| Lung carcinoma is one of the most common malignant tumors in China, and it is the most important object of the chest radiological research. In conventional studies, radiologists center their attention on the morphologic feature and the pathological matter of lung carcinoma. With the advent of new imaging techniques combined morphologic study with functional analysis, the radiological research of lung carcinoma has met new challenges.In 1971, Folkman, the professor of Harvard University, first proposed the theory of " angiogenesis " : tumor angiogenesis, the process by which new blood vessels are formed from the existing vessels, is essential for tumor growth and tumor metastasis. The study of angiogenesis then became the hot spot of cancer research in following decades. Numerous studies have shown that increased microvessel density of solid tumor is correlated to poor overall survival , poorer disease-free survival ,and/or increased risk for metastasis. In some studies, measurement of angiogenic activity has been shown to have independent prognostic value. Currently, there are two general methods of assessing the angiogenic capacity of a tumor. The first is done indirectly with a biochemical assay to detect angiogenic or antiangiogenic factors in the serum, urine, orcerebrospinal fluid of cancer patients, and the second one is through the measurement of tumor vascularity in a biopsy specimen. But these two methods have some disadvantages and were limited to apply in clinic studies.In 1979, Leon Axel first proposed a method for determining tissue perfusion from dynamic contrast enhanced CT data. With the advent of spiral and multi-slice CT, the functional imaging technique has played a more and more important role in angiogenic research. More recently, clinical use of CT functional imaging has been facilitated by the release of commercial software packages and has been widely applied in tumor diagnoses, detection of potential or small metastasis, risk or prognosis stratification, evaluation of anti-angiogenesis therapies and assessment of acute stroke. In our study, the advanced multi-slice CT scanner was used to measure both tissue and vascular enhancement at small time intervals to detail modeling of the distribution of contrast agent in lung carcinoma and calculate the functional parameter perfusion, peak enhancement heights, relative blood volume and the capillary vessel permeability, then these parameters were correlated to histopathologic finds of micro-vessel density. The objective of this study was to find out the best functional CT imaging parameter to evaluate the angiogenesis of patients of lung carcinoma.Materials and Methods1. Patients: Following approval by the hospital ethics committee, 69 patients were examined in the radiology department of first hospital Zhejiang University between 2003 May and 2004 March. Patients were selected according to the following criteria: (1) presence of a nodule or mass focus in lung; (2) absence of contraindications to the administration of contrast medium; (3) probable ability to cooperate with the procedure. Among these patients, 34 patients who got lung carcinoma diagnosis by means of surgery in 2 weeks after the CT examination were bring into our research. All the 34 patients didn't bear any anti-cancer drug therapy and their pathological reports were provided.2. Protocol: Before the examination began, patients were carefully instructed in and practiced the breath-holding technique to reproduce precisely the same degree of in inspiration or expiration for each scan series. Before dynamic scanning, control scans were obtained from which the scan level that best demonstrated the focus was selected and the plain imaging was received. The first series of dynamic CT scan was administrated at 10 sec after a contrast medium injection (rate of 6ml/s, total for 40 ml). The section thickness was 4 X 25mm, and scanning time was 0.75 sec. The cycle time was 1.5 sec and the total scanning time was 30 sec. There was 20 sec relax time after the... |
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