Liver computed tomography (CT) perfusion is a noninvasive imaging technology which can quantitatively investigate liver function, and it is mainly used in the diagnosis of liver tumors and assessment of liver function in the state of chronic liver diseases. The use of liver CT perfusion was limited in the past because of the high radiation dose. Now new technologies are exploited and they make it possible to reduce the radiation burden while maintaining the imaging quality. This article discusses the research progress of low radiation dose CT perfusion in 3 aspects, including X-ray source, reconstruction algorithm, and improvement of CT scanners and optimization of scanning parameters. Although there are not too many studies of low radiation dose CT perfusion on liver now and many problems need to be solved, the clinical application of it will be very prospective.
ObjectiveTo comparatively analyze the image features of tumorous acute pancreatitis (T-AP) and non-tumorous acute pancreatitis (NT-AP). MethodsSixteen cases of histopathologically proven pancreatic tumors inducing acute pancreatitis and 30 cases of non-tumorous acute pancreatitis were collected, and studied their CT and MRI features. ResultsThere were 16 cases (100%) with focal nodules or masses in T-AP group and none in NT-AP group. The average innerdiameter of main pancreatic ducts in T-AP group was (9.6±6.8) mm, in which 14 cases (87.5%) were dilated. And the average innerdiameter of main pancreatic ducts in NT-AP group was (2.9±0.9) mm, in which 7 cases (23.3%) were dilated. The cases of sinistral portal hypertension (SPH), accompanying cholelithiasis and lymphadenosis between the two groups were 10 (62.5%), 3 (18.8%), 14 (87.5%), and 1 (3.4%), 25 (83.3%), 30 (100%), respectively. The occurrence of manifestation of focal nodules or masses, dilated main pancreatic ducts, SPH, and accompanying cholelithiasis were significantly different (P=0.000) between T-AP and NT-AP groups. While, the differences in enhancement pattern and the occurrence of lymphadenosis between the two groups were not significant (P > 0.05). ConclusionThe image features of T-AP are various. The application of CT and MRI could provide effective diagnostic guidelines for patients with T-AP.
Objective To discuss the CT imaging differences between hepatic neuroendocrine neoplasms (NENs) and hepatocellular carcinoma (HCC). Methods The clinical and CT data of 42 patients with hepatic NENs (hepatic NENs group) and 49 patients with HCC (HCC group), who were confirmed by pathology in the West China Hospital of Sichuan University from June 2011 to June 2016, were collected and analyzed retrospectively. This study was based on whether the lesions were larger than 3 cm or not, then CT findings of hepatic NENs patients and HCC patients in different stratification were compared. Results When the lesions were less than 3 cm, the location, contour, and enhancement patterns in the portal vein phase of the tumor had significant differences between the hepatic NENs group and the HCC group (P<0.05), multiple liver lesions, the round shape, and prolonged enhancement in the portal vein phase were more often seen in the hepatic NENs group, but there was no significant on diameter of tumor, boundary of lesion, pseudocapsules, scan density, hypervascularity, enhancement degree in arterial phase, enhancement patterns in arterial phase, daughter foci at liver, retraction, neoplastic artery, arteriovenous invaded, portal vein tumor thrombus, diameter of lymph node, and enhancement degree of lymph node between the 2 groups (P>0.05). And when the lesions were greater than or equal to 3 cm, the location, contour, enhancement patterns in the portal vein phase of the tumor, pseudocapsule, neoplastic artery, and arteriovenous invaded had significant differences between the hepatic NENs group and the HCC group (P<0.05), these CT images were often seen in the hepatic NENs group, such as multiple liver lesions, the lobulated shape, the portal venous phase continuous strengthening, no pseudocapsule, no neoplastic artery, and no arteriovenous invaded, but there was no significant difference on the diameter of tumor, boundary of lesion, scan density, hypervascularity, enhancement degree in arterial phase, enhancement patterns in arterial phase, daughter foci at liver, retraction, portal vein tumor thrombus, diameter of lymph node, and enhancement degree of lymph node between the2 groups (P>0.05). Conclusions No matter whether the lesions’ size are larger than 3 cm or not, the location, contour, and enhancement patterns in the portal vein phase could help for differentiating hepatic NENs from HCC. When the lessions are larger than 3 cm, pseudocapsule, neoplastic artery, and arteriovenous invaded may be useful to differentiate.
This article presented readers with typical enhanced CT and MR images of a patient with epithelioid hemangioendothelioma, and briefly described the pathological mechanisms behind the typical imaging signs, in order to enhance the readers’ understanding and awareness of the typical imaging signs of this rare disease, and thus reduce its underdiagnosis rate and misdiagnosis rate.
Primary liver cancer is the sixth most common malignancy and the third leading cause of cancer-related death worldwide, and hepatocellular carcinoma (HCC) constitutes the majority of primary liver cancer cases. The Liver Imaging Reporting and Data System (LI-RADS) was introduced to standardize the lexicon, acquisition, interpretation, reporting, and data collection of imaging results in patients at increased risk for HCC. LI-RADS allows effective categorization of focal liver lesions, and has been applied in the full clinical spectrum of HCC from diagnosis, biological behavior characterization, prognosis prediction, to treatment response assessment. This review aimed to summarize the recent applications of CT/MRI LI-RADS in the diagnosis, biological behavior characterization and prognosis prediction of HCC, discuss current challenges and shed light on potential future directions.
【Abstract】Objective To investigate the CT manifestations of chronic virus hepatitis B. Methods According to the inclusion and exclusion criteria, the clinical data and laboratory information of 120 patients with chronic virus hepatitis B were reviewed retrospectively. All patients underwent standardized contrast-enhanced spiral CT dual-phase scanning of the upper abdomen. The changes of the liver, bile duct, spleen, portal venous system, lymph node of the upper abdomen, peritoneal cavity and pleural cavity were observed and noted. Results CT manifestations of chronic virus hepatitis B were as follows: ①changes of the configuration and shape of the liver, ② changes of the density of the liver, ③intrahepatic perivascular lucency, ④thickening of gallbladder wall and edema of the gallbladder fossa, ⑤splenomegaly, ⑥enlargement of abdominal lymph nodes, ⑦ascites, ⑧abnormalities related to portal hypertension (collateral circulation), and ⑨secondary thoracic changes (pleural and pericardial effusion). Conclusion Chronic virus hepatitis B can demonstrate several abnormal findings involving the liver, gallbladder, lymph nodes, spleen, etc on contrast-enhanced CT scanning.
【Abstract】Objective To investigate the appropriate reconstruction techniques of multidetectorrow spiral CT angiography (MDCTA) to depict the collateral vessels in cavernous transformation of the portal vein (CTPV) caused by tumor thrombosis of hepatocellular carcinoma (HCC). Methods MDCTA scanning was performed during the portal venous phase after intravenous contrast materials in 18 HCC patients with CTPV induced by tumor thrombosis. Raw data were reconstructed with thin slice thickness followed by 2D and 3D angiographic reconstruction methods, including maximum intensity projection(MIP), shade surface display （SSD） and volume rendering technique(VRT). Results MDCTA with MIP reconstruction accurately depicted both the tumor thrombus within the portal vein and the collateral vessels of CTPV including the biliary (cystic vein and pericholedochal veinous plexus) and the gastric (left and right gastric veins) branches. However, VRT and SSD methods did poorly in showing the tumor thrombus and the collateral vessels. Conclusion MDCTA with MIP reconstruction is the method of choice to evaluate the collateral vessels of CTPV.
Objective To investigate the spiral CT manifestations of the collateral circulation pathways resulting from splenic vein occlusion (SVO) duo to pancreatic diseases. Methods The CT imaging and clinical data of 33 cases of pancreatic disease with SVO, including 28 cases of pancreatic carcinoma, 3 cases of acute pancreatitis and 2 cases of chronic pancreatitis, were retrospectively analyzed.Results Tortuous and dilated vessels were observed in the areas between splenic hilum and gastric fundus and/or along the gastric greater curvature in all 33 cases. In isolated SVO cases, the short gastric vein (SGV, 86%)，coronary vein (CV, 79%)，gastroepiploic vein (GEV, 79%) and gastrocolic trunk (GCT, 57%) were varicose and dilated. While in nonisolated SVO，other collateral veins such as the right superior colic vein (RSCV, 37%），middle colic vein (MCV, 37%） and posterior superior pancreaticoduodenal vein (PSPDV, 21%） were seen as well. Conclusion The two predominant collateral pathways of SVO are ①SGV→gastric fundal veins→CV， and ②GEV→GCT→SMV. They have characteristic imaging features on spiral CT and are of clinical significance in both preoperative staging of pancreatic carcinoma and the evaluation of pancreatogenic segmental portal hypertension.
ObjectiveTo investigate the CT presenting rate and features of gastric bare area (GBA, including the area posterior to GBA and the adipose tissue in the gastrophrenic ligament) without pathologic changes.MethodsThirty cases with superior peritoneal ascites, but without pathological involvement of GBA were included into the study to show the normal condition of GBA, including the presenting rate and CT features. We selected some cases with GBA invasion by inflammation or neoplasm to observe their CT features. ResultsAll cases with superior peritoneal ascites showed the GBA against the contrast of ascites with the presenting rate of 100%. The GBA appeared at the level of gastricesophageal conjunction and completely disappeared at the level of hepatoduodenal ligament and Winslow’s foramen. The maximum scope of GBA presented at the level of the sagital part of the left portal vein with mean right to left distance of （4.39±0.08）cm (3.8~5.7 cm) (distance between the left and right layer of the gastrophrenic ligament). In acute pancreatitis, the width of GBA increased, in which local hypodensity area could be seen. In gastric leiomyosarcoma invading GBA, the mass could not separate from the crus of the diaphragm. In lymphoma and metastasis invading GBA, the thickness of GBA increased and the density was heterogeneous, in which lymph nodes presenting as small nodes or fused mass. ConclusionThe results of this study show that it is helpful to use contrast enhanced spiral CT scanning to observe the change of GBA and to diagnose retroperitoneal abnormalities that involving GBA comprehensively and accurately.
ObjectiveTo assess value of preoperative clinical data and enhanced CT imaging features in predic-tion of microvascular invasion (MVI) and early recurrence (recurrence in one year) after curative resection for hepatoce-llular carcinoma (HCC). MethodsA retrospective analysis was conducted for 150 patients with HCC who underwent curative tumor resection in West China Hospital of Sichuan University from April 2014 to May 2015. The roles of preoperative CT characteristics and clinical data on MVI and early recurrence after curative tumor resection were evaluated by univariate and multivariate analyses. Resultscompared with HCC with no MVI and no early recurrence after curative resection, univariate analysis results showed that HCC with MVI and early recurrence had larger tumor size (P=0.002, P=0.005), a higher proportion of non-smooth tumor margin (P<0.001, P<0.001), and tumor multifocality (P=0.005, P=0.038), HCC with MVI had a higher proportion of incomplete tumor capsule (P=0.032), HCC with early recurrence had a higher proportion of incomplete and absence tumor capsules (P=0.038) and a faster washout on portal venous phase-the percentage attenuation ratio on the portal venous phase (P=0.049) and relative washout ratio on the portal venous phase (P=0.020) were higher. A multivariate logistic regression analysis results showed that non-smooth tumor margin (OR=7.075, P<0.001; OR=4.125, P<0.001) and tumor multifocality (OR=3.290, P=0.008; OR=2.354, P=0.047) were the independent predictors for MVI and early recurrence after curative tumor resection, HCC with early recurrence also had a faster washout on the portal venous phase (OR=1.023, P=0.017). ConclusionNon-smooth tumor margin and tumor multifocality are independent risk factors for MVI and early recurrence after curative tumor resection, and HCC with early recurrence has a faster washout on portal venous phase. Preoperative enhanced CT imaging could predict MVI and early recurrence after curative tumor resection and CT imaging findings are helpful to choose reasonable treatment and predict prognosis.