Investigating the elliptic anisotropy of identified particles in p-Pb collisions with a multi-phase transport model

The elliptic azimuthal anisotropy coefficient(v_(2))of the identified particles at midrapidity(|η|<0.8)was investigated in p-Pb collisions at√s_(NN)=5.02 TeV using a multi-phase transport model(AMPT).The calculations of differential v_(2)based on the advanced flow extraction method of light flavor hadrons(pions,kaons,protons,andΛ)in small collision systems were extended to a wider transverse momentum(p_(T))range of up to 8 GeV/c for the first time.The string-melting version of the AMPT model provides a good description of the measured p_(T)-differential v_(2)of the mesons but exhibits a slight deviation from the baryon v_(2).In addition,we observed the features of mass ordering at low p_(T)and the approximate number-of-constituentquark(NCQ)scaling at intermediate p_(T).Moreover,we demonstrate that hadronic rescattering does not have a significant impact on v_(2)in p-Pb collisions for different centrality selections,whereas partonic scattering dominates in generating the elliptic anisotropy of the final particles.This study provides further insight into the origin of collective-like behavior in small collision systems and has referential value for future measurements of azimuthal anisotropy.

Computed tomography-based nomogram of Siewert type Ⅱ/Ⅲ adenocarcinoma of esophagogastric junction to predict response to docetaxel, oxaliplatin and S-1

BACKGROUND Neoadjuvant chemotherapy(NAC)has become the standard care for advanced adenocarcinoma of esophagogastric junction(AEG),although a part of the patients cannot benefit from NAC.There are no models based on baseline computed tomography(CT)to predict response of Siewert type II or III AEG to NAC with docetaxel,oxaliplatin and S-1(DOS).AIM To develop a CT-based nomogram to predict response of Siewert type II/III AEG to NAC with DOS.METHODS One hundred and twenty-eight consecutive patients with confirmed Siewert type II/III AEG underwent CT before and after three cycles of NAC with DOS,and were randomly and consecutively assigned to the training cohort(TC)(n=94)and the validation cohort(VC)(n=34).Therapeutic effect was assessed by disease-control rate and progressive disease according to the Response Evaluation Criteria in Solid Tumors(version 1.1)criteria.Possible prognostic factors associated with responses after DOS treatment including Siewert classification,gross tumor volume(GTV),and cT and cN stages were evaluated using pretherapeutic CT data in addition to sex and age.Univariate and multivariate analyses of CT and clinical features in the TC were performed to determine independent factors associated with response to DOS.A nomogram was established based on independent factors to predict the response.The predictive performance of the nomogram was evaluated by Concordance index(C-index),calibration and receiver operating characteristics curve in the TC and VC.RESULTS Univariate analysis showed that Siewert type(52/55 vs 29/39,P=0.005),pretherapeutic cT stage(57/62 vs 24/32,P=0.028),GTV(47.3±27.4 vs 73.2±54.3,P=0.040)were significantly associated with response to DOS in the TC.Multivariate analysis of the TC also showed that the pretherapeutic cT stage,GTV and Siewert type were independent predictive factors related to response to DOS(odds ratio=4.631,1.027 and 7.639,respectively;all P<0.05).The nomogram developed with these independent factors showed an excellent performance to predict response to DOS in the TC and VC(C-index:0.838 and 0.824),with area under the receiver operating characteristic curve of 0.838 and 0.824,respectively.The calibration curves showed that the practical and predicted response to DOS effectively coincided.CONCLUSION A novel nomogram developed with pretherapeutic cT stage,GTV and Siewert type predicted the response of Siewert type II/III AEG to NAC with DOS.

Current research status of transarterial therapies for hepatocellular carcinoma

With continuous advancements in interventional radiology,considerable progress has been made in transarterial therapies for hepatocellular carcinoma(HCC)in recent years,and an increasing number of research papers on transarterial therapies for HCC have been published.In this editorial,we comment on the article by Ma et al published in the recent issue of the World Journal of Gastrointestinal Oncology:“Efficacy and predictive factors of transarterial chemoembolization combined with lenvatinib plus programmed cell death protein-1 inhibition for unresectable HCC”.We focus specifically on the current research status and future directions of transarterial therapies.In the future,more studies are needed to determine the optimal transarterial local treatment for HCC.With the emergence of checkpoint immunotherapy modalities,it is expected that the results of trials of transarterial local therapy combined with systemic therapy will bring new hope to HCC patients.

Pt_(x)Cu_(y)/C电催化剂甲醇氧化反应性能及机理研究

直接甲醇燃料电池(DMFC)是一种将甲醇燃料的化学能直接转化为电能的能量转换装置,具有能量转化效率高、环境友好、燃料来源丰富等优势,在移动电源等领域具有广泛应用前景,但阳极铂基电催化剂的性能及成本制约着DMFC的发展。本论文通过简单的液相浸渍还原法,制备了系列PtCu/C纳米电催化剂,电化学性能测试结果表明,电催化剂对甲醇氧化反应(MOR)活性顺序为商品Pt/C<Pt_(3)Cu/C<PtCu_(4)/C<PtCu/C<PtCu_(3)/C,且活性最高的PtCu_(3)/C电催化剂表现出较为优异的电化学稳定性。结合物相表征、电化学测试及DFT计算,阐释了PtCu_(3)/C催化剂中存在的少量CuO相能够促进水分子解离产生*OH,通过双功能机制促进类CO反应中间物种氧化为CO_(2)。因此,相比于商品Pt/C,虽然PtCu_(3)/C电催化剂的ECSA不足其一半,但质量比活性和面积比活性分别提高1.88倍和3.74倍。

Advanced imaging techniques in the therapeutic response of transarterial chemoembolization for hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the major causes of morbidity and mortality in patients with chronic liver disease. Transarterial chemoembolization(TACE) can significantly improve the survival rate of patients with HCC and is the first treatment choice for patients who are not suitable for surgical resections. The evaluation of the response to TACE treatment affects not only the assessment of the therapy efficacy but also the development of the next step in the treatment plan. The use of imaging to examine changes in tumor volume to assess the response of solid tumors to treatment has been controversial. In recent years, the emergence of new imaging technology has made it possible to observe the response of tumors to treatment prior to any morphological changes. In this article, the advances in studies reporting the use of computed tomography perfusion imaging, diffusionweighted magnetic resonance imaging(MRI), intravoxel incoherent motion, diffusion kurtosis imaging, magnetic resonance spectroscopy, magnetic resonance perfusionweighted imaging, blood oxygen level-dependent MRI, positron emission tomography(PET)/computed tomography and PET/MRI to assess the TACE treatment response are reviewed.

Platelet count combined with right liver volume and spleen volume measured by magnetic resonance imaging for identifying cirrhosis and esophageal varices

AIM: To determine whether the combination of platelet count(PLT) with spleen volume parameters and right liver volume(RV) measured by magnetic resonance imaging(MRI) could predict the Child-Pugh class of liver cirrhosis and esophageal varices(EV).METHODS: Two hundred and five cirrhotic patients with hepatitis B and 40 healthy volunteers underwent abdominal triphasic-enhancement MRI and laboratory examination of PLT in 109/L. Cirrhotic patients underwent endoscopy for detecting EV. Spleen maximal width(W), thickness(T) and length(L) in mm together with spleen volume(SV) and RV in mm3 were measured by MRI, and spleen volume index(SI) in mm3 was obtained by W × T × L. SV/PLT, SI/PLT and RV × PLT/SV(RVPS) were calculated and statistically analyzed to assess cirrhosis and EV.RESULTS: SV/PLT(r = 0.676) and SI/PLT(r = 0.707) increased, and PLT(r =-0.626) and RVPS(r =-0.802) decreased with the progress of Child-Pugh class(P < 0.001 for all). All parameters could determine the presence of cirrhosis, distinguish between each class of Child-Pugh class, and identify the presence of EV [the areas under the curve(AUCs) = 0.661-0.973]. A m o n g p a ra m e t e r s, R V P S c o u l d b e s t d e t e r m i n e presence and each class of cirrhosis with AUCs of 0.973 and 0.740-0.853, respectively; and SV/PLT could best identify EV with an AUC of 0.782.CONCLUSION: The combination of PLT with SV and RV could predict Child-Pugh class of liver cirrhosis and identify the presence of esophageal varices.

Acute interstitial edematous pancreatitis:Findings on non-enhanced MR imaging

AIM： To study the appearances of acute interstitial edematous pancreatitis （IEP） on non-enhanced MR imaging. METHODS： A total of 53 patients with IEP diagnosed by clinical features and laboratory findings were underwent MR imaging. MR imaging sequences included fast spoiled gradient echo （FSPGR） fat saturation axial T1-weighted imaging, gradient echo T1-weighted （in phase）, single shot fast spin echo （SSFSE） T2-weighted, respiratory triggered （R-T） T2-weighted with fat saturation, and MR cholangiopancreatography. Using the MR severity score index, pancreatitis was graded as mild （0-2 points）, moderate （3-6 points） and severe （7-10 points）. RESULTS： Among the 53 patients, IEP was graded as mild in 37 patients and as moderate in 16 patients. Forty-seven of 53 （89%） patients had at least one abnormality on MR images. Pancreas was hypointense relative to liver on FSPGR T1-weighted images in 18.9% of patients, and hyperintense in 25% and 30% on SSFSE T2-weighted and R-T T2-weighted images, respectively. The prevalences of the findings of IEP on R-T T2-weighted images were, respectively, 85% for pancreatic fascial plane, 77% for left renal fascial plane, 55% for peripancreatic fat stranding, 42% for right renal fascial plane, 45% for perivascular fluid, 40% for thickened pancreatic Iobular septum and 25% for peripancreatic fluid, which were markedly higher than those on in-phase or SSFSE T2-weighted images （P 〈 0.001）. CONCLUSION： IEP primarily manifests on non- enhanced MR images as thickened pancreatic fascial plane, left renal fascial plane, peripancreatic fat stranding, and peripancreatic fluid. R-T T2-weighted imaging is more sensitive than in-phase and SSFSE T2- weighted imaging for depicting IER

Albumin and magnetic resonance imaging-liver volume to identify hepatitis B-related cirrhosis and esophageal varices

AIM:To investigate whether liver lobe volume and albumin(ALB) could predict the presence and severity of liver cirrhosis,and esophageal varices.METHODS:Seventy-one cirrhotic patients with hepatitis B and 21 healthy individuals were enrolled in this study.All the participants underwent abdominal enhanced magnetic resonance imaging to measure each liver lobe volume,and biochemical workup for testing ALB and Child-Pugh class.All cirrhotic patients underwent upper gastrointestinal endoscopy to show the presence of cirrhotic esophageal varices.Right liver lobe volume(RV),left medial liver lobe volume(LMV),left lateral liver lobe volume(LLV),and caudate lobe volume(CV) were measured using enhanced magnetic resonance imaging.The ratios of RV to ALB(RV/ALB),LMV to ALB(LMV/ALB),LLV to ALB(LLV/ALB) and CV to ALB(CV/ALB) were calculated.Statistical analyses were performed to determine whether and how the combination of liver lobe volume measured using magnetic resonance imaging and albumin could predict the presence and severity of liver cirrhosis,and the presence of esophageal varices.RESULTS:RV,LMV,LLV and CV decreased(r =-0.51-0.373; all P < 0.05),while RV/ALB increased(r = 0.424; P < 0.05),with the progress of Child-Pugh classof liver cirrhosis.RV,LMV,CV,LLV/ALB and CV/ALB could identify presence of liver cirrhosis; LLV and LMV could distinguish Child-Pugh class A from B; RV,LMV,LLV,CV,RV/ALB and LLV/ALB could distinguish class A from C; RV and LLV/ALB could differentiate B from C; and RV,RV/ALB and CV/ALB could identify presence of esophageal varices(all P < 0.05).Among these parameters,CV/ALB could best identify the presence of liver cirrhosis,with an area under receiver operating characteristic curve(AUC) of 0.860,a sensitivity of 82.0% and a specificity of 83.0%.LLV could best distinguish class A from B,with an AUC of 0.761,a sensitivity of 74.4% and a specificity of 73.1%.RV could best distinguish class A from C,with an AUC of 0.900,a sensitivity of 90.3% and a specificity of 84.5%.LLV/ALB could best distinguish class B from C,with an AUC of 0.900,a sensitivity of 93.8% and a specificity of 81.5%.RV/ALB could best identify esophageal varices,with an AUC of 0.890,a sensitivity of 80.0% and a specificity of 83.5%.CONCLUSION:The combination of liver lobe volume and ALB has potential to identify presence and severity of cirrhosis,and presence of esophageal varices.

Renal Protective Activity of Hsian-tsao Extracts in Diabetic Rats

Objective To investigate the renal protective activity of Hsian-tsao Mesona procumbens Hemsl. water extracts in diabetic rats. Methods Thirty Sprague-dawley female rats were randomly divided into three groups （n=10 each）, ＂control group＂ with intraperitoneal saline injection, ＂diabetic group＂ with 60 mg of intraperitoneal streptozotocin injection per kg of body weight and ＂Hsian-tsao group＂ with intragastric administration of Hsian-tsao extraction everyday for 4 weeks after intraperitoneal streptozotocin injection. The body weight and blood sugar were measured before and after model induction in the three groups. Thrombospondin-1 （TSP-1） expressions in the kidney were monitored by immunohistochemistry. Kidney ultrastructural changes were also analyzed by using transmission electron microscopy. Results Before diabetic model induction, there were no significant differences among the three groups in body weight and blood sugar. Four weeks after the induction of diabetes, the differences became statistically significant. Electron microscopy also revealed disruption of the foot processes of the podocytes and other damages in diabetic group. These damages were significantly less severe in Hsian-tsao group when compared with the diabetic group. TSP-1 expressions in the kidney were significantly increased in both the diabetic group and Hsian-tsao group, but it was relatively lower in Hsian-tsao group than in diabetic group. Conclusion Our results showed that Hsian-tsao treatment in the diabetic rats effectively prevented the pathological alterations in the kidney and decreased the TSP- 1 expression. It was suggested that Hsian-tsao had protective effect on the kidneys of the diabetic rats.

The association between frailty of older stroke patients during hospitalization and one-year all-cause mortality:A multicenter survey in China

Objective:Frailty is a common geriatric syndrome defined as multiple deficits,impairing the capacity to figure out insult.Previous studies have reported a significant association between frailty and mortality in stroke patients.This study aimed to explore the association between frailty and mortality among older Chinese stroke patients.Methods:This study was a secondary analysis of a multicenter prospective cohort study conducted in older Chinese inpatients from October 2018 to February 2020,and patients with a primary diagnosis of stroke including hemorrhage and ischemia,were included in our study.Frailty of older inpatients with stroke from six hospitals was measured by the FRAIL scale,and a one-year follow-up was performed by well-trained nurses of these hospitals via telephone.Multivariable logistic regression was used to detect the association between frailty and one-year mortality.Results:A total of 530 stroke patients with an average age of 72.94(SD¼5.79)years were included in the present study.There were 37(7.0%)hemorrhagic strokes and 493(93.0%)ischemic strokes,with 228(43.0%)females in this population.The prevalence of frailty was 22.5%.In the logistic regression model with adjustment for age,sex,instrumental activities of daily living(IADL),basic activities of daily living(ADL),education,history of falls,BMI,smoking,alcohol consumption,low handgrip strength,type of stroke and polypharmacy,stroke patients with frailty had an increased risk of one-year mortality compared to those without frailty(OR¼3.38,95%CI:1.22e9.37,P¼0.019).Conclusion:Our study indicated that frailty was an independent risk factor for one-year all-cause mor-tality among older stroke patients in China.Frailty may be an essential factor for clinicians to consider before making a comprehensive treatment,and corresponding mixed interventions,including exercise training and nutritional programs,need to be conducted among older stroke patients.

GCH1 plays a role in the high-altitude adaptation of Tibetans

Tibetans are welt adapted to high-altitude hypoxia. Previous genome-wide scans have reported many candidate genes for this adaptation, but only a few have been studied. Here we report on a hypoxia gene （GCH1, GTP-cyclohydrolase I）, involved in maintaining nitric oxide synthetase （NOS） function and normal blood pressure, that harbors many potentially adaptive variants in Tibetans. We resequenced an 80.8 kb fragment covering the entire gene region of GCH1 in 50 unrelated Tibetans Combined with previously published data, we demonstrated many GCHI variants showing deep divergence between highlander Tibetans and lowlander Han Chinese. Neutrality tests confirmed a signal of positive Darwinian selection on GCH1 in Tibetans. Moreover, association analysis indicated that the Tibetan version of GCH1 was significantly associated with multiple physiological traits in Tibetans, including blood nitric oxide concentration, blood oxygen saturation and hemoglobin concentration. Taken together, we propose that GCH1 plays a role in the genetic adaptation of Tibetans to high altitude hypoxia.

Various diffusion magnetic resonance imaging techniques for pancreatic cancer

Pancreatic cancer is one of the most common malignanttumors and remains a treatment-refractory cancer with a poor prognosis. Currently, the diagnosis of pancreatic neoplasm depends mainly on imaging and which methods are conducive to detecting small lesions. Compared to the other techniques, magnetic resonance imaging(MRI) has irreplaceable advantages and can provide valuable information unattainable with other noninvasive or minimally invasive imaging techniques. Advances in MR hardware and pulse sequence design have particularly improved the quality and robustness of MRI of the pancreas. Diffusion MR imaging serves as one of the common functional MRI techniques and is the only technique that can be used to reflect the diffusion movement of water molecules in vivo. It is generally known that diffusion properties depend on the characterization of intrinsic features of tissue microdynamics and microstructure. With the improvement of the diffusion models, diffusion MR imaging techniques are increasingly varied, from the simplest and most commonly used technique to the more complex. In this review, the various diffusion MRI techniques for pancreatic cancer are discussed, including conventional diffusion weighted imaging(DWI), multi-b DWI based on intra-voxel incoherent motion theory, diffusion tensor imaging and diffusion kurtosis imaging. The principles, main parameters, advantages and limitations of these techniques, as well as future directions for pancreatic diffusion imaging are also discussed.

Diagnostic value of imaging examinations in patients with primary hepatocellular carcinoma

Primary hepatocellular carcinoma(PHC) includes hepatocellular carcinoma, intrahepatic cholangiocarcinoma and other pathological types and is characterized by rapid progression. Most of the clinical diagnoses are made at late stage or when distant metastasis occurs, increasing the difficulty of treatment and resulting in a poor prognosis. Therefore, the early diagnosis of PHC plays an important role in timely treatment and the improvement of prognosis. The gold standard for the diagnosis of primary liver cancer is liver biopsy, but it has limitations as an invasive examination. Presently, imaging has become the first choice for the diagnosis of liver cancer. We here summarize the new methods and techniques of imaging in diagnosis and evaluation of primary liver cancer in recent years, including ultrasonography, computed tomography perfusion imaging, diffusion-weighted imaging technology-voxel incoherent motion, diffusion tensor imaging, iterative decomposition of water and fat with echo asymmetry and least squares estimation-iron quantification, dynamic enhanced magnetic resonance imaging and hepatocyte-specific contrast medium imaging. Imaging diagnosis can not only evaluate the degree of differentiation, blood supply and perfusion, and invasiveness of the lesion, but also predict the prognosis, evaluate liver function, andprovide references for clinical diagnosis and treatment.

Progress of intravoxel incoherent motion diffusion-weighted imaging in liver diseases

Traditional magnetic resonance(MR)diffusion-weighted imaging(DWI)uses a single exponential model to obtain the apparent diffusion coefficient to quantitatively reflect the diffusion motion of water molecules in living tissues,but it is affected by blood perfusion.Intravoxel incoherent motion(IVIM)-DWI utilizes a double-exponential model to obtain information on pure water molecule diffusion and microcirculatory perfusion-related diffusion,which compensates for the insufficiency of traditional DWI.In recent years,research on the application of IVIM-DWI in the diagnosis and treatment of hepatic diseases has gradually increased and has achieved considerable progress.This study mainly reviews the basic principles of IVIM-DWI and related research progress in the diagnosis and treatment of hepatic diseases.

Application of intravoxel incoherent motion diffusion-weighted imaging in hepatocellular carcinoma

The morbidity and mortality of hepatocellular carcinoma(HCC)rank 6th and 4th,respectively,among malignant tumors worldwide.Traditional diffusion-weighted imaging(DWI)uses the apparent diffusion coefficient(ADC)obtained by applying the monoexponential model to reflect water molecule diffusion in active tissue;however,the value of ADC is affected by microcirculation perfusion.Using a biexponential model,intravoxel incoherent motion(IVIM)-DWI quantitatively measures information related to pure water molecule diffusion and microcirculation perfusion,thus compensating for the shortcomings of DWI.The number of studies examining the application of IVIM-DWI in patients with HCC has gradually increased over the last few years,and many results show that IVIMDWI has vital value for HCC differentiation,pathological grading,and predicting and evaluating the treatment response.The present study principally reviews the principle of IVIM-DWI and its research progress in HCC differentiation,pathological grading,predicting and evaluating the treatment response,predicting postoperative recurrence and predicting gene expression prediction.

Evaluation of primary adrenal insufficiency secondary to tuberculous adrenalitis with computed tomography and magnetic resonance imaging:Current status

As one kind of infectious diseases of adrenal gland, adrenal tuberculosis can result in a life-threatening disorder which is called primary adrenal insufficiency(PAI) due to the destruction of adrenal cortex. Computed tomography(CT) and magnetic resonance imaging(MRI) play significant roles in the diagnosis of this etiology of PAI based on the CT and MRI appearances of the adrenal lesions. In this mini-review, we intend to study the CT and MRI features of adrenal tuberculosis, which could be helpful to both endocrinologist and radiologist to establish a definitive diagnosis for adrenal tuberculosis resulting in PAI.

EP300 contributes to high-altitude adaptation in Tibetans by regulating nitric oxide production

The genetic adaptation of Tibetans to high altitude hypoxia likely involves a group of genes in the hypoxic pathway, as suggested by earlier studies. To test the adaptive role of the previously reported candidate gene EP300 （histone acetyltransferase p300）, we conducted resequencing of a 108.9 kb gene region of EP300 in 80 unrelated Tibetans. The allele-frequency and haplotype-based neutrality tests detected signals of positive Darwinian selection on EP300 in Tibetans, with a group of variants showing allelic divergence between Tibetans and lowland reference populations, including Han Chinese, Europeans, and Africans. Functional prediction suggested the involvement of multiple EP300 variants in gene expression regulation. More importantly, genetic association tests in 226 Tibetans indicated significant correlation of the adaptive EP300 variants with blood nitric oxide （NO） concentration. Collectively, we propose that EP300 harbors adaptive variants in Tibetans, which might contribute to high-altitude adaptation through regulating NO production.

Hepatic abnormal perfusion visible by magnetic resonance imaging in acute pancreatitis

AIM:to study the prevalence and patterns of hepatic abnormal perfusion(HAP)visible by magnetic resonance imaging(MRI)in acute pancreatitis(AP).METHODS:Enhanced abdominal MRI was performed on 51 patients with AP.these patients were divided into two groups according to the MRI results:those with signs of gallstones,cholecystitis,common bile duct(CBD)stones or dilatation of the CBD on MRI and those without.the prevalence,shape and distribution of HAP in the two groups were analyzed and compared.the severity of AP was graded using the MR severity index(MRSI).the correlation between the MRSI and HAP was then analyzed.RESULTS:Of the 51 patients with AP,32(63%)showed at least one sign of gallbladder and CBD abnormalities on the MR images,while 19(37%)showed no sign of gallbladder or CBD abnormalities.Nineteen patients(37%)had HAP visible in the enhanced images,including strip-,wedge-or patch-shaped HAP distributed in the hepatic tissue adjacent to the gallbladder and left and right liver lobes.there were no significant differences in the prevalence of HAP(χ2=0.305,P=0.581>0.05)or HAP distribution in the liver(χ2=2.181,P=0.536>0.05)between patients with and without gallbladder and CBD abnormalities.there were no significant differences in the MRSI score between patients with and without HAP(t=0.559,P=0.552>0.05).HAP was not correlated with the MRSI score.CONCLUSION:HAP is common in patients with AP and appears strip-,patch-or wedge-shaped on MRI.HAP on MRI cannot be used to indicate the severity of AP.

Could intravoxel incoherent motion diffusion-weighted magnetic resonance imaging be feasible and beneficial to the evaluation of gastrointestinal tumors histopathology and the therapeutic response?

Gastrointestinal tumors(GTs)are among the most com-mon tumors of the digestive system and are among the leading causes of cancer death worldwide.Functional magnetic resonance imaging(MRI)is crucial for assessment of histopathological changes and therapeutic responses of GTs before and after chemotherapy and radiotherapy.A new functional MRI technique,intravoxel incoherent motion(IVIM),could reveal more detailed useful information regarding many diseases.Currently,IVIM is widely used for various tumors because the derived parameters(diffusion coefficient,D;pseudo-perfusion diffusion coefficient,D*;and perfusion fraction,f)are thought to be important surrogate imaging biomarkers for gaining insights into tissue physiology.They can simultaneously reflect the microenvironment,microcirculation in the capillary network(perfusion)and diffusion in tumor tissues without contrast agent intra-venous administration.The sensitivity and specificity of these parameters used in the evaluation of GTs vary,the results of IVIM in GTs are discrepant and the variability of IVIM measurements in response to chemotherapy and/or radiotherapy in these studies remains a source of controversy.Therefore,there are questions as to whether IVIM diffusion-weighted MRI is feasible and helpful in the evaluation of GTs,and whether it is worthy of expanded use.

Role of radiomics in the diagnosis and treatment of gastrointestinal cancer

Gastrointestinal cancer(GIC)has high morbidity and mortality as one of the main causes of cancer death.Preoperative risk stratification is critical to guide patient management,but traditional imaging studies have difficulty predicting its biological behavior.The emerging field of radiomics allows the conversion of potential pathophysiological information in existing medical images that cannot be visually recognized into high-dimensional quantitative image features.Tumor lesion characterization,therapeutic response evaluation,and survival prediction can be achieved by analyzing the relationships between these features and clinical and genetic data.In recent years,the clinical application of radiomics to GIC has increased dramatically.In this editorial,we describe the latest progress in the application of radiomics to GIC and discuss the value of its potential clinical applications,as well as its limitations and future directions.