With the development of radiologic intervention, the treatments of aortic dissection are getting more and more diversified. In recent years, Debakey Ⅲ and DebakeyⅠaortic dissection has been usually treated with endovascular graft exclusion, or combined surgical and endovascular treatment. It is therefore more important to evaluate the aorta and its complications after interventional treatments. Because multidetector-row computed tomography (MDCT) has advantages, such as short examination time, high spatial resolution, and simple operation, this modality has become a first choice of non-invasive methods for the follow-up of aortic diseases after the intervention. Now the MDCT presentations and their anatomic-pathologic features of aortic dissection after endovascular graft exclusion or combined surgical and endovascular treatment are reviewed in this article.
【Abstract】ObjectiveTo evaluate the main CT features, the morbidity of CT signs and the anatomic-pathologic bases of secondary pyogenic peritonitis (SPP). MethodsTwentyfour patients of the SPP were retrospectively studied. Emphasis was placed on the spiral CT manifestations of the SPP correlating with their anatomic-pathologic bases and the occurrence as well as the signs of primary lesions which resulted in the SPP. ResultsThe main CT manifestations of SPP revealed as follows: the thickened peritoneum, 16 in 24 cases (66.7%), of which 14 cases were smooth and 2 cases were irregular; the ascites, 15 in 24 cases (62.5%); the free air within peritoneal cavity, 9 in 24 cases (37.5%); the edema and thickening involved in the greater omentum, 8 in 24 cases (33.3%); the small bowel mesentery, 5 in 24 cases (20.8%); and the bowels’ wall, 5 in 24 cases (20.8%); the adhesions of bowels, 6 in 24 cases (25.0%). The CT manifestation of the promary lesions, which caused SPP, and the complications were shown as follows: the signs of primary lesion, 13 cases (54.2%); the inflammatory changes in retroperitoneal cavity 13 cases (54.2%); the involvements of chest 13 cases (54.2%); and the abscess in peritoneal and pelvic cavity 6 cases (25.0%). ConclusionThe main significant CT signs of SPP could be concluded as follows: thickened peritoneum, ascites, free air within peritoneal cavity, edematous and thickened greater omentum, the small bowel mesentery, and the bowels’ wall, as well as the adhesions of bowels. So, the CT scan can present plenty of CT signs, which are significant and very helpful for making an appropriate diagnosis of SPP.
【Abstract】Objective To investigate the imaging features of malignant invasion of major intrahepatic ductal structures (the portal and hepatic venous vasculature, the bilie duct) by primary hepatocellular carcinoma (HCC) using multidetector-row spiral CT (MDCT). Methods We retrospectively analyzed 68 documented HCC patients with tumorous invasion of the major intrahepatic ductal structures who had undergone contrast-enhanced dual-phase MDCT scanning of the upper abdomen.The morphological changes of the portal and hepatic venous vasculature, the bile duct, and the liver parenchyma at both the hepatic arterial phase and portal venous phase images were carefully observed and recorded. Results Among the 68 patients, 47 patients had malignant invasion of the intrahepatic portal venous vessels with secondary tumor thrombus formation; 12 patients had tumor involvement of the hepatic veins and intraheptic segment of the inferior vena cava; Tumor invasion of the bile duct was seen in 9 patents. The direct CT signs of tumor invasion of intrahepatic venous vessels included: ①dilatation or enlargement of the involved vein with intraluminal softtissue “filling defect”； ②enhancement of the tumor thrombus at hepatic arterial phase, the so-called “venous arterialization” phenomenon. The indirect CT signs included: ①arterial-venous shunt, ②early and heterogeneous enhancement of the hepatic parenchyma adjacent to HCC focus, ③cavernous transformation of the portal vein. The CT signs suggesting tumor invasion of the bile duct included: ①dilation of the bile ducts near or proximal to HCC lesion, ②soft-tissue nodule or mass inside the bile ducts. Conclusion Invasion of major intrahepatic ductal structures by HCC will present corresponding CT imaging features. Contrast-enhanced MDCT dualphase scanning combined with appropriate image postprocessing techniques can better evaluate the malignant invasion of major intrahepatic ductal structures.
ObjectiveTo analyze the influencing factors for image quality of 18F-deoxyglucose (FDG) positron emission tomography (PET)/CT systemic tumor imaging and explore the method of control in order to improve the PET/CT image quality. MethodsRetrospective analysis of image data from March to June 2011 collected from 1 000 18F-FDG whole body tumor imaging patients was carried out. We separated standard films from non-standard films according to PET/CT image quality criteria. Related factors for non-standard films were analyzed to explore the entire process quality control. ResultsThere were 158 cases of standard films (15.80%), and 842 of non-standard films (84.20%). Artifact was a major factor for non-standard films (93.00%, 783/842) followed by patients’ injection information recording error (2.49%, 21/842), the instrument factor (1.90%, 16/842), incomplete scanning (0.95%, 8/842), muscle and soft tissue uptake (0.83%, 7/842), radionuclide contamination (0.59%, 5/842), and drug injection (0.24%, 2/842). The waste film rate was 5.80% (58/1 000), and the redoing rate was 2.20% (22/1 000). ConclusionComplex and diverse factors affect PET/CT image quality throughout the entire process, but most of them can be controlled if doctors, nurses and technicians coordinate and cooperate with each other. The rigorous routine quality control of equipment and maintenance, patients’ full preparation, appropriate position and scan field, proper parameter settings, and post-processing technology are important factors affecting the image quality.
ObjectiveTo discuss the CT characteristics of combined hepatocellular carcinoma and cholangiocarcinoma (cHCC-CC), and analyze the reasons for its misdiagnosis. MethodWe retrospectively analyzed the CT data of 7 patients diagnosed to have combined hepatocellular carcinoma and cholangiocarcinoma by postoperative pathological analysis between January 2009 and February 2015. We analyzed such characteristics as location, shape, density, enhanced features, surrounding invasion, mediastinal lymph node metastasis, cirrhosis and pyoperitoneum of the disease. ResultsThere were 7 tumors among the 7 patients. Plain scan showed slightly lower density nodules or masses. After the enhancement of arterial phase, 5 tumors showed obvious inhomogeneous enhancement but 2 mild marginal enhancement. During the portal venous phase and the delay stage, the regional degree of tumor foci was significantly decreased, but some regions sustained annular or nodular and patchy enhancement. Among the 7 cases, the portal vein was invaded in 2, bile duct in 1, lymph node metastasis in 2, cirrhosis in 1, and peritoneal effusion in 1. Preoperative diagnosis was correct in only 2 cases and the other 5 cases were misdiagnosed by CT. ConclusionsThe cHCC-CC possesses some characteristic appearances on CT. Analyzing the characteristics carefully combining with symptom and cytological examination of hydrothorax can reduce the incidence of misdiagnosis.
【Abstract】Objective To investigate the CT imaging features of metastatic hepatic adenocarcinomas from the digestive tract by using multidetectorrow helical CT (MDCT) with pathological correlation. Methods CT and clinical data of 36 patients with pathologically proven metastatic hepatic adenocarcinomas from the digestive tract were retrospectively reviewed. The primary tumors included 10 cases of gastric cancer, 1 duodenal cancer, 18 colonic carcinoma, 7 rectal cancer. All patients underwent MDCT plain scan and contrastenhanced dualphase scanning of upper or whole abdomen. The appearances of hepatic metastatic lesions on MDCT images at various enhancement phases were carefully observed. Results On plain CT scan 32 cases （88.9%） presented multiple nodules of low density at different sizes, 3 cases （8.3%） showed a single low-density nodule, and 1 case presented with a cystic mass. On contrast-enhanced scan, 4 cases (11.1%) showed faintly enhanced rim around the nodules on arterial phase; on portal venous phase 29 cases (80.6%) presented slight ringlike enhancement at the periphery of the nodule while the nodule core was markedly hypodense with intermediate soft tissue density area in between, giving rise to the typical appearance of “bull’seye” sign. Three cases (8.3%) showed no enhancement on either phase images. Conclusion The ring-like enhancement and the appearance of “bull’s-eye” on portal venous phase was characteristic CT features of metastatic hepatic adenocarcinoma from digestive tract.
【Abstract】ObjectiveBy using multidetector row spiral CT (MDCT) to investigate the CT imaging findings of gallbladder abnormalities caused by hepatic parenchymal diseases and those of inflammatory cholecystitis. MethodsCT and clinical data of 80 patients with gallbladder abnormalities were retrospectively reviewed. Fifty patients were in hepatic disease group, including 20 chronic hepatitis, 25 liver cirrhosis, and 5 cirrhosis with hepatocellular carcinoma. Thirty patients were in inflammatory group, including 19 chronic cholecystitis, 6 acute cholecystitis, 3 cholecystitis with acute pancreatitis, 1 gangrenous cholecystitis, and 1 xanthogranulomatous cholecystitis. All patients underwent MDCT plain scan and contrastenhanced dualphase scanning of upper abdomen. ResultsIn hepatic disease group, 48 cases had evenly thickened gallbladder wall (96%) with mean thickness of (3.67±0.49) mm; 38 cases had clear gallbladder outlines (76%); 38 cases had gallbladder wall enhancement of various degree (76%); 14 cases had gallbladder bed edema and localized nondependant pericholecystic fluid collection (28%). In inflammatory cholecystitis group, 28 cases had obscuring gallbladder outlines (93%) ; 26 cases had gallbladder wall evenly thickened (87%), 4 cases showed unevenly thicked wall (13%), the mean thickness being (4.54±1.14) mm; 30 cases had inhomogenous enhancement of the gallbladder wall (100%); 9 cases had highattenuation bile (30%); 4 cases had dependant pericholecystic fluid collection (13%); 5 cases had transient enhancement of adjacent hepatic bed in arterial phase (17%); microabscess and gas in the gallbladder wall was observed in 1 case respectively. ConclusionMDCT can offer imaging findings useful for differentiating abnormal gallbladder changes caused by hepatic parenchymal diseases from those due to inflammatory cholecystitis.
Objective To investigate the CT imaging features of hepatic angiomyolipoma and its clinical characteristics. Methods The clinical, radiological, and pathological data of 3 hepatic angiomyolipoma (HAML) patients were retrospectively collected, and the imaging and diagnostic features were analyzed.Results All 3 cases were females, 2 complained of abdominal pain and one was absent of symptom. Both the laboratory examinations were normal in 2 cases, and hepatitis B virus markers were positive in one case. For CT features, the mass located in the superior anterior segment of the right hepatic lobe, in the posterior inferior segment of the right hepatic lobe, and in the left medial lobe, respectively. There were components of fat and soft tissue attenuation in these masses, and in which the CT value of the fat component was from -80 HU to -20 HU (mean -50 HU). There were enhancement in different degree and enhanced vascular imaging could be seen within the lesions. During surgery, all 3 masses were outgrowed from the hepatic lobes. Immunostainning showed HMB45 (+), αSMA (+), S100 (+)，which were bly suggestive of HAML.Conclusion HAML is a rare benign tumor with characteristic CT appearance, and its definite diagnosis relies on the immunohistochemical staining of HMB-45.
ObjectiveTo explore the diagnostic value of CT-guided percutaneous needle aspiration biopsy (PTNB) for ground-glass opacity (GGO) pulmonary lesions. MethodsA retrospective design was used to collect clinical data of patients with GGO lesions admitted in the Affiliated Hospital of North Sichuan Medical College between Jan. 2009 to Jan 2015. Patients were divided into groups according the lesion size (≤10 mm, 10-20 mm,≥20 mm), length of needle path (≤5 cm, 5-9 cm,≥9 cm) and percentage of GGO component (50%-90%, >90%), respectively. The total and subgroups of sensitivity, specificity, and diagnostic accuracy of CT guided PTNB for diagnosing GGO were calculated and the differences among subgroups were compared using Fisher's exact test. Statistical analysis was conducted by using SPSS 17.0 software. ResultsA total of 60 patients involving 48 malignant and 12 benign lesions were included. The total sensitivity, specificity, and accuracy of CT guided PTNB for diagnosing GGO were 87.5%, 100% and 90%, respectively. There were no significant differences among the subgroups based on the lesion size, length of needle path, and percentage of GGO component (all P values >0.05). ConclusionCT-guided PTNB can be used as one of the diagnostic modalities for lung GGO lesions with a moderate diagnostic value.
Objective To probe CT grading criteria of vascular invasion in pancreatic cancer. Methods Retrieved articles in CNKI and PubMed about value of CT in preoperative assessment of vascular invasion in pancreatic cancer last ten years. Results Multislice helical CT is considered the best imaging method to assess the invaded peripancreatic vessels in pancreatic cancer. There are different CT criteria of vascular invasion in pancreatic cancer based on extension of hypodense tumor and its relation to blood vessels, on the degree of circumferential contiguity of tumor to vessel, on the degree of lumen stenosis, and on the degree of contiguity between tumor and vessels combined vascular caliber. Conclusion CT grading criteria are not uniform, each one has defects.