الفهرس 
ANTOMY OF THE LIVEROnly 14 pages are availabe for public view
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Abstract
Dual modality PET CT scanning provides accurately
fused morphologic (CT) and functional (PET) data sets. A very small tumor is well detected by PET but can be missed by CT. On the other hand, a large tumor with minimal functional deviations may be seen on a CT image, put may not be detected by PET. In both situations, PET CT would localize the tumor accurately.
PET CT has advantages over other imaging methods; it can differentiate benign from malignant lesions, staging and restaging tumors, detect functional changes before there is any change in clinical or radiological size of a mass, better in identify cancer that has spread, making up treatment plane and monitoring tumor response, detect tumor recurrence early and distinguish viable metabolically active tissue from scars.
PET CT is more and more widely applied in clinical practice. It is more sensitive and specific than PET , with a lower false positive and false negative rate.
Whole body positron emission tomography with (18)F-FDG in combination with CT scanning (PET CT) represents one the most sensitive imaging modalities for detection of hepatic metastases and extrahepatic tumor manifestations. For the staging and follow up of colorectal cancer, FDG- PET CT represent a standard imaging modality.
(18) F- FDG PET CT is useful in the evaluation of metastasis, poorly differentiated HCC although its role in the diagnosis of well differentiated HCC is more limited. Dual tracer PET CT had an incremental value and complementary advantage when compared with single tracer imaging in the evaluation of HCC . Recently, carbon-11 (C-11)-acetate has been shown to be useful in detecting those HCCs not seen on F-18-FDG PET studies. when a lesion is positive for both tracers or only for 11C-acetate, the likelihood of HCC is very high. When a liver lesion is positive only for FDG but is negative for 11C-acetate, the possibility of non-HCC malignancy or poorly differentiated HCC should be considered. In case both tracers are negative, benign pathology is very likely.
PET CT has advantages over conventional imaging techniques in designing and evaluating management of hepatic malignancy.
It has proved to be helpful in patients who have undergone radiofrequency ablation for hepatic metastases.
PET CT is very important in patient with unexplained high levels of tumor markers.