Positron emission tomography/computer tomography: Challenge to conventional imaging modalities in evaluating primary and metastatic liver malignancies

Table 1 Characteristics of PET and its novel sister modalities in detecting liver malignancies

Modalities	Characteristics
PET	By detecting 18F-FDG uptake, producing functional images but with very poor anatomical details
PET/CT	Integrated PET and CT system, locate 18F-FDG in specific anatomical sites
PET/MDCT	Best to monitor response to treatment, especially early ones with fine details

Table 2 Comparison between PET/CT and conventional imaging modalities of their values in examination of liver malignancies

Modalities	Specificity	Sensitivity	Accuracy
18F-FDG-PET/CT	+++	+++	+++
Ultrasound	+	++	-
CT	++	+++	+
MRI	++	++	++

- poor; + fair; ++ good; +++ excellent.