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Noninvasive evaluation of abdominal aortic and lower extremity arterial occlusive disease with 16-slice spiral computed tomography <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Xiaodan Zhang, Zhengyu Jin，Yan Zhang, Jian Xu, Xiaobo Zhang, Mingli Li，Haifeng Shi, Shuo Li
Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing 100730, P. R. China
ABSTRACT
Purpose: To determine the feasibility of 16-slice spiral computed tomography for the assessment of abdominal aortic and lower extremity arterial occlusive disease and the choise of the delay time.
Material and Methods: 50 patients (40 male, aged 45～87years) with suspected peripheral arterial occlusive disease underwent 16-slice spiral CT angiography of the abdominal aorta and lower extremity arteries. 50 patients were divided into two groups according to the delay time after the attenuation in abdominal aorta at the level of diaphragm was 100HU. 25 examinations (group 1) were performed by using the delay time of 4 seconds. The other 25 examinations (group 2) were performed by using the delay time of 10 seconds.The other scan parameters were the same in the two groups. CT angiograms were produced using reconstructions of maximal intensity projection、volume rendering technique、curved planar reconstruction. Arteries depicted at CT angiography were divided into 23 segments. Each arterial segment was assigned one of five possible grades based on the degree of stenosis :1,nomal ;2,mild（<50％）stenosis;3,moderate （50～74％）stenosis;4,severe（75～99％）stenosis;5,occluded.
Results: （1）Significant difference was found at the attenuation of abdominal aorta at the level of diaphragm, abdominal aorta at the level of two kidneys, the common iliac artery,external iliac artery between the two groups with the delay time of 4 and 10 seconds（p<0.05）. No significant difference was found at the attenuation of the common femoral artery, superficial femoral artery, popliteal artery and anterior tibial artery between the two groups（p>0.05）. Significant difference was found at the attenuation of the splenic vein and renal vein between the two groups（t=－3.415，－3.721，p<0.05）, the attenuation of the splenic vein and renal vein were higher with the delay time of 10 seconds than that of 4 seconds. No significant difference was found at the reaching time of between the two groups（t=0.054，p>0.05）. （2）Many stenotic and occlusive diseases of abdominal vessels and lower extremity arteries, the other abnormities were showed.
Conclusion: （1）The image quality of the delay time with 4 seconds was better than that of the delay time with 10 seconds when abdominal aortas and lower extremity arteries were simultaneously assessed by CTA with 16-slice spiral computed tomography. （2）16-slice spiral computed tomography could accomplish CTA imaging of abdominal aortas and lower extremity arteries with one examnation, and the diagnostic process was simplified.
Key Words: computed tomography ; CT angiography；diagnosis; lower extremity; arterial disease |
