Simplified liver imaging reporting and data system for the diagnosis of hepatocellular carcinoma on gadoxetic acid-enhanced magnetic resonance imaging

BACKGROUND The liver imaging reporting and data system(LI-RADS)diagnostic table has 15 cells and is too complex.The diagnostic performance of LI-RADS for hepatocellular carcinoma(HCC)is not satisfactory on gadoxetic acid-enhanced magnetic resonance imaging(EOB-MRI).AIM To evaluate the ability of the simplified LI-RADS(sLI-RADS)to diagnose HCC on EOB-MRI.METHODS A total of 331 patients with 356 hepatic observations were retrospectively analysed.The diagnostic performance of sLI-RADS A-D using a single threshold was evaluated and compared with LI-RADS v2018 to determine the optimal sLIRADS.The algorithms of sLI-RADS A-D are as follows:The single threshold for sLI-RADS A and B was 10 mm,that is,classified observations≥10mm using an algorithm of 10-19 mm observations(sLI-RADS A)and≥20 mm observations(sLI-RADS B)in the diagnosis table of LI-RADS v2018,respectively,while the classification algorithm remained unchanged for observations<10 mm;the single threshold for sLI-RADS C and D was 20 mm,that is,for<20 mm observations,the algorithms for<10 mm observations(sLI-RADS C)and 10-19 mm observations(sLI-RADS D)were used,respectively,while the algorithm remained unchanged for observations≥20 mm.With hepatobiliary phase(HBP)hypointensity as a major feature(MF),the final sLI-RADS(F-sLI-RADS)was formed according to the optimal sLI-RADS,and its diagnostic performance was evaluated.The times needed to classify the observations according to F-sLIRADS and LI-RADS v2018 were compared.RESULTS The optimal sLI-RADS was sLI-RADS D(with a single threshold of 20 mm),because its sensitivity was greater than that of LI-RADS v2018(89.8%vs 87.0%,P=0.031),and its specificity was not lower(89.4%vs 90.1%,P>0.999).With HBP hypointensity as an MF,the sensitivity of F-sLI-RADS was greater than that of LI-RADS v2018(93.0%vs 87.0%,P<0.001)and sLI-RADS D(93.0%vs 89.8%,P=0.016),without a lower specificity(86.5%vs 90.1%,P=0.062;86.5%vs 89.4%,P=0.125).Compared with that of LI-RADS v2018,the time to classify lesions according to FsLI-RADS was shorter(51±21 s vs 73±24 s,P<0.001).CONCLUSION The use of sLI-RADS with HBP hypointensity as an MF may improve the sensitivity of HCC diagnosis and reduce lesion classification time.

Multiparameter magnetic resonance imaging-based radiomics model for the prediction of rectal cancer metachronous liver metastasis

BACKGROUND The liver,as the main target organ for hematogenous metastasis of colorectal cancer,early and accurate prediction of liver metastasis is crucial for the diagnosis and treatment of patients.Herein,this study aims to investigate the application value of a combined machine learning(ML)based model based on the multiparameter magnetic resonance imaging for prediction of rectal metachronous liver metastasis(MLM).AIM To investigate the efficacy of radiomics based on multiparametric magnetic resonance imaging images of preoperative first diagnosed rectal cancer in predicting MLM from rectal cancer.METHODS We retrospectively analyzed 301 patients with rectal cancer confirmed by surgical pathology at Jingzhou Central Hospital from January 2017 to December 2023.All participants were randomly assigned to the training or validation queue in a 7:3 ratio.We first apply generalized linear regression model(GLRM)and random forest model(RFM)algorithm to construct an MLM prediction model in the training queue,and evaluate the discriminative power of the MLM prediction model using area under curve(AUC)and decision curve analysis(DCA).Then,the robustness and generalizability of the MLM prediction model were evaluated based on the internal validation set between the validation queue groups.RESULTS Among the 301 patients included in the study,16.28%were ultimately diagnosed with MLM through pathological examination.Multivariate analysis showed that carcinoembryonic antigen,and magnetic resonance imaging radiomics were independent predictors of MLM.Then,the GLRM prediction model was developed with a comprehensive nomogram to achieve satisfactory differentiation.The prediction performance of GLRM in the training and validation queue was 0.765[95%confidence interval(CI):0.710-0.820]and 0.767(95%CI:0.712-0.822),respectively.Compared with GLRM,RFM achieved superior performance with AUC of 0.919(95%CI:0.868-0.970)and 0.901(95%CI:0.850-0.952)in the training and validation queue,respectively.The DCA indicated that the predictive ability and net profit of clinical RFM were improved.CONCLUSION By combining multiparameter magnetic resonance imaging with the effectiveness and robustness of ML-based predictive models,the proposed clinical RFM can serve as an insight tool for preoperative assessment of MLM risk stratification and provide important information for individual diagnosis and treatment of rectal cancer patients.

Current status of magnetic resonance imaging radiomics in hepatocellular carcinoma:A quantitative review with Radiomics Quality Score

BACKGROUND Radiomics is a promising tool that may increase the value of magnetic resonance imaging(MRI)for different tasks related to the management of patients with hepatocellular carcinoma(HCC).However,its implementation in clinical practice is still far,with many issues related to the methodological quality of radiomic studies.AIM To systematically review the current status of MRI radiomic studies concerning HCC using the Radiomics Quality Score(RQS).METHODS A systematic literature search of PubMed,Google Scholar,and Web of Science databases was performed to identify original articles focusing on the use of MRI radiomics for HCC management published between 2017 and 2023.The methodological quality of radiomic studies was assessed using the RQS tool.Spearman’s correlation(ρ)analysis was performed to explore if RQS was correlated with journal metrics and characteristics of the studies.The level of statistical significance was set at P<0.05.RESULTS One hundred and twenty-seven articles were included,of which 43 focused on HCC prognosis,39 on prediction of pathological findings,16 on prediction of the expression of molecular markers outcomes,18 had a diagnostic purpose,and 11 had multiple purposes.The mean RQS was 8±6.22,and the corresponding percentage was 24.15%±15.25%(ranging from 0.0% to 58.33%).RQS was positively correlated with journal impact factor(IF;ρ=0.36,P=2.98×10^(-5)),5-years IF(ρ=0.33,P=1.56×10^(-4)),number of patients included in the study(ρ=0.51,P<9.37×10^(-10))and number of radiomics features extracted in the study(ρ=0.59,P<4.59×10^(-13)),and time of publication(ρ=-0.23,P<0.0072).CONCLUSION Although MRI radiomics in HCC represents a promising tool to develop adequate personalized treatment as a noninvasive approach in HCC patients,our study revealed that studies in this field still lack the quality required to allow its introduction into clinical practice.

Pre-operative enhanced magnetic resonance imaging combined with clinical features predict early recurrence of hepatocellular carcinoma after radical resection

BACKGROUND Indentifying predictive factors for postoperative recurrence of hepatocellular carcinoma(HCC)has great significance for patient prognosis.AIM To explore the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid(Gd-EOB-DTPA)enhanced magnetic resonance imaging(MRI)combined with clinical features in predicting early recurrence of HCC after resection.METHODS A total of 161 patients with pathologically confirmed HCC were enrolled.The patients were divided into early recurrence and non-early recurrence group based on the follow-up results.The clinical,laboratory,pathological results and Gd-EOB-DTPA enhanced MRI imaging features were analyzed.RESULTS Of 161 patients,73 had early recurrence and 88 were had non-early recurrence.Univariate analysis showed that patient age,gender,serum alpha-fetoprotein level,the Barcelona Clinic Liver Cancer stage,China liver cancer(CNLC)stage,microvascular invasion(MVI),pathological satellite focus,tumor size,tumor number,tumor boundary,tumor capsule,intratumoral necrosis,portal vein tumor thrombus,large vessel invasion,nonperipheral washout,peritumoral enhancement,hepatobiliary phase(HBP)/tumor signal intensity(SI)/peritumoral SI,HBP peritumoral low signal and peritumoral delay enhancement were significantly associated with early recurrence of HCC after operation.Multivariate logistic regression analysis showed that patient age,MVI,CNLC stage,tumor boundary and large vessel invasion were independent predictive factors.External data validation indicated that the area under the curve of the combined predictors was 0.861,suggesting that multivariate logistic regression was a reasonable predictive model for early recurrence of HCC.CONCLUSION Gd-EOB-DTPA enhanced MRI combined with clinical features would help predicting the early recurrence of HCC after operation.

Nomogram prediction of vessels encapsulating tumor clusters in small hepatocellular carcinoma≤3 cm based on enhanced magnetic resonance imaging

BACKGROUND Vessels encapsulating tumor clusters(VETC)represent a recently discovered vascular pattern associated with novel metastasis mechanisms in hepatocellular carcinoma(HCC).However,it seems that no one have focused on predicting VETC status in small HCC(sHCC).This study aimed to develop a new nomogram for predicting VETC positivity using preoperative clinical data and image features in sHCC(≤3 cm)patients.AIM To construct a nomogram that combines preoperative clinical parameters and image features to predict patterns of VETC and evaluate the prognosis of sHCC patients.METHODS A total of 309 patients with sHCC,who underwent segmental resection and had their VETC status confirmed,were included in the study.These patients were recruited from three different hospitals:Hospital 1 contributed 177 patients for the training set,Hospital 2 provided 78 patients for the test set,and Hospital 3 provided 54 patients for the validation set.Independent predictors of VETC were identified through univariate and multivariate logistic analyses.These independent predictors were then used to construct a VETC prediction model for sHCC.The model’s performance was evaluated using the area under the curve(AUC),calibration curve,and clinical decision curve.Additionally,Kaplan-Meier survival analysis was performed to confirm whether the predicted VETC status by the model is associated with early recurrence,just as it is with the actual VETC status and early recurrence.RESULTS Alpha-fetoprotein_lg10,carbohydrate antigen 199,irregular shape,non-smooth margin,and arterial peritumoral enhancement were identified as independent predictors of VETC.The model incorporating these predictors demonstrated strong predictive performance.The AUC was 0.811 for the training set,0.800 for the test set,and 0.791 for the validation set.The calibration curve indicated that the predicted probability was consistent with the actual VETC status in all three sets.Furthermore,the decision curve analysis demonstrated the clinical benefits of our model for patients with sHCC.Finally,early recurrence was more likely to occur in the VETC-positive group compared to the VETC-negative group,regardless of whether considering the actual or predicted VETC status.CONCLUSION Our novel prediction model demonstrates strong performance in predicting VETC positivity in sHCC(≤3 cm)patients,and it holds potential for predicting early recurrence.This model equips clinicians with valuable information to make informed clinical treatment decisions.

Application of texture signatures based on multiparameter-magnetic resonance imaging for predicting microvascular invasion in hepatocellular carcinoma:Retrospective study

BACKGROUND Despite continuous changes in treatment methods,the survival rate for advanced hepatocellular carcinoma(HCC)patients remains low,highlighting the importance of diagnostic methods for HCC.AIM To explore the efficacy of texture analysis based on multi-parametric magnetic resonance(MR)imaging(MRI)in predicting microvascular invasion(MVI)in preoperative HCC.METHODS This study included 105 patients with pathologically confirmed HCC,categorized into MVI-positive and MVI-negative groups.We employed Original Data Analysis,Principal Component Analysis,Linear Discriminant Analysis(LDA),and Non-LDA(NDA)for texture analysis using multi-parametric MR images to predict preoperative MVI.The effectiveness of texture analysis was determined using the B11 program of the MaZda4.6 software,with results expressed as the misjudgment rate(MCR).RESULTS Texture analysis using multi-parametric MRI,particularly the MI+PA+F dimensionality reduction method combined with NDA discrimination,demonstrated the most effective prediction of MVI in HCC.Prediction accuracy in the pulse and equilibrium phases was 83.81%.MCRs for the combination of T2-weighted imaging(T2WI),arterial phase,portal venous phase,and equilibrium phase were 22.86%,16.19%,20.95%,and 20.95%,respectively.The area under the curve for predicting MVI positivity was 0.844,with a sensitivity of 77.19%and specificity of 91.67%.CONCLUSION Texture analysis of arterial phase images demonstrated superior predictive efficacy for MVI in HCC compared to T2WI,portal venous,and equilibrium phases.This study provides an objective,non-invasive method for preoperative prediction of MVI,offering a theoretical foundation for the selection of clinical therapy.

Preoperative prediction of hepatocellular carcinoma microvascular invasion based on magnetic resonance imaging feature extraction artificial neural network

BACKGROUND Hepatocellular carcinoma(HCC)recurrence is highly correlated with increased mortality.Microvascular invasion(MVI)is indicative of aggressive tumor biology in HCC.AIM To construct an artificial neural network(ANN)capable of accurately predicting MVI presence in HCC using magnetic resonance imaging.METHODS This study included 255 patients with HCC with tumors<3 cm.Radiologists annotated the tumors on the T1-weighted plain MR images.Subsequently,a three-layer ANN was constructed using image features as inputs to predict MVI status in patients with HCC.Postoperative pathological examination is considered the gold standard for determining MVI.Receiver operating characteristic analysis was used to evaluate the effectiveness of the algorithm.RESULTS Using the bagging strategy to vote for 50 classifier classification results,a prediction model yielded an area under the curve(AUC)of 0.79.Moreover,correlation analysis revealed that alpha-fetoprotein values and tumor volume were not significantly correlated with the occurrence of MVI,whereas tumor sphericity was significantly correlated with MVI(P<0.01).CONCLUSION Analysis of variable correlations regarding MVI in tumors with diameters<3 cm should prioritize tumor sphericity.The ANN model demonstrated strong predictive MVI for patients with HCC(AUC=0.79).

Differentiation of hepatocellular carcinoma from its variousmimickers in liver magnetic resonance imaging:What arethe tips when using hepatocyte-specific agents?

Hepatocellular carcinoma is the most common primary hepatic malignant tumor.With widespread use of liver imaging,various cirrhosis-related nodules are frequently detected in patients with chronic liver disease,while diverse hypervascular hepatic lesions are incidentally detected but undiagnosed on dynamic computed tomography and magnetic resonance imaging(MRI).However,use of hepatocyte-specific MR contrast agents with combined perfusion and hepatocyte-selective properties have improved diagnostic performance in detection and characterization of focal liver lesions.Meanwhile,the enhancement patterns observed during dynamic phases using hepatocyte-specific agents may be different from those observed during MRI using conventional extracellular fluid agents,leading to confusion in diagnosis.Therefore,we discuss useful tips for the differentiation of hepatocellular carcinoma from similar lesions in patients with and without chronic liver disease using liver MRI with hepatocyte-specific agents.

Role of gadoxetic acid-enhanced liver magnetic resonance imaging in the evaluation of hepatocellular carcinoma after locoregional treatment

Locoregional treatments,as alternatives to surgery,play a key role in the management of hepatocellular carcinoma(HCC).Liver magnetic resonance imaging(MRI)enables a multiparametric assessment,going beyond the traditional dynamic computed tomography approach.Moreover,the use of hepatobiliary agents can improve diagnostic accuracy and are becoming important in the diagnosis and follow-up of HCC.However,the main challenge is to quickly identify classical responses to loco-regional treatments in order to determine the most suitable management strategy for each patient.The aim of this review is to provide a summary of the most common and uncommon liver MRI findings in patients who underwent loco-regional treatments for HCC,with a special focus on ablative therapies(radiofrequency,microwaves and cryoablation),transarterial chemoembolization,trans-arterial radio-embolization and stereotactic ablative radiotherapy techniques,considering the usefulness of gadoxetate disodium(Gd-EOB-DTPA)contrast agent.

Gadoxetic acid-enhanced magnetic resonance imaging for the detection of small hepatocellular carcinoma(≤ 2.0 cm) in patients with chronic liver disease:A meta-analysis

AIM To perform a meta-analysis assessing the value of gadoxetic acid-enhanced magnetic resonance imaging(Gd-EOB-MRI)in detecting small hepatocellular carcinoma(HCC)(≤2.0 cm)in patients with chronic liver disease.METHODS Databases,including MEDLINE and EMBASE,were searched for relevant original articles published from January 2008 to February 2015.Data were extracted,and summary estimates of diagnostic accuracy indexes such as sensitivity,specificity,diagnostic odds ratio,predictive value,and areas under summary receiver operating characteristic curve were obtained using a random-effects model,with further exploration employing meta-regression and subgroup analyses.RESULTS In 10 studies evaluating 768 patients,pooled perlesion sensitivity of Gd-EOB-DTPA was 91%(95%CI:83%-95%),with a specificity of 95%(95%CI:87%-98%).Overall positive likelihood ratio was 18.1(95%CI:6.6-49.4),for negative likelihood ratio(NLR)of 0.10(95%CI:0.05-0.19)and diagnostic odds ratio of182(95%CI:57-581).Subgroup analysis suggested that diagnostic performance of Gd-EOB-MRI for sub-centimeter HCC(≤1.0 cm)detection was low,with a sensitivity of69%(95%CI:59%-78%).In studies with both Gd-EOBMRI and diffusion-weighted imaging(DWI)performed,Gd-EOB-MRI/DWI combination was more sensitive than Gd-EOB-DTPA alone,whether for small lesions(86%vs77%)or sub-centimeter ones(80%vs 56%).CONCLUSION A limited number of small studies suggested that GdEOB-MRI has good diagnostic performance in the detection of small HCC(≤2.0 cm)among patients with chronic liver disease,but relatively lower performance for detection of sub-centimeter HCC(≤1.0 cm).Combination of Gd-EOB-MRI and DWI can improve the diagnostic sensitivity of MRI.

Liver magnetic resonance imaging for evaluation of response to treatment after stereotactic body radiation therapy of hepatocellular carcinoma

BACKGROUND Although stereotactic body radiation therapy(SBRT)is increasingly used,its application has not yet been regulated by the main international guidelines,leaving the decision to multidisciplinary teams.AIM To assess magnetic resonance imaging(MRI)features of hepatocellular carcinoma(HCC)treated with SBRT,highlighting the efficacy of the treatment and the main aspects of the lesion before and after the procedure.METHODS As part of a retrospective study,49 patients who underwent SBRT for HCC between January 2013 and November 2019 were recruited.Each patient under went a pre-treatment MRI examination with a hepatospecific contrast agent and a similar followup examination within 6 mo of therapy.In addition,22 patients underwent a second follow-up examination after the first 6 mo.The following characteristics were analysed:Features analysed compared to pre-treatment MRI examination,presence or absence of infield and outfield progression,ring-like enhancement,signal hyperintensity in T2-weighted sequences in the perilesional parenchyma,capsular retraction,and"band"signal hypointensity in T1-weighted gradient echo fat saturated sequences obtained during hepatobiliary excretion.RESULTS Signal hyperintensity in the T2-weighted sequences showed a statistically significant reduction in the number of lesions at the post-SBRT first control(P=0.0006).Signal hyperintensity in diffusionweighted imaging-weighted sequences was decreased at MRI first control(P<0.0001).A statistically significant increase of apparent diffusion coefficient values from a median of 1.01 to 1.38 at the first post-control was found(P<0.0001).Capsular retraction was increased at the late evaluation(P=0.006).Band-like signal hypointensity in the hepatobiliary phase was present in 94%at the late control(P=0.006).The study of the risk of outfield progression vs infield progression revealed a hazard ratio of 9.CONCLUSION The efficacy of SBRT should be evaluated not in the first 6 mo,but at least 9 mo post-SBRT,when infield progression persists at very low rates while the risk of outfield progression increases significantly.

Staging liver fibrosis with various diffusion-weighted magnetic resonance imaging models

BACKGROUND Diffusion-weighted imaging(DWI)has been developed to stage liver fibrosis.However,its diagnostic performance is inconsistent among studies.Therefore,it is worth studying the diagnostic value of various diffusion models for liver fibrosis in one cohort.AIM To evaluate the clinical potential of six diffusion-weighted models in liver fibrosis staging and compare their diagnostic performances.METHODS This prospective study enrolled 59 patients suspected of liver disease and scheduled for liver biopsy and 17 healthy participants.All participants underwent multi-b value DWI.The main DWI-derived parameters included Mono-apparent diffusion coefficient(ADC)from mono-exponential DWI,intravoxel incoherent motion model-derived true diffusion coefficient(IVIM-D),diffusion kurtosis imaging-derived apparent diffusivity(DKI-MD),stretched exponential model-derived distributed diffusion coefficient(SEM-DDC),fractional order calculus(FROC)model-derived diffusion coefficient(FROC-D)and FROC model-derived microstructural quantity(FROC-μ),and continuous-time random-walk(CTRW)model-derived anomalous diffusion coefficient(CTRW-D)and CTRW model-derived temporal diffusion heterogeneity index(CTRW-α).The correlations between DWI-derived parameters and fibrosis stages and the parameters’diagnostic efficacy in detecting significant fibrosis(SF)were assessed and compared.RESULTS CTRW-D(r=-0.356),CTRW-α(r=-0.297),DKI-MD(r=-0.297),FROC-D(r=-0.350),FROC-μ(r=-0.321),IVIM-D(r=-0.251),Mono-ADC(r=-0.362),and SEM-DDC(r=-0.263)were significantly correlated with fibrosis stages.The areas under the ROC curves(AUCs)of the combined index of the six models for distinguishing SF(0.697-0.747)were higher than each of the parameters alone(0.524-0.719).The DWI models’ability to detect SF was similar.The combined index of CTRW model parameters had the highest AUC(0.747).CONCLUSION The DWI models were similarly valuable in distinguishing SF in patients with liver disease.The combined index of CTRW parameters had the highest AUC.

Effect of magnetic resonance imaging in liver metastases

This letter to the editor is a commentary on a study titled"Liver metastases:The role of magnetic resonance imaging."Exploring a noninvasive imaging evaluation system for the biological behavior of hepatocellular carcinoma(HCC)is the key to achieving precise diagnosis and treatment and improving prognosis.This review summarizes the role of magnetic resonance imaging in the detection and evaluation of liver metastases,describes its main imaging features,and focuses on the added value of the latest imaging tools(such as T1 weighted in phase imaging,T1 weighted out of phase imaging;diffusion-weighted imaging,T2 weighted imaging).In this study,I investigated the necessity and benefits of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid for HCC diagnostic testing and prognostic evaluation.

Magnetic resonance imaging of portal vein invasion in hepatocellular carcinoma:A corroboration of 25 cases

AIMS Pre-operatively to assess tumor thrombus as- sociated with hepatocellular carcinoma in the portal vein. METHEDS Twenty-five patients diagnosed as hav- ing thrombus due to hepatocellular carcinoma were corroborated. MR imaging was perfomed with a 1.0T superconducting magnetic system. Both T1 and T2 weighed images and FLASH sequences were obtained in transverse plane. Additional FLASH images were ob- tained in coronal plane. RESULTS Thrombus in portal vein had a signal in- tensity similar to that of the main tumors. Intrinsic por- tal vein thrombus was in 16 patients. Six cases showed occlusive thrombus. Diffusely narrow portal branches were found in 3 patients. Portal venous thrombus showed an area of signal intensity which was replacing the normal flow void in the portal vein and showed a stumpy portal vein,irregular stenosis of portal vein and the formation of vascular net. CONCLUSION MRI was more sensitive and specific and a noninvasive method in detection of portal tumor thrombus used jointly with spin ech (SE) and gradient echo (GRE) techniques.

Revolutionizing disease diagnosis and management:Open-access magnetic resonance imaging datasets a challenge for artificial intelligence driven liver iron quantification

Artificial intelligence(AI),particularly machine learning(ML)and deep learning(DL)techniques,such as convolutional neural networks(CNNs),have emerged as transformative technologies with vast potential in healthcare.Body iron load is usually assessed using slightly invasive blood tests(serum ferritin,serum iron,and serum transferrin).Serum ferritin is widely used to assess body iron and drive medical management;however,it is an acute phase reactant protein offering wrong interpretation in the setting of inflammation and distressed patients.Magnetic resonance imaging is a non-invasive technique that can be used to assess liver iron.The ML and DL algorithms can be used to enhance the detection of minor changes.However,a lack of open-access datasets may delay the advancement of medical research in this field.In this letter,we highlight the importance of standardized datasets for advancing AI and CNNs in medical imaging.Despite the current limitations,embracing AI and CNNs holds promise in revolutionizing disease diagnosis and treatment.

Predicting distant metastasis in nasopharyngeal carcinoma using gradient boosting tree model based on detailed magnetic resonance imaging reports

BACKGROUND Development of distant metastasis(DM)is a major concern during treatment of nasopharyngeal carcinoma(NPC).However,studies have demonstrated im-proved distant control and survival in patients with advanced NPC with the addition of chemotherapy to concomitant chemoradiotherapy.Therefore,precise prediction of metastasis in patients with NPC is crucial.AIM To develop a predictive model for metastasis in NPC using detailed magnetic resonance imaging(MRI)reports.METHODS This retrospective study included 792 patients with non-distant metastatic NPC.A total of 469 imaging variables were obtained from detailed MRI reports.Data were stratified and randomly split into training(50%)and testing sets.Gradient boosting tree(GBT)models were built and used to select variables for predicting DM.A full model comprising all variables and a reduced model with the top-five variables were built.Model performance was assessed by area under the curve(AUC).RESULTS Among the 792 patients,94 developed DM during follow-up.The number of metastatic cervical nodes(30.9%),tumor invasion in the posterior half of the nasal cavity(9.7%),two sides of the pharyngeal recess(6.2%),tubal torus(3.3%),and single side of the parapharyngeal space(2.7%)were the top-five contributors for predicting DM,based on their relative importance in GBT models.The testing AUC of the full model was 0.75(95%confidence interval[CI]:0.69-0.82).The testing AUC of the reduced model was 0.75(95%CI:0.68-0.82).For the whole dataset,the full(AUC=0.76,95%CI:0.72-0.82)and reduced models(AUC=0.76,95%CI:0.71-0.81)outperformed the tumor node-staging system(AUC=0.67,95%CI:0.61-0.73).CONCLUSION The GBT model outperformed the tumor node-staging system in predicting metastasis in NPC.The number of metastatic cervical nodes was identified as the principal contributing variable.

Secondary rectal linitis plastica caused by prostatic adenocarcinoma-magnetic resonance imaging findings and dissemination pathways:A case report

BACKGROUND Secondary rectal linitis plastica(RLP)from prostatic adenocarcinoma is a rare and poorly understood form of metastatic spread,characterized by a desmoplastic response and concentric rectal wall infiltration with mucosal preservation.This complicates endoscopic diagnosis and can mimic gastrointestinal malignancies.This case series underscores the critical role of magnetic resonance imaging(MRI)in identifying the distinct imaging features of RLP and highlights the importance of considering this condition in the differential diagnosis of patients with a history of prostate cancer.CASE SUMMARY Three patients with secondary RLP due to prostatic adenocarcinoma presented with varied clinical features.The first patient,a 76-year-old man with advanced prostate cancer,had rectal pain and incontinence.MRI showed diffuse prostatic invasion and significant rectal wall thickening with a characteristic"target sign"pattern.The second,a 57-year-old asymptomatic man with elevated prostatespecific antigen levels and a history of prostate cancer exhibited rectoprostatic angle involvement and rectal wall thickening on MRI,with positron emission tomography/computed tomography PSMA confirming the prostatic origin of the metastatic spread.The third patient,an 80-year-old post-radical prostatectomy,presented with refractory constipation.MRI revealed a neoplastic mass infiltrating the rectal wall.In all cases,MRI consistently showed stratified thickening,concentric signal changes,restricted diffusion,and contrast enhancement,which were essential for diagnosing secondary RLP.Biopsies confirmed the prostatic origin of the neoplastic involvement in the rectum.CONCLUSION Recognizing MRI findings of secondary RLP is essential for accurate diagnosis and management in prostate cancer patients.

Transient elastography and diffusion-weighted magnetic resonance imaging for assessment of liver fibrosis in children with chronic hepatitis C

BACKGROUND Chronic hepatitis C(CHC)is a health burden with consequent morbidity and mortality.Liver biopsy is the gold standard for evaluating fibrosis and assessing disease severity and prognostic purposes post-treatment.Noninvasive altern-atives for liver biopsy such as transient elastography(TE)and diffusion-weighted magnetic resonance imaging(DW-MRI)are critical needs.AIM To evaluate TE and DW-MRI as noninvasive tools for predicting liver fibrosis in children with CHC.METHODS This prospective cross-sectional study initially recruited 100 children with CHC virus infection.Sixty-four children completed the full set of investigations including liver stiffness measurement(LSM)using TE and measurement of apparent diffusion coefficient(ADC)of the liver and spleen using DW-MRI.Liver biopsies were evaluated for fibrosis using Ishak scoring system.LSM and liver and spleen ADC were compared in different fibrosis stages and correlation analysis was performed with histopathological findings and other laboratory parameters.RESULTS Most patients had moderate fibrosis(73.5%)while 26.5%had mild fibrosis.None had severe fibrosis or cirrhosis.The majority(68.8%)had mild activity,while only 7.8%had moderate activity.Ishak scores had a significant direct correlation with LSM(P=0.008)and were negatively correlated with both liver and spleen ADC but with no statistical significance(P=0.086 and P=0.145,respectively).Similarly,histopatho-logical activity correlated significantly with LSM(P=0.002)but not with liver or spleen ADC(P=0.84 and 0.98 respectively).LSM and liver ADC were able to significantly discriminate F3 from lower fibrosis stages(area under the curve=0.700 and 0.747,respectively)with a better performance of liver ADC.CONCLUSION TE and liver ADC were helpful in predicting significant fibrosis in children with chronic hepatitis C virus infection with a better performance of liver ADC.

Research Progress on the Relationship between Magnetic Resonance Imaging and Clinical Pathological Characteristics of Liver Cancer

Liver cancer is one of the main malignant tumors in the digestive system.Early detection and treatment have positive significance in improving patient prognosis and reducing mortality.MRI is the main method for liver cancer examination,which mainly uses computers to compare imaging of different energy regions of tumors,observe the density and signal changes of liver cancer,and the degree of tumor enhancement.In particular,various new MRI functional imaging technologies,such as diffusion-weighted imaging,perfusion weighted imaging,delayed imaging,liver cell specific contrast agent enhanced imaging,etc.,can be used at the molecular level Multiple aspects such as cell function provide clinicians with richer diagnostic information.Therefore,further comparative analysis of MRI manifestations and pathological results of liver cancer can help to gain a deeper understanding of the biological behavior of tumors and provide a basis for treatment decision-making and prognosis evaluation.

Advances in computed tomography and magnetic resonance imaging of hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is the most common primary liver cancer.Imaging is important for establishing a diagnosis of HCC and early diagnosis is imperative as several potentially curative treatments are available when HCC is small.Hepatocarcinogenesis occurs in a stepwise manner on a background of chronic liver disease or cirrhosis wherein multiple genes are altered resulting in a range of cirrhosisassociated nodules.This progression is related to increased cellularity,neovascularity and size of the nodule.An understanding of the stepwise progression may aid in early diagnosis.Dynamic and multiphase contrast-enhanced computed tomography and magnetic resonance imaging still form the cornerstone in the diagnosis of HCC.An overview of the current diagnostic standards of HCC in accordance to the more common practicing guidelines and their differences will be reviewed.Ancillary features contribute to diagnostic confidence and has been incorporated into the more recent Liver Imaging Reporting and Data System.The use of hepatocyte-specific contrast agents is increasing and gradually changing the standard of diagnosis of HCC;the most significant benefit being the lack of uptake in the hepatocyte phase in the earlier stages of HCC progression.An outline of supplementary techniques in the imaging of HCC will also be reviewed.