Intrahepatic periportal abnormal intensity on MR images: an indication of various hepatobiliary diseases

The frequency and degree of intrahepatic periportal abnormal intensity (PAI) on magnetic resonance images in patients with or without various hepatobiliary and pancreatic diseases were analyzed. In 63 patients without hepatobiliary disease, except for a small metastatic liver tumor or cavernous hemangioma, no definite PAI was seen. Definite PAI was seen in all patients with obstructive jaundice, cholangitis, and cholangiocellular carcinoma. It was also clearly seen in all four cases of malignant lymphadenopathy in the hepatoduodenal ligament, in one of two cases of acute hepatitis, and in four of 47 cases of liver cirrhosis. However, in patients with bile duct dilatation or with gallstone or pancreatic disease without obstructive jaundice or cholangitis, no definite PAI was seen. Histologic studies of the liver performed in 23 patients with definite PAI showed edema, ductular proliferation, dilatation of lymph vessels, and inflammatory cell infiltration in portal tracts. It is concluded that definite intrahepatic PAI is a useful sign that indicates the presence of biliary or diffuse hepatic disease.     

MR imaging of the liver in primary hepatocellular carcinoma

In 10 patients with hepatoma, magnetic resonance (MR) and CT of the liver were subjectively compared and correlated with surgical or autopsy findings. In five cases MR defined the extent of the tumor better. Magnetic resonance was particularly useful in differentiating the tumor from otherwise abnormal areas of the liver, mostly focal cirrhosis. Magnetic resonance has the advantage of demonstrating major vessels in relation to the hepatoma without injection of any contrast agent. Calcifications well visualized on CT are not seen on MR. The lack of dynamic bolus CT in the majority of our cases as well as our inability to examine the entire liver with all three MR pulse sequences because of time restraint are significant limitations of this retrospective study.     

Portographic liver changes in idiopathic noncirrhotic portal hypertension

Intraoperative and transhepatic portograms in patients with noncirrhotic portal hypertension, or idiopathic portal hypertension, were compared with portograms of patients with liver cirrhosis. Although the portograms in idiopathic portal hypertension varied from case to case, they were distinctly different from those in cirrhosis. The most common features of the former included a paucity of medium-sized portal branches, irregular and often obtuse-angled division of the peripheral branches, occasional abrupt interruptions of them, an avascular area beneath the liver surface, nonopacification of some of the large intrahepatic portal branches and of their periphery, and increase of very fine vasculature around large intrahepatic portal branches. These findings are compatible with occlusion of intrahepatic portal vessels at various levels.     

Non-invasive portography: a microbubble-induced three-dimensional sonogram for discriminating idiopathic portal hypertension from cirrhosis

Objectives

The aim of this prospective study was to elucidate the efficacy of contrast-enhanced three-dimensional (3D) ultrasound with Sonazoid® (GF Healthcare, Oslo, Norway) as a non-invasive tool to discriminate idiopathic portal hypertension (IPH) from cirrhosis by demonstration of portal vein structure.

Methods

There were 16 patients: 11 with biopsy-proven cirrhosis and 5 with biopsy-proven IPH. Intrahepatic right portal vein images were taken by 3D ultrasound from 1 min after the injection of Sonazoid (0.0075 ml kg^–1). Portal vein appearances were compared between 3D ultrasound and percutaneous transhepatic portography (PTP) by four independent reviewers. Sensitivity, specificity and area under the receiver operating characteristic curve (Az) of the images were used for the diagnosis of cirrhosis/IPH, and interimaging, inter-reviewer and interoperator agreement were examined.

Results

Sensitivity, specificity and Az of PTP for the diagnosis of cirrhosis/IPH were 63.6%/100%, 100% and 0.9 (0.71–1.0) by Reviewer I and 90.9%/100%, 100% and 1.0 by Reviewer III, respectively. Similarly, sensitivity, specificity and Az of 3D ultrasound for diagnosis of cirrhosis/IPH were 54.5%/80%, 100% and 0.96 (0.84–1.0) by Reviewer II and 72.7%/80%, 100% and 0.97 (0.9–1.0) by Reviewer IV, respectively. Diagnostic agreement between PTP and 3D ultrasound was good between Reviewers I and II (κ=0.793) and good between Reviewers III and IV (κ=0.732). Inter-reviewer agreement was good between Reviewers I and III for PTP diagnosis (κ=0.735), and good between Reviewers II and IV for 3D ultrasound diagnosis (κ=0.792). Interoperator agreement of diagnostic results was good (κ=0.740).

Conclusion

Non-invasive visualisation of intrahepatic portal vein structure by contrast-enhanced 3D ultrasound with Sonazoid may have the potential to discriminate IPH from cirrhosis.Diagnosis of diffuse liver disease is a difficult but important issue in the appropriate management of patients, and cirrhosis should be correctly diagnosed because of the high risk of development of hepatocellular carcinoma [1-4]. Idiopathic portal hypertension (IPH) is also a disorder featuring chronic liver disease, resulting in oesophageal varices, hypersplenism and ascites [5,6]. IPH has different clinical aspects from cirrhosis including lower mortality from variceal rupture, better survival rate and reduced incidence of developing hepatocellular carcinoma [7,8]. However, differential diagnosis between these two liver diseases is sometimes complicated because of some common presentations caused by portal hypertension [9-12].An earlier study [13] reported that IPH has a unique vascular structure of the portal vein, paucity of medium-sized portal branches, irregular and often obtuse-angled division of the peripheral branches, their occasional abrupt interruptions, an avascular area beneath the liver surface, non-opacification of some of the large intrahepatic portal branches and of their periphery, and an increase in the very fine vasculature around large intrahepatic portal branches. It is considered that these findings reflect intrahepatic portal vein occlusion, which is believed to be the pathophysiology of IPH. Although such vascular findings may be helpful to discriminate IPH from cirrhosis, obtaining portal vein images requires interventional techniques that are affected by invasive procedures and radiation exposure.Significant recent advances in digital technology have led to ultrasound being used to demonstrate three-dimensional (3D) vascular images in the liver [14,15]. Furthermore, the detection rate of peripheral blood flow has improved with the application of microbubble ultrasound contrast agents [16,17]. Contrast harmonic imaging has the advantages of fewer artefacts, less dependence on the angle between the ultrasound beam and the vessel and an improved signal-to-noise ratio in comparison with Doppler sonography [18-20]. In addition, images under low mechanical index (MI) could cancel out most of the tissue signals to enable clear visualisation of the vascular structure [21]. On the basis of this information, we designed the present study to examine the possibility of using the newly developed ultrasound contrast agent Sonazoid® (GE Healthcare, Oslo, Norway) to demonstrate the intrahepatic portal vein structure by comparison with its angiographic appearance. The purpose of this study was to elucidate the efficacy of contrast-enhanced 3D ultrasound with Sonazoid under a low MI setting as a non-invasive tool to discriminate IPH from cirrhosis by demonstration of the intrahepatic portal vein structure.     

CT and MRI of siderotic regenerating nodules in hepatic cirrhosis.

The demonstration by CT of siderotic regenerating liver nodules in cirrhosis was evaluated and compared with that of MR imaging retrospectively in 27 patients with histologically diagnosed hepatic cirrhosis. Only in one of the two patients with marked iron deposits in regenerating nodules did CT demonstrate multiple high density nodules. In the other patient with marked iron deposits and in seven of the nine patients with moderate iron deposits, the liver parenchyma on CT was demonstrated as heterogeneous and of slightly high density without focal nodules. In 8 patients with mild to moderate iron deposits and in the 10 with no iron deposits, the liver parenchyma was homogeneous on CT. Multiple low intensity nodules in the liver were seen on fast low-angle shot (FLASH) MR images in all 17 patients with iron deposits in regenerating nodules. No low intensity nodules were seen on FLASH MR images in the 10 patients with no iron deposits. If there are iron deposits above a certain level, siderotic regenerating nodules may appear as nodules of high density on CT or as heterogeneous regions of high density liver parenchyma. Magnetic resonance is more sensitive than CT in demonstrating siderotic regenerating nodules.     

Computed tomography during arterial portography in idiopathic portal hypertension

Computed tomography (CT) during arterial portography was performed in two cases of idiopathic portal hypertension (IPH). Multiple patchy low-density areas with unclear margins and abnormally short distances between some of the medium-sized portal branches and the liver surface were demonstrated. These findings were distinctly different from those of liver cirrhosis. CT during arterial portography was useful for differentiating IPH from liver cirrhosis.     

Single photon emission computed tomograms of the liver: normal vascular intrahepatic structures

Because of the high target-to-background contrast obtained with single photon emission computed tomography (SPECT), normal intrahepatic vessels approximately 2 cm in diameter may appear as distinct focal defects in tomographic sections throughout the liver even though normal vessels rarely cause such defects on planar images. To assess this problem, five subjects without evidence of liver disease underwent tomography of the liver with Tc-99m sulfur colloid (TSC) and on a separate occasion tomography of the intrahepatic blood pool with Tc-99m autologous red blood cells (RBC). In each case, well demarcated defects were obvious in contiguous TSC liver tomograms in various planes. Direct comparison with RBC tomograms showed that all of these defects corresponded to intrahepatic veins, typically the right portal vein, its posterior branch, and the left portal vein. Knowledge of the intrahepatic vascular anatomy in a variety of tomographic planes, with examination of each defect in multiple orthogonal planes is necessary to avoid false positive interpretations. In some instances a study with RBC may also be required for more conclusive evaluation of defects seen on TSC liver tomograms.     

超声测量脾静脉与门静脉内径比对诊断特发性门脉高压的意义

目的研究特发性门脉高压综合征(IdiopathicPortalHypertensionSyndrome,IPH)的超声诊断标准。方法利用超声分别测量9例IPH与30例肝硬化组及30例正常对照组脾静脉(splenicvein,SpV)与门静脉主干(portalvein,PV)内径(Dsp,Dp),并计算它们的比值。结果IPH组Dsp/DP均大于1.0,与肝硬化组,正常对照组相比均有显著性差异(P<0.05)。结论Dsp/Dp大于1.0作为超声诊断标准能够简单易行地对IPH作出诊断。     

CT of liver cysts in patients with autosomal dominant polycystic kidney disease.

PURPOSE: The purpose of this study was to illustrate the CT appearances of liver cysts in patients with autosomal dominant polycystic kidney disease (ADPKD). MATERIAL AND METHODS: Contrast-enhanced CT images of 24 patients with ADPKD were retrospectively evaluated for the presence, number, size and distribution of liver cysts. An attempt was made to categorize these cysts into peribiliary cysts (located adjacent to larger portal triads or in the hepatic hilum) and intrahepatic cysts (within the liver parenchyma but not in contact with larger portal triads). When it was not possible to definitely categorize the cysts into either type, the cysts were labeled as indeterminate. RESULTS: Liver cysts were seen in 13 (54%) patients. Intrahepatic cysts were seen in 12 patients, and were mainly peripheral in location with sizes ranging from less than 10 mm to 8 cm. Peribiliary cysts were seen in all 13 patients and were usually less than 10 mm in size. These cysts were seen as discrete cysts (8 patients), a string of cysts (10 patients), or as a tubular structure paralleling the portal vessels, mimicking biliary dilatation (11 patients). Twelve patients also showed indeterminate cysts which defied definite categorization into either type; two common causes of confusion included large (more than 10 mm) discrete cysts in the hilar region and the presence of a vessel adjacent to peripheral cysts. CONCLUSION: Liver cysts in patients with ADPKD show a wide variety of appearances on CT. Familiarity with these findings is essential to avoid confusion with other abnormalities.     

Segmental intensity differences in the liver on MR images: a sign of intrahepatic portal flow stoppage

Segmental intensity differences (SIDs) in hepatic parenchyma free of tumor were noted in six patients with hepatic masses (hepatocellular carcinoma in five and metastatic liver cancer in one). Areas of SID were homogeneous in intensity. The intensity of the affected region was high in all six patients on T2-weighted magnetic resonance (MR) images and low in two on T1-weighted images. Three of five patients examined with plain computed tomography (CT) had corresponding segmental areas of low attenuation. Angiograms obtained in five patients showed occlusion of the intrahepatic portal vein, segmental staining corresponding to the region of the SID, or both. Twelve of 82 patients examined with MR imaging and angiography had similar findings on angiograms, and ten of them had abnormal intensity of anatomic distribution around or beside the liver tumors on MR images. MR imaging may be more sensitive than plain CT in the detection of secondary changes caused by intrahepatic portal flow stoppage.     

Imaging features of perivascular fatty infiltration of the liver: initial observations

PURPOSE: To retrospectively identify and describe the imaging features that represent perivascular fatty infiltration of the liver. MATERIALS AND METHODS: The institutional review board approved the study and waived informed consent. The study complied with the Health Insurance Portability and Accountability Act. Ten patients (seven women, three men; mean age, 78 years; range, 31-78 years) with fatty infiltration surrounding hepatic veins and/or portal tracts were retrospectively identified by searching the abdominal imaging teaching file of an academic hospital. The patients' medical records were reviewed by one author. Computed tomographic (CT), magnetic resonance (MR), and ultrasonographic (US) imaging studies were reviewed by three radiologists in consensus. Fatty infiltration of the liver on CT images was defined as absolute attenuation less than 40 HU without mass effect and, if unenhanced images were available, as relative attenuation at least 10 HU less than that of the spleen; on gradient-echo MR images, it was defined as signal loss on opposed-phase images compared with in-phase images; and on US images, it was defined as hyperechogenicity of liver relative to kidney, ultrasound beam attenuation, and poor visualization of intrahepatic structures. Perivascular fatty infiltration of the liver was defined as a clear predisposition to fat accumulation around hepatic veins and/or portal tracts. For multiphase CT images, the contrast-to-noise ratio was calculated for comparison of spared liver with fatty liver in each imaging phase. RESULTS: Fatty infiltration surrounded hepatic veins in three, portal tracts in five, and both hepatic veins and portal tracts in two patients. Six of the 10 patients had alcoholic cirrhosis, two reported regular alcohol consumption (one of whom had acquired immunodeficiency syndrome and hepatitis B), one was positive for human immunodeficiency virus, and one had no risk factors for fatty infiltration of the liver. In three of the 10 patients, fatty infiltration was misdiagnosed as vascular or neoplastic disease on initial CT images but was correctly diagnosed on MR images. CONCLUSION: Perivascular fatty infiltration of the liver has imaging features that allow its recognition.     

彩超诊断弥漫性肝癌的临床价值

目的总结彩超诊断弥漫性肝癌的声像学特征。方法对经MRI、CT及病理检查证实的182例弥漫性肝癌的超声图像特征及临床特点进行总结分析。结果 182例患者二维彩超显示:全部患者均有肝包膜改变,74.18%(135/182)呈波浪状改变,25.82%(47/182)呈锯齿状改变。70.88%(129/182)肝脏呈肿大表现,68.68%(125/182)患者门脉增宽,31.32%(57/182)有门脉栓子。弥漫性肝癌声像图大体分为2种类型:弥漫结节型和不规则斑块型,其中77.47%(141/182)为弥漫结节型,22.53%(41/182)为斑块型。全部患者CDFI显示:肝内血流信号走行失常,分布杂乱,可见血管绕行或散在斑点状、条状血流信号。结论肝包膜凹凸不平,肝实质回声呈弥漫性小结节或斑块改变,肝内血流信号失常,门静脉栓塞等彩超图像特征对诊断弥漫性肝癌具有重要的价值,但是彩超确诊弥漫性肝癌仍存在一定难度,应重点与肝硬化相鉴别。     

MR imaging of peripheral cholangiocarcinoma.

A prospective study was performed to compare MR spin-echo (SE) sequences [repetition time/echo time (TR/TE) 2,000/80, 500/44 ms], unenhanced CT, and rapid intravenous contrast enhanced CT in eight consecutive patients with peripheral cholangiocarcinoma. All the tumors (ranging from 5 to 9.6 cm in size) were detected with all four techniques. Tumor contrast, however, was qualitatively greatest on long TR/TE SE images. With long TR/TE SE images, tumors were demonstrated as well-demarcated homogeneous regions of high signal intensity, and the anatomic relations between tumors and intrahepatic blood vessels were easily perceived. Detection of small intrahepatic metastatic foci was best on long TR/TE images. Tumor invasion of the portal vein's branches was also best seen on long TR/TE SE images. These results indicate that long TR/TE SE sequence is the most effective initial screening method in demonstrating the presence and determining resectability of peripheral cholangiocarcinoma.     

Liver tumors in cirrhosis: experimental study with SPIO-enhanced MR imaging

The influence of cirrhosis on superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging of the liver was studied in 31 rats. Experimental models included carbon tetrachloride-induced cirrhosis and liver engrafting of rhabdomyosarcoma S4T cells. Hepatic uptake of SPIO measured with relaxometry decreased dramatically with histologic grade, while splenic uptake increased; the same results were achieved by calculating K values. Imaging of 13 tumorous cirrhotic rats confirmed these results by showing a muted decrease in liver signal intensity on spin-echo images after injection of SPIO. Nevertheless, all intrahepatic tumors could be visualized, as confirmed by postmortem examination. On gradient-echo images, postinjection contrast between the tumor and the liver was not affected by cirrhosis. Thus, despite strong impairment of hepatic uptake in cirrhosis, the diagnostic efficacy of MR imaging with SPIO did not seem to be significantly affected.     

Interesting RI accumulation in hepatic images with Tc-99m GSA SPECT scintigraphy in idiopathic portal hypertension

The authors report a case of idiopathic portal hypertension (IPH), which showed interesting RI accumulation on Single Photon Emission CT (SPECT) images, with Tc-99m galactosyl human serum albumin (GSA) scintigraphy. Accumulation of Tc-99m GSA was decreased in the periphery of the liver where strong enhancement was revealed only in the arterial phase on dynamic CT. These findings imply that portal flow is decreased in the periphery of the liver where arterial flow is dominant. It was thought that secondary reduced activity of GSA due to a decrease in portal flow results in reduced radioactivity in the periphery of the liver in IPH. This interesting accumulation of Tc-99m GSA may be one of the sign of IPH.     

Portosystemic shunting in portal hypertension: evaluation with portal scintigraphy with transrectally administered I-123 IMP

Portosystemic shunting was evaluated with rectal administration of iodine-123 iodoamphetamine (IMP) in seven patients without liver disease and 53 patients with liver cirrhosis. IMP (2-3 mCi [74-111 MBq]) was administered to the rectum through a catheter. Images of the chest and abdomen were obtained for up to 60 minutes with a scintillation camera interfaced with a computer. In all patients, images of the liver and/or lungs were observed within 5-10 minutes and became clear with time. In patients without liver disease, only liver images could be obtained, whereas the lung was visualized with or without the liver in all patients with liver cirrhosis. The portosystemic shunt index was calculated by dividing counts of lungs by counts of liver and lung. These values were significantly higher in liver cirrhosis, especially in the decompensated stage. Transrectal portal scintigraphy with IMP appears to be a useful method for noninvasive and quantitative evaluation of portosystemic shunting in portal hypertension.     

Anomaly of the portal vein with total ramification of the intrahepatic portal branches from the right umbilical portion: CT features

PURPOSE: To describe CT findings of portal vein anomaly with total ramification of the intrahepatic portal branches from the right umbilical vein. METHODS: Retrospective analysis was performed in 6 patients with portal vein anomaly with total ramification of the intrahepatic portal branches from the right umbilican vein. We analyzed the position of the umbilical portion of the portal vein and ligamentum teres, and determined the intrahepatic branching pattern of the portal vein. RESULTS: The umbilical portion and ligamentum teres were deviated to the right and seen above the gallbladder fossa in all 6 patients. All major braches of the portal vein ramified from the right umbilical vein in all 6 patients. CONCLUSION: The possibility of this portal vein anomaly should be kept in mind when hepatic resection or partial liver transplantation is required.     

Fallbericht: Massive untere gastrointestinale Blutung aus ilealen Varizen

Acute gastrointestinal bleeding in patients with liver cirrhosis is associated with a high mortality. Ileal varices and collaterals from ectopic vessels are extremely rare, encountered in less than 5% of the cirrhotic patients. The diagnosis is frequently delayed because the regular diagnostic methods such as gastroscopy or colonoscopy are unsuccessful in accurate the source of bleeding in the majority of the cases.We report an unusual case of massive and uncontrollable lower intestinal bleeding from ileal varices with right ovarian vein anastomosis in a 56 year-old female patient with liver cirrhosis and previous history of abdominal and pelvic surgery. The accurate angiographic and computed tomography diagnosis allowed fast decompression of the portal venous system using a transjugular intrahepatic portosystemic shunt.     

Angiographic studies of the totally arterialized rat liver

Twenty-three angiographies were performed in 20 rats with a totally arterialized liver. The arterialization was obtained by the construction of an end-to-side portacaval shunt (PCS) and an arteriovenous (AV) fistula between the left gastric artery and the portal stump. Microsurgical technique was necessary because of the small diameter of the AV fistula (0.5 mm). The angiographic examinations showed an AV fistula patency rate of 70% and a PCS rate of 100%. A successively increasing diameter of the fistula with dilation of the intrahepatic portal vessels was demonstrated in the rats with a patent arterioportal fistula. Tortuous and irregular vessels were also observed. All these signs suggest an overarterialization which developed despite the use of a very small AV fistula. None of the three rats examined histologically had cirrhosis of the liver. Further research is needed to attempt to avoid or minimize the deleterious effects of overarterialization of the portal tree, while utilizing the advantages of a dual liver blood supply in patients with decompressive PCS.     

经皮经肝肝内门体分流术的多层CT影像研究

目的 探讨严重肝硬化患者肝实质、门静脉与肝静脉或肝后段下腔静脉在影像上的特征,评估经皮经肝肝内门 体分流术(PTIPS)的可行性及安全性,为该技术的临床应用提供解剖依据。方法 50例经临床及影像证实的严重肝硬化患者,在多层螺旋CT(MDCT)上模拟PTIPS,选右侧腋中线第8或第9肋间为经皮穿刺点A点,门静脉右支主十远端为门静脉穿刺点B点,肝右静脉汇入下腔静脉处为肝静脉或下腔静脉穿刺点C点,门静脉主干起始处为D点。A、B、C 三点连线为经皮经肝穿刺道,C、B、D 三点连线即门体分流道。所有患者肝脏CT增强扫描后行MPR后处理,测量数据用x±s表示,并计算总体均数的95％可信区间。同时分析门静脉右支与肝后段下腔静脉、肝动脉及胆管的解剖关系。结果 模拟穿刺针体内部分的长度（A-B-C长度）为(145.7±14.8) mm;穿刺针的弯度（A-B径线与B-C径线夹角）为(145.0±9.9)°;肝实质段分流道的长度（B-C长度）为(42.7±7.2) mm;当门静脉主干闭塞时,分流道长度（C-B-D长度）为(117.7 ±11.6) mm;分流道的角度（B-C径线与B-D径线夹角）为(108.5±5.9)°。50例患者中肝后段下腔静脉位于门静脉右支背侧者24例,位于同一平面者26例;肝右动脉及右肝管均位于门静脉右支腹侧。经门静脉右支穿刺肝右静脉或肝后段下腔静脉的路径中无大的动脉、胆管等重要结构。结论 从解剖学角度分析,PTIPS具有可行性及安全性,通过量化穿刺针的长度、角度及分流道长度、角度,可为该技术的临床应用提供解剖依据。