Background Over the last years, Diffusion-weighted Imaging (DWI) has been largely investigated as a tool to provide noninvasive detection [1] and quantification of liver fibrosis [2-3]. Fibrosis results from the accumulation of extracellular matrix components, which causes distortion of the parenchymal architecture [4], and theoretical restriction of water diffusion in the affected liver [5]. As expected, hepatic apparent diffusion coefficient (ADC), measured by means of DWI, has been shown to decrease proportionally to the degree of fibrosis and/or inflammation [6-9]. Nonetheless, the mechanism underlying ADC...

Patients Over the period June-December 2010 we prospectively enrolled twenty-four subjects. Of these, twelve were patients with clinically and histologically proven hepatic cirrhosis (7 male, 5 female; age range 45-71, mean 54.1 y-o), addressed to Magnetic Resonance Imaging (MRI) surveillance of regenerative nodules (n=11) and hepatocellular carcinoma treated with radiofrequency ablation (n=1). All patients showed a Child-Pugh grade A. Median time between hepatic biopsy and MRI examination was of 7.2 months. Remaining twelve subjects (8 male, 4 female; age range 26-53, mean 31.4 years-old) were...

Consistency of measurements Despite the presence of outliers, no significant difference was observed by comparing liver ADC (Tab. 2) and perfusion fraction f (Tab. 3) of the plane 1 vs. that of the plane 2, both in controls and cirrhotics (p>0.01;unpaired t-test). These results were obtained regardless of the motion-probing gradient direction that has been applied. It is arguable that the methodology of ADC measurement and the use of ultra-high field strength provided consistent results throughout the liver in our model. ADC and within controls...

1. Liver ADC at 3.0T Liver ADC values in healthy subjects have been reported either significantly increased [15] or decreased (but not significantly) [16] at 3.0 T as compared to those obtained at 1.5T. “Noise floor” from lower signal-to-noise ratio (SNR) at 1.5T and decrease in liver T2 relaxation time at 3.0T have been proposed as potential explanations for these opposite findings, respectively. By considering both planes of measurement, the ADCs we showed in controls (Tab. 4-5) are consistent with those reported by Dale et...

1. Taouli B, Chouli M, Martin AJ, et al. Chronic hepatitis: role of diffusion-weighted imaging and diffusion tensor imaging for the diagnosis of liver fibrosis and inflmmation. J Magn Resonon Imaging 2008;28:89-95 2. JA Talwalkar, M Yin, JL Fidler, et al. Magnetic resonance imaging of hepatic fibrosis: Emerging clinical applications. Hepatolgy 2007;47:332-342 3. Kumaresan Sandrasegaran, Fatih M. Akisik, Chen Lin. Value of Diffusion-Weighted MRI for Assessing Liver Fibrosis and Cirrhosis. AJR 2009; 193:1556-1560 4. Taouli B, Koh DM. Diffusion-weighted MR Imaging of the Liver. Radiology...

Dr. Rossano Girometti Istituto di Radiologia Diagnostica Università di Udine via Colugna, 50 33100- Udine Italy [email protected] Do not hesitate to contact me for any question or comment.