC)among physicians from different levels of cancer centers,thereby providing a reference for quality control in multi-center clinical trials.Methods Twelve patients with NPC of different TMN stages were randomly selected.Three physicians from the same municipal cancer center manually delineated the target volume(GTVnx)and OAR for each patient.The manually modified and confirmed target volume(GTVnx)and OAR delineation structures by radiotherapy experts from the regional cancer center were used as the standard delineation.The absolute volume difference ratio(△V_diff),maximum/minimum volume ratio(MMR),coefficient of variation(CV),and Dice similarity coefficient(DSC)were used to compare the differences in organ delineation among physicians from different levels of cancer centers and among the 3 physicians from the same municipal cancer center.Furthermore,the IOV of GTVnx and OAR among physicians from different levels cancer centers were compared across different TMN stages.Results Significant differences in the delineation of GTVnx were observed among physicians from different levels of cancer centers.Among the 3 physicians,the maximum values of △V_diff,MMR,and CV were 97.23%±83.45%,2.19±0.75,and 0.31±0.14,respectively,with an average DSC of less than 0.7.Additionally,there were considerable differences in the delineation of small-volume OAR such as the left and right optic nerves,chiasm,and pituitary,with average MMR>2.8,CV>0.37,and DSC<0.51.However,relatively smaller differences were observed in the delineation of large-volume OAR such as the brainstem,spinal cord,left and right eyeballs,and left and right mandible,with average△V_diff<42%,MMR<1.55,and DSC>0.7.Compared with the differences among physicians from different levels cancer centers,the differences among the 3 physicians from the municipal cancer center were slightly reduced.Furthermore,there were also differences in the delineation of target volumes for NPC among physicians from different levels cancer centers,depending on the staging of the disease.Compared with the delineation of target volumes for earlier stage patients(stages I or II),the differences among physicians in the delineation of target volumes for advanced stage patients(stages III or IV)were smaller,with average △V_diff and DSC of 98.31%±67.36%vs 69.38%±72.61%(P<0.05)and 0.55±0.08 vs 0.72±0.12(P<0.05),respectively.Conclusion There are differences in the delineation of GTVnx and OAR in radiation therapy for NPC among physicians from different levels of cancer centers,especially in the delineation of target volume(GTVnx)and small-volume OAR for early-stage patients.To ensure the accuracy of multicenter clinical trials,it is recommended to provide unified training to physicians from different levels of cancer centers and review their delineation results to reduce the effect of differences on treatment outcomes.

Objective:To explore the feasibility of applying ArcherQA to independent dose verification of MR-guided online adaptive radiotherapy (ART) plans performed on Elekta Unity 1.5 Tesla (T) magnetic resonance-linear accelerator (MR-Linac).Methods:The dose calculation accuracy of ArcherQA under a specific magnetic field was validated using a homogeneous water phantom. A total of 32 patients who received MR-guided online ART on Elekta Unity were randomly selected by lottery, with 32 offline plans and 177 online plans for five treatment sites (brain, mediastinum, liver, kidney, and vertebral body) enrolled. Finally, the γ pass rates (threshold: 10%; criteria: 3 mm/3% and 2 mm/2%) were compared among the result upon independent dose verification of ArcherQA, measurements of ArcCheck, and calculations using the Monaco treatment planning system (TPS) to quantitatively evaluate the accuracy and efficiency of ArcherQA in independent dose verification of online plans on Elekta Unity.Results:ArcherQA was proven accurate in calculating the dose distribution of therapeutic photon beams under the specific magnetic field. With the 3 mm/3% criterion, the γ pass rates of verification result exceeded 99% in all square fields of a water phantom. Under the stricter 2 mm/2% criterion, the γ pass rates also surpassed 95% in all square fields except 20 cm × 20 cm field. Regarding the verification of treatment plans, the ArcherQA result were found to be highly consistent with those measured or calculated using ArcCheck and Monaco TPS, with the average γ pass rates exceeding 99% under the 3 mm/3% criterion and above 97% under the 2 mm/2% criterion. ArcherQA was acceptably efficient for independent dose verification of online plans, with 50 to 150 s, (108 s on average) required to complete the independent dose verification of 177 online plans.Conclusions:ArcherQA allows for accurately and efficiently calculating the dose distribution of therapeutic photon beams under a specific magnetic field, establishing it as an effective supplementary tool for independent dose calculation of MR-guided offline and online ART plans, thereby ensuring the safety of patient treatment plans.

Objective This study was designed to explore the therapeutic effect of psoralen on type Ⅱ collagen-induced rheumatoid arthritis in mice and its molecular mechanism.Methods DBA/1J mice were immunized with type II bovine collagen to induce rheumatoid arthritis.The model mice were randomly divided into Psoralen group(PSO),methotrexate group(MTX) and model group(Vehicle).Clinical signs of arthritis in the mice were monitored.The spleen index was assessed.Splenic Th1 and Th2 cells were counted by flow cytometry.ELISA was used to detect the levels of inflammation-associated factors TNF-α,IL-6 and IL-1β in the serum.Results Compared with the vehicle group,the ankle swelling and limitation of joint activity in the PSO group were significantly reduced,the spleen index and Th1 cell percentage were significantly decreased,and the Th2 cell percentage showed no significant change in the PSO group.Expression of TNF-α,IL-6 and IL-1β in serum was notably decreased in the PSO group.All the indexes showed no significant difference between the PSO and MTX groups.Conclusions Psoralen may attenuate the severity of type II collagen-induced rheumatoid arthritis in mice by regulating the balance of Th1/Th2 cells and inhibiting the expression of TNF-α,IL-6 and IL-1β.