الفهرس 
Introduction
Segmental liver anatomyOnly 14 pages are availabe for public view
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Abstract
Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and has poor prognosis unless treated. (Cha et al, 2002). Unfortunately, more than 80% of patients with HCC have underlying cirrhosis, and only 10–15% of HCC patients are eligible for liver resection due to the severity of underlying cirrhosis or the diffuse distribution of the tumor (Patt et al, 2002). Other treatment options for patients with unresectable HCCs are transcatherter arterial chemoembolization (TACE) or transarterial radioembolization (using yttrium-90 microspheres). These transarterial therapies are based on the idea that HCC is supplied mainly by the hepatic artery. TACE causes a cytotoxic effect on malignant cells, as well as obliteration of the feeding arteries of the tumor. (Braga et al, 2005).
(MRI) are widely used in the post-treatment follow-up of these patients, for the detection of residual or recurrent tumors after treatment, as well as for the depiction of post-treatment complications. The early detection of residual or recurrent tumor is important for planning new interventions
Magnetic resonance spectroscopy (MRS) complements magnetic resonance imaging (MRI) as a non-invasive means for the characterization of tissue
Kuo et al. reported 1H MRS in vivo to be technically feasible also at 3.0 T for the evaluation of focal hepatic lesions and noted limitations in distinguishing between normal liver, benign and malignant tumors ( Kuo et al, 2004)
The aim of the study was to evaluate the role of magnetic resonance spectroscopy in the follow up of hepatocellular carcinoma after Trans-Arterial Chemo-Embolisation.
Our study was carried on 22 patients diagnosed to have HCC firstly by tri phasic computed tomography (CT) then we assessed the Cho level by MR spectroscopy, all patients underwent TACE , then they were followed up after 1 to 2 months by tri phasic CT and confirmed by MR spectroscopy after that .
In patients with HCC reexamined shortly after TACE, reduced Cho and reduced Cho/lipid ratios were observed.
In our study MRS measured before TACE showed an elevated choline peak in the recurrent part of the tumor but there was no elevation in choline peak in the necrotic part of the tumor. After TACE, the lack of a definite choline peak at either site suggested that the treated necrotic HCC remained at a lower choline concentration and that TACE effectively decreased the choline concentration in the recurrent part of the tumor.
In our study we found that the lipid concentration in patients with HCC higher than those normal and the level of lipid resonance at 0.9–1.4 ppm concentrarion is increased after TACE because of the embolization agent iodized oil deposition ( Chiao-Yun Chen, et al 2006)
Conclusion: in vivo proton MRS is technically feasible for evaluation of focal hepatic lesions. Based on our preliminary study, it has the potential to detect the early metabolite change in malignant liver tumor after TACE and malignant tumors tend to have higher cho/lipid ratio.
Recommendations
Another approach might be to try to find other stable and constant resonance for internal reference in liver by improving signal-to-noise ratio and spectral resolution, though this approach might again lengthen the acquisition time. Owing to the limited number of our cases in this preliminary work, the usefulness of the proton MRS in the evaluation of treatment effect in patients with HCC after TACE and the sensitivity of this technique to detect recurrent tumors need to be confirmed in further large-series, interdisciplinary studies.