Computed tomography perfusion in differentiating portal hypertension: A correlation study with hepatic venous pressure gradient

BACKGROUND Hepatic venous pressure gradient(HVPG)is the gold standard for diagnosis of portal hypertension(PH),invasiveness and potential risks in the process of measurement limited its widespread use.AIM To investigate the correlation of computed tomography(CT)perfusion parameters with HVPG in PH,and quantitatively assess the blood supply changes in liver and spleen parenchyma before and after transjugular intrahepatic portosystemic shunt(TIPS).METHODS Twenty-four PH related gastrointestinal bleeding patients were recruited in this study,and all patients were performed perfusion CT before and after TIPS surgery within 2 wk.Quantitative parameters of CT perfusion,including liver blood volume(LBV),liver blood flow(LBF),hepatic arterial fraction(HAF),spleen blood volume(SBV)and spleen blood flow(SBF),were measured and compared before and after TIPS,and the quantitative parameters between clinically significant PH(CSPH)and non-CSPH(NCSPH)group were also compared.Then the correlation of CT perfusion parameters with HVPG were analyzed,with statistical significance as P<0.05.RESULTS For all 24 PH patients after TIPS,CT perfusion parameters demonstrated decreased LBV, increased HAF, SBV and SBF, with no statistical difference in LBF. Compared withNCSPH, CSPH showed higher HAF, with no difference in other CT perfusion parameters. HAFbefore TIPS showed positive correlation with HVPG (r = 0.530, P = 0.008), while no correlation wasfound in other CT perfusion parameters with HVPG and Child-Pugh scores.CONCLUSIONHAF, an index of CT perfusion, was positive correlation with HVPG, and higher in CSPH thanNCSPH before TIPS. While increased HAF, SBF and SBV, and decreased LBV, were found afterTIPS, which accommodates a potential non-invasive imaging tool for evaluation of PH.

Positron emission tomography/computed tomography with ^(18)F-fluorodeoxyglucose identifies tumor growth or thrombosis in the portal vein with hepatocellular carcinoma

Patients suffering from hepatocellular carcinoma (HCC) with tumor thrombus in the portal vein generally have a poor prognosis. Portal vein tumor thrombus must be distinguished from portal vein blood thrombus, and this identification plays a very important role in management of HCC. Conventional imaging modalities have limitations in discrimination of portal vein tumor thrombus. The application of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) for discrimination between tumor extension and blood thrombus has been reported in few cases of HCC, while portal tumor thrombosis and portal vein clot identified by 18F-FDG PET/CT in HCC patients has not been reported so far. We present two HCC cases, one with portal vein tumor thrombus and one thrombosis who were identified with 18F-FDG PET/CT. This report illustrates the complimentary value of combining the morphological and functional imaging in achieving a correct diagnosis in such clinical situations.

Clinical anatomy of hepatic vessels by computed tomography angiography:A minireview

The liver has a complex vascular anatomy with a unique dual blood supply.Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma.In most vascular disorders,the effects on the liver are generally subclinical because of its abundant blood supply.However,early diagnosis of such vascular diseases can significantly reduce patient morbidity and mortality.Because imaging findings of vascular disease are not always readily apparent,diagnosis can be difficult.Computed tomography angiography is an excellent imaging modality for visualizing the vascular anatomy of patients for treatment planning.In this review article,we focus on the vascular anatomy of the liver and the imaging findings in some acute hepatic vascular diseases.

Computed tomography findings in fatal cases of enormous hepatic portal venous gas

AIM: To assess the computed tomography (CT) findings in the patients with hepatic portal venous gas (HPVG) who presented with a short fatal clinical course in our hospital in order to demonstrate if there was any sign for prediction.METHODS: Between January 1997 and December 2000, CT scan of the abdomen was performed on 949 patients with acute abdominal pain in our emergency department.Five patients were found having HPVG. The CT images and clinical presentations of all these five patients were reviewed. RESULTS: In reviewing the CT findings of the cases, HPVG in bilateral hepatic lobes, abnormal gas in the superior mesenteric veins, small bowel intramural gas, and bowel distension were observed in all patients. Dry gas in multiple branches of the mesenteric vein was also revealed in all cases. All the patients expired due to irreversible septic shock within 48 h after their initial clinical presentation in emergency room. Two patients had acute pancreatitis with grade D and E Balthazar classification and they expired within 24 h due to progressing septic shock under aggressive medical treatment and life support. Two patients with underlying end stage renal disease expired within 48 h even though emergent surgical intervention was undertaken. The excited bowels revealed severe ischemic change. One patient expired only a few hours after the CT examination. CONCLUSION: HPVG is a diagnostic clue in patients with acute abdominal conditions, and CT is the most specific diagnostic tool for its evaluation. The dry mesenteric veins are the suggestive fatal sign, especially for the deteriorating patients, with the direct effect on gastrointestinal perfusion.

Computed tomography perfusion study of hemodynamic changes and portal hyperperfusion in a rabbit model of small-for-size liver

BACKGROUND:Portal hyperperfusion in the small-for-size (SFS) liver can threaten survival of rabbits.Therefore,it is important to understand the hemodynamic changes in the SFS liver.METHODS:Twenty rabbits were divided into two groups:a control group and a modulation group.The control group underwent an extended hepatectomy.The modulation group underwent the same procedure plus splenectomy to reduce portal blood flow.CT perfusion examinations were performed on all rabbits before and after operation.Perfusion parameter values,especially portal vein perfusion (PVP),were analyzed.RESULTS:PVP in the modulation group was lower than in the control group after operation (P=0.002).In the control group,postoperative PVP increased by 193.7±55.1% compared with preoperative PVP.A weak correlation was found between the increased percentage of PVP and resected liver-to-body weight ratio (RLBWR) (r=0.465,P=0.033).In the modulation group,postoperative PVP increased by 101.4±32.5%.No correlation was found between the increased percentage of PVP and RLBWR (r=0.167,P=0.644).Correlations were found between PVP and serum alanine aminotransferase,aspartate aminotransferase,and total bilirubin after surgery (P<0.05).CONCLUSION:We successfully evaluated the characteristics of hemodynamic changes as well as the effects of splenectomy in the SFS liver in rabbits by the CT technique.

Abdominal cross-sectional imaging of the associating liver partition and portal vein ligation for staged hepatectomy procedure

Associating liver partition and portal vein ligation for staged hepatectomy(ALPPS) is a recently introduced technique aimed to perform two-stage hepatectomy in patients with a variety of primary or secondary neoplastic lesions. ALPSS is based on a preliminary liver resection associated with ligation of the portal branch directed to the diseased hemiliver(DH), followed by hepatectomy after an interval of time in which the future liver remnant(FLR) hypertrophied adequately(partly because of preserved arterialization of the DH). Multidetector computed tomography(MDCT) and magnetic resonance imaging(MRI) play a pivotal role in patients' selection and FLR assessment before and after the procedure, as well as in monitoring early and late complications, as we aim to review in this paper. Moreover, we illustrate main abdominal MDCT and MRI findings related to ALPPS.

Treatment of portal vein tumor thrombus using ^(125)Iodine seed implantation brachytherapy

We reported two cases of liver metastasis with portal vein tumor thrombus that developed after liver transplantation for hepato cellular carcinoma (HCC). Both the patients were women aged 43 and 55 years, who had liver metastasis and portal vein tumor thrombus formation after liver transplantations for HCC.

CT diagnosis of cavernous transformation of portal vein

Objective: To study the CT features of cavernous transformation of the portal vein (CTPV) and to evaluate the diagnostic reliability of CT. Methods: Ten patients with CTPV underwent abdominal precontrast and contrast CT. The CT findings were compared with DSA and surgical findings. Results: Characteristic features included loss of the normal structure of the portal system and the presence of multiple, sinuous, periportal vascular structures which were enhanced during the portal phase. Transient abnormality of hepatic perfusion, characterized by the image of homogeneous bands, can be observed in arterial phase, which is not detectable in venous phase. Conclusion: CT proved to be reliable for the diagnosis of CTPV, and provides essential information for clinical treatment planning. Additional DSA examination and US were indicated for atypical patients for a more reliable diagnosis.

Diagnostic Value of 16 Slices Spiral-CT for Portal Vein Disorders

Summary: The diagnostic value of 16-slices spiral computed tomography (CT) for portal vein disorders was evaluated. Forty-one patients were scanned by the 16-slices spiral-CT. The celiac trunk, portal vein and their branches were reconstructed by volume rendering (VR), multiplanar volume reconstruction (MPVR) and maximum intensity projection (MIP) technique, and the results were compared with digital subtraction angiography (DSA). VR, MPVR and MIP could display celiac trunk, portal vein, inferior vena cava and their branches and extent of portal vein-vena cava shunt, portal vein emboli and the fistula of hepatic artery-portal vein. The results from 16-slices CT were better than DSA and identical with pathologic ones. The vessel three-dimension reconstruction technique of 16-slices spiral CT is valuable for evaluating the portal systemic disorders.

Significance of an Advanced Image-Based Virtual Monoenergetic Reconstruction of Dual Source Dual-Energy CT Data at Low keV Increases Image Quality for Portal Vein System of Pancreatic Cancer Patients

Purpose: To explore the significance of dual-source computed tomography (DECT) virtual monoenergetic reconstructions technology in improving image quality for portal vein system of pancreatic cancer patients. Materials and methods: 47 patients with clinically suspected pancreatic cancer (all confirmed by pathology) were collected. Routine plain scan was performed with Siemens Force dual-source dual-energy CT followed by 3 scans respectively carried out in arterial phase, portal phase and delayed phase. Traditional virtual monoenergetic reconstructions (Mono_E) and new generation of virtual monoenergetic reconstructions (Mono+) were respectively performed on portal vein images to obtain virtual single energy images including Mono_ E70 keV, Mono_E 55 keV and Mono+ 70 keV and Mono+ 55 keV. The signal-to-noise ratio (SNR) and noise of portal vein, normal pancreatic tissues and pancreatic lesions of 100 kV, Mono_E and Mono+ images were compared. In addition, the contrast noise ratio of portal vein and lesions as well as pancreatic tissues and lesions (CNR PV, CNRtumor) were also compared. At the same time, two imaging physicians with rich clinical experiences read the films and scored the images of each group by using the 5-point scoring method. Results: Mono+ 55 keV images including SNRpv, SNRpanc, SNRtumor, Noise, CNRpv, CNRtumor were statistically different from 100 KV images and Mono_E images (P < 0.05). As for the subjective score, Mono+ 55 keV image score also had the highest score, which had statistical significance (P < 0.05). The results showed that Mono+ 55 keV images had the best quality. Conclusion: The new generation of virtual Mono+ post-treatment can reduce image noise. Low energy Mono+ images can improve the contrast between pancreatic cancer lesions and portal of pancreatic cancer patients.

Functional transition:Inconsistently parallel to the increase in future liver remnant volume after preoperative portal vein embolization

BACKGROUND Preoperative portal vein embolization(PVE)is a widely used strategy to enable major hepatectomy in patients with insufficient liver remnant.PVE induces hypertrophy of the future liver remnant(FLR)and a shift of the functional reserve to the FLR.However,whether the increase of the FLR volume(FLRV)corresponds to the functional transition after PVE remains unclear.AIM To investigate the sequential relationship between the increase in FLRV and functional transition after preoperative PVE using 3-dimensional(3D)computed tomography(CT)and 99mTc-galactosyl-human serum albumin(99mTc-GSA)singlephoton emission computed tomography(SPECT)fusion images.METHODS Thirty-three patients who underwent major hepatectomy following PVE at the Department of Gastroenterological Surgery I,Hokkaido University Hospital between October 2013 and March 2018 were enrolled.Three-phase dynamic multidetector CT and 99mTc-GSA SPECT scintigraphy were performed at pre-PVE,and at 1 and 2 wk after PVE;3D 99mTc-GSA SPECT CT-fused images were constructed from the Digital Imaging and Communications in Medicine data using 3D image analysis system.Functional FLRV(FFLRV)was defined as the total liver volume×(FLR volume counts/total liver volume counts)on the 3D 99m Tc-GSA SPECT CT-fused images.The calculated FFLRV was compared with FLRV.RESULTS FFLRV increased by a significantly larger extent than FLRV at 1 and 2 wk after PVE(P<0.01).The increase in FFLRV and FLRV was 55.1%±41.6%and 26.7%±17.8%(P<0.001),respectively,at 1 wk after PVE,and 64.2%±33.3%and 36.8%±18.9%(P<0.001),respectively,at 2 wk after PVE.In 3 of the 33 patients,FFLRV levels decreased below FLRV at 2 wk.One of the three patients showed rapidly progressive fatty changes in FLR.The biopsy at 4 wk after PVE showed macroand micro-vesicular steatosis of more than 40%,which improved to 10%.Radical resection was performed at 13 wk after PVE.The patient recovered uneventfully without any symptoms of pos-toperative liver failure.CONCLUSION The functional transition lagged behind the increase in FLRV after PVE in some cases.Evaluating both volume and function is needed to determine the optimal timing of hepatectomy after PVE.

双源CT双动脉期增强扫描对肝动脉-门静脉瘘的评估价值及风险因素分析

目的:探讨双源CT双动脉期增强扫描模式对肝动脉-门静脉瘘(HAPVF)的评估价值及风险因素分析。方法:选取HAPVF和非HAPVF患者各60例,分别为HAPVF组和非HAPVF组,行双源CT双动脉期增强扫描,比较2组临床指标及CT征象差异。以DSA为金标准,对比动脉早期、动脉晚期和双动脉期对HAPVF的诊断敏感度、特异度,以及对HAPVF分型的诊断准确率。应用logistic回归分析探讨HAPVF的危险因素,采用ROC曲线评估危险因素预测HAPVF的价值。结果:双动脉期诊断HAPVF的敏感度、特异度、阳性预测值、阴性预测值及分型准确率均明显高于单独2期(均P<0.05)。2组肝癌大小、包膜类型、门静脉癌栓比较,差异均有统计学意义(均P<0.05)。logistic回归分析显示,肝癌大小、包膜类型、门静脉癌栓均是HAPVF的独立危险因素。ROC曲线表明,单因素预测HAPVF效果最好的是包膜类型,其次是门静脉癌栓,再次是肝癌大小。综合多因素联合预测分析显示,肝癌大小+包膜类型+门静脉癌栓预测效果最好。结论:双源CT双动脉期增强扫描模式对HAPVF的诊断敏感度、特异度较高,且在HAPVF分型中具有较好的诊断效果。HAPVF的临床及影像学征象具有一定特点,其中肝癌大小、包膜类型、门静脉癌栓均是HAPVF的独立危险因素,三者联合预测效果最好,能为临床及时诊治提供可靠依据。

探究1024×1024重建矩阵结合Karl算法对CT门静脉成像的门脉图像质量和肝脏体积测量的影响

目的:探究1024×1024重建矩阵结合Karl算法对CT门静脉成像的门脉图像质量和肝脏体积测量的影响。方法:回顾性分析行全腹部增强CT检查的患者40例,所有患者均采用联影uCT760进行扫描。成像参数:管电压120 kV,管电流设置为剂量调制等级3,重建512×512矩阵,Karl 5级图像,获得图像为常规组(A组)。使用常规组的原始数据重建得到实验组(B组)图像:采用1024×1024矩阵,结合Karl 5、7、9级重建获得B_(1)~B_(3)组图像。应用联影智能科研平台系统测量肝脏体积,比较A、B两组门静脉和肝脏CT值、标准差(SD)值、对比噪声比(CNR)、肝脏体积值及图像主观评分。结果:B组门静脉和肝脏CT值与A组比较差异无统计学意义(P=0.079~0.766)。随着Karl等级的提高,B组门静脉和肝脏的SD值逐渐下降(P<0.001),CNR逐渐升高(P<0.001),肝脏体积值差异无统计学意义(P=0.999)。主观评价上,随着Karl等级的增加,B组伪影评分逐渐降低(P<0.05),图像噪声、门静脉边缘锐利度、远端血管显示清晰度及显示的门静脉分支数逐渐提高(P<0.05),B3组图像质量最佳,优于A组。结论:采用1024×1024重建矩阵结合Karl 9级重建算法能够优化门静脉图像质量,且准确测量肝脏体积。

ASIR算法对肝硬化患者碘摄入量、辐射剂量及门静脉CT图像质量的影响

目的 研究自适应统计迭代重建(ASIR)算法对肝硬化患者碘摄入量、辐射剂量及门静脉计算机断层扫描(CT)图像质量的影响。方法 以2020年1月至2022年12月河南中医药大学第一附属医院收治的68例肝硬化患者为研究对象,采用随机数字表法分为滤波反投影法(FBP)组(34例)和ASIR组(34例)。所有患者均进行门静脉CT检查,其中FBP组进行FBP重建(0%ASIR),对比剂用量450 mgI·kg^(-1),管电压100 kV;ASIR组进行ASIR重建(40%ASIR),对比剂用量350 mgI·kg^(-1),管电压100 kV。统计两组一般资料,比较两组碘摄入量、辐射剂量及门静脉CT、对比噪声比(CNR)、信噪比(SNR)值、图像质量主观评分。结果 ASIR组碘摄入量低于FBP组(P<0.05);ASIR组和FBP组有效剂量(ED)、CT剂量容积指数(CTDIvol)、剂量长度乘积(DLP)比较,差异无统计学意义(P>0.05)。ASIR组门静脉主干、右支、左支CT、CNR、SNR值及门静脉图像噪声、伪影、门静脉3级分支结构显示主观评分均高于FBP组(P<0.05)。结论 与FBP重建相比,ASIR重建用于肝硬化患者门静脉CT检查可提高门静脉CT、CNR、SNR值,提高CT成像的客观和主观图像质量,但可有效降低碘摄入量,且不会增加辐射剂量,有助于提高安全性。

有无肝硬化肝细胞癌患者的影像特征及实验室检查指标间的比较研究

目的:比较有、无肝硬化肝细胞癌(HCC)患者的CT特征、测量参数、各期扫描CT值及实验室检查指标的差异,以提高HCC的诊断准确率。方法:回顾性收集经病理证实且未经治疗的52例HCC患者的CT及实验室检查资料。分析CT特征,并测量门静脉最大径、肝脏和病灶体积、最大截面面积及各期扫描CT值。52例根据是否合并肝硬化分为合并肝硬化组24例和无肝硬化组28例。2组计数资料比较行χ^(2)检验,正态分布和非正态分布的计量资料分别行独立样本t检验和Mann-WhitneyU检验。CT特征、测量参数与实验室检查指标间行Spearman相关分析。结果:2组年龄和性别差异均无统计学意义(P=0.073,0.463);2组胆碱酯酶、直接胆红素、间接胆红素和AFP水平差异均有统计学意义(均P<0.05)。2组病灶CT征象、肝脏和病灶体积、最大截面面积差异均无统计学意义(均P>0.05),肝实质门静脉期和病灶平扫CT值、腹水和/或脾大情况及门静脉最大径差异均有统计学意义(均P<0.05)。HCC病灶体积与病灶坏死、形状、转移情况、肝脏体积及部分血清酶水平均呈正相关,与病灶平扫、门静脉期和延迟期CT值呈负相关。肝硬化与腹水和/或脾大、门静脉最大径、直接胆红素、间接胆红素及AFP呈正相关。结论:HCC合并肝硬化组与无肝硬化组间在CT特征、测量参数等方面差异不明显;合并肝硬化组多发生腹水及门脉高压表现;HCC病灶大小与实验室检查指标密切相关。

双层探测器光谱CT 100 kVp单能量图像在门静脉成像中的应用

目的评估第二代双层探测器光谱CT(DLCT)在100 kVp低辐射剂量条件下CT门静脉成像(CTPV)的图像质量。方法收集2023年5月—2024年3月在武汉亚心总医院使用DLCT扫描的腹部增强检查110例[男54例,女56例,(57.47±15.07)岁]。采用随机法分为对照组A组120 kVp(n=50)与研究组B组100 kVp(n=60)。将A组CTPV的原始数据重建为常规混合能量图像(CI),B组CTPV的原始数据重建为CI和40~80 keV(间隔10 keV)的虚拟单能量图像(VMI)。测量所有图像的门静脉主干及左右分支的CT值、标准差(SD)、信噪比(SNR)和对比信噪比(CNR),并由两位影像科医生进行主观图像质量评分。结果A组有效辐射剂量(ED)为(4.05±1.23)mSv,B组为(1.92±0.21)mSv,辐射剂量降低了52.59%。B组40、50、60 keV VMI的门静脉及其分支平均CT值、SNR和CNR均高于A、B两组的CI(所有P<0.0001),其中40和50 keV VMI的SNR和CNR最高,两者间差异无显著性(P<0.05)。40和50 keV VMI的SD和A组处于相同的水平(P>0.05),60~80 keV VMI的SD显著低于A组(P<0.05)。主观图像质量评估显示50 keV VMI评分为5分(最佳)的占比最高(75%),主观一致性较好(所有Kappa值>0.8)。结论采用100 kVp DLCT的50 keV VMI,和120 kVp的常规图像相比,降低辐射剂量的同时,可获得满足临床诊断需求的图像质量。

Extensive hepatic-portal and mesenteric venous gas due to sigmoid diverticulitis

Hepatic portal venous gas is most often associated with extensive bowel necrosis due to mesenteric infarction.Mortality exceeds 75% with this condition.The most common precipitating factors include ischemia,intra-abdominal abscesses and inflammatory bowel disease.In this report,we present a 75-year-old woman with extensive hepatic portal and mesenteric venous gas due to colonic diverticulitis.She had a 10-year history of type diabetes mellitus and hypertension.She was treated by sigmoid resection and Hartmann's procedure and discharged from the hospital without any complications.

Contrast-enhanced ultrasound in portal venous system aneurysms: A multi-center study

AIM: To investigate contrast-enhanced ultrasound (CEUS) findings in portal venous system aneurysms (PVSAs).

Incidental meandering right pulmonary vein,literature review and proposed nomenclature revision

We report a case of an anomalous pulmonary vein on chest X-ray resembling a scimitar sign in an 80-year-old female undergoing investigation of syncope.Multislice computed tomography(CT) with multiplanar reformatting and maximum intensity projections demonstrated an aberrant right inferior pulmonary vein coursing inferomedially towards the diaphragm before turning superiorly and draining normally into the left atrium.The diagnosis of an incidental meandering right pulmonary vein was established.The case is used to review the literature on this rare pulmonary anomaly,including pathogenesis,its relationship with scimitar syndrome and scimitar variant,and diagnosis,with an emphasis on the role modern CT techniques can play in noninvasive diagnosis.A revision to the nomenclature of pulmonary vascular anomalies is proposed to help reduce confusion in the literature.

64层螺旋CT门静脉造影对门静脉高压侧支循环的研究

目的评价64层螺旋CT门静脉造影对门静脉高压侧支循环的诊断价值。方法正常者30例、肝硬化患者27例,行64层螺旋CT门静脉造影检查,容积数据采用最大强度投影法(MIP)、容积再现法(VR)及多平面重组法(MPR)三维重建,观察门静脉高压肝内门静脉、属支及侧支循环的影像学特征。结果64层螺旋CT门静脉造影能准确显示侧支循环分布范围、初步评估病变程度;门静脉高压症组门静脉属支管径显著大于正常组(P=0.000);肝功能对于其管径改变无显著影响(P值分别为0.343、0.778、0.367、0.370);脾/胃-肾静脉分流的存在对门静脉直径有影响(P=0.000);脾静脉与胃左静脉共同分担门静脉压力及参与胃脾区高压形成,两者直径呈正相关性(r=0.653,P=0.000);64层螺旋CT诊断食管胃底静脉曲张与胃镜诊断有高度一致性(Kappa值为0.832)。结论64层螺旋CT门静脉造影能够多角度、立体观察侧支循环情况,对预测其并发症、手术方案的制定具有重要的指导意义。