الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 187 |  |  |
| | | from | 187 | | |
Abstract
Imaging is an important decision-making tool in the diagnosis of focal liver
lesions (FLLs), as it can accurately differentiate benign from malignant lesions
in most of the cases. Most FLLs have a characteristic imaging aspect, allowing a
confident final diagnosis.
MR elastography (MRE) is a phase contrast–based MRI technique for
direct visualization and quantitative measurement of propagating mechanical
shear waves in biologic tissue.
MRE has been found useful for noninvasive assessment of hepatic fibrosis.
Studies have shown that MRE can be used to differentiate normal liver from
fibrotic liver with a high degree of accuracy and that the technique is promising
for evaluating the stage of hepatic fibrosis.
Also, MRE has been found to have promise for differentiating benign
breast lesions from malignant tumors. Inspired by the successful application of
MRE to noninvasive evaluation of fibrosis of the liver in our clinical practice, we
sought to evaluate the utility of MRE in characterizing liver tumors.
Diffusion-weighted imaging (DWI) has been reported to be beneficial for
the early detection of small focal hepatic lesions, in addition to its capability of
characterizing lesions without the need of depending on contrast-enhanced study.
DWI can characterize specific tissue properties without any harm to
patients, especially for those who are at risk for complications of a biopsy
procedure. More importantly, lack of ionizing radiation, high contrast and spatial
resolution have made DWI a promising diagnostic tool of benign and malignant
tumors of various organs.
The aim of this study was to evaluate the role of magnetic resonance
elastography and diffusion weighted-magnetic resonance imaging in diagnosis
and differentiation between benign and malignant hepatic focal lesions.
This study was conducted on ninety patients (mean age 52 years) with
hepatic focal lesions (29 benign and 61 malignant). Benign lesions included
hepatocellular adenoma, hepatic hemangioma, and focal nodular hyperplasia.
Malignant lesions included cholangiocarcinoma, hepatocellular carcinoma and
metastatic hepatic lesion.
All patients were subjected to full history taking, clinical examination,
laboratory investigations, dynamic MRI, MRE and DW-MRI.
Summary of results
There was no significant different regarding age, total bilirubin, direct
bilirubin, albumin, ALT, AST, hemoglobin, WBCs, creatinine,
platelets, PC, and INR between benign group and malignant group.
Benign FLLs had significantly higher mean ADC values than
malignant FLLs. While Malignant FLLs showed significantly higher
mean stiffness than benign FLLs.
HEMs showed the highest mean ADC among the FLLs, which was
higher than that of FNHs and of all malignant FLLs. The mean ADC
of HCAs was significantly higher than that in all malignant tumors.
The MRE and DWI were found to be effective in differentiating benign
and malignant focal liver lesions (p<0.001). MRE and DWI cutoff
values were >4.23, and ≤1.43, respectively; sensitivity and specificity
results were 96.7%, 93.1% and 85.2%, 89.7% and the area under the
curve values were 0.991, and 0.894, respectively.
In comparison analysis of ROC curves showed that MRE performed
better than DWI for differentiating malignant from benign FLLs.
There were significant negative correlations between stiffness [i.e.,
stiffness (r: -.559; p<0.001)] and ADC.