Effect of diffusion time on liver DWI: An experimental study of normal and fibrotic livers. Issue 5 (20th November 2013)

• Record Type: Journal Article
• Authors: Zhou, Iris Y.; Gao, Darwin S.; Chow, April M.; Fan, Shujuan; Cheung, Matthew M.; Ling, Changchun; Liu, Xiaobing; Cao, Peng; Guo, Hua; Man, Kwan; Wu, Ed X.
• Is Part Of: Magnetic resonance in medicine. Volume 72:Issue 5(2014:Nov.)
• Page Start: 1389
• Page End: 1396
• Publication Date: 2013-11-20
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25035
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm25035-sec-0001" sec-type="section"> <title>Purpose</title> <p>To investigate whether diffusion time (Δ) affects the diffusion measurements in liver and their sensitivity in detecting fibrosis.</p> </sec> <sec id="mrm25035-sec-0002" sec-type="section"> <title>Methods</title> <p>Liver fibrosis was induced in Sprague‐Dawley rats (n = 12) by carbon tetrachloride (CCl<sub>4</sub>) injections. Diffusion‐weighted MRI was performed longitudinally during 8‐week CCl<sub>4</sub> administration at 7 Tesla (T) using single‐shot stimulated‐echo EPI with five b‐values (0 to 1000 s/mm<sup>2</sup>) and three Δs. Apparent diffusion coefficient (ADC) and true diffusion coefficient (D<sub>true</sub>) were calculated by using all five b‐values and large b‐values, respectively.</p> </sec> <sec id="mrm25035-sec-0003" sec-type="section"> <title>Results</title> <p>ADC and D<sub>true</sub> decreased with Δ for both normal and fibrotic liver at each time point. ADC and D<sub>true</sub> also generally decreased with the time after CCl<sub>4</sub> insult. The reductions in D<sub>true</sub> between 2‐week and 4‐week CCl<sub>4</sub> insult were larger than the ADC reductions at all Δs. At each time point, D<sub>true</sub> measured with long Δ (200 ms) detected the largest changes among the 3 Δs examined. Histology revealed gradual collagen deposition and presence of intracellular fat vacuoles after CCl<sub>4</sub> insult.</p> </sec> <sec id="mrm25035-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Our results demonstrated the Δ dependent diffusion measurements, indicating restricted diffusion in both normal and fibrotic liver. D<sub>true</sub> measured with long Δ acted as a more sensitive index of the pathological alterations in liver microstructure during fibrogenesis. Magn Reson Med 72:1389–1396, 2014. © 2013 Wiley Periodicals, Inc.</p> </sec> </abstract>