The Clinical Evaluation Of Compressed-sensing Technique For Intracranial Time-of-flight MR Angiography And Magnetic Resonance Cholangiopancreatography

Objective 1.To explore the clinical value of compressed sensing(CS)technique for intracranial time-of-flight MR Angiography(TOF-MRA)and to compare the effects of different accelerators on CS imaging.2.This study was designed to explore the value of compressed sensing(CS)technique for and magnetic resonance cholangiopancreatography(MRCP)and compare the quality of images.Material and Methods 1.Twenty-one subjects underwent both parallel imaging(PI)and CS TOF-MRA of the cerebral angiography at a 3.0T MR scanner.Two acceleration factors(AF=4.6 and 10.3)were used for CS TOF-MRA.As a result,3 groups of MRA were obtained for each subject,including PI,CS5 and CS10.The diagnostic quality and the visibility of small branching vessels were qualitatively analyzed.We analyzed the signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),and the edge sharpness of intracranial arteries.2.Twenty receivers who underwent both conventional 3D navigator-triggered T2-weighted MRCP using sampling perfection with application optimized contrasts(SPACE)and 3D breath-hold CS-MRCP using SPACE with 3.6% k-space sampling at 3T.Each patient obtained 2 groups of images(conventional-MRCP and CS-MRCP).Two radiologists then independently analyzed the examinations for overall image quality,bile duct、pancreatic duct visualization and image sharpness and background suppression,with the higher score indicating better image quality.Results 1.The scan times of PI,CS5 and CS10 were 4 minutes 48 seconds,5 minutes 4 seconds and 2 minutes 31 seconds respectively.For the image diagnostic quality,CS5 was superior to PI and CS10 was equivalent to PI(P=0.086),the small branching vessels could best visualized in CS5 group.For the objective image quality of SNRs and CNRs,CS5 was superior to CS10(P=0.008,0.018,respectively),while no statistical difference was found between PI and CS group.The edge sharpness of the intracranial arteries in CS groups was significantly higher than that of PI group,of which,CS5 was superior to CS10(P<0.005).2.The scan times of conventional Con-MRCP and CS-MRCP were 280±63.5 seconds(mean±standard deviation),17 seconds respectively.In all patients CS-MRCP showed better overall image quality 、 image visualization and sharpness of the bile duct(P=0.0001、<0.0001、0.001,respectively),but no statistical difference was found between pancreatic duct visualization and sharpness(P=0.056 、 0.727,respectively).For the background suppression,Con-MRCP was superior to CS-MRCP(P=0.0001).Conclusion 1.Conventional MR sequence,CS can reduced the scan time and provide comparable or better image quality,had a good application value in clinical practice for the patients who can not bear the long scan time.2.CS-MRCP reduced the san time compared with Con-MRCP,and can provide comparable or better image quality,had a good value in clinical practice particularly in patients with irregular breathing patterns.