ABSTRACT
Objective To investigate the application of semi-quantitative analysis of dual energy lung perfusion imaging(DEPI)in patients with acute pulmonary embolism(PE)before and after treatment.Methods 25 patients with acute PE diagnosed by dual source CT were recruited consecutively.All of them underwent CT pulmonary angiography(CTPA)and DEPI before and after treatment. Radiologists visually evaluated the PE numbers,its distribution(central or peripheral)and its nature(occlusive or non-occlusive)on CTPA.DEPI visual analysis and semi-quantitative analysis before and after treatment in different types of PE evaluated by CTPA were analyzed statistically.Results Four types of PE(central occlusive PE,central non-occlusive PE,peripheral occlusive PE and peripheral non-occlusive PE)were classified according to embolic sites and the extent of embolization.Comparing to CTPA as a standard reference,the positive rates of DEPI visual analysis were 100.00%,70.54%,87.23%,76.19% before treatment,100.00%, 76.67%,86.67%,77.78% after treatment,respectively.Significant differences were found in central occlusive PE,central non-occlusive PE and peripheral occlusive PE with mean difference of CT values before and after treatment[(70.7 ± 10.1)HU vs(29.8 ± 6.0)HU,P<0.01;(50.1 ± 9.6)HU vs(29.3 ± 7.8)HU,P< 0.01;(53.4 ± 11.4)HU vs(27.4 ± 8.9)HU,P<0.01,respectively].Although(24.5 ± 8.2)HU (after treatment)were lower than(28.5 ± 9.0)HU(before treatment),no significant difference was found in the type of peripheral non-occlusive PE(P> 0.05).Conclusion The combination of CTPA and DEPI can offer more comprehensive information of the acute PE therapeutic evaluation before and after treatment.
ABSTRACT
The history,hardware,imaging principle and technical characteristics of dual-energy CT machine were described.The causes,clinical diagnosis and treatment of urinary calculi were analyzed.Dual-energy CT had its technical characteristics,clinical significance,advantages and practicality expounded in detail when used to determine the components of urinary calculi.