Carcinoembryonic antigen in the diagnosis,treatment,and follow-up of focal liver lesions

In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small amounts from healthy adults after birth.CEA is widely used not only for diagnostic tumor markers but also importantly for the management of some gastrointestinal tumors.The most common clinical use is surveillance for the monitoring of colorectal carcinoma.However,CEA can become elevated in several malign or benign characterized pathologies.Serum CEA level may vary depending on the location of the lesion,whether it metastasizes or not,and its histopathological characteristics.It has been determined that cases with high preoperative CEA have a more aggressive course and the risk of metastasis to the lymph tissue and liver increases.In this editorial review,we focused on evaluating the role of CEA in clinical practice with a holistic approach,including the diagnostic and prognostic significance of CEA in patients with focal liver lesions,the role of CEA in follow-up after definitive surgery,and also hepatic resection for metastasis,and the management of all patients with raised CEA.

Complementary comments on metastatic liver lesions with exceptional and rare cases

Liver metastases can appear in different forms in magnetic resonance imaging.Contrary to popular belief,while radiologists report hypovascular or hypervascular metastatic lesions,exceptional examples may be detected in various tumors.The aim of this article is to improve this review by presenting rare and atypical examples of liver metastasis,as well as cases that might potentially be misdiagnosed as metastases during the process of differential diagnosis.

Imaging features and management of focal liver lesions

Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-documented medical history,physical examination,laboratory tests,and appropriate imaging methods.Although benign FLLs are more common than malignant ones in adults,even in patients with primary malignancy,accurate diagnosis of incidental FLLs is of utmost clinical significance.In clinical practice,FLLs are frequently evaluated non-invasively using ultrasound(US),computed tomography(CT),and magnetic resonance imaging(MRI).Although US is a cost-effective and widely used imaging method,its diagnostic specificity and sensitivity for FLL characterization are limited.FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI.MRI is a problem-solving method with high specificity and sensitivity,commonly used for the evaluation of FLLs that cannot be characterized by US or CT.Recent technical advancements in MRI,along with the use of hepatobiliary-specific MRI contrast agents,have significantly improved the success of FLL characterization and reduced unnece-ssary biopsies.The American College of Radiology(ACR)appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients.ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommend-ations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios.The American College of Gastroenterology(ACG)Clinical Guideline offers evidence-based recommend-ations for both the diagnosis and management of FLL.American Association for the Study of Liver Diseases(AASLD)Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma.In this article,FLLs are reviewed with a comprehensive analysis of ACR Appropri-ateness Criteria,ACG Clinical Guideline,AASLD Practice Guidance,and current medical literature from peer-reviewed journals.The article includes a discussion of imaging methods used for the assessment of FLL,current recommended imaging techniques,innovations in liver imaging,contrast agents,imaging features of common nonmetastatic benign and malignant FLL,as well as current management recommendations.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.

Machine perfusion and the prevention of ischemic type biliary lesions following liver transplant:What is the evidence?

The widespread uptake of different machine perfusion(MP)strategies for liver transplant has been driven by an effort to minimize graft injury.Damage to the cholangiocytes during the liver donation,preservation,or early posttransplant period may result in stricturing of the biliary tree and inadequate biliary drainage.This problem continues to trouble clinicians,and may have catastrophic consequences for the graft and patient.Ischemic injury,as a result of compromised hepatic artery flow,is a well-known cause of biliary strictures,sepsis,and graft failure.However,very similar lesions can appear with a patent hepatic artery and these are known as ischemic type biliary lesions(ITBL)that are attributed to microcirculatory dysfunction rather than main hepatic arterial compromise.Both the warm and cold ischemic period duration appear to influence the onset of ITBL.All of the commonly used MP techniques deliver oxygen to the graft cells,and therefore may minimize the cholangiocyte injury and subsequently reduce the incidence of ITBL.As clinical experience and published evidence grows for these modalities,the impact they have on ITBL rates is important to consider.In this review,the evidence for the three commonly used MP strategies(abdominal normothermic regional perfusion[A-NRP],hypothermic oxygenated perfusion[HOPE],and normothermic machine perfusion[NMP])for ITBL prevention has been critically reviewed.Inconsistencies with ITBL definitions used in trials,coupled with variations in techniques of MP,make interpretation challenging.Overall,the evidence suggests that both HOPE and A-NRP prevent ITBL in donated after circulatory death grafts compared to cold storage.The evidence for ITBL prevention in donor after brain death grafts with any MP technique is weak.

Investigation of lacrimal sac space-occupying lesions using color doppler ultrasound, computed tomography, and computed tomography dacryocystography

AIM:To observe the imaging features of color Doppler ultrasound(CDU)and computed tomography(CT)or computed tomography dacryocystography(CT-DCG)in different types of lacrimal sac space-occupying lesions(SOLs).METHODS:This retrospective case series study included 21 patients with lacrimal sac SOLs who underwent lacrimal sac surgery between January 2018 and March 2022.The imaging features of CDU and CT or CT-DCG in these patients were extracted from the examination cloud system.The images were observed and analyzed.RESULTS:The detection rate of lacrimal SOLs between CDU(21/21,100%)and CT or CT-DCG(20/21,95.2%)had no statistically significant difference(P=1.0).CDU could detect the blood flow signals in all SOLs except mucocele and mucopeptide concretion.Among them,polyps had characteristic imaging changes on CDU and CT-DCG.The mucoceles and mucopeptide concretions had characteristic imaging changes on CDU,which could provide more information for differential diagnosis.CONCLUSION:The morphology and internal blood flow signals of lacrimal sac SOLs can be observed using CDU.CT or CT-DCG has advantages in observing structural damage around the lacrimal sac mass.Therefore,CDU may be used as a routine examination to exclude lacrimal sac SOLs before dacryocystorhinostomy in the absence of preoperative CT or CT-DCG.

Gd-EOB-DTPA-enhanced magnetic resonance imaging for focal liver lesions in Chinese patients:a multicenter,open-label,phase Ⅲ study

BACKGROUND:Contrast agents help to improve visibility in magnetic resonance(MR)imaging.However,owing to the large interstitial spaces of the liver,there is a reduction in the natural contrast gradient between lesions and healthy tissue.This study was undertaken to evaluate the efficacy and safety of the liverspecific MR imaging contrast agent gadoxetate disodium(GdEOB-DTPA)in Chinese patients.METHODS:This was a single-arm,open-label,multicenter study in patients with known or suspected focal liver lesions referred for contrast-enhanced MR imaging.MR imaging was performed in 234 patients before and after a single intravenous bolus of Gd-EOB-DTPA(0.025 mmol/kg body weight).Images were evaluated by clinical study investigators and three independent,blinded radiologists.The primary efficacy endpoint was sensitivity in lesion detection.RESULTS:Gd-EOB-DTPA improved sensitivity in lesion detection by 9.46%compared with pre-contrast imaging for the average of the three blinded readers(94.78%vs 85.32%for Gd-EOB-DTPA vs pre-contrast,respectively).Improvements in detection were more pronounced in lesions less than 1cm.Gd-EOB-DTPA improved diagnostic accuracy in lesion classification.CONCLUSIONS:This open-label study demonstrated that Gd-EOB-DTPA improves diagnostic sensitivity in liver lesions,particularly in those smaller than 1 cm.Gd-EOB-DTPA also significantly improves the diagnostic accuracy in lesion classification,and furthermore,Gd-EOB-DTPA is safe in Chinese patients with liver lesions.

Ultrasound elastographic techniques in focal liver lesions

Elastographic techniques are new ultrasound-based imaging techniques developed to estimate tissue deformability/stiffness. Several ultrasound elastographic approaches have been developed, such as static elastography, transient elastography and acoustic radiation force imaging methods, which include point shear wave and shear wave imaging elastography. The application of these methods in clinical practice aims at estimating the mechanical tissues properties. One of the main settings for the application of these tools has been liver stiffness assessment in chronic liver disease, which has been studied mainly using transient elastography. Another field of application for these techniques is the assessment of focal lesions, detected by ultrasound in organs such as pancreas, prostate, breast, thyroid, lymph nodes. Considering the frequency and importance of the detection of focal liver lesions through routine ultrasound, some studies have also aimed to assess the role that elestography can play in studying the stiffness of different types of liver lesions, in order to predict their nature and thus offer valuable non-invasive methods for the diagnosis of liver masses.

Clinical value of contrast-enhanced ultrasonography in the characterization of focal liver lesions:a prospective multicenter trial

BACKGROUND: Contrast-enhanced ultrasonography (CEUS) is increasingly accepted in clinical settings for diagnostic imaging of focal liver lesions (FLLs). This study aimed to assess the efficacy of CEUS in the characterization of FLLs in comparison with final diagnosis based on gold standard assessment. METHODS: The study was approved by the local ethics committee and participating patients provided written informed consent. A total of 148 patients with 164 FLLs were studied. Unenhanced ultrasonography (US) and CEUS were performed using fundamental and harmonic imaging, respectively. Contrast enhancement was assessed during the arterial, portal and late vascular phases after intravenous administration of contrast (SonoVue (R), Bracco, Italy). Sensitivity, specificity and diagnostic accuracy of US and CEUS were compared in identifying the lesion as benign, malignant or indeterminate and its actual tumor type. Final diagnosis was established by biopsy (129/164), MR imaging (11/164) or medical history (24/164). RESULTS: When compared to the gold standard, the number of indeterminate diagnoses was reduced from 56.7% (93/164) as assessed by fundamental imaging to 6.1% (10/164) after SonoVue (R) enhanced US examination. Sensitivity and specificity improved from 49% and 25% at baseline US to 93% and 75% with CEUS, respectively (P<0.01). Diagnostic accuracy of CEUS was 88% in contrast to 41% of baseline US. CONCLUSION: SonoVue (R) enhanced US improves the characterization of FLLs and may limit the need for further investigations.

Signal transducer and activator of transcription 3 promotes the Warburg effect possibly by inducing pyruvate kinase M2 phosphorylation in liver precancerous lesions

BACKGROUND Study shows that signal transducer and activator of transcription 3(STAT3) can increase the Warburg effect by stimulating hexokinase 2 in breast cancer and upregulate lactate dehydrogenase A and pyruvate dehydrogenase kinase 1 in myeloma. STAT3 and pyruvate kinase M2(PKM2) can also be activated and enhance the Warburg effect in hepatocellular carcinoma. Precancerous lesions are critical to human and rodent hepatocarcinogenesis. However, the underlying molecular mechanism for the development of liver precancerous lesions remains unknown. We hypothesized that STAT3 promotes the Warburg effect possibly by upregulating p-PKM2 in liver precancerous lesions in rats.AIM To investigate the mechanism of the Warburg effect in liver precancerous lesions in rats.METHODS A model of liver precancerous lesions was established by a modified Solt-Farber method. The liver pathological changes were observed by HE staining and immunohistochemistry. The transformation of WB-F344 cells induced with Nmethyl-N'-nitro-N-nitrosoguanidine and hydrogen peroxide was evaluated by the soft agar assay and aneuploidy. The levels of glucose and lactate in the tissue and culture medium were detected with a spectrophotometer. The protein levels of glutathione S-transferase-π, proliferating cell nuclear antigen(PCNA), STAT3,and PKM2 were examined by Western blot and immunofluorescence.RESULTS We found that the Warburg effect was increased in liver precancerous lesions in rats. PKM2 and p-STAT3 were upregulated in activated oval cells in liverprecancerous lesions in rats. The Warburg effect, p-PKM2, and p-STAT3 expression were also increased in transformed WB-F344 cells. STAT3 activation promoted the clonal formation rate, aneuploidy, alpha-fetoprotein expression,PCNA expression, G1/S phase transition, the Warburg effect, PKM2 phosphorylation, and nuclear translocation in transformed WB-F344 cells.Moreover, the Warburg effect was inhibited by stattic, a specific inhibitor of STAT3, and further reduced in transformed WB-F344 cells after the intervention for PKM2.CONCLUSION The Warburg effect is initiated in liver precancerous lesions in rats. STAT3 activation promotes the Warburg effect by enhancing the phosphorylation of PKM2 in transformed WB-F344 cells.

Focal liver lesions:Practical magnetic resonance imaging approach

With the widespread of cross-sectional imaging, a growth of incidentally detected focal liver lesions(FLL) has been observed. A reliable detection and characterization of FLL is critical for optimal patient management. Maximizing accuracy of imaging in the context of FLL is paramount in avoiding unnecessary biopsies, which may result in post-procedural complications. A tremendous development of new imaging techniques has taken place during these last years. Nowadays, Magnetic resonance imaging(MRI) plays a key role in management of liver lesions, using a radiation-free technique and a safe contrast agent profile. MRI plays a key role in the non-invasive correct characterization of FLL. MRI is capable of providing comprehensive and highly accurate diagnostic information, with the additional advantage of lack of harmful ionizing radiation. These properties make MRI the mainstay for the noninvasive evaluation of focal liver lesions. In this paper we review the state-of-the-art MRI liver protocol, briefly discussing different sequence types, the unique characteristics of imaging non-cooperative patients and discuss the role of hepatocyte-specific contrast agents. A review of the imaging features of the most common benign and malignant FLL is presented, supplemented by a schematic representation of a simplistic practical approach on MRI.

Liver retransplantation for ischemic-type biliary lesions after orthotopic liver transplantation:a clinical report of 66 cases

BACKGROUND: Ischemic-type biliary lesions (ITBLs) play an extremely important role in influencing the long-term survival and quality of life of recipients after orthotopic liver transplantation (OLT). Some patients can be cured by interventional therapies, however others lose their grafts at last and receive liver retransplantation (re-OLT). The aim of this study was to analyze the data of 66 patients who had received re-OLT at our center because of ITBL and to discuss the treatment of ITBL after OLT. METHODS: We retrospectively analyzed 66 re-OLT cases due to ITBL from September 2001 to February 2007 at our center. The Kaplan-Meier method and the Cox-Mantel test were used to identify factors associated with mortality for univariate analysis and multivariate analysis, respectively. RESULTS: Fifty-five of 66 ITBL cases underwent interventional therapies before re-OLT. The actuarial survival at I month and I year for these patients was 83% and 74%, respectively. Prognostic factors for mortality in univariate analysis were model of end-stage liver disease score (MELD) >16.5 (chi(2)=5.856, P=0.016), cold ischemia time >8 hours (chi(2)=6.539, P=0.011), infections (chi(2)=5.550, P=0.018) and complications (chi(2)=12.168, P=0.002) after re-OLT. In the multivariate analysis (Cox regression), the risk factors independently associated with mortality were MELD score >16.5 (RR: 3.140; P=0.035), cold ischemia time >8.2 hours (RR: 0.192; P=0.016) and complications (RR: 3.896, P=0.003). CONCLUSIONS: The incidence of ITBL in China is higher than in other countries. Based on our experience, MELD score, cold ischemia time and complications after re-OLT are risk factors independently associated with mortality in retransplanted ITBL patients.

Contrast-enhanced ultrasonography in the evaluation of incidental focal liver lesions: A cost-effectiveness analysis

AIM To determine whether contrast-enhanced ultrasonography(CEUS) as the first-line method is more costeffective in evaluating incidentally discovered focal liver lesions(FLLs) than is computed tomography(CT) and magnetic resonance imaging(MRI). METHODS Between 2010 and 2015, our prospective study enrolled 459 patients with incidentally found FLLs. The biological nature of FLLs was assessed by CEUS in all patients. CT or MRI examinations were added in unclear cases. The sensitivity and specificity of CEUS were calculated. The total costs of CEUS examinations and of the added examinations performed in inconclusive cases were calculated. Afterwards, the theoretical expenses for evaluating incidentally discovered FLLs using CT or MRI as the first-line method were calculated. The resultswere compared. RESULTS The total cost of the diagnostic process using CEUS for all enrolled patients with FLLs was 75884 USD. When the expenses for additional CT and MRI examinations performed in inconclusive cases were added, the total cost was 90540 US dollar(USD). If all patients had been examined by CT or MR as the first-line method, the costs would have been 78897 USD or 384235 USD, respectively. The difference between the cost of CT and CEUS was 3013 USD(4%) and that between MRI and CEUS was 308352 USD(406.3%). We correctly described 97.06% of benign or malignant lesions, with 96.99% sensitivity and 97.09% specificity. Positive predictive value was 94.16% and negative predictive value was 98.52%. In cases with 4 and more lesions, malignancy is significantly more frequent and inconclusive findings significantly less frequent(P < 0.001).CONCLUSION While the costs of CEUS and CT in evaluating FLLs are comparable, CEUS examination is far more costeffective in comparison to MRI.

Rare cystic liver lesions: A diagnostic and managing challenge

Cystic formations within the liver are a frequent finding among populations.Besides the common cystic lesions,like simple liver cysts,rare cystic liver lesions like cystadenocarcinoma should also be considered in the differential diagnosis.Thorough knowledge of each entity’s nature and course are key elements to successful treatment.Detailed search in PubMed,Cochrane Database,and international published literature regarding rare cystic liver lesions was carried out.In our research are included not only primary rare lesions like cystadenoma,hydatid cyst,and polycystic liver disease,but also secondary ones like metastasis from gastrointestinal stromal tumors lesions.Up-to date knowledge regarding diagnosis and management of rare cystic liver lesions is provided.A diagnostic and therapeutic algorithm is also proposed.The need for a multidisciplinary approach by a team including radiologists and surgeons familiar with liver cystic entities,diagnostic tools,and treatment modalities is stressed.Patients with cystic liver lesions must be carefully evaluated by a multidisciplinary team,in order to receive the most appropriate treatment,since many cystic liver lesions have a malignant potential and evolution.

Enhanced recovery after surgery program in the patients undergoing hepatectomy for benign liver lesions

Background:Enhanced recovery after surgery(ERAS)has shown effectiveness in terms of reducing the hospital stay and cost.However,the benefit of ERAS in patients undergoing hepatectomy for benign liver lesions is still unclear.Methods:ERAS was implemented in our center since March 1st,2018.From September 2016 to Febru-ary 2018,109 patients were enrolled into the control group,and from March 2018 to June 2019,124 patients were enrolled into the ERAS group.All the indicators related to operation,liver functions,and postoperative outcomes were included in the analysis.Results:The clinicopathologic baselines were similar in these two groups.A significantly higher propor-tion of patients underwent laparoscopic surgery in the ERAS group.On the whole,intraoperative blood loss(100.00 mL vs.200.00 mL,P<0.001),blood transfusion(3.23%vs.10.09%,P=0.033),total bilirubin(17.10μmol/L vs.21.00μmol/L,P=0.041),D-dimer(2.08μg/mL vs.2.57μg/mL,P=0.031),postoperative hospital stay(5.00 d vs.6.00 d,P<0.001),and postoperative morbidity(16.13%vs.32.11%,P=0.008)were significantly shorter or less in the ERAS group than those in the control group.After stratified by operation methods,ERAS group showed significantly shorter postoperative hospital stay in both open and laparoscopic operation(both P<0.001).In patients underwent open surgery,ERAS group demonstrated significantly shorter operative duration(131.76±8.75 min vs.160.73±7.23 min,P=0.016),less intra-operative blood loss(200.00 mL vs.450.00 mL,P=0.008)and less postoperative morbidity(16.00%vs.44.44%,P=0.040).Conclusions:ERAS program may be safe and effective for the patients underwent hepatectomy,especially open surgery,for benign liver lesions.

Clinical Value of Contrast-enhanced Ultrasound in Differentiating Benign and Malignant Focal Liver Lesions

To explore the clinical value of contrast-enhanced ultrasound （CEUS） in differentiating benign and malignant focal liver lesions （FLLs） with SonoVue, CEUS was used to examine 113 patients with focal liver lesions （FLLs） in our hospital during July 2005 to December 2006. All the patients underwent contrast-enhanced CT （CECT） or contrast-enhanced MRI （CEMRI）. Except for patients with focal fatty sparings （n=18） and with hemangiomas （n=8）, all the patients were confirmed by operation or ultrasonic-guided liver puncture biopsy. A sulfur hexafluoride gas-based contrast agent was used with a MI of 0.15 to 0.17. Forty-eight cases of malignant FLLs, including 30 hepatocellular carcinomas （HCCs）, 2 cholangiocarcinomas and 16 metastatic tumors, were detected. Seventy-eight cases of benign FLLs, including 33 hemangiomas, 9 focal nodular hyperplasias （FNHs）, 19 focal fatty sparings, 5 abscesses, 7 regenerative nodules and 2 inflammatory pseudo-tumor, were involved. The contrast pattern of benign and malignant FLLs was quite different. CEUS has higher specificity and sensitivity than conventional ultrasound in differentiating benign and malignant FLLs.

R2^(*) value derived from multi-echo Dixon technique can aid discrimination between benign and malignant focal liver lesions

BACKGROUND R2^(*)estimation reflects the paramagnetism of the tumor tissue,which may be used to differentiate between benign and malignant liver lesions when contrast agents are contraindicated.AIM To investigate whether R2^(*)derived from multi-echo Dixon imaging can aid differentiating benign from malignant focal liver lesions(FLLs)and the impact of 2D region of interest(2D-ROI)and volume of interest(VOI)on the outcomes.METHODS We retrospectively enrolled 73 patients with 108 benign or malignant FLLs.All patients underwent conventional abdominal magnetic resonance imaging and multi-echo Dixon imaging.Two radiologists independently measured the mean R2^(*)values of lesions using 2D-ROI and VOI approaches.The Bland-Altman plot was used to determine the interobserver agreement between R2^(*)measurements.Intraclass correlation coefficient(ICC)was used to determine the reliability between the two readers.Mean R2^(*)values were compared between benign and malignant FFLs using the nonparametric Mann-Whitney test.Receiver operating characteristic curve analysis was used to determine the diagnostic performance of R2^(*)in differentiation between benign and malignant FFLs.We compared the diagnostic performance of R2^(*)measured by 2D-ROI and VOI approaches.RESULTS This study included 30 benign and 78 malignant FLLs.The interobserver reproducibility of R2^(*)measurements was excellent for the 2D-ROI(ICC=0.994)and VOI(ICC=0.998)methods.Bland-Altman analysis also demonstrated excellent agreement.Mean R2^(*)was significantly higher for malignant than benign FFLs as measured by 2D-ROI(P<0.001)and VOI(P<0.001).The area under the curve(AUC)of R2^(*)measured by 2D-ROI was 0.884 at a cut-off of 25.2/s,with a sensitivity of 84.6%and specificity of 80.0%for differentiating benign from malignant FFLs.R2^(*)measured by VOI yielded an AUC of 0.875 at a cut-off of 26.7/s in distinguishing benign from malignant FFLs,with a sensitivity of 85.9%and specificity of 76.7%.The AUCs of R2^(*)were not significantly different between the 2D-ROI and VOI methods.CONCLUSION R2^(*)derived from multi-echo Dixon imaging whether by 2D-ROI or VOI can aid in differentiation between benign and malignant FLLs.

Detection of focal liver lesions in cirrhotic liver using contrast-enhanced ultrasound

Patients with liver cirrhosis are at increased risk of hepatocellular carcinoma(HCC).Conventional or baseline ultrasound(BUS)is often used as the first-line tool for HCC surveillance or detection,but the accuracy of BUS in HCC detection or differentiation from other focal liver lesions(FLLs)is limited.Contrast-enhanced ultrasound(CEUS)represents a recent revolution in the field of ultrasonography and it has become increasingly important in the detection and evaluation of FLLs.In CEUS,HCC typically exhibits arterial hyper-enhancement and portal-venous washout represented by hypoenhanced lesions in the portal venous and late phases.The detection rate of HCC was significantly higher with CEUS compared with BUS.Even regenerative or some dysplastic nodules may exhibit arterial hyperenhancement as they are differentiated from HCC by its iso-enhancing pattern in portal and late phases.The contrast-enhancement patterns of other different types of benign and malignant FLLs,as well as their detection rates with CEUS,were also discussed.

Assessment of optic nerve and optic tract alterations in patients with orbital space-occupying lesions using probabilistic diffusion tractography

AIM: To investigate the diffusion changes in both the optic nerve and optic tract in orbital space-occupying lesion patients with decreased visual acuity, and its clinical significance using probabilistic diffusion tractography(PDT). METHODS: Twenty patients with orbital space-occupying lesions and 25 age-and gender-matched healthy persons were included. All patients and controls underwent routine orbital magnetic resonance imaging and diffusion tensor imaging(DTI), using a 3.0 T magnetic resonance scanner(Trio Tim Siemens). After the image data were preprocessed, each DTI parameters of the optic nerve and optic tract was obtained by PDT, including fractional anisotropy(FA), mean diffusivity(MD), axial diffusivity(AD) and radial diffusivity(RD). The asymmetry index(AI) of each parameter was calculated. Compared the parameters of the affected side optic nerve and ipsilateral optic tract with the contralateral side by paired sample t-test;compared AI of parameters of optic nerve and optic tract between the patient group and the control group by independent sample t-test. Patients were divided into threesubgroups according to the low vision grade standard of WHO, compared the FA and AI of FA between the three subgroups by single factor variance analysis. RESULTS: The affected side optic nerve presented significantly decreased FA, increased MD, AD, and RD values compared to the unaffected side(P<0.05). The AI of FA, MD, AD, and RD of optic nerve in the patients was significantly higher than that of the controls(P<0.05). The comparison results of the optic tract showed that there was no significant difference between the patient group and control group in terms of the bilateral optic tracts in patients(P>0.05). The AIs of the FA value of the optic nerve in the eyesight <0.1 subgroup was significantly higher than that in the other groups(P<0.05). CONCLUSION: FA, MD, AD, and RD of the affected side optic nerve of the orbital space-occupying lesions have significantly changed, the FA value is the most sensitive. The PDT could be a useful tool to provide valid quantitative markers of optic nerve injuries and evaluate the severity of orbital diseases, which other examinations cannot be acquired.

Multiphase convolutional dense network for the classification of focal liver lesions on dynamic contrast-enhanced computed tomography

BACKGROUND The accurate classification of focal liver lesions(FLLs)is essential to properly guide treatment options and predict prognosis.Dynamic contrast-enhanced computed tomography(DCE-CT)is still the cornerstone in the exact classification of FLLs due to its noninvasive nature,high scanning speed,and high-density resolution.Since their recent development,convolutional neural network-based deep learning techniques has been recognized to have high potential for image recognition tasks.AIM To develop and evaluate an automated multiphase convolutional dense network(MP-CDN)to classify FLLs on multiphase CT.METHODS A total of 517 FLLs scanned on a 320-detector CT scanner using a four-phase DCECT imaging protocol(including precontrast phase,arterial phase,portal venous phase,and delayed phase)from 2012 to 2017 were retrospectively enrolled.FLLs were classified into four categories:Category A,hepatocellular carcinoma(HCC);category B,liver metastases;category C,benign non-inflammatory FLLs including hemangiomas,focal nodular hyperplasias and adenomas;and category D,hepatic abscesses.Each category was split into a training set and test set in an approximate 8:2 ratio.An MP-CDN classifier with a sequential input of the fourphase CT images was developed to automatically classify FLLs.The classification performance of the model was evaluated on the test set;the accuracy and specificity were calculated from the confusion matrix,and the area under the receiver operating characteristic curve(AUC)was calculated from the SoftMax probability outputted from the last layer of the MP-CDN.RESULTS A total of 410 FLLs were used for training and 107 FLLs were used for testing.The mean classification accuracy of the test set was 81.3%(87/107).The accuracy/specificity of distinguishing each category from the others were 0.916/0.964,0.925/0.905,0.860/0.918,and 0.925/0.963 for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.The AUC(95%confidence interval)for differentiating each category from the others was 0.92(0.837-0.992),0.99(0.967-1.00),0.88(0.795-0.955)and 0.96(0.914-0.996)for HCC,metastases,benign non-inflammatory FLLs,and abscesses on the test set,respectively.CONCLUSION MP-CDN accurately classified FLLs detected on four-phase CT as HCC,metastases,benign non-inflammatory FLLs and hepatic abscesses and may assist radiologists in identifying the different types of FLLs.