Large regenerative nodules in a patient with Budd-Chiari syndrome after TIPS positioning while on the liver transplantation list diagnosed by Gd-EOB-DTPA MRI

BACKGROUND:Large regenerative nodules (LRNs) are hyperplastic benign nodules most commonly associated with Budd-Chiari syndrome (BCS),caused by outflow obstruction of the hepatic veins or vena cava.To our knowledge,no cases of LRNs arising in BCS after transjugular intrahepatic portosystemic shunt (TIPS) positioning and detected by GdEOB-DTPA MRI have been reported in the literature.METHODS:A 58-year-old woman with BCS,on the liver transplantation (LT) list,underwent a follow-up enhanced MRI.Two years earlier,a TIPS had been placed.In 2008,recurrent hepaticoencephalopathy resistant to medical treatment fulfilled the LT criteria for BCS treated with TIPS and the patient was therefore added to the LT list.CT performed before TIPS had not detected any hepatic lesions.CT performed six months after TIPS showed its complete patency but documented two indeterminate hypervascular liver lesions.RESULTS:MRI performed with Gd-EOB-DTPA revealed additional hypervascular lesions with uptake and retention of the medium in the hepatobiliary phase,thus reflecting a benign behavior of hepatocellular composition.These MRI features were related to LRNs as confirmed by histopathologic analysis.CONCLUSIONS:Gd-EOB-DTPA-enhanced MRI is potentially superior to standard imaging using gadolinium chelates or spiral CT,especially for the differential diagnosis of hypervascular lesions.Gd-EOB-DTPA MRI may become the imaging method of choice for evaluating LT list patients with BCS after TIPS placement.

Non-cirrhotic portal hypertension with large regenerative nodules: A diagnostic challenge

Non-cirrhotic portal hypertension is a poorly understood condition characterized by portal hypertension in the absence of conventional hepatic cirrhosis and described in association with blood coagulation disorders, myeloproliferative and immunological diseases and with exposure to toxic drugs. Very recently, precise classification criteria have been proposed in order to define four distinct subcategories. The present case highlights how the clinical presentation, the confounding results from imaging studies, and the difficulties in the histological evaluation often render cases of non-cirrhotic portal hypertension a real diagnostic challenge. It also underscores the classification problems which can be faced once this diagnosis is performed. Indeed, the different subcategories proposed result from the prevalent subtypes in a spectrum of hepatic regenerative responses to a variety of injuries determining microcirculatory dis-turbances. More flexibility in classification should derive from this etiopathogenic background.

MR Features of Regenerative Nodules and Dysplastic Nodules in the Cirrhotic Liver

Summary： In order to study MR features of the regenerative nodule （RN） and dysplastic nodule （DN） of the cirrhotic liver, 26 cases of cirrhotic liver with RNs and DNs, of which 8 cases accompanied with hepatocellular carcinoma, were subjected to MRI. Eighteen of 26 cases underwent additional enhanced MRI with administration of Gd-DTPA on T1WI and 10 of the 18 cases did additional SPIO （Feridex） enhancement on T2W1. Clinical data showed normal level of α-fetoprotein in 18 cases except 8 cases accompanied with HCC. The results showed that 12 cases had RNs with nodules measuring 〈1 cm. The MR appearance of those RNs showed isointensity on T1WI and hypointensity on T2WI. The intensity of those RNs was isointense to the surrounding hepatic parenchyma on enhanced MRI with administration of Gd-DTPA or SPIO. Among the 14 cases of DNs, 8 cases had nodules measuring 1-3 cm in size and 6 had macroregenerative nodule measuring 〉3 cm. In 8 cases with DNs measuring 1-3 cm in size, 5 cases appeared hyperintense on T1W1 and hypointense on T2W1 as well as the enhancement as that of nodules with （1 cm in size; and the remaining 3 cases appeared hypointense on T1WI and hyperintense on T2WI, and were not isointense to the surrounding hepatic parenchyma on enhanced MRI but hyperintense on SPIO enhanced MRI. In 6 cases of macroregenerative nodule measuring 2〉3 cm in size, 2 cases appeared hyperintense to the surrounding hepatic parenchyma on T1, T2WI and enhanced MRI; 4 cases showed hyperintense on TlWI, and hypointense on T2WI and enhanced MRI. Sometimes, normal vessels were seen to pass through the surface of macroregenerative nodules. It was suggested that RNs of cirrhosis had features on MRI that usually allow distinction from hepatocellular carcinoma but not always from dysplastic nodules （DNs）. A helpful distinction between HCC and DNs is that the latter are almost never hyperintense on T2WI. Additionally, low grade DNs appear hypoimense on SPIO enhanced MR1.

Classification tool for the systematic histological assessment of hepatocellular carcinoma, macroregenerative nodules, and dysplastic nodules in cirrhotic liver

AIM： To design a classification tool for the histological assessment of hepatocellular carcinoma （HCC）, dysplastic nodules （DN）, and macroregenerative nodules （MRN） in cirrhotic liver. METHODS： Two hundred and twelve hepatocellular nodules （106 HCC; 74 IRN, 32 DN） were assessed systematically, quantitatively, and semiquantitatively as appropriate for 10 histological features that have been described as helpful in distinguishing small HCC, DN, and MRN in cirrhotic livers. The data were analyzed by multiple correspondence analysis （MCA）. RESULTS： HCA distributed HCC, DN, and HRN as defined by traditional histological evaluation as well as the individual histological variables, in a ＂malignancy scale＂. Based on the MCA data representation, we created a classification tool, which categorizes an individual nodular lesion as MRN, DN, or HCC based on the balance of all histological features （i.e., vascular invasion, capsular invasion, tumor necrosis, tumor heterogeneity, reticulin loss, capillarization of sinusoids, trabecular thickness, nuclear atypia, and mitotic activity）. The classification tool classified most （83%） of a validation set of 47 nodules in the same way as the routine histological assessment. No discrepandes were present for DN and MRN between the routine histological assignment and the dassification tool. Of 25 HCC assigned by routine assessment in the validation set, 8 were assigned to the DN category by the classification tool. CONCLUSION： We have designed a classification tool for the histological assessment of HCC and its putative precursors in cirrhotic liver. Application of this toolsystematically records histological features of diagnostic importance in the evaluation of small HCC.

Evaluation of contrast-enhanced ultrasound for diagnosis of dysplastic nodules with a focus of hepatocellular carcinoma in liver cirrhosis patients

Objective： To compare the enhancement features of dysplastic nodnles with a focus of hepatocellular carcinoma （DN-HCC） versus HCC and regenerative nodules （RN） in cirrhotic patients. Methods： One hundred and ninety-three cirrhotic patients were enrolled in this study; they had 215 focal liver lesions, 1.0-3.5 cm in size, which were examined using contrast-enhanced ultrasound （CEUS） with SonoVue and diagnosed as HCC, RN or DN-HCC by biopsy. Samples were obtained using 18-gauge needles in the different enhanced areas. The enhancement features of DN-HCC, HCC and RN were evaluated. Results： There were 86 HCC lesions, 102 RN lesions, and 27 DN-HCC lesions diagnosed by biopsy. Of 86 HCC lesions, 87.2% （75/86） showed complete enhancement during the arterial phase, and 12.8% （11/86） had inhomogeneous enhancement, with no enhancement in the central area during the arterial phase; 100% （86/86） exhibited washout during the late phase. Of 102 RN lesions, 95.1% （97/102） had delayed or simultaneous enhancement during the arterial phase, and 4.9% （5/102） displayed slight enhancement during the arterial phase; 26.5% （27/102） exhibited washout and 73.5% （75/102） exhibited no washout during the late phase. In 27 DN-HCC lesions, only part of the lesions enhanced during the arterial phase and washed out during the late phase; the other areas had delayed or simultaneous enhancement during the arterial phase, and 29.6% （8/27） exhibited slight washout in the late phase. In 86 HCCs, the pathological feature was HCC in the enhanced area of 75 lesions, hepatocellular fatty degeneration in the slightly enhanced area of 7 lesions, and hepatocellular necrosis in the unenhanced area and HCC in the enhanced area of 4 lesions. In 102 RNs, the pathological diagnosis was hepatocyte proliferation with or without fatty degeneration. In 27 DN-HCCs, the pathological feature was HCC in the enhanced area and hepatocye regeneration in the unenhanced area. Conclusions： CEUS is useful for the diagnosis of focal liver lesions in cirrhotic patients. CEUS can help determine the progression from RN to DN-HCC to HCC by analyzing the hemodynamics. CEUS can promote the diagnostic accuracy of a biopsy by providing more accurate information on the site of the biopsy.

Mineralogy of Manganese Oxide Minerals in Iron Manganese Nodules of Several Main Soils in China

X-ray diffraction and selective chemical dissolution methods were used to investigate the composition of Mn oxide minerals in Fe-Mn nodules of several main types of soils in China. The changes of relative intensity of X-ray diffraction patterns were studied both before and after chemically selective dissolution. It was found that lithiophorite was a common Mn oxide in all examined Fe-Mn nodules. Todorokite, however, was a predominant Mn oxide in Fe-Mn nodules in caf-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules of arp-udic Luvisols in Wuhan and Zaoyang, Hubei Province, contained birnessite and vernadite. Hollandite was found in Fe-Mn nodules of alt-udic Ferrisols of Yizhang, Hunan Province; arp-udic Luvisols of Zaoyang, Hubei Province; and cal-aquic Vertisols of Linyi, Shandong Province. The Fe-Mn nodules in alt-udic Ferrisols of Guiyang, Hunan Province, had a few coronadites. Mineralogy of Mn oxide minerals in soil Fe-Mn nodules was related to soil environment, soil types and quantities of relevant cations.

Hydrogenation reaction characteristics and properties of its hydrides for magnetic regenerative material HoCu_2

The hydrogenation reaction characteristics and the properties of its hydrides for the magnetic regenerative material HoCu_2(CeCu_2-type) of a cryocooler were investigated. The XRD testing reveals that the hydrides of HoCu_2 were a mixture of Cu, unknown hydride Ⅰ, and unknown hydride Ⅱ. Based on the PCT(pressure-concentration-temperature) curves under different reaction temperatures, the relationships among reaction temperature, equilibrium pressure, and maximum hydrogen absorption capacity were analyzed and discussed. The enthalpy change ΔH and entropy change ΔS as a result of the whole hydrogenation process were also calculated from the PCT curves. The magnetization and volumetric specific heat capacity of the hydride were also measured by SQUID magnetometer and PPMS, respectively.

Evaluation of the dual vascular supply patterns in ground-glass nodules with a dynamic volume computed tomography

BACKGROUND In recent years,the detection rate of ground-glass nodules(GGNs)has been improved dramatically due to the popularization of low-dose computed tomography(CT)screening with high-resolution CT technique.This presents challenges for the characterization and management of the GGNs,which depends on a thorough investigation and sufficient diagnostic knowledge of the GGNs.In most diagnostic studies of the GGNs,morphological manifestations are used to differentiate benignancy and malignancy.In contrast,few studies are dedicated to the assessment of the hemodynamics,i.e.,perfusion parameters of the GGNs.AIM To assess the dual vascular supply patterns of GGNs on different histopathology and opacities.METHODS Forty-seven GGNs from 47 patients were prospectively included and underwent the dynamic volume CT.Histopathologic diagnoses were obtained within two weeks after the CT examination.Blood flow from the bronchial artery[bronchial flow(BF)]and pulmonary artery[pulmonary flow(PF)]as well as the perfusion index(PI)=[PF/(PF+BF)]were obtained using first-pass dual-input CT perfusion analysis and compared respectively between different histopathology and lesion types(pure or mixed GGNs)and correlated with the attenuation values of the lesions using one-way ANOVA,student’s t test and Pearson correlation analysis.RESULTS Of the 47 GGNs(mean diameter,8.17 mm;range,5.3-12.7 mm),30(64%)were carcinoma,6(13%)were atypical adenomatous hyperplasia and 11(23%)were organizing pneumonia.All perfusion parameters(BF,PF and PI)demonstrated no significant difference among the three conditions(all P>0.05).The PFs were higher than the BFs in all the three conditions(all P<0.001).Of the 30 GGN carcinomas,14 showed mixed GGNs and 16 pure GGNs with a higher PI in the latter(P<0.01).Of the 17 benign GGNs,4 showed mixed GGNs and 13 pure GGNs with no significant difference of the PI between the GGN types(P=0.21).A negative correlation(r=-0.76,P<0.001)was demonstrated between the CT attenuation values and the PIs in the 30 GGN carcinomas.CONCLUSION The GGNs are perfused dominantly by the PF regardless of its histopathology while the weight of the BF in the GGN carcinomas increases gradually during the progress of its opacification.

A novel x-ray circularly polarized ranging method

Range measurement has found multiple applications in deep space missions. With more and further deep space ex- ploration activities happening now and in the future, the requirement for range measurement has risen. In view of the future ranging requirement, a novel x-ray polarized ranging method based on the circular polarization modulation is proposed, termed as x-ray circularly polarized ranging （XCPolR）. XCPolR utilizes the circular polarization modulation to process x-ray signals and the ranging information is conveyed by the circular polarization states. As the circular polarization states present good stability in space propagation and x-ray detectors have light weight and low power consumption, XCPolR shows great potential in the long-distance range measurement and provides an option for future deep space ranging. In this paper, we present a detailed illustration of XCPolR. Firstly, the structure of the polarized ranging system is described and the signal models in the ranging process are established mathematically. Then, the main factors that affect the ranging accuracy, including the Doppler effect, the differential demodulation, and the correlation error, are analyzed theoretically. Finally, numerical simulation is carded out to evaluate the performance of XCPolR.

Prospective Study of Low-and Standard-dose Chest CT for Pulmonary Nodule Detection:A Comparison of Image Quality,Size Measurements and Radiation Exposure

Objective:To comprehensively and accurately analyze the out-performance of low-dose chest CT(LDCT)vs.standard-dose CT(SDCT).Methods:The image quality,size measurements and radiation exposure for LDCT and SDCT protocols were evaluated.A total of 117 patients with extra-thoracic malignancies were prospectively enrolled for non-enhanced CT scanning using LDCT and SDCT protocols.Three experienced radiologists evaluated subjective image quality independently using a 5-point score system.Nodule detection efficiency was compared between LDCT and SDCT based on nodule characteristics(size and volume).Radiation metrics and organ doses were analyzed using Radimetrics.Results:The images acquired with the LDCT protocol yielded comparable quality to those acquired with the SDCT protocol.The sensitivity of LDCT for the detection of pulmonary nodules(n=650)was lower than that of SDCT(n=660).There was no significant difference in the diameter and volume of pulmonary nodules between LDCT and SDCT(for BMI<22 kg/m^(2),4.37 vs.4.46 mm,and 43.66 vs.46.36 mm^(3);for BMI>22 kg/m^(2),4.3 vs.4.41 mm,and 41.66 vs.44.86 mm^(3))(P>0.05).The individualized volume CT dose index(CTDI_(vol)),the size specific dose estimate and effective dose were significantly reduced in the LDCT group compared with the SDCT group(all P<0.0001).This was especially true for dose-sensitive organs such as the lung(for BMI<22 kg/m^(2),2.62 vs.12.54 mSV,and for BMI>22 kg/m^(2),1.62 vs.9.79 mSV)and the breast(for BMI<22 kg/m^(2),2.52 vs.10.93 mSV,and for BMI>22 kg/m^(2),1.53 vs.9.01 mSV)(P<0.0001).Conclusion:These results suggest that with the increases in image noise,LDCT and SDCT exhibited a comparable image quality and sensitivity.The LDCT protocol for chest scans may reduce radiation exposure by about 80% compared to the SDCT protocol.

Attention Based Multi-Patched 3D-CNNs with Hybrid Fusion Architecture for Reducing False Positives during Lung Nodule Detection

In lung nodules there is a huge variation in structural properties like Shape, Surface Texture. Even the spatial properties vary, where they can be found attached to lung walls, blood vessels in complex non-homogenous lung structures. Moreover, the nodules are of small size at their early stage of development. This poses a serious challenge to develop a Computer aided diagnosis (CAD) system with better false positive reduction. Hence, to reduce the false positives per scan and to deal with the challenges mentioned, this paper proposes a set of three diverse 3D Attention based CNN architectures (3D ACNN) whose predictions on given low dose Volumetric Computed Tomography (CT) scans are fused to achieve more effective and reliable results. Attention mechanism is employed to selectively concentrate/weigh more on nodule specific features and less weight age over other irrelevant features. By using this attention based mechanism in CNN unlike traditional methods there was a significant gain in the classification performance. Contextual dependencies are also taken into account by giving three patches of different sizes surrounding the nodule as input to the ACNN architectures. The system is trained and validated using a publicly available LUNA16 dataset in a 10 fold cross validation approach where a competition performance metric (CPM) score of 0.931 is achieved. The experimental results demonstrate that either a single patch or a single architecture in a one-to-one fashion that is adopted in earlier methods cannot achieve a better performance and signifies the necessity of fusing different multi patched architectures. Though the proposed system is mainly designed for pulmonary nodule detection it can be easily extended to classification tasks of any other 3D medical diagnostic computed tomography images where there is a huge variation and uncertainty in classification.

肝硬化再生结节与小肝癌结节的影像学特征分析

目的:分析肝硬化再生结节与小肝癌结节的影像学特征。方法:回顾性分析2020年6月—2023年6月贺州市人民医院收治的66例肝硬化患者的影像学资料,探讨肝硬化再生结节与小肝癌结节的影像学特征。结果:磁共振成像-弥散加权成像(MRI-DWI)扫描发现,肝硬化再生结节组患者平均病灶大小、表观弥散系数(ADC)均高于小肝癌结节组,差异均具有统计学意义(t=6.903、5.593,P<0.05);肝硬化再生结节组T_(1)WI稍高信号及等信号呈现率高于小肝癌结节组(χ^(2)=12.158、10.627,P<0.05),等信号或低信号呈现率则低于小肝癌结节组(χ^(2)=31.611,P<0.05);肝硬化再生结节组T_(2)WI低信号呈现率高于小肝癌结节组,等信号、高信号或稍高信号呈现率低于小肝癌结节组,差异具有统计学意义(χ^(2)=54.393,P<0.05)。结论:磁共振成像能够更好地鉴别出肝硬化再生结节与小肝癌结节,提高早期肝癌的诊断率。

Giant Hepatic Regenerative Nodule in a Patient With Hepatitis B Virus-related Cirrhosis

Hepatic regenerative nodules are reactive hepatocellular proliferations that develop in response to liver injury.Giant hepatic regenerative nodules of 10 cm or more are extremely rare and have only been reported in patients with biliary atresia or Alagille syndrome.A 50-year-old man presented with a pathologically confirmed giant 11.3×9.4×11.2 cm hepatic regenerative nodule and hepatitis B virus-related cirrhosis.Imaging of intrahepatic nodule included mild hyperenhancement in the portal phase of contrast-enhanced CT and the hepatobiliary phase in the gadoxetic acid-enhanced MRI scan,as well as the portal vein crossing through sign in the setting of liver cirrhosis.This case highlights the imaging characteristics of giant hepatic regenerative nodules in hepatitis cirrhosis.

肝硬化再生结节和退变结节的MRI表现:初步研究结果

目的 研究肝硬化再生结节和退变结节的MRI表现。资料与方法 前瞻性地研究 2 6例肝硬化再生结节和退变结节的MRI表现 ,其中合并肝癌 8例。 2 6例中有 12例行CT平扫 ,6例行CT增强扫描 ;2 6例均行MRI平扫 ,18例行Gd DTPA增强MRI,10例行超顺磁性氧化铁 (菲立磁 )增强MRI。临床实验室检查中 ,除 8例合并有肝癌的患者甲胎蛋白显著增高外 ,其余 18例甲胎蛋白均正常。结果 2 6例中 12例结节灶直径 <1cm ,8例在 1～3cm ,6例 >3cm。MRI表现 :12例直径 <1cm的结节灶在T1WI呈等信号 ,T2 WI呈低信号 ,Gd DTPA和菲立磁增强与正常肝实质呈同步强化 ,在CT上呈高密度改变。结节灶直径 1～ 3cm的 8例中 ,5例结节在T1WI呈高信号 ,T2 WI呈低信号 ,强化同前 ;另 3例在T1WI呈低信号的结节 ,在T2 WI呈高信号 ,其强化与正常肝实质不同步 ,在菲立磁增强扫描中呈高信号 ;CT平扫均呈等密度。 6例直径 >3cm的结节中 2例在T1WI、T2 WI均呈等高信号 ,菲立磁增强扫描呈高信号 ,Gd DTPA增强MRI示巨大结节较周围邻近正常肝组织信号高 ;4例在T1WI呈高信号 ,在T2 WI呈低信号 ,菲立磁增强扫描呈低信号 ,Gd DTPA增强扫描巨大结节无强化 ,较周围邻近正常肝组织信号低 ,有时可见血管经过巨大结节表面。CT显示 6例呈等或稍高密度。在MRI上可?

肝硬化结节及小肝癌患者3.0T MRI检查结果分析

目的评价3.0 T MRI检查在肝硬化再生性结节(RN)、异型增生性结节(DN)和小肝癌(SHCC)诊断和鉴别诊断中价值。方法回顾性分析经病理检查确诊的69例RN、DN及SHCC患者的3.0 T MRI平扫及容积采集技术(LAVA)三期动态增强扫描特点。结果 RN主要表现为T2WI低信号,动态增强方式呈"缓慢上升型";DN主要表现为T2WI高、低信号,信号较均匀结节的动态方式以"速升缓降型"为主,可有"结中结"(特征表现);SHCC主要表现为T1WI低信号、T2WI高信号,动态增强方式为"速升速降型"。结论肝硬化结节及小肝癌在3.0 T MRI上各有较为典型的表现,临床可据此进行诊断与鉴别诊断;对其他强化类型的肝脏病灶应结合肿瘤血管的扭曲增粗及包膜等表现排除SHCC。

DWI在肝硬化癌前病变鉴别诊断中的临床价值

目的探讨核磁共振弥散加权成像(DWI)技术ADC值在肝硬化再生结(RN)、癌前病变(DN)、早癌及原发性小肝癌(SHCC)的鉴别诊断中价值。方法采用ADC值测定结合容积采集技术LAVA动态扫描,在228例肝硬化患者中,再生结节性(RN)患者121例,DN结节9例,原发性肝癌98例,其中小肝癌(SHCC)及早期小癌(ESHCC)21例;正常组90例;测定ADC值的演变过程。结果本研究鉴别诊断RN结节、DN结节、HCC的检出率分别为45.15%、3.36%、36.57%,其中SHCC及ESHCC的检出率7.84%。测定RN结节的ADC值为(2.0±0.22)×10-3 mm2/s、DN结节的ADC值为(1.50±0.27)×10-3 mm2/s,演变为SHCC或ESHCC时其ADC值下降为(1.17±0.19)×10-3 mm2/s。结论随着肝硬化-再生结节-癌前结节-肝癌的病理演变过程,其ADC值呈逐渐下降趋势,各组ADC均值存在显著性差异(P<0.05),DWI技术可以对肝硬化各个阶段病变进行较为准确可信的判断。

肝内结节性病变MRI信号改变与血供的关系

【目的】以肝硬化基础上发生的再生性结节(RN)、增生性结节(DN)、小肝癌(SHCC)的MRI信号表现推断病灶的血供特点,分析病灶血供与信号变化的对应关系。【方法】对经病理证实的17个DN、16个RN和45个SHCC病灶进行回顾性分析,观察病灶的大小、信号强度、强化的方式和时间,推断病灶的血供特点,分析病灶血供与信号变化的关系。【结果】RN为T1WI高、T2WI低的信号,动态增强为缓慢上升型,提示动脉、门脉血供均少;DN在T1WI高、中、低信号均有,T2WI为等信号和稍高信号,动态增强为速升缓降型,提示动脉供血增多、门脉正常;SHCC以T1WI低、T2WI高信号为主,动态增强为速升速降型,提示动脉血供增多、门脉减少。由RN到SHCC,相应的T1WI和T2WI信号高低之间有统计学差异(P<0.05)。【结论】从RN到SHCC,动脉血供逐渐增多,门脉血供逐渐减少,T2WI信号由低转高,T1WI由高转低,血供与信号之间有一定的对应关系。

核磁共振对肝硬化肝内结节的诊断价值

目的总结肝硬化再生结节(RN)、肝不典型增生结节(DN)和小肝癌结节的核磁共振表现并探讨核磁共振(MR)诊断价值。方法回顾分析60例结节性肝硬化病例(合并DN 7个,肝癌结节16个)MR检查资料,患者行脂肪抑制的T1WI、T2WI、正反相位T1WI及动态增强扫描和弥散加权(DWI)扫描,总结肝内结节的信号特点。结果在常规脂肪抑制下肝硬化结节T1WI多为等信号或稍高信号,T2WI多为低信号,增强后与周围正常肝组织强化相似或信号稍低;DN在T1WI多为较高信号,T2WI多为稍低或等信号,增强后强化不明显;癌结节T1WI多为稍低或等信号,偶有稍高信号,T2WI多为较高信号,DWI为高信号,强化多为动脉中晚期强化,门静脉期以后强化减退。结论核磁共振可以对大多数RN、DN和小肝癌结节明确诊断和鉴别。

多层螺旋CT四期动态扫描对肝硬化小结节定性诊断的初步评价

目的评价多层螺旋CT(MSCT)四期动态扫描对肝硬化小结节的检出率,并对检出敏感性和定性准确性进行研究。方法经B超检查有直径小于3cm的肝硬化小结节者60例,行多层螺旋CT四期动态扫描,统计各期病灶的检出数,观察病灶强化方式,计算检出敏感性。采用美国GE公司的Lightspeed 4层螺旋扫描机行增强后四期扫描,第一期的延迟时间为25s,第二期为50s左右,第三期为90s,第四期180s。结果60例共发现72个,其中56个小肝癌,再生结节6个,退变结节10个。平扫发现36个病灶(63%,36/56);第一期、第二期、第三期及第四期病灶检出敏感性分别为66%、58%、50%、92%。结论肝硬变小结节增强扫描表现形式复杂,螺旋CT四期扫描可以充分显示肝硬化小结节各期的增强表现,充分反映小结节血供的特点,提高了病灶的检出率和定性诊断的准确率、

HBV相关肝硬化结节演变的多模态MRI研究

目的:通过与病理结果进行对照分析,总结肝硬化再生结节多步演变的多模态MRI影像特征,探讨肝硬化再生结节的早期诊断及鉴别诊断价值。方法:搜集乙肝肝硬化患者50例(85个结节),回顾性分析其MRI平扫及增强扫描资料,对病理证实的多步演变结果与对应的MRI影像表现进行对照研究。结果:MRI检出82个结节,检出率为96.5%,T2WI和动态增强扫描是检测再生结节较敏感的序列,检出率分别为93.9%和96.3%,磁敏感成像(SWI)的检出率稍低(69.5%);再生结节(RN)与低级不典型增生结节(LGDN)(χ2=8.348,P=0.004)、高级不典型增生结节(HGDN)与肝细胞癌(HCC)(χ2=4.612,P=0.032)的MRI诊断符合率差异均有统计学意义。T1WI图像上LGDN的信噪比(SNR)值与RN、HGDN、HCC比较差异均有统计学意义(P值均<0.05);T2WI图像上HCC的SNR值与RN、LGDN、HGDN比较差异均有统计学意义(P值均<0.05)。结论:MRI是目前检测肝硬化结节最敏感的无创性检查方法,通过MRI与病理的对照分析,多模态序列从不同角度反映了肝硬化再生结节的影像学特征及演变规律,对肝硬化再生结节的诊断及鉴别诊断具有一定价值。