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Cerebral β-amyloid deposits and regional glucose metabolism assessed by PET are used to distinguish between Alzheimer disease (AD) and other dementia syndromes. In the present multicenter study, we estimated the prevalence of β-amyloid deposits on PET imaging in a wide variety of dementia syndromes and mild cognitive impairment (MCI) within a memory clinic population. Methods: Of the 1,193 consecutive patients with cognitive impairment (CI) who received 1 11 C-PIB PET or 18 F-AV45 PET or both 11 C-PIB PET and 18 F-AV45 PET, 960 were diagnosed with AD, 36 with frontotemporal dementia (FTD), 5 with dementia with Lewy bodies, 144 with MCI, 29 with vascular dementia, 4 with corticobasal syndrome, and 15 with unclassifiable dementia. Baseline clinical diagnoses were independently established without access to PET imaging results. Apolipoprotein E (ApoE) genotype analysis was performed on CI patients and 231 sex- and age-matched controls. Results: Of the 1,193 CI patients, 860 (72.1%) were amyloid-positive. The prevalence of amyloid positivity in AD and MCI patients was 86.8% (833/960) and 9.7% (14/144), respectively. In FTD patients, the prevalence of β-amyloid deposits was 5.6% (2/36). In the 4 corticobasal syndrome patients, 2 were amyloid-positive. Three of the 5 patients with dementia with Lewy bodies showed amyloid positivity, as did 6 of the 29 vascular dementia (20.7%) patients. The ApoEε4 allele frequency was significantly increased in amyloid-positive CI patients (30.5%) as compared with other amyloid-negative CI patients (14%) or controls (7.3%). Conclusion: Amyloid imaging may potentially be the most helpful parameter for differential diagnosis in dementia, particularly to distinguish between AD and FTD. Amyloid PET can be used in conjunction with the ApoEε4 allele genetic risk test for amyloid deposits., (© 2020 by the Society of Nuclear Medicine and Molecular Imaging.)

The aim of the study was to obtain an overview of the clinical and neuroimaging features of Chinese patients with subtypes of frontotemporal lobe degeneration (FTLD).We evaluated the demographic features, clinical presentation, and lobe atrophy depicted by magnetic resonance imaging (MRI) in 133 patients with FTLD. Two positron emission tomography (PET) scans were performed at baseline: [C]Pittsburgh compound B PET to assess amyloid-β plaque load and [F]fluorodeoxyglucose (FDG) PET to assess glucose metabolism.The behavioral variant of FTD (bvFTD) was the most common subtype (67.7%) of FTLD. The percentages of progressive nonfluent aphasia (PNFA) and semantic dementia (SD) were similar. Cerebral lobe atrophy was seen in 87.7% of the cases. The Activities of Daily Living scale, Mini-Mental State Examination, and Montreal Cognitive Assessment scores were significantly correlated with the degree of overall atrophy. The severity of abnormal behavior was correlated with right anterior and right posterior temporal atrophy scores. The overall atrophy scores and atrophy score in the left temporal region were related to cognitive outcomes and Activities of Daily Living scores. Most of the bvFTD patients presented symmetric/asymmetric hypometabolism in the bilateral temporal cortex, frontal cortex, anterior cingulate cortex, insula, and caudate nucleus. All the PNFA patients presented left dominant hypometabolism in the frontal cortex. All the SD patients presented left dominant hypometabolism in the anterior temporal cortex.FTLD is not rare in cognitive clinics, and the ratios of subtypes in Chinese patients are similar to other ethnic groups. Overall atrophy scores, determined by MRI, were related to the severity of cognitive dysfunction and deficits in Activities of Daily Living. Patterns of hypometabolism, determined by [F]FDG PET, were more specific to subtypes of FTLD and may help provide differential diagnoses of variants of FTLD.

11C-PD153035, a potent and specific ATP-competitive tyrosine kinase inhibitor (TKI) of the EGF receptor, has been developed for PET imaging of epidermal growth factor receptor (EGFR) in lung cancer. The objective of the present study was to investigate the relationship of the accumulation of 11C-PD153035 and the EGFR expression level in human gliomas and to explore whether 11C-PD153035 can be used in the molecular imaging of glioma with EGFR overexpression. Eleven patients with histopathologically proven gliomas underwent 11C-PD153035 PET/CT examination before surgery. Combining MRI with the 11C-PD153035 PET/CT image, 2 specimens from different C-PD153035 uptake regions of each tumor and adjacent normal brain tissue were selected as the biopsy targets through the stereotactic technique. The radioactivity concentrations were analyzed as the mathematical maximum standardized uptake value (SUVmax) in region of interest (ROI). The EGFR expression in the biopsied tissues was analyzed by immunohistochemical staining (IHC) and western blotting. The SUVmax/WM (11C-PD153035 uptake in the white matter of the contralateral normal hemisphere) ratio was used to indicate the EGFR expression level in the ROI in PET/CT, and it was correlated with the EGFR expression detected by IHC and western blot analysis. The results demonstrated that 6 of the 8 patients with glioblastoma (GBM) were obviously visualized by 11C-PD153035 PET/CT, whereas 2 patients with GBM, 1 with anaplastic astrocytoma, and 2 with oligodendroglioma did not show significant 11C-PD153035 uptake. There were positive correlations between the SUVmax/WM and the results of IHC (r = 0.955, P < 0.01) and western blotting(r = 0.889, P < 0.010). Our preliminary findings suggest that 11C-PD153035 PET/CT is a promising method for the EGFR-targeted molecular imaging of human GBM, which may be translated into the clinic to select the appropriate population of patients for EGFR-targeted therapy and to assess the early targeted therapeutic response of malignant gliomas.

Objective: The clinical manifestations and the imaging features in (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography ((18)F-FDG PET) of extrapulmonary tuberculosis were not specific and therefore it was difficult to be differentiated from malignancy. This paper tried to analyze the clinical characteristics and findings by (18)F-FDG PET-CT in extrapulmonary tuberculosis, in order to improve the diagnosis of this disease., Methods: Thirty-nine patients with extrapulmonary tuberculosis underwent (18)F-FDG PET-CT imaging from 2003 - 2011. The diagnosis was confirmed by histopathological examination in all the cases. There were 11 males and 28 females, aging 20 - 67 (60 ± 18) years. A past history of tuberculosis was collected in 5 cases. The PET images were reviewed visually and scored semi-quantitatively with standardized uptake value. The lesions were judged by PET imaging features in conjunction with CT slices and the fused images., Results: Fever was present in 13 cases, and night sweating, weakness and malaise in 17 cases. Pleural effusion was found in 7 cases. Abdominal distention and masses were found in 6 cases, while neck mass was present in 2 cases. Laboratory tests showed that hypoalbuminemia, sedimentation rate increase and positive tuberculin tests were present in 15 cases. CA125 was increased in 3 cases. In PET-CT, lymph node tuberculosis manifested as single or multiple enlarged lymph nodes coalesced and calcified with significant FDG uptake, but ring-like FDG-avidity was also found in some of the lymph nodes. Pleural or peritoneal tuberculosis showed heterogeneous or nodular thickening and in a radio-tracer distribution. Bone tuberculosis manifested as osteolytic osseous destruction and paravertebral cold abscess, while focal radio-agent ring-like intense uptake was present in half the cases. In patients with intestinal tuberculosis, ileocecal circumferential or eccentric thickening was observed, with focal or diffuse high FDG activity. Tuberculosis in adrenal gland, liver, and oviducts all showed lesions with high FDG uptake., Conclusions: (18)F-FDG PET-CT was helpful for the differential diagnosis of extrapulmonary tuberculosis from malignancy. Osseous and lymph node tuberculosis showed ring-like FDG uptake, which maybe of diagnostic value.

Objective: To investigate the difference in glucose metabolism on (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) imaging for differential diagnosis of idiopathic Parkinson's disease (IPD) from several parkinsonian-plus syndromes using SPM2 approach., Methods: (18)F-FDG PET was performed for 18 IPD patients, 22 multiple system atrophy (MSA) patients, 13 progressive supranuclear palsy (PSP) patients, 5 corticobasal degeneration (CBD) patients, 7 dementia with Lewy bodies (DLB) patients and 1 normal pressure hydrocephalus (NPH) patient. Imaging-based diagnosis was obtained by statistical parametric mapping (SPM2) software to analyze the differences and overlaps among these groups., Results: The (18)F-FDG PET images analyzed with SPM2 demonstrated that a reduction in glucose metabolism occurred in bilateral parietal area for IPD, in bilateral putamen for MSA-P, in bilateral cerebellum for MSA-C, in midbrain and the middle frontal cortex for PSP, in asymmetrical metabolism of the cortex and the basal ganglia for CBD, in bilateral occipital and parieto-occipital areas for DLB. The metabolic reductions in a patient of NPH group were observed in the ventricular system., Conclusions: This study identifies different patterns of glucose metabolism in parkinsonism. (18)F-FDG PET imaging may contribute to early differential diagnosis in clinically ambiguous cases of parkinsonism., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Uterine leiomyosarcoma is an uncommon malignant neoplasm of smooth muscle origination and is associated with a poor prognosis. We report two cases of uterine leiomyosarcoma that presented with pulmonary metastases. 2-deoxy-2-(¹⁸F)fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) was performed to identify the primary carcinoma and found the focus located in the uterus. The follow-up magnetic resonance imaging (MRI) confirmed the diagnosis was uterine leiomyosarcoma.

Gliomatosis cerebri (GC) is a rare neuroepithelial tumor which includes 2 types. Type 1: A 12-year-old boy presented with headache and vomiting. MRI showed the diffuse long T2 signal intensity without enhancement in the right hemisphere. ¹¹C-Methionine PET showed local intense tracer accumulation. Type 2: A 59-year-old woman presented with right hemiparesis and headache. MRI revealed diffuse long T2 signal intensity in multiple lobes, and the left occipital lobe yielded heterogeneous enhancement. ¹¹C-Choline PET showed multiple hypermetabolic foci in the same areas. Our findings show that multiple tracer PET might not only reflect the true extent of GC infiltration but also evaluate GC malignant processes more accurately than MRI.

Objective: To evaluate the value of (18)F-FDG and (11)C-MET PET-CT scan in differentiation of brain ringlike-enhanced lesions on MRI imaging., Methods: Forty-one brain ringlike-enhanced lesions on MRI imaging including 30 brain tumors and 11 non-neoplastic lesions confirmed pathologically or clinically underwent (18)F-FDG and (11)C-MET PET-CT brain scan. Among them, 15 patients who were suspected to have brain metastasis received body scan by (18)F-FDG PET-CT. Both images were analyzed visually and semi-quantitatively., Results: Visual analysis: for brain tumors the diagnostic sensitivity, specificity and accuracy of (18)F-FDG PET-CT was 53.3%, 72.7%, 58.5%, versus 96.7%, 90.9%, 95.1% of (11)C-MET PET-CT, respectively. All the primary foci in 9 patients with brain metastases were detected by body (18)F-FDG PET-CT scan. Semiquantitative analysis: There was a significant difference in the uptake between highly differentiated malignant and poorly differentiated tumors as well as non-neoplastic lesions for both tracers (P < 0.01), while between low-grade malignant tumors and non-neoplasm lesions, there was a difference in uptake only by (11)C-MET (P < 0.01). No significant difference between the uptakes in brain metastasis and glioblastomas was found by both tracers (P > 0.05)., Conclusion: Both (18)F-FDG and (11)C-MET PET-CT are useful in differentiation of brain ringlike-enhanced lesions on MRI imaging. (11)C-MET PET-CT is more helpful than (18)F-FDG PET-CT in differential diagnosis of low-grade neoplastic from non-neoplastic lesions. Combination of (18)F-FDG and (11)C-MET PET-CT scans can improve the accuracy of differential diagnosis for brain ringlike-enhanced lesions on MRI imaging.

FDG PET-CT imaging is increasingly accepted as a modality for evaluation of many malignancies, but FDG also can be accumulated intensely by inflammatory lesions. We present a case of a 60-year-old woman with intermittent fever, chills, fatigue, and dyschezia. CT scans indicated colon carcinoma with thoracic and retroperitoneal lymph node metastases. Whole body FDG PET-CT was performed to confirm and stage the malignant disease and showed intense FDG uptake in those lesions. However, histopathology confirmed tuberculosis. The literature describing FDG accumulation in constitutional tuberculous lesions is sparse, and one must be aware of patterns of FDG accumulation in tuberculosis in the diagnosing malignancies.

Two patients presented with provisional diagnoses of glioma. Computed tomography (CT) and magnetic resonance imaging failed to show the boundaries of the tumor clearly. Positron emission tomography (PET)/CT with [(18)F]fluorodeoxyglucose and (11)C-methionine clearly showed the location, extent, and heterogeneity of the tumors. The tumors were resected under PET/CT neuronavigation guidance. Histological examination of the specimens showed that PET/CT neuronavigation provided reliable distinction between normal brain and glioma, and that the uptake of PET tracers can indicate the degree of proliferation.

Objective: To observe effects of combination of different points on glucose metabolism in the patient of cerebral infarction., Methods: Neiguan (PC 6), Shuigou (GV 26), Fengchi (GB 20), Sanyinjiao (SP 6), Yinlingquan (SP 9), Taichong (LR 3) were selected for the Xingnao Kaiqiao group (n =7), and Hegu (LI 4), Quchi (LI 11), Zusanli (ST 36), Yanglingquan (GB 34) and Xuanzhong (GB 39) for the routine acupuncture group (n = 5). PET-CT was used to observe the local cerebral glucose metabolism., Results: The cerebral regions activated in the the Xingnao Kaiqiao group included infarction center, gyrus temporalis superior, thalamus, gyrus temporalis inferior, gyrus rectus, insula, lateral occipital lobe, parietal lobe and cerebellum, and in the routine acupuncture group included gyrus frontalis inferior, caudate nucleus, cingulated gyrus, hippocampus, precuneus and parietal lobe., Conclusion: PET is very suitable for exploring acupuncture mechanisms in treatment of cerebral infarction, and further shows the specificity of acupoints-brain functional region.