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 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 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.
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.
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.
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 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.
ObjectiveTo summarize the value of imaging in the evaluation of non-surgical therapy for pancreatic cancer.MethodThe relevant literatures about imaging evaluation of non-surgical therapy for pancreatic cancer were collected to make an review.ResultsAt present, most of the imaging evaluation of non-surgical therapy for pancreatic cancer were based on the assessment of morphological characteristics of tumors, such as contrast-enhanced CT and MRI. However, only morphological changes of tumors could not accurately evaluate the response of pancreatic cancer after non-surgical treatment. A few studies had explored the value of functional imaging and artificial intelligence.ConclusionsNon-surgical therapy provides new treatment opportunities for unresectable pancreatic cancer, especially the proposed of neoadjuvant therapy, which provides the possibility of operation for patients with advanced pancreatic cancer. More imaging indicators with stronger objectivity, higher accuracy, and wider universality need to be improved and developed in the future.
【Abstract】ObjectiveTo investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. MethodsThirty-five patients of chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0T MRI device. Apparent diffusion coefficient (ADC) of the liver were measured respectively when b value were set as 100, 400, 600 and 800 s/mm2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). ResultsWhen b value was set as 800 s/mm2, statistical difference was showed between the fibrosis group and the nonfibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. ConclusionDWI is a valuable method for grading and staging of chronic viral hepatitis.
Objective To understand and analyze technique development of magnetic resonance elastography (MRE) and its application in chronic liver disease. Method The relevant literatures about the application of MRE in the field of chronic liver disease were reviewed. Results The liver fibrosis was a common pathway of chronic liver disease, which would progress to cirrhosis of the liver if untreated. The diagnosis and assessment of fibrosis was important in the treatment of patients with chronic liver disease. The liver biopsy was considered to be the reference standard for clinical assessment of liver fibrosis. However, this technique was invasive and still had inevitable drawbacks in the clinical practice. With the update of the imaging technology and equipment, the MRE had been developed as a safe and noninvasive examination method for the evaluation of liver fibrosis in the chronic liver disease, early diagnosis of nonalcoholic fatty liver disease, evaluation of focal liver lesions, and other clinical applications. Conclusion MRE is currently regarded as an attractive noninvasive technique in management of chronic liver disease.