| Objective To explore the clinical feasibility of evaluating intracranial arterial diseases by utilizing ZTE-MRA with hybrid ASL(HASL)tagging.Methods In this study,67 patients with suspected or confirmed cerebrovascular diseases were enrolled in this study.MRA images were collected based on cASL/hASL labeling and ZTE readout under 3.0T field intensity,respectively.The acquisition noise(sound intensity measurement and subjective score)of two kinds of MRA examination were evaluated respectively.Three neuroradiologists used double-blind and randomized methods to measure the image quality(IQ)score,signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)of each segment of intracranial artery(including bilateral internal carotid artery(C1-C7),anterior cerebral artery(A1-A2),middle cerebral artery(M1-M2),posterior cerebral artery(P1-P2),vertebral artery(VA)and basilar artery(BA))in two kinds of MRA images.The grade of arterial stenosis(4 points),the measurement of aneurysm and the signal intensity of the lesion were recorded at the same time.Wilcoxon rank sum test was used to analyze the subjective noise score and IQ score of the two MRA tests.Single factor analysis of variance(ANOVA)and minimum significant difference(LSD)test were used to analyze the background environment and the difference of sound intensity between the two MRA scans.Paired t-test was used to compare the differences of SNR and CNR in two MRA images of each segment.Kendall harmony coefficient(W)and intra-group correlation coefficient(ICC)were used to analyze the inter-observer consistency.Kappa test(k)was used to evaluate the classification of arterial stenosis,and ICC value was used to evaluate the consistency of aneurysm measurements between modes.Results Noise reduction and perception for hASL-ZTE-MRA was similar to cASL-ZTE-MRA.The mean IQ score for hASL-ZTE-MRA were on diagnostic scale and slightly higher(P<0.05)than that of cASL-ZTE-MRA(4.1±0.6 vs 3.9±0.6).hASL-ZTE-MRA provided higher(P<0.05)SNR/CNR than that of cASL-ZTE-MRA(53.8±12.4 vs 47.9±12.0;49.2±12.0 vs 43.7±11.5).Signal uniformity was improved on hASL-ZTE-MRA,particularly among the anterior circulation(P<0.05).In comparison to cASL-ZTE-MRA,on hASL-ZTE-MRA,stenotic lesions were accurately assessed;flow in the stent or aneurysm remnant was better depicted(P<0.05);AVM nidus was preferred with increased SNR(P<0.05).No significant differences for the aneurysm measurement were found between MRAs(P=0.95),in addition to the slightly higher SNR(P<0.05)on hASL-ZTE-MRA.Conclusion On the basis of keeping low noise,hASL-ZTE-MRA improves image quality,vascular contrast and signal uniformity through efficient labeling.In the diagnosis of intracranial stenosis and occlusive disease,hASL-ZTE-MRA can improve the diagnostic efficiency of stenosis to a certain extent,better display the blood flow in stent or residual neck of aneurysm,and improve the ability to display the details of AVM lesions to a certain extent.It has certain feasibility and imaging advantages in the evaluation of intracranial arterial diseases. |
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