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Purpose The patients with varicose veins of lower limbs need to undergo extensive CT or X-ray examinations with high doses of radiation before and after treatment.The aim of this study is to investigate the value of low-dose CT contrast-enhanced scan for the superficial varicosis of lower limbs.Materials and Methods Forty patients diagnosed as superficial varicosis of lower limbs were selected prospectively.According to the scanning parameters,40 patients were randomly divided into four groups:group Ⅰ (standard group) scanned by 120 kV and 250 mAs,group Ⅱ scanned by 120 kV and 100 mAs,group Ⅲ scanned by 100 kV and 200 mAs,group Ⅳ scanned by 80 kV and 300 mAs.The effective dose (ED),signal noise ratio (SNR),contrast noise ratio (CNR) and image quality were evaluated.Results (① There were no significant differences in age,body mass index and height between the four groups (P＞0.05).② The ED values of the four groups were statistically significant (P＜0.05).③ The differences of SNR and CNR had statistical significance between the four groups (F=3.7 and 3.6,P＜0.05).All images met the diagnostic requirements.Conclusion The lower tube voltage and the higher tube current (80 kV,300 mAs) can reduce the radiation dose and have less influence on the image quality,which can meet the clinical diagnostic requirements and can be used as routine scanning parameters for patients with superficial varicosis of lower limbs.
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Objective To explore the clinical value of 256-slice CT whole hepatic perfusion imaging in transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).Methods Twenty-three patients with hepatocellular carcinoma underwent whole hepatic perfusion with the JOG technique one week before TACE.The scanning data of cancer and liver tissues were analyzed using the perfusion software.The cancer tissue perfusion was repeated 4 to 6 weeks after treatment and was compared with that before treatment.Results (1) Before TACE,the HCC lesions were shown on the hepatic arterial perfusion (HAP) map as homogeneous hyper-perfusion lesions in 8 patients and as inhomogeneous hyper-perfusion lesions in 15 patients.The HAP and hepatic arterial perfusion index (HAPI) values of the tumor were higher than those of the liver tissues,while the hepatic portal perfusion (HPP) values of the tumor was lower than that of the liver tissues.The differences were all significant (P ＜ 0.05).(2) Mter TACE,the tumors were totally filled with lipiodol in 3 patients,partially filled with lipiodol in 13 patients,and sparsely filled with lipiodol in the remaining 3 patients.There was no blood perfusion in the lipiodol-filled areas and in the cancer necrotic tissues,but in the sparsely or partially lipiodol-filled areas blood perfusion could still be seen.21 patients received another session of TACE 6 to 8 weeks later.The results between the hepatic arterial digital subtraction angiography (DSA) and the CT perfusion were 100％ matching.The HAP and HAPI values of the tumor decreased when compared with before treatment,and the difference was significant (both P ＜0.05).The HPP values decreased slightly with no significant difference (P ＞ 0.05),while higher HAP and HPI and lower HPP were observed in the active cancer tissues when compared with the liver tissues after treatment (P ＜ 0.05).Conclusion 256-slice MSCT whole liver perfusion imaging can quantitatively reflect abnormal perfusion of hepatocellular carcinoma tissues and postoperative active tissues,and has important guiding significance in the preoperative evaluation,and the postoperative follow up of patients treated with TACE.
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Purpose To explore the value of direct CT venography (CTV) for the diagnosis of varicose veins of lower limb. Materials and methods Forty patients diagnosed as varicose veins of lower limbs were enrolled. 40 patients with 56 involved limbs underwent direct CTV examination, and their images were stratified and evaluated according to the severity and the scope of the disease. Main assessment:definition and scope of CT axial scans combined with volume rendering (VR) and maximum intensity projection for the display of the varicose veins; situation for the display of perforating veins, deep veins and iliac veins;diagnostic compliance between CTV and DSA. Results All of the 56 involved limbs underwent laser intra-cavity occlusion surgery, among them 7 cases with 11 limbs underwent venous angiography under DSA at the same time. In the evaluation of the VR, excellent proportion was 92.86%(52/56), moderate proportion was 7.14%(4/56). Among the deep veins, ratio of the imaging that was able to meet the diagnostic standard was 94.34%, 88.46%and 27.27%, respectively for calf vein, femoral vein and external iliac vein. The total demonstration rate of perforating veins was 98.21%(55/56). Diagnostic compliance between CTV and DSA was 100.00%. Conclusion Lower extremity direct CTV imaging is convenient and noninvasive for patients with varicose veins, with high compliance with DSA results, thus is significantly valuable for the guide of clinical treatment.