BACKGROUND:Exosomes have become one of the frontiers of biomedical research in recent years because of their promising applications in clinical diagnosis and therapy. OBJECTIVE:To reveal the basic research and technology development trend of exosomes at home and abroad,and provide suggestions for related scientific and technological research and development in China. METHODS:This paper presented a quantitative analysis of the overall research and development situation,the frontier hotspots and future development trends in this research area by means of bibliometric methods and tools. RESULTS AND CONCLUSION:The research and development hotspots in this area have entered a high growth phase with the application of new tools and methods.Many new technologies and products are facing clinical applications and markets with the development of a large number of clinical translation experiments.Comparative analysis at home and abroad reveals that China has made more remarkable achievements in basic research in this field,but there are still weaknesses in the possession of independent intellectual property rights,clinical technology translation,and regulatory system standardization and management,which need to be further strengthened in the future.

Purpose To evaluate the added value of time of flight(TOF)and point spread dispersion(PSF)reconstruction in mediastinal lymph node metastasis of lung cancer in 18F-FDG PET/CT imaging.Materials and Methods Sixty-eight lung cancer patients with mediastinal lymph node metastasis who underwent PET/CT examination in the First People's Hospital of Foshan from March 9,2020 to July 23,2021 were analyzed retrospectively.The different methods,including ordered subsets estimation maximization(OSEM),OSEM+TOF,OSEM+PSF,OSEM+TOF+PSF,were used to reconstruct the images.The resolution of different reconstruction algorithms for mediastinal lymph node metastasis of lung cancer,as well as the differences of signal-to-noise ratio(SNR)and standard uptake value(SUV)were compared,respectively.Results The highest values of SUVmean,SUVmax and SNR were obtained via OSEM+TOF+PSF method,which increased by 21.99%,22.86%and 60.14%,compared with conventional OSEM method(t=28.321,19.11,11.059,all P<0.01).The difference percentage in smaller lesions that diameter≤22 mm was significantly higher than that in larger lesions that diameter>22 mm(24.1%vs.21.1%,25.3%vs.19.3%,70.6%vs.63.3%;Z=-3.658,-4.313,-2.154,all P<0.05),and the difference percentage in low contrast lesions that SNR≤15.31 was significantly higher than that in high contrast lesions that SNR>15.31(23.6%vs.21.4%,25.3%vs.21.1%,85.7%vs.46.0%;Z=-3.519,-2.336,-5.106,all P<0.05).Among the evaluation results of lesion detectability of different reconstruction algorithms,OSEM+TOF+PSF image showed the mediastinal lymph node metastasis most clearly(87.4%of the lesions were clearly existing),which was significantly higher than that of OSEM image(73.1%of lesions were clearly existing)(χ2=11.704,P=0.001),however,the proportion of lesions clearly existing in OSEM+PSF image did not significantly increase compared with OSEM image(73.1%vs.75.8%;χ2=0.361,P=0.548).Conclusion The combination of TOF and PSF can significantly improve the detection ability,SNR and SUV of mediastinal lymph node metastasis of lung cancer,especially in small and low contrast lesions.

ObjectiveTo compare the effect of proprioceptive neuromuscular training methods on pain and motor ability of knee in patients with early knee osteoarthritis (KOA) . MethodsFrom November, 2022 to May, 2023, 60 early KOA patients from Beijing Bo'ai Hospital and community were randomly divided into groups A, B and C, with 20 patients in each group. Group A received proprioceptive neuromuscular facilitation (PNF), group B received neuromuscular exercise (NEMEX), and group C received PNF and NEMEX, for six weeks. They were assessed with Visual Analogue Scale for pain (VAS), angle reappearance test, difference of pre-motor reaction time (VM-VL), active range of motion (AROM) of knee flexion, 10-meter walk test (10MWT), and Knee Injury and Osteoarthritis Outcome Score (KOOS) before and after treatment. ResultsAll the indexes improved in all the groups after treatment (|t| > 2.532, P < 0.05). Among the groups, the VAS score was the least in group A, and then groups C and B; the angle reappearance error was the least in group C, and similar in groups A and B; the VM-VL was the least in groups A and C, followed by group B. ConclusionPNF, NEMEX and PNF+NEMEX can relieve the pain and improve the motor function of knee in patients with early KOA, however, PNF is the most effective on relieving pain, and PNF+NEMEX is the most effective on improving knee function.

ObjectiveTo observe the architectural parameter changes of the muscles around the knee in middle-aged and elderly women with early knee osteoarthritis (KOA) by musculoskeletal ultrasound, and to clarify the indicators of muscles that affect early KOA. MethodsFrom January to August, 2022, 20 healthy middle-aged and elderly healthy women (controls) and 20 middle-aged and elderly women with unilateral early KOA (KOA group) were recruited through Beijing Bo'ai Hospital, to measure muscle thickness of the popliteus muscle, the muscle thickness and the pennation angle of the quadriceps, as rectus femoris, vastus intermedius, vastus lateralis, vastus medialis longus and vastus medialis oblique. ResultsCompared with the healthy limb of KOA group, and the controls, the muscle thickness of vastus medialis longus, vastus medialis oblique and popliteus muscle of the affected limb of KOA group became thinner (t > 2.133, P < 0.05); the proportion of thickness of vastus medialis oblique to thickness of vastus lateralis became smaller (t > 3.660, P < 0.05). The pennation angle was smaller in the affected limb of KOA group than in the matched dominant side of the controls (t = 3.101, P < 0.05). Logistic regression analysis showed that the muscle thickness of vastus medialis oblique (OR = 0.235, 95%CI 0.068 to 0.805, P = 0.021) and popliteus muscle (OR = 0.387, 95%CI 0.152 to 0.980, P = 0.045) were related to the onset of early KOA. ConclusionThe thickness of vastus medialis longus, vastus medialis oblique and popliteus muscle decrease, and the balance of the strength of vastus medialis oblique and vastus lateralis weakens in the affected limbs of the middle-aged and elderly women with early KOA. The thickness of vastus medialis oblique and popliteus muscle are protective factors for onset of KOA.

ObjectiveTo analyze the epidemiological and clinical characteristics of children's lower extremity amputation and amputation rehabilitation, and to explain the causes of children's amputation and the complications after amputation. MethodsFrom January, 2016 to March, 2021, 51 amputation related children were retrospectively analyzed. The correlation between the cause of amputation and complications post amputation were analyzed. ResultsTraumatic amputations accounted for 58.82%, and the main cause was traffic accidents (70%). Amputations caused by diseases accounted for 41.18%, and the main cause was congenital limb deformities (80.95%). Traumatic amputation was more likely to have stump complications than expected (P < 0.05). The possibility of stump complications after disease-specific amputation was lower than expected (P < 0.05). ConclusionTraffic trauma is the main cause of amputation in children and is characterized clinically by a high incidence of unsatisfactory stumps, mainly due to soft tissue abnormalities, and most cases require stump revision to improve the poor residuals for prosthetic restoration of ambulation. Congenital pseudarthrosis of the tibia is the main cause of disease-specific amputation, and the outcome of amputation often cannot be definitely avoided even after long-term limb preservation treatment.

Objective:To investigate the clinical efficacy and safety of 90Sr- 90Y β-ray low dose applicator, topical timolol maleate, and their combination in the treatment of superficial infantile hemangioma (IH). Methods:From May 14, 2013 to April 11, 2017, 400 children (126 males, 274 females, age 5.3(3.9, 7.1) months) with superficial IH in Department of Nuclear Medicine, the First People′s Hospital of Foshan were prospectively enrolled. All patients were randomly divided into 4 treatment groups according to the proportion of 1∶1∶1∶1 by the method of random number table: topical timolol maleate (group A, control group), 90Sr- 90Y β-ray low dose applicator (group B), single course applicator combined with timolol (group C), and multi-course applicator combined with timolol (group D). Lesions were followed up to the 104 th week (W104). Cure rate of W104 was considered as primary end point. Efficacy and safety of different treatment were compared. Kruskal-Wallis rank sum test, Mann-Whitney U test, and logistic regression analysis were used for statistical analysis. Results:Totally, 438 lesions in 400 cases were included in this prospective study. There was no significant difference in baseline characteristics among 4 groups ( χ2 values: 1.709-11.616, H values: 3.681-7.653, all P>0.05). As of W104, 11 lesions (2.51%, 11/438) were lost follow-up, 32 lesions (7.31%, 32/438) were with early withdrawal, 357 lesions (81.51%, 357/438) were cured, 15 lesions (3.42%, 15/438) were with residual, 23 lesions (5.25%, 23/438) were with rebound growth, and no serious adverse events occurred in the 4 groups. Multivariate analysis showed that lesions thickness (<3 mm vs ≥ 3 mm, odd ratio ( OR)=16.689, 95% CI: 7.908-35.223; χ2=54.555, P<0.001) and treatment (considering group A as reference category, OR (95% CI) of group B, C and D were 16.842(6.179-45.901), 4.801(2.167-10.638) and 39.127(10.468-146.243), respectively; χ2=47.663, P<0.001) were independent factors affecting the cure rate of W104. 90Sr- 90Y low-dose fractionation radiotherapy was significantly better than topical timolol maleate ( OR=16.842, 95% CI: 6.179-45.901), and the combination with timolol could significantly reduce the cumulative absorbed dose of radiotherapy (group D vs B: 16(8, 16) vs 16(16, 24) Gy; z=-4.947, P<0.001). Conclusion:90Sr- 90Y low dose applicator therapy is superior to topical timolol maleate for superficial IH, and the combination with timolol could significantly reduce the cumulative absorbed dose of applicator.

Objective:To explore the influence of time of flight (TOF) and point spread function (PSF) on PET/CT image quality and standardized uptake value (SUV) based on a phantom study.Methods:PET/CT imaging were performed using Jaszczak phantom and International Electrotechnical Commission (IEC) body phantom respectively, and conventional clinical imaging protocol (3 min/bed) was used for three consecutive imaging. The ordered subsets expectation maximization (OSEM), OSEM+ TOF, OSEM+ PSF and OSEM+ TOF+ PSF were used to reconstruct the raw data respectively. The differences of image resolution, image uniformity, contrast, signal to noise ratio (SNR) and SUV among different reconstruction algorithms were compared by using one-way analysis of variance and the least significant difference (LSD) t test. The correlations between SNR, mean SUV (SUV mean), maximum SUV (SUV max) and the sphere diameter were analyzed by Pearson correlation analysis. Results:The minimum image resolution for the hot column was 6.4 mm by OSEM and OSEM+ PSF reconstruction, while it was 4.8 mm by OSEM+ TOF and OSEM+ TOF+ PSF reconstruction. The contrast was significantly better by OSEM+ TOF ((78.56±1.21)%) and OSEM+ TOF+ PSF ((78.85±1.17)%) reconstruction than that by OSEM reconstruction ((73.44±1.47)%; F=61.068, t values: 9.503, 10.018, both P<0.001). The maximum and minimum nonuniformity percentages were significantly better for images reconstructed with OSEM+ PSF than those reconstructed with OSEM ( F values: 10.286, 27.630, t values: -2.599, 7.698, both P<0.05). In IEC phantom imaging, the SNR and SUV max of hot sphere were higher by OSEM+ PSF and OSEM+ TOF+ PSF reconstruction than those by OSEM reconstruction (SNR: (98.99±34.76)%, (98.29±28.66)%, (73.64±26.05)%; F=5.712, t values: 3.209, 3.412, both P<0.05; SUV max: 8.96±2.72, 9.28±2.17, 8.01±2.21; F=3.931, t values: 2.154, 2.863, both P<0.05), but there was no significant difference between OSEM+ TOF and OSEM reconstruction ( t values: 0.297, 0.272, both P>0.05). Among the four reconstruction methods, the SNR and SUV mean increased with the increase of the sphere diameter ( r values: 0.913-0.963, all P<0.05), but SUV max in images reconstructed with OSEM+ PSF and OSEM+ TOF+ PSF had no significant correlations with the sphere diameter ( r values: 0.496, 0.614, both P>0.05). Conclusions:Under specific acquisition and reconstruction conditions, TOF mainly improves image resolution and contrast, while PSF mainly improves image uniformity and SNR. The combination of the two method can obtain better image quality and significantly improve the SUV of hot lesions.

Objective To investigate the differences of acquisition protocols from continuous bed motion (CBM) and step-and-shoot (SS) modes and to observe their effects on image quality and standard uptake value (SUV) in 18 F-fluorodeoxyglucose (FDG) PET/CT.Methods A total of 30 patients (13 males,17 females;40-71 years) who underwent 18F-FDG PET/CT from June 2017 to September 2017 were selected.Simulated acquisition protocols for a specific range (upper margin of the skull to the lower edge of sciatic bone) were established with CBM and SS modes.The differences between 2 modes for actual length requiring for a specific acquisition range and the differences in CT radiation dose were compared.Real PET/ CT scans were performed using CBM and SS modes consecutively,and the differences in image quality and SUV were compared.Paired t test andx2 test were used to analyze the data.Results For the specific acquisition range,the average acquisition length of CBM was reduced by 6.65％ ((87.11 ± 3.78) vs (93.32 ±6.02) cm;t=-7.737,P＜0.001) and the CT radiation dose was reduced by 6.88％ ((812±170) vs (872±192) mGy · cm;t=-6.432,P＜0.001) for each patient compared with the results of SS.There were no significant differences in maximum SUV (SUVmax) and mean SUV (SUVmean) between SS and CBM in normal tissues including liver,bone and waist muscles (t values:from-1.895 to 0.132,all P＞0.05).The SUVmax of leg muscles at the end of the image was significantly higher in SS than that in CBM (1.24±0.53 vs 1.06±0.42;t=3.450,P＜0.01).There were no statistically significant differences in SUVmax and SUV between SS and CBM in 40 FDG high uptake lesions (t values:0.420 and-0.260,both P＞0.05).There were 73.33％ (22/30) patients had images with overall high quality during SS and the percentage was 80.00％ (24/30) during CBM (x2 =0.373,P＞0.05).The percentage of patients with images of high quality at the end was 16.67％(5/30) during SS,which was significantly less than that during CBM (63.33％,19/30;x2 =13.611,P＜0.001).Conclusions For the specific acquisition range,CBM can reduce unnecessary CT scan range and radiation dose compared with SS.There is no significant difference in image quality and SUV from normal tissue and lesion except for the end of the image.

Objective To explore the quantitative determination of standardized uptake value(SUV)of lumbar vertebra by 99Tcm-methylene diphosphonate(MDP)bone imaging with SPECT/CT.Methods A total of 90 patients(16 males,74 females,age:(60.0±11.2)years)who underwent 99Tcm-MDP bone imaging and local lumbar SPECT/CT imaging from May 2017 to November 2017 were retrospectively analyzed.CT attenuation correction,scatter correction and 3-dimensional ordered subset expectation maximization(3D-OSEM)reconstruction were used.The radioactive counts of lumbar vertebra LL-L4 in patients with high MDP-uptake(including degenerative changes and bone metastases)and patients with non-high MDP-uptake(including osteoporosis and non-osteoporosis)were measured.Basing on that,the radioactivity of unit volume in lumbar and lesion was calculated and converted to SUV.The difference of SUV for lumbar and lesions from different types of patients was analyzed,and the correlation between lumbar SUV and varies of parameters were also analyzed.Data were analyzed by two-sample t test and Pearson correlation analysis.Results The mean SUV(SUVmean)and maximum SUV(SUVmax)of L1-L4 in 54 patients with non-high MDP-uptake were 4.64±1.03 and 7.09±1.61 respectively.They were positively correlated with bone mineral content,CT value and body weight(r values:0.433-0.700,all P<0.05),and negatively correlated with age(r values;-0.514 and -0.456,both P<0.001).The SUVmean and SUVmax of patients with osteoporosis were 3.81±0.76 and 5.86±1.34 respectively,which were significantly lower than those of non-osteoporosis(5.13±0.84 and7.82±1.30;t values:-5.892 and-5.240,both P<0.001).The SUVmean and SUVmax of 37 metastases were 16.40±6.07 and 24.25±11.35 respectively in 16 patients,which were significantly higher than those in patients with degenerative changes(20 patients with 27 lesions;9.30±3.16 and 13.48±5.21;t values:6.074 and 5.083,both P<0.001).Conclusion Based on the specific reconstruction algorithm and correction method,the SUV of lumbar vertebra on 99Tcm-MDP SPECT/CT bone imaging can be obtained,and the bone mineral metabolism can be reflected.

Objective To evaluate the impact of 3-dimensional ordered subset expectation maximization (3D-OSEM),2-dimensional ordered subset expectation maximization (2D-OSEM),filtered-back projection (FBP),and the number of OSEM iterations and subsets on quantitative results in SPECT/CT.Methods A Jaszczak cylindrical phantom and NEMA/IEC body phantom were performed in routine SPECT/CT using CT attenuation correction,scatter correction and 3D-OSEM reconstructed image.The system volume sensitivity (cpm/kBq) was acquired from the reconstructed image of Jaszczak phantom,and the absolute activity concentration (kBq/ml) of the hot sphere from IEC phantom was calculated and compared with true activity concentration,then quantitative error was calculated.With changing the reconstruction algorithm (2D-OSEM,FBP) and OSEM reconstruction parameters (number of iterations and subsets) to reconstruct the IEC phantom,the differences of quantitative results from different reconstruction algorithms and OSEM iterations and subsets were compared.Results When reconstructing images with 3D-OSEM,2D-OSEM and FBP,the quantitative error of each sphere increased with the decrease of the spherical volume (r=-0.831,-0.831,-0.826,all P＜0.05).The quantitative error of different volume spheres among three reconstruction algorithms was statistically significant (F=8.850,P＜0.05).Among them,the result of 3D-OSEM was less than that of 2D-OS EM (P＜0.05),and of 2D-OSEM was less than of FBP (P＜0.05).The quantitative error of different volume spheres decreased with the increasing of number of iterations (r=-0.721,-0.681,-0.691,-0.711,-0.845,-0.893,all P＜0.05) and decreased with the increase of number of subsets (r=-0.670,-0.694,-0.717,-0.852,-0.956,-0.998,all P＜0.05).Conclusion The quantitative accuracy of 3D-OSEM reconstruction based on CT attenuation correction and scattering correction is significantly better than that of 2D-OSEM and FBP.Choosing the appropriate OSEM reconstruction parameters is helpful to improve the quantification accuracy in SPECT/CT.