Objective To review the principles and techniques of CT perfusion imaging and its applications in the imaging diagnosis of abdominal disorders. Methods All the relevant literatures were reviewed. The principles and techniques of CT perfusion imaging were described and summarized in detail. The functional information of a target abdominal organ (e.g. the liver and pancreas) revealed by CT perfusion imaging, such as hemodynamics and microcirculation status, was also evaluated. Results In addition to the morphologic information, CT perfusion imaging can also provide functional information about the circulation parameters of target abdominal organs. Moreover, such functional information can be generated for the neovasculature and microcirculation of tumor lesions of abdominal organs, which is very helpful for not only the diagnosis, but also the evaluation of tumor invasiveness and response to treatment. Conclusion CT perfusion imaging offers an effective method for studying abdominal disorders by providing functional information that is quite useful for the differential diagnosis and assessment of therapeutic response.
Objective To introduce the imaging modalities used for the evaluation of postoperative complications of orthotopic liver transplantation (OLT) and to present the imaging findings of these complications. Methods The literatures related to the imaging methods and imaging manifestations of OLT complications were reviewed. Results Ultrasound was the initial imaging technique used for the detection of complications in the early postoperative period. Spiral CT and MRI yielded more accurate and comprehensive evaluation of postoperative complications in later stage. So far, there had been no specific imaging findings to suggest rejection reaction. The spectrum of imaging manifestations of OLT complications, such as vascular complications, biliary complications, liver parenchymal complications, and so on, were summarized and illustrated. Conclusion Imaging examination (especially ultrasound, spiral CT and MRI ) plays an important role in the evaluation of postoperative complications of OLT.
Objective To assess value and limitations of non-invasive methods in assessing liver fibrosis．Methods By summarized current situation and advancement of serum fibrotic markers, ultrasound, CT and MRI in assessing liver fibrosis, we investigated their value and limitations. Results In addition to diagnosis, non-invasive methods of assessing liver fibrosis assess severity of liver fibrosis. For liver fibrosis, however, non-invasive methods can not monitor effectively reaction to therapy and progression. Conclusion Non-invasive methods play important roles in diagnosis and assessing severity of liver fibrosis, and reduce the need of liver biopsy.
Objective To review the CT appearances and important differential diagnoses of various primary and secondary mesenteric neoplasms. Methods By describing the mesenteric anatiomy and major routes for the dissemination of metastatic mesenteric tumors, the article presents both the common and rare types of various primary and secondary mesenteric neoplasms, and addresses the characteristic CT appearances and important aspects of the differential diagnosis. Results CT study, especially the multislice spiral CT (MSCT), along with the clinical history and other related information, can nicely depict various mesenteric tumors and well differentiate them from infectious, inflammatory or vascular processes affecting the mesentery. Conclusion CT is the imaging method of choice for the evaluation of tumors of small bowel mesentery.
Objective To summarize the research status and progress of imaging diagnosis of periampullary carcinoma. Methods The literatures on imaging diagnosis of periampullary carcinoma were reviewed. Results At present, the commonly used imaging diagnosis methods for periampullary carcinoma mainly include ultrasound, CT, MRI, and endoscopic retrograde cholangiopancreatography. Some other new imaging techniques had also been applied in the diagnosis and evaluation of periampullary carcinoma. Conclusions Different imaging methods have their own advantages and disadvantages in the diagnosis of periampullary carcinoma. Therefore, the detection rate and diagnostic accuracy of periampullary carcinoma can be improved by rational selection of imaging techniques or combined application of multiple techniques.
Objective To investigate the CT manifestations of acute pancreatitis (AP) and its complications and to evaluate the imaging modalities for staging the severity of AP. Methods Literatures on CT manifestations of AP and its complications and severity staging of AP were reviewed.Results CT has shown an early overall detection rate of 90% for pancreatic necrosis with close to 100% sensitivity 4 days after episode. The CT severity index has shown a bly positive correlation with the development of local complications and mortality of AP.Conclusion Contrastenhanced CT is the imaging modality of choice to help detect pancreatic necrosis, stage the severity of the inflammatory processes, and depict local complications.
ObjectiveTo evaluate the diagnostic value of CT, MRI, and magnetic resonance cholangiopancreatography (MRCP) in the localization and qualitative diagnosis of biliary obstruction.MethodsA total of 80 patients with biliary obstruction in our hospital from January 2018 to June 2020 were retrospectively collected. The patients were all examined by CT, MRI, and MRCP. The imaging images of all patients were interpreted by two radiologists with more than 5 years of working experience. Taking the results of operation and histopathology as the gold standard, the diagnostic value of CT, MRI+MRCP, CT+MRI+MRCP in the localization and qualitative diagnosis of biliary obstruction lesions were evaluated.ResultsCompared with the location results of surgery and histopathology, the coincidence rates of CT+MRI+MRCP and MRI+MRCP were higher than that of CT (P<0.05), but there was no significant difference between CT+MRI+MRCP and MRI+MRCP (P>0.05); compared with the benign and malignant results of surgery and histopathology, the coincidence rates of CT, CT+MRI+MRCP and MRI+MRCP were close, and there was no statistical significance among them (P>0.05).ConclusionsMRI+MRCP and CT+MRI+MRCP have the same value in the localization and qualitative diagnosis of biliary obstruction. However, MRI+MRCP have the advantages ofnon-radiation or contrast media, it is more suitable for patients who are worried about the impact of radiation, have contrast media allergy or renal insufficiency.
ObjectiveTo summarize the status and progress of imaging studies of pancreatic neuroendocrine neoplasms (pNENs).MethodThe relevant literatures published recently at domestic and abroad about the imaging of pNENs were collected and reviewed.ResultsDue to poor visibility of pancreatic body and tail, the application of ultrasound (US) was limited. Compared with US, endoscopic ultrasound (EUS) and contrast-enhanced ultrasound (CEUS) could improve the detection rate of pNENs. The ability of plain CT scans to differentiate pathological grades was still controversial, but the value of enhanced scan was higher. CT texture analysis was feasible in the discrimination of nonhypervascular pNENs and pancreatic ductal adenocarcinoma (PDAC). Teta2 was the parameter with the highest diagnostic performance. The enhanced features of MRI were similar to CT. Combined with the apparent diffusion coefficient (ADC) value, the diagnostic and classification capabilities of MRI were improved, and the sensitivity and specificity of different ADC thresholds were also different. 68Ga-tetraazacyclododecane tetraacetic acid (68Ga-DOTA) peptide PET-CT had good preliminary diagnostic value for well-differentiated pNENs, and 18Fluoro-fluorodeoxyglucose (18F-FDG) PET-CT had limited diagnostic value.ConclusionsSomatostatin receptor imaging is of high diagnostic value and can guide clinical treatment and predict prognosis, but it has not been widely used in China. Conventional morphological images have advantages in the diagnosis and classification of pNENs. Therefore, it is important to choose a proper image inspection method.
Objective To review the value of imaging assessment for perioperative period of liver transplantation. Methods The related literatures in recent years were reviewed, and the applications of various kinds of radiological techniques in perioperative period of liver transplantation and radiological strategies of major complications after liver transplantation were summarized. Results Transplantation has become an effective option for treatment of patients with irreversible severe liver dysfunction. Radiological assessment supplies prompt and accurate information for clinic to increase the success rate and reduce the complications. So it plays an irreplaceable role. Conclusions Radiology assessment is important for screening donors and recipients before liver transplantation， following up and monitoring the complications. The doctor of imaging department could grasp the different imaging appearance in perioperative period of liver transplantation.
Objective To determine the frequencies and patterns of gastrointestinal wall thickening at muti-slice computed tomography (MSCT) in patients with hepatic cirrhosis. Methods One hundred and nine patients with cirrhosis and 130 patients without cirrhosis for gastrointestinal wall thickening were retrospectively analyzed by the abdominal MSCT scans. The frequencies of wall thickening were determined in the cirrhosis patients and in those without cirrhosis. The segmental distribution, symmetry and enhancement pattern were evaluated in all patients with cirrhosis for gastrointestinal wall thickening. Results Gastrointestinal wall thickening was seen in 72 cases (66%) with cirrhosis patients and in 12 cases (9%) without cirrhosis patients (Plt;0.005). The jejunum and ascending colon were the most common sites of gastrointestinal wall thickening, which was involved in 32 and 31 patients respectively. The scans of 46 (64%) patients with gastrointestinal wall thickening showed multisegmental distribution. Gastrointestinal wall thickening was concentric and homogeneous in all patients with cirrhosis. Conclusion Gastrointestinal wall thickening is common in patients with hepatic cirrhosis. It frequently involves multiple segments. The jejunum and ascending colon are the most common sites of involvement. MSCT plays an invaluable role in diagnostic evaluation of bowel wall thickening in patients with hepatic cirrhosis.