Objective:In order to make up for the gap in the digital model of twins in the study of fetal radiation dosimetry, this study intends to construct a computational twins phantom based on low-dose CT images.Methods:The low-dose CT images of a pregnant patient were segmented by the combination of threshold automatic segmentation and manual segmentation, which were derived into stereolithography files. The maternal contour, fetal contour and bone structure were constructed using 3D modeling software, and the organ mass was adjusted according to the reference values of ICRP Publication 89 and WHO report after the organs were scaled on a specific scale.Results:The first set of Non-Uniform Rational B-Splines (NURBS) surface phantom of twins in China was established. The external contours, bones, size, position and posture of the phantom were completely consistent with those of the real human body. Each fetus had 25 organs or tissues. After optimization and adjustment, the relative deviation between the twin phantom and the reference value of organ mass was less than 10%.Conclusions:In this study, a personalized computational phantom of twins based on low-dose CT images is constructed, which fills the gap in the twin model. It is helpful in estimating the dose by the fetus from ionizing radiation received in the process of radiation diagnosis of pregnant women with twins.

BACKGROUNDTo investigate the indication, complication and efficacy of bronchial artery embolization for the management of lung cancer with massive hemoptysis.

METHODSThirty-eight cases of lung cancer with massive hemoptysis were retrospectively analyzed in our hospital from January 1996 to January 2003. All cases presented with acute hemoptysis from 220 to 980 ml daily, with a mean of 290 ml daily. A digital subtracted bronchial arteriogram was perfomed and bleeding arteries were embolized.

RESULTSHemoptysis decreased gradually in all cases and ceased in 3 or 4 days after embolization. Recurrence was found only in one case 2 months after embolization and second embolization was applied to control hemoptysis. No serious complications occured.

CONCLUSIONSBronchial artery embolization is safe and efficient for the management of lung cancer with massive hemoptysis.

Objective To investigate the relationship of programmed death ligand-1 (PD-L1) with clinicopathological characteristics,radiosensitivity and prognosis of the patients with esophageal squamous cell carcinoma(ESCC). Methods Ninety ESCC patients who received radical radiotherapy diagnosed by ESCC in Affiliated Hospital of North Sichuan Medical College were enrolled. Twenty cases of normal esophageal mucosa were used as the controls. The expression of PD-L1 was detected by using immunohistochemical SP method. Results The expression of PD-L1 protein was not correlated with age, gender, the maximum diameter of tumor, the length of lesion, the local aggressive of tumor, clinical stage and primary tumor volume (all P> 0.05). However, it was statistically correlated with the lymphatic metastasis (χ2= 4.404, P= 0.036). Meanwhile, PD-L1 positive expression was sensitive to radiation(χ2=4.888, P< 0.05). Single factor analysis showed that the maximum diameter of tumor and radiosensitivity were correlated with progression-free survival (PFS) (χ2=6.239,P =0.013;χ2=6.852,P =0.008; χ2= 6.312, P= 0.012) and overall survival (OS) (χ2=8.170, P = 0.004; χ 2= 4.261, P = 0.039; χ2= 5.003, P= 0.025) of ESCC patients. Multifactor analysis showed that the radiosensitivity and the maximum diameter of tumor affected PFS (OR= 0.512, 95 % CI 0.275-0.954, P= 0.035) and OS (OR= 0.507, 95 % CI 0.266-0.968, P= 0.039) in ESCC patients, respectively.Conclusions The level of PD-L1 expression is increased significantly in ESCC tissues compared with the normal esophageal mucosa tissues. PD-L1 may be a novel biomarker for predicting metastatic potential and radiosensitivity in ESCC patients, rather than the prognosis predictors of ESCC patients treated by radiotherapy.

Objective: To quantitatively assess biochemical alterations in the cartilage of the subtalar and midtarsal joints in chronic lateral ankle instability (CLAI) patients with isolated anterior talofibular ligament (ATFL) injuries and combined calcaneofibular ligament (CFL) injuries using MRI T2 mapping. Materials and Methods: This study was performed according to regulations of the Committee for Human Research at our institution, and written informed consent was obtained from all participants. Forty CLAI patients (26 with isolated ATFL injuries and 14 with combined ATFL and CFL injuries) and 25 healthy subjects were recruited for this study. All participants underwent MRI scans with T2 mapping. Patients were assessed with the American Orthopedic Foot and Ankle Society (AOFAS) rating system. The subtalar and midtarsal joints were segmented into 14 cartilage subregions. The T2 value of each subregion was measured from T2 mapping images. Data were analyzed with ANOVA, the Student’s t test, and Pearson’s correlation coefficient. Results: T2 values of most subregions of the subtalar joint and the calcaneal facet of the calcaneocuboid joint in CLAI patients with combined CFL injuries were higher than those in healthy controls (all p < 0.05). However, there were no significant differences in T2 values in subtalar and midtarsal joints between patients with isolated ATFL injuries and healthy controls (all p > 0.05). Moreover, T2 values of the medial talar subregions of the posterior subtalar joint in patients with combined CFL injuries showed negative correlations with the AOFAS scores (r = -0.687, p = 0.007; r = -0.609, p = 0.021, respectively). Conclusion CLAI with combined CFL injuries can lead to cartilage degeneration in subtalar and calcaneocuboid joints, while an isolated ATFL injury might not have a significant impact on the cartilage in these joints.

Objective To study the portal venous systemic thrombosis (PVST) in early acute pancreatitis (AP) and its correlations with the classification and severity of AP. Methods A total of 396 patients with AP were admitted to the affiliated hospital of north sichuan medical college from January 2013 to May 2017 and underwent MRI in the early stage of AP. PVST was evaluated on the T1WI, T2WI fat-suppression, and dynamic-enhancement sequences. Evaluating the MR imaging, AP was graded as mild, moderate, and severe AP based on the MR severity index (MRSI) and was also classified into interstitial edematous AP and necrotizing AP. According to the New Revised Classification of AP 2012, AP in the clinic setting was graded as mild, moederately severeand severe AP. χ2 test or Fisher exact test calculated the differences of the prevalence of PVST in different severity and classification of AP, Mann-Whitney U test calculated the difference of hospitalization time between patients with PVST and those without PVST. Results Among the 396 patients with AP, PVST was detected in 30 patients (7.5％,30/396), it formed most frequently in splenic vein(73.3％, 22/30), followed by portal (30.0％, 9/30) and superior mesenteric(16.7％, 5/30) veins. According to MRSI, there were 205, 177, and 14 patients with mild, moderate, and severe AP, respectively;among mild, moderate, and severe AP, there were 2, 21, and 7 patients with PVST, respectively (χ2=41.455, P<0.01), there were also statistical differences in the prevalence of portal and splenic vein thrombosis (P<0.05), but there was no statistical difference in the prevalence of superior mesenteric vein thrombosis (P>0.05). Three hundred and eleven patients had interstitial edematous AP and 65 patients had necrotizing AP, among which there were 11 and 19 patients with PVST(χ2=48.447,P<0.01), the prevalence of portal, splenic and superior mesenteric vein thrombosis in necrotizing AP were all higher than that in interstitial edematous AP (P<0.05). Based on the New Revised Classification of AP 2012, there were 194, 184 and 18 patients with mild, moderately severe, and severe AP, respectively; among mild, moderately severe, and severe AP, there were 0, 25, and 5 patients with PVST, respectively (χ2=42.130, P<0.01), there was no statistical differences in the prevalence of portal, splenic and superior mesenteric vein thrombosis (P>0.05). Patients with PVST and those without PVST in the early AP, the hospitalization time [median (interquartile range)] were 18 (13 to 22) days and 13 (10 to 19) days (Z=-2.913, P=0.004). Conclusion PVST in early AP presented more frequently with the increase in severity of AP based on both the MRSI and Newly Revised Classification of AP 2012, along with longer duration ofhospitalization.

The radiation risk caused by CT examination is of great concern. Organ dose is considered to be the most significant technical parameter for quantifying the patient radiation dose and assessing the corresponding risk. At present, the methods to obtain patient organ dose caused by CT examination mainly include physical phantom measurement, direct human body measurement, dose conversion coefficient, Monte Carlo simulation, and dose calculation software. Although different methods have their own characteristics and application, the individualization of organ dose is always the goal of radiation protection and dosimetry research. Patient-specific phantom developed with artificial intelligence and GPU-accelerated Monte Carlo simulation make it possible to calculate the patient-specific organ dose, and the patient-specific organ dose extrapolated by the CT detector signal provides a new solution.