ObjectiveTo discuss the value of dual-source CT Flash scanning in reducing the dose of radiation in 3D cardiac imaging.
MethodWe collected 60 patients from March to August 2014 who should undergo cardiac 3D CT scanning before radiofrequency ablation. They were randomly divided into group A and B with 30 in each. Patients in group A underwent flash technology scanning, while those in group B accepted conventional retrospective electrocardiography-gated scanning. CARE Dose techniques were used to collect data. Scanning parameters were the same for both groups:collimation was 128×0.6 mm, reconstruction thickness was 0.75 mm, reconstruction interval was 0.7 mm, and field of view was 180-200 mm. After image acquisition, we measured the CT values and noise of left atrium and various branches of the pulmonary veins (upper left, lower left, upper right, and lower right). Statistical software was used for the two groups of images to analyze the carrier noise ratio (CNR), signal noise ratio (SNR), blinded scores, computed tomography dose index (CTDIvol), and dose-length product (DLP) of the left atrium and pulmonary vein.
ResultsCNR and SNR of the left atrium and various pulmonary veins between the two groups had no significant differences (P>0.05) . Blinded scores between the two groups were not significantly different (P>0.05) . CTDIvol in group A and group B was respectively (2.92±0.38) and (20.15±12.09) mGy, with a significant difference (t=?7.803, P<0.001) . DLP of group A was (59.30±6.67) mGy·cm, significantly lower than that in group B [(334.43±216.71) mGy·cm] (t=?6.591, P<0.001) . Flash-efficient radiation dose was (0.83±0.94) mSv in group A, far below that in group B [(4.53±3.03) msv], and the difference was statistically significant (t=?6.684, P<0.001) .
ConclusionsDual-source CT Flash technology applied in 3D cardiac scanning can reduce radiation dose as well as meet the needs of image diagnosis.
The dose data produced by treatment plan system (TPS) in intensity-modulated radiation therapy (IMRT) has many gradient edge points. Considering this feature we proposed a new interpolation algorithm called treatment plan dose interpolation algorithm based on gradient feature in intensity-modulated radiation therapy (TDAGI), which improves the Canny algorithm to detect the gradient edge points and non-edge points by using the gradient information in the dose data plane. For each gradient edge point, the corresponding gradient profile was traced and the profile's sharpness was calculated, and for each non-edge point, the dispersion was calculated. With the sharpness or dispersion, the kernel coefficients of bi-cubic interpolation can be obtained and can be used as the central point to complete the bi-cubic interpolation calculation. Compared with bi-cubic interpolation and bilinear interpolation, the TDAGI algorithm is more accurate. Furthermore, the TDAGI algorithm has the advantage of gradient keeping. Therefore, TDAGI can be used as an alternative method in the dose interpolation of TPS in IMRT.
【Abstract】Objective To research relation of apoptosis muscular cell in 103Pd radioactive stent of dog biliary muscular formation and inhibition of biliary ductal stricture. Methods Twelve dogs were randomly divided into two groups, which were general stent group and 103Pd radioactive stent group. General stent and 103Pd radioactive stent were respectively put into extrahepatic biliary tract of two groups. After 30 days all dogs were killed, and biliary tract were taken out. Apoptotic cells were detected by immunohistochemical methodsand agar electrophoresis, and nucleus browyellow was positive cell. Dog biliary duct cross-sections were stained by hematoxylin-erosin; area and perimeter of lumen,thickness of inner membrane and stenosis degree in bile duct were analysed by image analysis software of computer.Results The apoptotic biliary duct smooth muscle cell ［(87.9±7.96)/cm2］ was more significantly increased in the 103Pd radioactive stent group than in the general stent group ［(5.6±0.51)/cm2］, P＜0.05; and comparing with the general stent group, the 103Pd radioactive stent significantly reduced biliary muscular formation thickness. Conclusion The result shows that 103Pd radioactive stent can inhibit proliferation of biliary ductal smooth muscle cell.
ObjectiveTo investigate the synergistic antitumor effects of ionizing radiation and the cytosine deaminase (CD)/5-flurocytosine (5-FC) system therapy in human pancreatic cancer cell.MethodsThe expression vector containing CD was transfected into the human pancreatic cancer cell line PC3. The clones were picked out after G418 selection. The CD gene integration and expression were confirmed by the RT-PCR. The cytotoxicity to the cells with or without CD and (or) ionizing radiation under the treatment with 5-FC was measured by the MTT assay. The clonogenic assay was used to investigate the radiosensitizing effect of 5-FC on the PC3 cells transfected or untransfected with CD gene.ResultsThe CD gene was stably expressed in the PC3 cells transfected with CD gene. The cytotoxic effect of 5-FC was superior on the PC3 cells transfected than that of untransfected with CD gene (P<0.05) and which were enhanced in combination with the ionizing radiation (P<0.05). The CD/5-FC enhanced the radiosensitivity of PC3 cells transfected with CD gene (P<0.05). The change in the radiosensitivity was quantified by calculating the sensitization enhancement ratio (SER) at the clinically relevant dose of 2 Gy. The SER was 1.5 in the PC3 cells transfected with CD gene by giving ionizing radiation of 2 Gy.ConclusionsCD/5-FC system is a potenial radiosensitizer in PC3 cells transfected with CD gene. Ionizing radiation and CD/5-FC system is more effective for killing effect of PC3 cells than ionizing radiation or CD/5-FC system alone.
ObjectiveTo investigate the diagnostic value of CT-derived fractional flow reserve (CT-FFR) and fat attenuation index (FAI) based on artificial intelligence-assisted diagnostic software in coronary artery stenosis. MethodsA retrospective analysis was conducted on patients clinically suspected of coronary artery syndrome who underwent coronary computed tomography angiography at Guangdong Province Traditional Chinese and Western Medicine Hospital between June 2021 and May 2025. Patients were divided into two groups according to scanning protocols: group A underwent conventional retrospective electrocardiography-gated scanning, while group B used Flash_ChestPlin mode. Invasive coronary angiography data served as the gold standard for diagnosing vascular stenosis (stenosis rate<50% defined as negative group, ≥50% with clinical symptoms as positive group). Radiation dose was compared between the two scanning protocols. The diagnostic efficacy of CT-FFR, pericoronary FAI, and transluminal attenuation gradient (TAG) based on artificial intelligence system for coronary stenosis was analyzed, including sensitivity, specificity, and area under the curve (AUC). ResultsA total of 567 vessels from 189 patients were analyzed, including 105 males, 84 females with a mean age of (62.5±12.3) years and a mean body mass index of (24.21±3.5) kg/m2. There were 112 patients in the group A and 77 patients in the group B. The radiation dose in the group B was significantly lower than that in the group A [69.7 (58.1, 84.1) mGy·cm vs. 420.4 (338.6, 514.2) mGy·cm, P<0.001]. Significant differences in FAI and CT-FFR were observed between negative and positive groups under both scanning protocols (P<0.05), while no significant difference existed in TAG (P>0.05). In the group A, the AUC values for diagnosing stenosis were 0.925 for CT-FFR, 0.610 for FAI, and 0.516 for TAG. Corresponding values in the group B were 0.889, 0.677, and 0.548 respectively, with CT-FFR demonstrating optimal diagnostic performance. ConclusionUnder both conventional scanning and Flash scanning, the artificial intelligence-based CT-FFR demonstrates good diagnostic performance for coronary artery stenosis, and the Flash protocol significantly lowers radiation dose, indicating substantial potential for clinical application.
The Monte Carlo N-Particle (MCNP) is often used to calculate the radiation dose during computed tomography (CT) scans. However, the physical calculation process of the model is complicated, the input file structure of the program is complex, and the three-dimensional (3D) display of the geometric model is not supported, so that the researchers cannot establish an accurate CT radiation system model, which affects the accuracy of the dose calculation results. Aiming at these two problems, this study designed a software that visualized CT modeling and automatically generated input files. In terms of model calculation, the theoretical basis was based on the integration of CT modeling improvement schemes of major researchers. For 3D model visualization, LabVIEW was used as the new development platform, constructive solid geometry (CSG) was used as the algorithm principle, and the introduction of editing of MCNP input files was used to visualize CT geometry modeling. Compared with a CT model established by a recent study, the root mean square error between the results simulated by this visual CT modeling software and the actual measurement was smaller. In conclusion, the proposed CT visualization modeling software can not only help researchers to obtain an accurate CT radiation system model, but also provide a new research idea for the geometric modeling visualization method of MCNP.
Objective To analyze the stabil ity and cl inical outcomes of arthroscopic anterior cruciate l igament (ACL) reconstruction with γ irradiated patellar tendon allograft compared with autograft. Methods From January 2004 to October 2007, 69 patients undergoing arthroscopic ACL reconstruction were prospectively randomized consecutively into two groups: group A (autograft, n=36) and group B (γ irradiated allograft, n=33). In group A, there were 30 males and 6 females with an average age of 30.1 years, including 30 cases of simple ACL rupture and 6 cases of ACL rupture with medial accessory l igament injury; ACL rupture was caused by sports in 28 cases, by traffic accident in 5 cases, and by others in 3 cases; and the time from injury to operation was 1.4 months on average. In group B, there were 26 males and 7 femaleswith an average age of 32.5 years, including 27 cases of simple ACL rupture and 6 cases of ACL rupture with medial accessory l igament injury; ACL rupture was caused by sports in 27 cases, by traffic accident in 4 cases, and by others in 2 cases; and the time from injury to operation was 1.5 months on average. There were no significant differences in general data between two groups (P gt; 0.05). The same arthroscopic technique was used in all ACL reconstructions done by the same surgeon. The cl inical outcome was evaluated and compared by general conditions, pivot shift test, Lachman test, KT-2000 arthrometer testing, Daniel’s one-leg hop test, International Knee Documental Committee (IKDC) scoring, Lysholm knee scoring scale, and Tegner activity score. Results All patients were followed up for 39.5 months (group A) and 37.6 months (group B). In group A, patella fracture occurred in 1 case and anterior knee pain in 2 cases postoperatively. No compl ication occurred in group B. The hospital ization times in groups A and B were (15.6 ± 2.4) days and (15.5 ± 1.5) days, respectively, showing no significant difference (P gt; 0.05). The operation time of group A was longer than that of group B and the fever time of group A was shorter than that of group B, showing significant differences (P lt; 0.05). At the final follow-up, there were significant differences (P lt; 0.05) in Lachman test and the pivot shift test between two groups, between pre- and post-operation; there were no significant differences (P gt; 0.05) in Daniel’s one-leg hop test, the IKDC, Lysholm, and Tegner activity scores between two groups, however, there was a decreased trend in the functional and activity levels in group B. And there was significant difference between pre- and post-operation (P lt; 0.05). At the final follow-up, the differences between normal side and affected side were (2.4 ± 0.6) mm in group A and (5.5 ± 3.6) mm in group B, showing significant difference (P lt; 0.05). There was significant difference in tibial advancement between pre- and post-operation (P lt; 0.05). Conclusion The functional and activity level of the knee after ACL reconstruction with autograft and γ irradiated patellar tendon allograft were similar, but anterior and rotational stabil ity of the involved knee decreases significantly in the group with γ irradiated patellar tendon allograft.
ObjectiveTo compare the clinical therapeutic efficacy of radiofrequency ablation (RFA) and external beam radiation (XRT) in the treatment of early hepatocellular carcinoma (HCC). MethodsThe early HCC patients were collected in the SEER (Surveillance, Epidemiology, and End Results) database, from 2010 to 2015, according to the established inclusion and exclusion criteria. The patients were assigned into an XRT group and a RFA group according to according treatment plans. The propensity score matching (PSM) was performed at a ratio of 1∶4 based on age, gender, race, alpha-fetoprotein (AFP), cirrhosis, and tumor diameter. The overall survival of the patients of the two groups was compared, and the risk factors affecting the long-term prognosis for the early HCC patients were analyzed. ResultsA total of 2 861 early HCC patients were collected, including 2 513 in the RFA group and 348 in the XRT group. After PSM, a total of 1 582 patients were enrolled, including 343 in the XRT group and 1 239 in the RFA group. After PSM, the proportion of tumor with larger diameter (>5 cm) in the XRT group was still higher than that in the RFA group (P<0.001), but there were no statistically significant differences in the other clinical pathological characteristics between them (P>0.05). The Kaplan-Meier survival curves of the RFA group was better than that of the XRT group (HR=1.65, P<0.001); The stratified analysis based on the tumor diameter revealed that the survival curves of the RFA group were superior to those of the XRT group in the HCC patients with tumor diameters <3 cm, 3–5 cm, and >5 cm (<3 cm: HR=1.79, P<0.001; 3–5 cm: HR=1.50, P<0.001; >5 cm: HR=1.67, P=0.003). The results of the multivariate Cox regression model analysis showed that the older age (≥65 years), higher AFP level (≥400 μg/L), larger tumor diameter (≥3 cm), and later AJCC stage (stage Ⅱ) were the risk factors for overall survival in the early HCC patients (HR>1, P<0.05), while the XRT treatment was a risk factor for shortening overall survival in the HCC patients [HR(95%CI)=1.62(1.41, 1.86), P<0.001]. ConclusionThe data analysis results from the SEER database suggest that the long-term overall survival of RFA treatment is superior to XRT treatment for patients with AJCC stage Ⅰ or Ⅱ.
ObjectiveTo systematically summarize recent advancements in the application of artificial intelligence (AI) in key components of radiotherapy (RT), explore the integration of technical innovations with clinical practice, and identify current limitations in real-world implementation. MethodsA comprehensive analysis of representative studies from recent years was conducted, focusing on the technical implementation and clinical effectiveness of AI in image reconstruction, automatic delineation of target volumes and organs at risk, intelligent treatment planning, and prediction of RT-related toxicities. Particular attention was given to deep learning models, multimodal data integration, and their roles in enhancing decision-making processes. ResultsAI-based low-dose image enhancement techniques had significantly improved image quality. Automated segmentation methods had increased the efficiency and consistency of contouring. Both knowledge-driven and data-driven planning systems had addressed the limitations of traditional experience-dependent approaches, contributing to higher quality and reproducibility in treatment plans. Additionally, toxicity prediction models that incorporated multimodal data enabled more accurate, personalized risk assessment, supporting safer and more effective individualized RT. ConclusionsRT is a fundamental modality in cancer treatment. However, achieving precise tumor ablation while minimizing damage to surrounding healthy tissues remains a significant challenge. AI has demonstrated considerable value across multiple technical stages of RT, enhancing precision, efficiency, and personalization. Nevertheless, challenges such as limited model generalizability, lack of data standardization, and insufficient clinical validation persist. Future work should emphasize the alignment of algorithmic development with clinical demands to facilitate the standardized, reliable, and practical application of AI in RT.
Liver computed tomography (CT) perfusion is a noninvasive imaging technology which can quantitatively investigate liver function, and it is mainly used in the diagnosis of liver tumors and assessment of liver function in the state of chronic liver diseases. The use of liver CT perfusion was limited in the past because of the high radiation dose. Now new technologies are exploited and they make it possible to reduce the radiation burden while maintaining the imaging quality. This article discusses the research progress of low radiation dose CT perfusion in 3 aspects, including X-ray source, reconstruction algorithm, and improvement of CT scanners and optimization of scanning parameters. Although there are not too many studies of low radiation dose CT perfusion on liver now and many problems need to be solved, the clinical application of it will be very prospective.
