The Feasibility And Clinical Value Of 3.0T Non-enhanced Magnetic Resonance Angiography In The Diagnosis Of Lower Extremity Arterial Disease

PurposeTo explore the feasibility and clinical value of 3.0T magnetic resonance imaging Triggered Angiography None Contrast Enhanced(TRANCE)technique in the diagnosis of lower extremity arterial disease.Materials and methodsCollected from March 2016 to July 2016,Henan University of Traditional Chinese Medicine,the first Affiliated Hospital,the clinical symptoms of lower extremity arterial disease in 15 patients with all the imaging data.All patients underwent NCE-MRA examination and then enhanced magnetic resonance CE-MRA examination.The lesions were detected in 15 patients,and for further accurate diagnosis and treatment,in a month with CTA or DSA examination.The range of magnetic resonance imaging is the lower part of the abdominal aorta to the ankle joint level.The lower extremity arterial system is divided into 17 segments(lower abdominal aorta,left and right iliac,external iliac artery,left and right shares,superficial femoral artery,left and right popliteal artery,left and right tibial artery,posterior tibial artery,left and right peroneal artery).A physician measured the signal to noise ratio(SNR)and contrast to noise ratio(CNR)of the 255 segments of the lower extremities in 15 patients;the quality of NCE-MRA and CE-MRA images were evaluated by two imaging physicians,and the degree of stenosis was evaluated.The data were analyzed by statistical software SPSS20.0,the SNR and CNR of NCE-MRA angiography,were expressed by?x±s.The Wilcoxon paired signed rank sum test was used to evaluate the image quality of NCE-MRA and CE-MRA.The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of NCE-MRA in the diagnosis of lower extremity arterial stenosis(grade 2 and grade 3)were calculated by using CE-MRA as standard.Kappa test was used to test the consistency of NCE-MRA and CE-MRA in the diagnosis of arterial stenosis of lower extremity.To further explore the diagnostic efficacy of NCE-MRA,the sensitivity,specificity,positive predictive value,negative predictive value and accuracy of NCE-MRA in the diagnosis of lower extremity arterial stenosis(grade 2 and grade 3)were calculated by using DSA/CTA as the gold standard.Kappa test was used to test the consistency of NCE-MRA and DSA/CTA in the diagnosis of arterial stenosis of lower extremity.ResultsOf the 15 patients,four patients had unilateral acral ulcers or gangrene,five had unilateral or bilateral lower extremity resting pain,and six had intermittent claudication.Five patients were examined by DSA and 10 patients underwent CTA.In 15 patients,the mean SNR and CNR of the 255 arterial blood vessels of the lower extremities were 140.24±28.80 and 118.88±27.55 respectively.For the intravenous contamination of this score,the calf of the arterial NCE-MRA and CE-MRA as 1 and 2 were 30 and 19,and the intravenous contamination was less than CE-MRA,the difference was statistically(Z=4.583,P <0.01).The abdominal arterial NCE-MRA and CE-MRA as 1 and 2 were 12 and 15,respectively,and the intravenous contamination was more than CE-MRA,the difference was statistically significant(Z=2.070,P<0.05).The sensitivity,specificity,positive predictive value,negative predictive value and accuracy were 92.19%,97.91%,93.65%,97.40% and 96.47% respectively in the diagnosis of superior stenosis of lower extremity with CE-MRA as the standard.The Kappa test showed that NCE-MRA and CE-MRA had better agreement in the diagnosis of lower extremity arterial stenosis(Kappa = 0.906,P <0.05).The sensitivity,specificity,positive predictive value,negative predictive value and accuracy of NCE-MRA were 96.72%,97.94%,93.65%,98.96% and 97.65% respectively in the diagnosis of lower extremity arterial stenosis with DSA/CTA as the gold standard.The results of Kappa test showed that NCE-MRA and DSA/CTA had better agreement in the diagnosis of lower extremity arterial stenosis(Kappa = 0.936,P <0.05).ConclusionUsing 3.0T magnetic resonance TRANCE technique can be used to obtain high image quality lower extremity arterial imaging,can clearly show the lower extremity arterial system and stenosis and extent.Non-enhanced magnetic resonance angiography in the diagnosis of lower extremity arterial disease has a higher success rate.NCE-MRA in the detection of lower extremity arterial stenosis of the sensitivity and specificity is higher,and have some diagnostic value.NCE-MRA can provide a reliable alternative to clinical examination methods.