脂肪肝的CT定量定性分析与中医证型相关性研究

目的:通过CT对非酒精性脂肪肝(NAFL)进行定性定量诊断分析,探讨NAFL的CT诊断与中医证型之间的相关性。方法:选取NAFL 229例,分为肝郁脾虚、痰湿内阻、痰瘀互结、肝肾不足、湿热内蕴5个中医证型,均行肝脏螺旋CT扫描,测量肝、脾CT值,将不同中医证型NAFL的轻中重CT分级及肝、脾CT比值进行统计分析。结果:中医证型之间CT定量诊断的轻、中、重分级差异有统计学意义(P<0.01);5个证型之间肝、脾CT比值差异有统计学意义(P<0.01),肝、脾CT比值按照秩次排列为肝郁脾虚证>湿热内蕴证>痰湿内阻证>痰瘀互结证>肝肾不足证。结论:NAFL的CT定量诊断与中医证型密切相关,各中医证型脂肪浸润程度的变化,与NAFL中医病因病机、证型演变相吻合,提示肝、脾CT比值可作为区分NAFL中医证型的客观性指标之一。     

^18F-FDG PET／CT在诊断转移性肝肿瘤中的应用

目的：探讨^18F-FDG PEF／CT在诊断转移性肝肿瘤中的应用。方法：回顾性分析49例转移性肝肿瘤患者的PET／CT影像资料,探讨^18F-FDG PET／CT诊断转移性肝肿瘤的影像表现及应用价值。结果：49例转移性肝肿瘤患者中45例^18F-FDG PET／CT表现为病灶^18F-FDG摄取明显高于周围正常肝组织;其中25例进行了延迟显像,22例表现为SUVmax及T／N值明显升高;发现肝转移同时伴有肝外转移患者38例。结论：^18F-FDG PET／CT诊断转移性肝肿瘤灵敏度高,准确,并可以同时对全身情况加以评价,对肿瘤患者肝转移的评价及治疗具有重要指导作用。     

肝衰竭的CT影像表现及病理对照

目的 探讨肝衰竭肝坏死和再生的CT影像表现.方法 回顾件分析5例肝衰竭患者原位肝移植术前的CT表现,并与术后的人体标本和病理结果 相对照,分析其影像特征.结果 肝衰竭的CT影像表现有3种:(1)大块状融合病灶2例:病理结果 分别为肝细胞的大块状坏死和聚合的结节样再生.CT平扫相应表现为地图样分布的低密度和高密度区;增强扫描肝内坏死区强化出现在静脉期,聚合的肝细胞结节样再生以动脉期强化明显.(2)弥漫的结节状病灶2例:病理结果 分别为肝内弥漫的结节状坏死和结节状再生.CT平扫均表现为弥漫的稍高密度结节灶;增强扫描动脉期均出现强化,前者静脉期及延迟期表现为结节状低密度灶,后者静脉期及延迟期表现为等密度改变.(3)多发小片状病灶1例:病理为肝内分散的肝细胞小片状坏死.平扣肝脏密度弥漫性减低;增强扫描静脉期表现为肝周的小片状强化,动脉期及延迟期为等密度改变.结论 肝衰竭的CT影像表现具有特征性.

Abstract：

Objective To investigate CT findings of hepatic necrosis and regeneration after liver failure.Methods Five patients with liver failure underwent CT scan before orthotopic liver transplantation.These findings were retrospectively reviewed and correlated with gross specimen and pathologic findings obtained after transplantation.Results Among 5 cases,the CT appearances of liver failure can be divided into 3 types.(1)Massive confluent aggregate foci in 2 patients demonstrated low attenuation and high attenuation as geographical patlerns on CT scans before contrast enhancement.respectively.The histopathological liver changes showed massive necrosis and regencratinn. Regions of necrosis enhanced to attenuation greater than that of normal liver parenchyma in portal-venous phase,the regions of regeneration enhanced to attenuation greater than that of normal liver parenchyma in arterial phase on postcontrast CT images.(2)In 2 patients,diffuse nodules of liver demonstrated high attenuation on plain CT scans,which was nodular necrosis and nodular regeneration pathologically.All enhanced to attenuation greater than that of normal liver parenchyma in arterial phase.The former showed hypointensity in portal-venous phase and equilibrium phase.The latter enhanced to attenuation equal to that of normal liver parenchyma in portalvenous phase and equilibrium phase on postcontrast CT images.(3)Multiple small foci in 1 case demonstrated low attenuatiun on precontrast CT images and enhanced to hyperintensity in portal-venous phase and isointensity in arterial phase and equilibrium phase on postcontrast CT images.The histopathological liver changes showed multiple necrosis.Conclusion Liver failure may reveal characteristic imaging patterns at CT.     

药物性肝病的CT表现与病理对照

目的:探讨药物性肝病的影像表现及其病理基础.方法:回顾性分析50例药物性肝病的临床、影像及病理资料,所有病例均行肝穿病理检查及腹部CT平扫和增强扫描.结果:50例药物性肝病的腹部CT扫描中48例出现异常,其中局灶性肝损害29例(58%),弥漫性肝脏损害14例(28%),肝硬化表现5例(10%);肝脏外形改变,表面欠光整...     

CT测定肝脏铁含量的研究进展

多种肝脏疾病和肝外疾病可致肝脏铁过载,引起和促使肝纤维化、肝硬化。临床已有的肝脏铁含量测定方法（肝穿刺活检、实验室检查、超导量子干涉仪、MRI和CT）分别存在不同程度的局限性。其中,CT作为肝脏疾病诊断常用的检查方法,近年来在肝脏铁含量测定方面取得了长足的进步,包括单能CT值估算法、双能CT差值法（△H法）和双能CT三物质分离算法（overlay法）。对CT测定肝脏铁含量的技术进展和临床应用进行综述。     

Hepatic steatosis: combined echography-computerized tomography imaging

The authors report their experience with the combined use of US and CT in the study of diffuse and subtotal fatty infiltration of the liver. An apparent disagreement was initially found between the two examinations in the study of fatty infiltration. Fifty-five patients were studied with US and CT of the upper abdomen, as suggested by clinics. US showed normal liver echogenicity in 30 patients and diffuse increased echogenicity (bright liver) in 25 cases. In 5 patients with bright liver, US demonstrated a solitary hypoechoic area, appearing as a "skip area", in the quadrate lobe. In 2 patients with bright liver, the hypoechoic area was seen in the right lobe and exhibited no typical US features of "skip area". Bright liver was quantified by measuring CT density of both liver and spleen. The relative attenuation values of spleen and liver were compared on plain and enhanced CT scans. In 5 cases with a hypoechoic area in the right lobe, CT findings were suggestive of hemangioma. A good correlation was found between bright liver and CT attenuation values, which decrease with increasing fat content of the liver. Moreover, CT attenuation values confirmed US findings in the study of typical "skip areas", by demonstrating normal density--which suggests that CT can characterize normal tissue in atypical "skip areas".     

Assessment of thermal sensitivity of CT during heating of liver:an ex vivo study

Objectives The purpose of this study was to assess the thermal sensitivity of CT during heating of ex-vivo animal liver. Methods Pig liver was indirectly heated from 20 to 90 °C by passage of hot air through a plastic tube. The temperature in the heated liver was measured using calibrated thermocouples. In addition, image acquisition was performed with a multislice CT scanner before and during heating of the liver sample. The reconstructed CT images were then analysed to assess the change of CT number as a function of temperature. Results During heating, a decrease in CT numbers was observed as a hypodense area on the CT images. In addition, the hypodense area extended outward from the heat source during heating. The analysis showed a linear decrease of CT number as a function of temperature. From this relationship, we derived a thermal sensitivity of CT for pig liver tissue of -0.54±0.03 HU °C(-1) with an r(2) value of 0.91. Conclusions The assessment of the thermal sensitivity of CT in ex-vivo pig liver tissue showed a linear dependency on temperature ≤90 °C. This result may be beneficial for the application of isotherms or thermal maps in CT images of liver tissue.     

放射治疗相关肝损伤的CT影像及其影响因素

放射治疗致肝损伤的病理表现为典型的肝静脉闭塞性疾病。正常肝脏、肝硬化肝脏放射性肝损伤CT平扫显示为照射区低密度改变,而脂肪肝放射性肝损伤显示为照射区高密度改变。正常肝脏、肝硬化肝脏动态CT增强扫描表现不同。放射性肝损伤的不同表现与肝脏基础相关。放射性肝损伤的发生与照射剂量、肝脏基础、放射性肝炎的关系需进一步研究。     

螺旋CT多期扫描对肝脓肿的诊断意义

目的：探讨肝脓肿螺旋CT多期扫描表现及相关病理改变。方法：对22例患者30个病灶的螺旋CT平扫、动脉、门脉期扫描征象及相关病理改变进行回顾性分析。结果：肝脓肿在螺旋CT扫描征象上具有多样性，其CT征象与肝脓肿所处时期密切相关。结论：螺旋CT多期扫描有助于肝脓肿的诊断，同时，对判断肝脓肿的病理过程和指导临床工作具有重要意义。     

A computer-simulated liver phantom (virtual liver phantom) for multidetector computed tomography evaluation

Objective The purpose of study was to develop a computer-simulated liver phantom for hepatic CT studies. A computer-simulated liver phantom was mathematically constructed on a computer workstation.Materials and methods The computer-simulated phantom was calibrated using real CT images acquired by an actual four-detector CT. We added an inhomogeneous texture to the simulated liver by referring to CT images of chronically damaged human livers. The mean CT number of the simulated liver was 60 HU and we added numerous 5-to 10-mm structures with 60±10 HU/mm. To mimic liver tumors we added nodules measuring 8, 10, and 12 mm in diameter with CT numbers of 60±10, 60±15, and 60±20 HU. Five radiologists visually evaluated similarity of the texture of the computer-simulated liver phantom and a real human liver to confirm the appropriateness of the virtual liver images using a five-point scale.Results The total score was 44 in two radiologists, and 42, 41, and 39 in one radiologist each. They evaluated that the textures of virtual liver were comparable to those of human liver.Conclusions Our computer-simulated liver phantom is a promising tool for the evaluation of the image quality and diagnostic performance of hepatic CT imaging.     

肝癌的CT血管造影

目的：介绍三种螺旋ＣＴ肝脏血管造影的方法，评价其对肝癌诊断的作用。材料和方法：用三种螺旋ＣＴ肝脏血管造影的方法对４９例肝癌患者作５１次检查：肝脏动脉造影ＣＴ（ＣＴＡ）、经动脉门静脉造影ＣＴ（ＣＴＡＰ）和经术中植入门静脉的药物输入系统（ＤＤＳ）直接门静脉造影ＣＴ（ＣＴＰ）。结果：这些方法可发现直径３ｍｍ的病灶，明确显示肿瘤的血供情况。结论：ＣＴＡ，ＣＴＡＰ和ＣＴＰ有利于肝脏多发和小肿瘤病灶的检出以及其鉴别诊断，ＣＴＡ和ＣＴＡＰ虽为创伤性检查，因其敏感性很高，可在肝脏肿瘤外科手术前和需明确肿瘤的血供时选用；对植入ＤＤＳ的患者，术后复查宜常规ＣＴＰ检查。     

基于PC机的CT肝脏灌注成像和定量测量方法初探

目的初步探讨基于PC机的CT肝脏灌注成像和定量测量方法的可行性。方法以10例行肝脏动态增强扫描的患者为研究对象,合理建立双输入单隔室模型,通过去卷积运算,获得肝脏灌注参数,并绘出肝脏灌注图像。结果基于PC机的肝脏灌注成像和定量测量可真实反映肝组织血流灌注量的变化。结论基于PC机的CT肝脏灌注成像和定量测量方法的初步研究有临床应用价值。     

生食泥鳅致肝寄生虫感染的CT表现(附38例报告)

目的探讨生食泥鳅所致肝寄生虫感染特殊的多层螺旋CT表现。资料与方法回顾性分析38例因生食泥鳅致肝寄生虫感染患者的CT表现及临床资料,探讨其相关病理机制。结果生食泥鳅所致肝寄生虫感染主要表现为肝内多发片状低密度,动脉期周边轻度强化,门静脉期持续轻度强化,甚至可呈等密度,边界不清。结论肝寄生虫感染的CT表现有其特征性,多层螺旋CT增强扫描有助于提高其检出率。     

Analysis of increased hepatic density during chronic amiodarone therapy

Amiodarone is an amphiphilic, iodinated, benzofuran derivative that is known to be effective for refractory ventricular tachyarrhythmia. Amiodarone also is known to cause a variety of side effects, related to its accumulation in multiple organs. The deposition of amiodarone and its metabolite, desethylamiodarone (DA), in liver elevates liver function tests and increases liver attenuation on computed tomography (CT). Although several groups have reported increased liver attenuation in patients receiving chronic amiodarone therapy, there is still no clear statistically significant relationship between liver CT attenuation and the cumulative dose of amiodarone, or between plasma levels of amiodarone and DA. CT scans were originally performed for the evaluation of pulmonary fibrosis in 13 patients (7 men and 6 women; mean age, 69.9 years, range 35 to 86 years) receiving chronic amiodarone therapy. Liver CT attenuation tended to increase in these patients. We found no significant correlation between liver CT attenuation and the cumulative dose of amiodarone. However, the CT attenuation of the liver was correlated significantly with the plasma level of amiodarone and DA. It was also suggested that liver CT scan is a useful means of evaluating the plasma levels of amiodarone and DA, and for estimating their deposition in liver.     

Focal hepatic intrinsically hyperattenuating lesions at unenhanced CT: Not always calcifications

Due to the growing use of CT, there has been an increase in the frequency of detecting focal liver lesions. Intrinsically hyperattenuating hepatic lesions or pseudolesions are not uncommon at unenhanced CT. Hyperattenuating hepatic lesions can be divided into non-calcified and calcified.Causes of intrinsic hyperattenuation include hemorrhage, thrombosis, and calcifications. Focal liver lesions can show hyperattenuation on unenhanced CT in case of severe liver steatosis.Recognition of etiologies associated with hyperattenuation on unenhanced CT can help the radiologist in characterizing focal liver lesions and pseudolesions. In this paper, we describe the spectrum of intrinsically hyperattenuating focal liver lesions and pseudolesions at unenhanced CT.     

Focal sparing around the gallbladder in fatty liver: an useful sign in the diagnosis of borderline cases by CT

The role of CT in the diagnosis of fatty liver is well established. CT has been proved to be a useful noninvasive tool for the demonstration of fatty infiltration of the liver. The characteristic finding is a diffuse decrease in the attenuation within the liver compared with that of the spleen. Commonly, fatty infiltration of the liver is generalized and both CT scans and sonograms can easily demonstrate changes related to this condition. Sometimes, fatty infiltration of the liver is focal and occasionally, it is generalized with focal sparing of the normal liver tissue creating some problems in the diagnosis. Recently, some reports have mentioned the appearance of a focal sparing area in the generalized fatty liver. We often found a high attenuation region around the gallbladder bed in the fatty liver patients on CT examination. There appears to be some relationship between the high density around the gallbladder area and the fatty liver. A retrospective study was undertaken to evaluate the relationship. In this paper, we presented the CT scans of 57 fatty liver cases and compared them with the CT scans of 50 normal patients to discuss the possible cause of the phenomenon and its usage in the diagnosis of the fatty liver.     

Quantitative evaluation of fatty liver by computed tomography in rabbits

Biochemical, histologic, and computed tomographic (CT) examinations of the liver were performed in 32 rabbits in which fatty liver was induced by prolonged intravenous fat infusion. In two groups of rabbits, in which 2 and 4 g/kg/day of fat emulsion was administered, respectively, posttreatment reduction in CT value of mild degree was observed, but the reduction was insignificant from the standpoint of diagnosis from CT images. In the group that received 8 g/kg/day of fat emulsion, posttreatment change in CT value was -14.9 +/- 5.1 H, a sufficient reduction for a diagnosis of fatty liver of moderate degree. No significant change in CT value was seen in the no-treatment group or in the group in which 80 ml/kg/day of normal saline solution was infused for 4 weeks. Reduction in CT value in fatty liver might be due largely to accumulation of triglyceride and cholesterol in the liver cells. Significant correlation was found between changes in CT value of the liver and degrees of histologic fat accumulation in the liver cells. Consecutive measurement of CT values of the liver during prolonged intravenous hyperalimentation is a nonaggressive method of diagnosing fatty liver.     

脂肪肝单能CT定量诊断的实验研究

目的　研究兔脂肪肝模型中肝脏脂肪含量与肝脏CT值之间的相互关系 ,为CT定量诊断脂肪肝提供理论依据。材料与方法　对造成不同程度脂肪肝的实验组 16只家兔和正常对照组 4只健康家兔分别行单能CT检查 ,测定肝脏的CT值。心脏穿刺取血 ,测定血清丙氨酸转氨酶 (ALT)、天门冬氨酸转氨酶 (AST)、碱性磷酸酶 (ALP)的水平。对肝脏进行组织学检查 ,用图像分析系统测量并计算肝脏脂滴占肝脏单位体积的百分比 (VP值 )。结果　实验组的VP值与CT值之间在统计学上有显著性意义的线性负向相关关系 (r =- 0 .90 ,t=7.5 4 ,P <0 .0 0 1) ;重度脂肪肝组血清ALT、AST、ALP水平较正常组、轻度脂肪肝组、中度脂肪肝组高 (P <0 .0 1)。结论　单能CT的肝脏CT值可以定量诊断脂肪肝的肝脏脂肪含量 ,判断脂肪肝的程度 ,效果优于血清ALT、AST、ALP等指标     

通过深度学习模型从增强CT图像合成平扫CT图像的质量分析

目的通过基于卷积神经网络深度学习方法从增强CT合成平扫CT图像, 临床主观和客观评估合成平扫CT图像(DL-SNCT)与金标准平扫CT图像的相似性, 探讨其潜在临床价值。方法同时行常规平扫和增强CT扫描的患者34例, 通过深度学习模型将增强CT图像合成DL-SNCT图像, 以平扫CT图像为金标准, 主观评价DL-SNCT的图像质量(评价指标包括解剖结构清晰度、伪影、噪声、图像结构完整性、图像变形, 均采用4分制);利用配对t检验比较DL-SNCT与金标准平扫CT图像不同血供特点的解剖部位(主动脉、肾脏、肝实质、臀大肌)以及不同强化模式的肝脏病变(肝癌、肝血管瘤、肝转移瘤、肝囊肿)的CT值。结果主观评价上, DL-SNCT图像在伪影、噪声、图像结构完整性、图像变形方面评分都达到4分, 与平扫CT图像评分相一致(P>0.05);在解剖结构清晰度方面评分略低于平扫CT图像[(3.59±0.70)分vs. 4分)], 差异有统计学意义(Z=-2.89, P <0.05)。对于不同解剖部位而言, DL-SNCT图像主动脉、肾脏的CT值显著高于平扫CT图像(t=-12.89、-9.58...     

不典型肝脓肿的CT诊断

目的:分析不典型肝脓肿的CT表现,分析和探讨其影像学特点。方法:回顾近年经临床或病理证实的12例不典型肝脓肿患者的CT资料,所有患者均行CT平扫及增强检查。结果:不典型肝脓肿CT平扫表现为低密度肿块,增强可见周围强化征、肿块缩小征、蜂窝状强化和延时强化。结论:不典型肝脓肿CT平扫无特征表现,增强扫描有一定特征性表现,有助于不典型肝脓肿的诊断。