双能量CT肺动脉成像在儿科肾病综合征病人肺栓塞诊断中的应用

目的评价双能量CT肺动脉成像（DE-CTPA）在儿科肾病病人肺动脉栓塞诊断中的应用价值。材料与方法由2名放射科医师复习了2010年4月—2011年6月共52例年龄≤18岁的肾病病人的DE-CTPA影像和CTPA影像,记录灌注缺损或充盈缺损的有无,确立肺栓塞的诊断;在双能量CT灌注影像上记录肺栓塞区域的CT强化值。结果 52例患儿中,11例（21.2%,11/52）病人有肺栓塞。其中9例在CTPA上表现为叶（n=3）、段（n=5）和亚段（n=1）肺动脉内充盈缺损,其余2例CTPA上未见异常征象,而DE-CTPA上表现为亚段和亚亚段灌注缺损。11例病人中有8例在DE-CTPA上表现为叶（n=3）、段（n=5）分布的栓子,即以肺叶和肺段分布的灌注缺损区,另3例非闭塞性亚段肺栓塞未出现典型灌注缺损。双能量CT自动化分区所测得肺栓塞区域的CT强化值（37.8±15.6）HU和（49.5±14.1）HU,t=-2.663,P=0.014]和手工所测得的肺栓塞区域的CT强化值（19.1±11.2）HU和（49.6±12.7）HU,t=-8.841,P〈0.001]均低于非栓塞区域所测得的CT强化值。结论本组儿科肾病综合征病人肺栓塞检出率为21.2%,DE-CTPA能显示儿童肺栓塞所致的灌注缺损,具有提高儿科病人肺栓塞检出率的潜力。

Dual energy CT pulmonary angiography for evaluation of pulmonary embolism in pediatric patients with nephrotic syndrome

Objective The purpose of this study was to evaluate the value of dual energy CT pulmonary angiography（DE-CTPA） in detection of pulmonary embolism in the children with nephritic syndrome.Materials and Methods Fifty-two patients aged ≤18 years were included into this study from April 2010 to June 2011.Two radiologists reviewed and recorded the presence of perfusion defects or filling defects at dual energy CT perfusion images and CTPA images.CT enhancement values of embolic and nonembolic regions were measured with automatic and manual methods.Results Of 52 patients,11（21.2%,11/52） patients had pulmonary embolism.Of 11 patients with pulmonary embolism,9 patients had lobar（n=3）,segmental（n=5）,and subsegmental（n=1） filling defects,while two patients were negative at the initial CTPA from average weighted images but positive at dual energy CT perfusion images.Eight patients had lobar（n=3）,segmental（n=5） perfusion defects while 3 patients had no typical perfusion defects at dual energy CT perfusion images.Automatic and manual measurements showed the CT enhancement value of embolic regions measured with automatic method （37.8±15.6） HU vs.（49.5±14.1） HU,t=-2.663,P=0.014] and CT enhancement value measured with annual method （19.1±11.2） HU vs.（49.6±12.7） HU,t=-8.841,P0.001] were lower than those of nonembolic regions.Conclusions The incidence of pulmonary embolism was 21.2% in pediatric patients with nephritic syndrome in this study.Dual energy CTPA can show the perfusion defects resulting from pulmonary embolism,having a potential to improve the detection of pulmonary embolism in pediatric population.