The Study Of 64-detector Spiral CT Enhancement And Perfusion Scan In The Diagnosis Of Liver Cirrhosis And Small Hepatocellular Carcinoma

Background and objectiveLong-term development of chronic liver disease will inevitably lead to cirrhosis of the liver. The severity of cirrhosis is directly related to the patient's health and their lifestyle. However, since the liver has very strong compensatory functions, early liver cirrhosis may not be diagnosed as the clinical symptoms of it may not be present. With further development of the disease, the progressive deterioration of their condition is inevitable. Studies have shown that cirrhosis of tumor nodules is a complex multi-stage process from the regenerative nodules (RN)-low-grade dysplastic nodule-high-grade dysplastic nodule-with micro-foci of abnormal nodules to small hepatocellular carcinoma (SHCC). Therefore, the early detection of SHCC, with its background of accurate assessment of liver functions and forecasts to improve the prognosis of patients plays a significant part in clinical application. Clinically, SHCC usually refers to a single nodule with a diameter less than 3 centimeters or two nodules with a diameter less than 3 centimeters. This purpose of this research by 64-slice spiral CT is to study the following issues: 1.64-slice spiral CT of single, double arterial phase scanning for the advantages and disadvantages.2. Normal liver cirrhosis with varying degrees of differences between parameters of liver perfusion and contact.3. Normal liver and liver cancer with different pathological types of small differences between the perfusion parameters and connections.4. Different pathological types of SHCC with or without contact with the background liver in order to get more and more accurate SHCC and liver imaging background information to provide more clinical objective reference.Materials and methods1. Study1.1 Selected by clinical, biochemical and imaging studies of healthy volunteers without exception as a control group of 17 cases.1.2 Selected from 2008.5～2010.3 enhanced by 64-slice spiral CT scan and clinical suspicious for small liver cancer was 73 cases. Line double arterial phase (including morning and evening) enhanced scan in 38 cases,35 cases of a single arterial phase. Background of liver cirrhosis in which 26 patients with mild, moderate 17 cases of liver cirrhosis and severe liver cirrhosis in 11 cases. Confirmed by surgery and pathology scores of SHCC in 23 cases,19 cases of differentiated, poorly differentiated in 11 cases.2. Apparatus and equipmentThe United States, GE 64-slice lightspeed VCT machine; AW4.3 workstation software package perfusion-3.0-reperfusion liver tumor perfusion.3. Scanning Method3.1 Liver, multi-phase enhanced scanning methodFasting 4 to 8 hours, Patients with fasting were asked to drink 800～1000ml of water before scanning, patients lied in the supine position on the scanning table; conventionally first taking a scan of the whole liver, and then preparing the patients for multi-phase enhanced scanning. A one-time injection of non-ionic contrast agent (Omnipaque 350mgI/ml) 100ml at the rate of 4.0ml/s was injected intravenously through a power injector. Intelligent tracking technology (Smart Prep) triggered scanning was used to control the scan at real time; abdominal aorta was taken as the target blood vessel, the use of small dose of the same layer dynamics Test Method (Test Bolus) was used to obtain the time-density curves (TDC), with CT values of up to 120HU as a trigger point to start the scan. Thirty-eight cases of this study were done using dual-arterial phase enhanced scanning (artery angiography early after the injection of about 20s or so, late arterial injection of contrast agents in the 30s, the portal venous phase after injection of contrast medium in the 60s, delay after injection of contrast medium of 120s in the scan).35 cases with a single arterial phase scan (arterial phase after injection of contrast agent around the 30s or so, the portal venous phase after injection of contrast medium in the 65s, delay after injection of contrast medium of the 125s).3.2 CTP scanning methodFasting 4 to 8 hours, Patients with fasting were asked to drink 800-1000ml of water before scanning, pressure was applied on the right side of the patients with routine use of abdominal bandage in order to reduce artifacts during the scan, and they were asked to do quiet little slower shallow mouth breathing, tumor perfusion levels were selected (as far as possible, including abdominal aorta, portal vein or its branches the maximum area level), then through the forearm vein rapid injection of a one-time non-ionic contrast agent (Ioversol 320mgI/ml) 45ml at the rate of 4ml/s was given. The right level was selected to do continuous dynamic contrast-enhanced scans. According to liver tumor perfusion protocol (liver tumor perfusion), axis scan mode was done and proceeded with 45s multi-layer dynamic perfusion scanning. Slice thickness 5mm/4i (reconstruction to 10mm/2i), scanning Wild:Large, Voltage (Kv): 120KV, current (mA):60mA, axial scan images obtained 200 layers 5mm. Derived from image input scanning workstation AW4.3 (Advantage Windows 4.3) to post-processing.4. Data Processing4.1 The data processing of stage-4 enhanced CT.Reconstruction of post-imaging acquisition routine liver crown, sagittal, and lesions using volume rendering (VR), maximum intensity projection (MIP), and thickening of MIP as the reconstruction of post-processing methods.4.2 Perfusion parameter analysis and the calculation of perfusion parametersThe reconstructed images were sent to AW4.3 workstations, GE's perfusion-3.0 in the liver perfusion model, deconvolution software data processing was used. In the series trying to identify the abdominal aorta and portal vein or its branches as a feeding artery and outflow vein, size, placement by 2-6 pixels in order to avoid partial volume effect. Then defined threshold, usually 0～200HU, remove the surrounding bone, fat, air and other organizations studied. At last region of interest (ROI) selection, access to time density-Curve (TDC) and the perfusion parameters:blood flow (BF), blood volume (BV), mean transit time (MTT), the surface permeability (PS) and hepatic arterial fraction (HAF) and in accordance with the data obtained, the amount of hepatic artery infusion (HAP) HAP=BF×HAF was calculated. 4.3 The ROI of choice:abdominal aorta, portal vein or its branch vessels within the ROI pixels in size 2-6 months, the liver parenchyma of the ROI to avoid large blood vessels as far as possible, and the substantive part of selecting it from the volume effect impact. ROI selection of lesions should fully represent the substance of the lesion. It should not reach the edge of target area, in order to free from partial volume effects at the same time; should avoid large blood vessels and tumor necrosis and cystic degeneration areas. All values measured were repeated three times during the study period, and the average value was noted.5. Dispose of pathology specimenBiopsy specimen observation and taking photographs were assisted in the completion by a pathologist. SHCC were divided into three groups (including well-differentiated, moderately differentiated and poorly differentiated).6. Statistical MethodsAll data were handled by SPSS 16.0 statistical package. Measurement data were demonstrated in x±s, and the reference ranges using 95% confidence interval.Comparison among the three groups were compared using single factor analysis of variance (ANOVA), multiple comparisons between mean were done with LSD if variance was regular, using Games-Howell method if variance was irregular, P<0.05 represented statistically significant difference.Results1.38 regular pairs of arterial-phase enhanced scanning of cases of SHCC were found in 47 lesions, including early arterial phase found in 12 were obvious enhanced lesions, and tiny blood vessels were seen nourishing the dependent lesions, Late arterial phase found in 30 were obvious enhanced lesions, the lesions in the portal venous phase and delayed phase had slightly low density. In the 35 regular single arterial phasic enhanced scans, lesions were found in 39 cases, of which 33 were discovered in the arterial phase.2. Normal liver cirrhosis with varying degrees of liver perfusion values between the obvious differences, with the severity of liver cirrhosis, perfusion BF, BV became smaller, while the perfusion MTT, HAF, PS, and HAP increased.3. Perfusion HAF, HAP in normal liver and mild, moderate, and severe liver cirrhosis was statistically significant between the different combinations with the LSD method, normal perfusion values varying degrees of liver cirrhosis compared to 22 showed that perfusion HAF in the normal group with severe cirrhosis, mild and moderate to severe liver cirrhosis between; perfusion HAP with severe cirrhosis and normal, mild liver cirrhosis were significantly different between groups.4. The lower the degree of differentiation of SHCC, and BV, BF, PS, HAF, HAP higher values, MTT values were lower.5. HAF and PS were high in the highly differentiated SHCC, and HAP was high in poorly differentiated SHCC, poorly differentiated SHCC was statistically significant difference.6. This study found that:with the severity of cirrhosis, occurring in SHCC based on their degree of differentiation was lower.Conclusion1. For the early detection rate of small HCC, the 64-slice CT dual, single arterial phase scans have advantages and disadvantages, the detection rate of small liver cancer had no significant difference.2. Perfusion scan may help to confirm the degree of liver cirrhosis, the degree of differentiation of SHCC and make effective forecasting and assessment.3. Cirrhosis of liver and SHCC development are inseparable, the degree of cirrhosis and SHCC are closely related to the degree of differentiation.