Distribution of water, fat, and metals in normal liver and in liver metastases influencing attenuation on computed tomography

The quantity of water, lipid and some metals was measured in autopsy specimens of 8 normal livers, 9 livers with fatty change, and in 12 livers with metastases of various origins. These parameters contribute to the CT number measured in the liver. Water played a major role in demonstration of liver metastases as a low-density area on CT. Other contributory factors include iron, magnesium and zinc. Lipid and calcium had no influence in this respect. Heavy accumulation of calcium in a metastatic lesion gives a high-density area on CT. However, even when a metastatic lesion was perceived on CT as a low-density area, the calcium content of the lesion was not always lower than that of the non-tumour region.     

In vivo, high-field, 3-Tesla 1H MR spectroscopic assessment of liver fibrosis in HCV-correlated chronic liver disease

PURPOSE: Histology is the gold standard by which to diagnose and score hepatic fibrosis. Recently, it has been proposed that hepatic magnetic resonance spectroscopy (MRS) could provide an accurate representation of the disease process. The aim of this study was to correlate the in vivo high-field (3-Tesla) (1)H MRS features of noncirrhotic chronic hepatitis C patients stratified according to the histopathological stages of fibrosis. MATERIALS AND METHOD: Six healthy controls and 23 patients with biopsy-proven precirrhotic hepatitic C virus (HCV)-related liver disease were included. The subdivision of patients into the histopathological stages of fibrosis was based on the Ishak fibrosis (F) scoring system: mild hepatitis (0< or =F< or =1), moderate (2< or =F< or =3) and severe hepatitis (4< or =F< or =5). For correlation analysis, the Spearman nonparametric test was used. Differences between groups were calculated with the nonparametric Mann-Whitney U test. A p value <0.05 was considered significant. The particular metabolite content was evaluated in relative units (RU), according to the pattern metabolite/H(2)O=area of the metabolite x1,000/area of nonsuppressed water. RESULT: A significant statistical difference was observed between control vs. mild and moderate vs. severe disease severity in choline-containing compounds (CCC)/H(2)O ratios (p=0.0379 and p=0.0003) and in glutamine/glutamate (Glx)/H(2)O ratios (p=0.004 and p<0.0001), whereas a statistically significant difference in the lipid/H(2)O ratios was achieved only between control vs. moderate and between moderate vs. severe stages of disease (p=0.011 and p=0.0030). CONCLUSION: High-field (1)H MRS successfully differentiates between mild/moderate vs. severe stages of chronic hepatitis and can be considered a complement to most standard imaging protocols in the liver.     

Nuclear magnetic resonance of the liver,spleen, and pancreas

This review includes the initial experience with NMR imaging of the liver, spleen, and pancreas at the University of California, San Francisco, using a prototype 0.35 Tesla system. This experience shows great promise for detection of hepatic metastases using T₁-weighted pulse sequences. T₂-weighted pulse sequences appear sensitive for detecting cavernous hemangioma of the liver and may allow tissue specific discrimination of the benign lesion from cancer. NMR is also suitable for evaluating diffuse metabolic alterations and is sensitive and specific for the diagnosis of iron overload. Detection of fatty liver requires use of chemical shift techniques as conventional NMR imaging pulse sequences are relatively insensitive. Motion artifacts and lack of an effective bowel contrast agent limits imaging of the pancreas and retroperitoneum, where CT remains the procedure of choice. The normal spleen has longer T1 and T2 relaxation times than liver or pancreas and NMR has not been successful in diagnosing splenic metastases or lymphoma on a routine basis. We conclude that NMR imaging will be valuable in the diagnosis of focal liver disorders; until fast scan techniques and effective magnetic contrast agents are available for oral and/or intravenous use, other abdominal applications will remain limited.     

Modern, non-invasive diagnostic of focal liver lesions

Ultrasonography and computed tomography are widely used methods in the detection and differentiation of focal liver lesions although they do not allow tumor characterization and the determination of malignancy in many cases. The Multislice-CT is the most reliable method for the detection of smallest lesions however, for more detailed analyses of morphological characteristics and assessment of potential malignancy other diagnostic procedures have to be applied. Based on histological changes MRI with tissue specific contrast media and specific scintigrafic procedures are valuable. Thus, the combination of ultrasonography and magnetic imaging could provide the ideal diagnostic pathway to determine the dignity, but also to differentiate the various benign tumors.     

Murine S factors for liver, spleen, and kidney.

Preclinical evaluation of new radiopharmaceuticals is performed in animal systems before testing is started in humans. These studies, often performed in murine or other rodent models, are important in understanding the relationship between absorbed dose and response, which can be translated to preclinical results for humans. In performing such calculations, either electrons are assumed to deposit all of their energy locally or idealized models of mouse anatomy are used to determine absorbed fractions. Photon contributions are generally considered negligible. To improve the accuracy of such absorbed dose calculations, mouse-specific S factors for (131)I, (153)Sm, (32)P, (188)Re, and (90)Y have been generated, and the photon and electron portions have been tabulated separately. Absorbed fractions for 5 monoenergetic electrons, ranging in energy from 0.5 to 2 MeV, are also provided. METHODS: Female athymic mouse MR images were obtained on a 4.7-T MRI device. Fifteen T1-weighted, 1.5-mm-thick slices (0.5-mm gap) were collected. Using a previously developed software package, 3-dimensional Internal Dosimetry (3D-ID), organ contours were drawn to obtain a 3-dimensional representation of liver, kidneys, and spleen. Using a point-kernel convolution, the mean absorbed dose to each organ from the individual contributions of each source organ were calculated. S factor equivalent values were obtained by assuming a uniform distribution of radioactivity in each organ. Results were validated by comparing 3D-ID generated electron S factors for different-sized spheres with published data. Depending on matrix size, sphere size, and radionuclide, 1% (256(2) matrix) to 18% (64(2) matrix) agreement was obtained. RESULTS: S factor values were calculated for liver, spleen, and right and left kidneys. Cross-organ electron-absorbed fractions of up to 0.33 were obtained (e.g., (90)Y right kidney to liver). Comparisons between S factor values and values obtained assuming complete absorption of electron energy yielded differences of more than 190% ((90)Y spleen self-dose). CONCLUSION: The effect of cross-organ and self-absorbed dose is dependent on emission energy and organ geometry and should be considered in murine dose estimates. The approach used to generate these S factors is applicable to other animal systems and also to nonuniform activity distributions that may be obtained by small-animal SPECT or PET imaging or by quantitative autoradiography.     

TNT与肝、脾损害的关系

三硝基甲苯(TNT)是常见的亲肝性毒物,可经皮肤、呼吸道、消化道进入人体,长期接触高浓度的TNT可对眼晶状体、肝脏、血液和神经系统造成损害,其对肝脏损害主要是影响肝脏的解毒功能、排泄功能以及糖代谢.肝损害的产生可能是由于TNT与体内氨基酸结合,导致氨基酸缺乏,间接引起肝细胞营养不良性片状坏死[1].我们于1992年与1993年分别对某化工厂TNT作业工人的肝、脾损害状况进行B超探测,比较两年的检查结果,现报告如下.     

25 946例行肝穿刺检查肝病病例的临床病理、流行病学及转归的研究

目的 研究1980年1月-2008年6月中国大陆肝脏疾病患者的主要疾病构成谱,临床病理学及流行病学特点,以及部分肝病患者的转归.方法 采用回顾性分析与病理学和血清学实验室再检测相结合的方法 ,对1980年1月-2008年6月主要来自中国大陆31个省市的25 946例行肝穿刺(简称肝穿)的肝病患者(含1 448例罹患肝病的军人)进行临床、病理、实验室分析研究,并对其中的1 322例慢性乙型病毒性肝炎患者进行了为期0.5～18年动态肝穿(2～8次肝穿)随访,观察慢性乙型肝炎的转归状况.结果 本组研究病例中男女比为3:1,年龄范围41d～91岁(32.35±14.4岁),肝病分布以18～37岁为高峰,其中冀、豫、京、鲁、晋为前5位肝病病例来源地.本组病例诊断肝脏疾病谱涵盖100余种,其中感染与非感染性肝病组分别占73.05%和26.95%.该两大类肝病于2000年后均呈总体上升趋势,其中非感染性肝病升幅更为显著.本组的随访资料显示,慢性乙型肝炎是肝衰竭、肝硬化和肝癌的首位相关性肝病,丙型肝炎为肝硬化、肝癌的次位相关性肝病;0.26%的甲型肝炎和0.51%的戊型肝炎病理上存在慢性化病变;1 322例慢性乙型肝炎随访患者中,转归为肝硬化、肝癌的比例分别为15.36%(203例)和1.06%(14例),演变间隔时间分别为46.375±16.93个月和60.29±39.15个月,肝纤维化上升1个S期以上的比例占14.22%(188例),纤维化进展间隔时间为22.20±20.65个月,而肝纤维化程度下降1个S期以上和稳定病例分别占33.36%(441例)和36.01%(476例).结论 本研究基本明确了近28年间中国大陆居民的肝病疾病谱及发病状况,其中不乏疑难或少见病例.本研究阐述了中国大陆主要肝病的一般临床流行病学特点,并从临床病理角度进一步明确了中国慢性乙型肝炎的转归及演变时间.     

Double cancer,cholangiocellular and hepatocellular carcinomas,in the cirrhotic liver

A 70-year-old male patient presented with cirrhotic liver caused by hepatitis C virus and complicated with hepatocellular carcinoma. The carcinoma was effectively treated by transarterial chemoembolization, but cholangiocellular carcinoma occurred in a different segment of the liver and rapidly grew and metastasized systemically. He died 13 months after the first admission. Double cancer of the liver is uncommon, but it must be considered in the differential diagnosis of cases of hepatocellular carcinoma associated with chronic hepatitis or cirrhosis. Failure to note the occurrence of cholangiocellular carcinoma is thought to be a diagnostic pitfall in the follow-up studies of patients with hepatocellular carcinoma.