Publications (2)3.21 Total impact
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ABSTRACT: To evaluate the reproducibility of the pancreatic apparent diffusion coefficient (ADC) measured at different MR scanners. Twenty-four healthy volunteers underwent three consecutive diffusion-weighted imaging (DWI) at a GE 1.5 Tesla (T), a Siemens 1.5T and a Philips 3.0T (session 1), and imaged again using the same protocol at the same GE 1.5T (session 2) 12 days later. The ADC values of pancreas were measured at all three MR scanners. Paired-sample t-test and the Bland-Altman method were used for ADC data analysis. The individual mean ADC values of pancreatic head, body, and tail (in 10(-3) mm(2) /s) measured at GE 1.5T (2.24, 2.01, 1.88 for observer 1 and 2.23, 2.00, 1.92 for observer 2) and Siemens 1.5T (2.24, 2.04, 1.84 for observer 1 and 2.20, 1.98, 1.84 for observer 2) were significantly higher than those at Philips 3.0T (2.06, 1.80, 1.56 for observer 1 and 2.02, 1.79, 1.60 for observer 2) (P = 0.000-0.008). There was no significant difference of ADC values either between GE 1.5T and Siemens 1.5T (P = 0.115-0.966), or between imaging session 1 and 2 at GE 1.5T (P = 0.072-0.938). The range of mean difference ± limits of agreement (in 10(-3) mm(2) /s) was -0.07-0.04 ± 0.39-0.53 between two 1.5T scanners, and -0.04-0.04 ± 0.24-0.47 between two imaging sessions at GE 1.5T. The measured ADC values of pancreas are affected by the field strength of scanner, but show good reproducibility between different MR systems with same field strength and at the same MR system over time. J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.Journal of Magnetic Resonance Imaging 12/2014; 40(6). DOI:10.1002/jmri.24492 · 3.21 Impact Factor
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ABSTRACT: To investigate the role of perfusion-weighted magnetic resonance imaging (MRI) in evaluation of cirrhotic liver. With a 4F catheter, 1% diluted carbon tetrachloride (1 ml/kg) was selectively injected into right or left hepatic artery of 12 dogs fortnightly. The half liver into which carbon tetrachloride was injected was called as study side (SS), while the other half liver without carbon tetrachloride injection was called as study control side (SCS). Conventional and perfusion-weighted MRI were performed in every 4 weeks. Via a 4F catheter, 5ml gadolinium diethylentriamine pentaaceti acid (Gd-DTPA) dilution was injected into superior mesenteric artery at the 5th scan. The signal intensity-time curves of SS, SCS, and portal vein were completed in MR workstation. The maximal relative signal increase (MRSI), peak time (tp), and slope of the curves were measured. On conventional MR images, no abnormalities of externality and signal intensity were observed in both SS and SCS of liver at each stage. The mean tp, MRSI, and slope of intensity-time curves in normal liver were 10.56 seconds, 1.01, and 10.23 arbitrary unit (au)/s, respectively. Three parameters of curves didn't show obvious change in SCS of liver at every stage. Abnormal perfusion curves occurred in SS of liver at the 12th week after the 1st injection. The abnormality of perfusion curve in SS was more and more serious as the times of injection increased. The mean tp, MRSI, and slope intensity-time curves in SS of liver were 19.45 seconds, 0.43, and 3.60 au/s respectively at the 24th week. Perfusion-weighted imaging can potentially provide information about portal perfusion of hepatic parenchyma, and to some degree, reflect the severity of cirrhosis.Chinese Medical Sciences Journal 01/2007; 21(4):252-7.