Objective To compare trunk muscle activation,muscle co-contraction levels and plantar pressure distribution between patients with chronic low back pain(cLBP)and healthy subjects during static standing.Methods From July,2021 to July,2022,17 healthy subjects(healthy control group)and 18 cLBP patients(cLBP group)were recruited from the Department of Rehabilitation Medicine,the First Affiliated Hospital of Sun Yat-sen Uni-versity.Demographic information was collected for both groups,as well as the pain intensity,functional disabili-ty,and center of pressure displacement parameters of the cLBP group in static standing.A plantar pressure plate was used to record plantar pressure distribution in static standing task.Simultaneously,a wireless surface electro-myography(sEMG)system was used to record the activity of the transverse abdominis(TrA),erector spinae(ES)and lumbar multifidus(LM).The activation levels of each muscle and the co-contraction index(CCI)between trunk muscle pairs were analyzed.Results Compared with the healthy control group,the cLBP group showed higher activation levels of the bilateral LM(∣t∣>2.479,P<0.05)and higher lumbar-abdominal muscle CCI of left LM-left TrA(t=2.212,P=0.042),left LM-right TrA(t=2.868,P=0.008)and right LM-right TrA(U=75.000,P=0.009).In the cLBP group,pres-sure decreased in the right big toe region(t=2.825,P=0.009),and increased in the right medial and left lateral heel regions(U<77.000,P<0.05).Conclusions During static standing,patients with cLBP require higher level of trunk muscle activation and co-contrac-tion,with a posterior shift in plantar pressure distribution,which might be due to the adoption of different postur-al compensation strategies to maintain postural stability.

Objective To compare trunk muscle activation,muscle co-contraction levels and plantar pressure distribution between patients with chronic low back pain(cLBP)and healthy subjects during static standing.Methods From July,2021 to July,2022,17 healthy subjects(healthy control group)and 18 cLBP patients(cLBP group)were recruited from the Department of Rehabilitation Medicine,the First Affiliated Hospital of Sun Yat-sen Uni-versity.Demographic information was collected for both groups,as well as the pain intensity,functional disabili-ty,and center of pressure displacement parameters of the cLBP group in static standing.A plantar pressure plate was used to record plantar pressure distribution in static standing task.Simultaneously,a wireless surface electro-myography(sEMG)system was used to record the activity of the transverse abdominis(TrA),erector spinae(ES)and lumbar multifidus(LM).The activation levels of each muscle and the co-contraction index(CCI)between trunk muscle pairs were analyzed.Results Compared with the healthy control group,the cLBP group showed higher activation levels of the bilateral LM(∣t∣>2.479,P<0.05)and higher lumbar-abdominal muscle CCI of left LM-left TrA(t=2.212,P=0.042),left LM-right TrA(t=2.868,P=0.008)and right LM-right TrA(U=75.000,P=0.009).In the cLBP group,pres-sure decreased in the right big toe region(t=2.825,P=0.009),and increased in the right medial and left lateral heel regions(U<77.000,P<0.05).Conclusions During static standing,patients with cLBP require higher level of trunk muscle activation and co-contrac-tion,with a posterior shift in plantar pressure distribution,which might be due to the adoption of different postur-al compensation strategies to maintain postural stability.

Objective:To explore the effect of different post-processing parameters of digital radiography (DR) on the quality of chest X-ray for pneumoconiosis diagnosis, and to provide suggestions on parameter setting suitable for this kind of DR machine.Methods:From January 1, 2022 to June 30, 2022, the chest films of 35 workers in the department of radiology of Hangzhou occupational disease prevention and treatment hospital were randomly selected and printed after setting different image post-processing parameters. The quality of chest film was evaluated by the measurement of optical densitometer and the combination of subjective and objective by professional physicians.Results:When the density is set to 2 and the contrast/detail contrast is 4.5, the optical density of each area of DR chest film meets the requirements of chest X-ray quality, and the qualified rate of physician quality evaluation is the highest.Conclusion:Reasonable setting of image post-processing parameters can improve the quality of chest radiograph.

Objective:To explore the effect of different post-processing parameters of digital radiography (DR) on the quality of chest X-ray for pneumoconiosis diagnosis, and to provide suggestions on parameter setting suitable for this kind of DR machine.Methods:From January 1, 2022 to June 30, 2022, the chest films of 35 workers in the department of radiology of Hangzhou occupational disease prevention and treatment hospital were randomly selected and printed after setting different image post-processing parameters. The quality of chest film was evaluated by the measurement of optical densitometer and the combination of subjective and objective by professional physicians.Results:When the density is set to 2 and the contrast/detail contrast is 4.5, the optical density of each area of DR chest film meets the requirements of chest X-ray quality, and the qualified rate of physician quality evaluation is the highest.Conclusion:Reasonable setting of image post-processing parameters can improve the quality of chest radiograph.

Pneumoconiosis is a serious occupational disease in China. Early imaging examination is one of the important measures for the diagnosis, treatment and prevention of pneumoconiosis. Digital radiography (DR) and computed tomography (CT) play an important role in the screening and diagnosis of pneumoconiosis, as well as the recent rise of artificial intelligence (AI) technology. This paper reviews the latest progress in technical parameter debugging and quality control of DR, optimization of AI computer-aided system and CT-aided diagnosis of pneumoconiosis, summarizes the advantages and problems in the application of the three technologies, providing research directions for imaging diagnosis of pneumoconiosis.

Objective:To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared.Methods:The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation.Results:Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration ( r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion:The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.

Objective:To connect with the measurement data of asbestos dust fiber concentration in foreign countries, improve the accuracy of asbestos fiber detection in China, and understand the dust exposure in the working environment of asbestos and man-made mineral fiber production and processing sites in Zhejiang Province. The fiber count concentrations of working environment in glass fiber, ceramic fiber and asbestos processing plants were measured and compared.Methods:The dust concentration in the working environment of two glass fiber factories, one ceramic fiber factory and eight asbestos products processing factories was measured. The total dust mass concentration was measured according to GBZ/T 192.1-2007, and the fiber count concentration was measured by phase contrast microscope. Kruskal Wallis was used to test and compare the dust concentration in the working environment of each post. The correlation between asbestos mass concentration and fiber count concentration was analyzed by Spearman correlation.Results:Under the phase contrast microscope, there were many short and fine asbestos fibers in the field of vision, and there were many impurities around. The average dust concentration of asbestos processing plant was 3.2 f/ml, and the dust concentration of cotton ginning was the highest (6.68 f/ml) . There was a significantly positive correlation between asbestos fiber count concentration and mass concentration ( r=0.535, P=0.033) . The average fiber count concentration of glass fiber factory was 0.001 f/ml, and the highest was 0.005 f/ml. The average fiber count concentration of ceramic fiber factory was 0.001 f/ml, and the highest was 0.006 f/ml. Conclusion:The fiber count concentration in the working environment of asbestos factory in Zhejiang Province is obviously over the standard, which is one of the important reasons for the high incidence of mesothelioma in this area. Short and small asbestos fibers are easy to be ignored when counting. It is necessary to improve the actual operation process of fiber counting to form a laboratory standard in China.

Objective To investigate the diagnostic value and the impact on treatment decision of 18F-FDG PET/CT in differentiated thyroid carcinoma (DTC) patients with elevated serum thyroglobulin (Tg) levels and negative radioiodine 131I post-therapy whole body scan (131I-RxWBS).Methods Totally 72 patients with DTC who had elevated serum Tg levels and negative 131I-RxWBS were enrolled,and 18F-FDG PET/CT was performed.The imaging results of 18F-FDG PET/CT were compared with the clinical results of surgical pathology or 6 to 36 months follow up.The diagnostic efficacy of 18F-FDG PET/CT in detection of recurrence and/or metastasis of DTC with elevated Tg levels and negative 131I-RxWBS was evaluated.Results The accuracy,sensitivity,specificity,positive prediction value and negative prediction value of 18F-FDG PET/CT in diagnosis of DTC with elevated Tg levels and negative 131I-RxWBS was 83.33％ (60/72),89.47％ (34/38),76.47％ (26/34),80.95％ (34/42) and 86.67％ (26/30),respectively.18F-FDG PET/CT changed the treatment strategies of 35 patients (35/72,48.61 ％) among 72 patients,while recurrence or metastasis of DTC was not found during clinical follow-up in 23 of these 35 patients (23/35,65.71％) who underwent reoperation,but was detected in the other 12 patients (12/35,34.29％).Conclusion 18F-FDG PET/CT is a valuable method for detection of recurrence and/or metastasis of DTC with elevated Tg levels and negative 131I-RxWBS,also for guiding the follow-up treatment strategy.

Objective To analyze the CT features of osteosarcoma and chondrosarcoma and to explore the value of CT differential diagnosis.Methods The CT findings of 35 cases with osteosarcoma and 22 cases with chondrosarcoma confirmed by operation and pathology were analyzed retrospectively.P<0.05 for the difference was statistically significant.Results Periosteal reaction, Codman triangle, radial spicule, type Ⅰ and Ⅳ calcium-like density, long tubular soft tissue mass around greater than 1/2, the ratio of tumor CT to muscle CT (△T/△M) was statistically significant.Of all the above image performance, the sensitivity and specificity of the type I calcium-like density were the highest, while those of the type Ⅳ calcium-like density were the lowest.Conclusion The osteosarcoma is more likely to have the signs of periosteal reaction, Codman triangle, radial spicule and type Ⅰ calcium-like density, while the chondrosarcoma is more likely to have the signs of type Ⅳ calcium-like density.

Purpose To explore the clinical value of131I-whole body scan (131I-WBS) and 18F-FDG PET/CT on the metastatic management of patients with differentiated thyroid cancer (DTC) after operation.Materials and Methods Serum thyroglobulin (Tg) of 27 patients after DTC surgery was measured one day before131I therapy, and the patients underwent131I-WBS on 3-5 days after131I therapy. According to the results of Tg and 131I-WBS, all the patients were divided into 4 types as follows: type I: Tg (+),131I-WBS (-); type II: Tg (+),131I-WBS (+); type III: Tg (-),131I-WBS (+); and type IV: Tg (-), 131I-WBS (-). Then the patients received18F-FDG PET/CT scan within a week after 131I-WBS. The results of131I-WBS and18F-FDG PET/CT scan were analyzed according to histopathologic findings or clinical and imaging follow-up of at least 6 months as diagnosis standard.Results The examinations uncovered that metastasis occurred in 52 lesions of 22 cases out of the 27 cases.131I-WBS revealed 24 metastatic lesions (46.2%) in 8 cases (36.4%), and18F-FDG PET/CT showed 35 metastatic lesions (67.3%) in 15 cases (68.2%), the difference with statistic significance (χ2=4.46 and 4.74,P<0.05). Metastasis were confirmed in 13 type I cases (100.0%); 5 type II cases (100.0%); 3 type III cases (100.0%) and 1 type IV case (16.7%), respectively. The rate of detecting metastasis by 18F-FDG PET/CT was 100.0% in type I, 20.0% in type II, 0% in type III respectively, the difference with statistic significance (χ2=9.14 and 10.11,P<0.05); and 100.0% in type IV, the difference without statistic significance (χ2=1.25,P>0.05). Based on that, therapeutic plans were modified for 13 patients with type I metastasis and 1 patient with type IV metastasis.Conclusion131I-WBS and18F-FDG PET/CT are complementary for detecting metastatic lesion and help to decide the following treatment of DTC patients after surgery. Moreover,18F-FDG PET/CT shows advantages in detecting metastatic lesion in Tg-positive and negative131I-WBS type of DTC patients after surgery, thus can provide an important clinical guidance for this type of patients.