Objective(s): In this study, we aimed to describe the characteristics of portal vein tumor thrombosis (PVTT), complicating hepatocellular carcinoma (HCC) in contrast-enhanced FDG PET/CT scan.Methods: In this retrospective study, 9 HCC patients with FDG-avid PVTT were diagnosed by contrast-enhanced fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT), which is a combination of dynamic liver CT scan, multiphase imaging, and whole-body PET scan. PET and CT DICOM images of patients were imported into the PET/CT imaging system for the re-analysis of contrast enhancement and FDG uptake in thrombus, the diameter of the involved portal vein, and characteristics of liver tumors and metastasis.Results: Two patients with previously untreated HCC and 7 cases with previously treated HCC had FDG-avid PVTT in contrast-enhanced FDG PET/CT scan. During the arterial phase of CT scan, portal vein thrombus showed contrast enhancement in 8 out of 9 patients (88.9%). PET scan showed an increased linear FDG uptake along the thrombosed portal vein in all patients. The mean greatest diameter of thrombosed portal veins was 1.8±0.2 cm, which was significantly greater than that observed in normal portal veins (P<0.001). FDG uptake level in portal vein thrombus was significantly higher than that of blood pool in the reference normal portal vein (P=0.001). PVTT was caused by the direct extension of liver tumors. All patients had visible FDG-avid liver tumors in contrast-enhanced images. Five out of 9 patients (55.6%) had no extrahepatic metastasis, 3 cases (33.3%) had metastasis of regional lymph nodes, and 1 case (11.1%) presented with distant metastasis. The median estimated survival time of patients was 5 months.Conclusion: The intraluminal filling defect consistent with thrombous within the portal vein, expansion of the involved portal vein, contrast enhancement, and linear increased FDG uptake of the thrombus extended from liver tumor are findings of FDG-avid PVTT from HCC in contrast-enhanced FDG PET/CT.

Background: Nowadays, diagnosis of dementia is made through several clinical criteria, as in DSM IV and Petersen criteria (specificity 75% and sensitivity 31%). Thereby, a reliable and more accurate diagnostic tool is needed. One of the promising examinations is FDG-PET Scan, which have sensitivity as high as 78-97% along with specificity of 74-86%. Purpose is to describe the characteristic of FDG PET scan images in dementia patients.Case Report: Ten cases of cognitive impairment was reported with 4 cases suggestive of Alzheimer dementia, 2 cases of frontotemporal dementia, 2 cases of mild cognitive impairment, 1 normal aging, and 1 cases of cognitive impairment in young adult with depression. FDG-PET Scan examination in Alzheimer dementia cases reveals significant hypometabolism particularly in frontotemporal and posterior cingulate cortex. Contrast with frontotemporal dementia results in hypometabolism of frontal, temporal, and parietotemporal area. In mild cognitive impairment examination, mild hypometabolism was found in cingulate posterior and parietotemporal cortex. In normal aging case, normal level of metabolism was discovered in most of the brain area. In the other hand, the result of cognitive impairment in young adult with depression case was hypometabolism in cingulate posterior and inferior parietal cortex.Conclusion: FDG-PET Scan could be used as diagnostic tool to support the diagnosis of cognitive impairment in various levels by discovering the specific hypometabolism area in brain.

Introduction: Brain FDG PET scan is ideal for assessment of some brain disease. Iran, cause of some problem, has no experience of PET yet but 3 years ago the first FDG imaging was started in cooperation with a national research group from ENT and Head & Neck Research Center, Iran University of Medical Sciences which their main goal is to evaluate treatment response of patients with tinnitus to gabapantine and to find any brain changes as a document. They came to us to nuclear medicine department of atomic energy organization of Iran to do scan in two periods of time as pre and post treatment.Methods: The interesting part of this research for our department which made us to involve is two things, first to assess the efficiency of FDG that produced in the first time in cyclotron and the second to test DHC system for brain PET image. Although we did both SPECT and FDG PET scan for almost 65 subjects with DHC system but only PET images is our mandatory focus at least for our department. With FDG images data they found that Brain PET scan can be valuable imaging technique in the assessment of patients with tinnitus which Characteristics of abnormalities depend on age and side of tinnitus.Results: We found that although the DHC-PET scan has not as good quality as real ring PET but it still can work.Conclusion: The more disadvantage and in the other word the limitation of this system is the lower resolution and more attenuation of DHC which is a defect for this system to assess the sub-cortical tissue and to evaluate the small lesion in brain and the other one is a weak anatomical mapping which needs a precise fusion of those image with MRI.