scholarly journals [18F]-Fluoro-Deoxy-Glucose Positron Emission Tomography Scan Should Be Obtained Early in Cases of Autoimmune Encephalitis

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
C. R. Newey ◽  
A. Sarwal ◽  
S. Hantus

Introduction. Autoimmune encephalitis (AE) is a clinically challenging diagnosis with nonspecific neurological symptoms. Prompt diagnosis is important and often relies on neuroimaging. We present a case series of AE highlighting the importance of an early [18F]-fluoro-deoxy-glucose positron emission tomography (FDG-PET) scan.Methods. Retrospective review of seven consecutive cases of autoimmune encephalitis.Results. All patients had both magnetic resonance imaging (MRI) and FDG-PET scans. Initial clinical presentations included altered mental status and/or new onset seizures. Six cases had serum voltage-gated potassium channel (VGKC) antibody and one had serum N-methyl-D-aspartate (NMDA) antibody. MRI of brain showed mesial temporal lobe hyperintensity in five cases of VGKC. The other two patients with VGKC or NMDA AE had restiform body hyperintensity on MRI brain or a normal MRI, respectively. Mesial temporal lobe hypermetabolism was noted in three cases on FDG-PET, despite initial unremarkable MRI. Malignancy workup was negative in all patients.Conclusion. A high index of suspicion for AE should be maintained in patients presenting with cognitive symptoms, seizures, and limbic changes on neuroimaging. In cases with normal initial brain MRI, FDG-PET can be positive. Additionally, extralimbic hyperintensity on MRI may also be observed.

2005 ◽  
Vol 23 (16) ◽  
pp. 3713-3717 ◽  
Author(s):  
Mariëtte C.A. van Kouwen ◽  
Fokko M. Nagengast ◽  
Jan B.M.J. Jansen ◽  
Wim J.G. Oyen ◽  
Joost P.H. Drenth

Purpose 2-(18F)-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) is a noninvasive imaging technique used clinically to detect malignant tumors. FDG-PET has been established as a tool for diagnosis of recurrent or metastatic colorectal carcinoma. Several case series suggest that FDG-PET also detects larger adenomas. The goal of this study was to investigate whether FDG-PET is able to detect colonic adenomas. Patients and Methods FDG-PET was performed in 100 consecutive patients in whom colonic adenomas were suspected on barium enema (n = 47) or sigmoidoscopy (n = 53). A positive scan was defined as focal large bowel FDG accumulation. FDG-PET was followed in all cases by colonoscopy, and removed adenomas were examined histopathologically. Results Colonoscopy confirmed the presence of adenomas in 68 of 100 patients. In 35 patients, there was focal FDG accumulation at site of the adenoma. The sensitivity of FDG-PET increased with adenoma size (21%, adenomas 1 to 5 mm; 47%, 6 to 10 mm; and 72%, > 11 mm). The sensitivity of FDG-PET also increased with the grade of dysplasia (33%, low grade; 76%, high grade; and 89%, carcinomas). The overall specificity was 84%. Conclusion FDG-PET detects colonic adenomas and the diagnostic test characteristics improve with size and grade of dysplasia of the adenoma.


2005 ◽  
Vol 152 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Athina Markou ◽  
Patrick Manning ◽  
Banu Kaya ◽  
Sam N Datta ◽  
Jamshed B Bomanji ◽  
...  

We report a case of a young woman with Cushing’s syndrome (CS), in whom although endocrine investigations and negative pituitary imaging were suggestive of ectopic ACTH secretion, the results of inferior petrosal sinus (IPS) sampling after coricotropin-releasing hormone (CRH) stimulation were suggestive of pituitary ACTH hypersecretion. 111In-labelled octreotide and high-resolution computer tomography (CT) revealed a lesion possibly responsible for the ACTH source in the thymus. Thymectomy confirmed concomitant ectopic CRH and probable ACTH production by a thymic neuroendocrine carcinoma. After an 8-year remission period the patient developed a clinical and biochemical relapse. A high-resolution computed tomography (CT) scan of the thorax showed a 2-cm nodule in the thymic bed, which was positive on a [18F]fluoro-2-deoxy-d-glucose ([18F]FDG) positron emission tomography (PET) scan. However, a repeated thymectomy did not result in remission. A repeat [18F]FDG PET study showed persistent disease in the thymic bed and also uptake in the adrenals. The patient underwent bilateral adrenalectomy, which resulted in clinical remission. A further [18F]FDG PET scan 8 months later showed no progression of the thymic tumor and confirmed complete excision of the adrenals. This is a rare case of concomitant CRH and ACTH secretion from a thymic carcinoid tumor; the case illustrates the usefulness of functional imaging with [18F]FDG PET in the diagnosis, management and follow-up of neuroendocrine tumors.


Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 230
Author(s):  
Giulia Ferrarazzo ◽  
Silvia Chiola ◽  
Selene Capitanio ◽  
Maria Isabella Donegani ◽  
Alberto Miceli ◽  
...  

2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (FDG PET/CT) has an established clinical value in the diagnosis and initial staging of multiple myeloma (MM). In the last ten years, a vast body of literature has shown that this tool can also be of high relevance for monitoring therapy responses, making it the recommended imaging approach in this field. Starting from the strengths and weaknesses of radiological imaging in MM, the present review aims to analyze FDG PET/CT’s current clinical value focusing on therapy response assessment and objective interpretation criteria for therapy monitoring. Given the potential occurrence of patients with MM showing non-FDG-avid bone disease, new opportunities can be provided by non-FDG PET tracers. Accordingly, the potential role of non-FDG PET tracers in this setting has also been discussed.


2009 ◽  
Vol 27 (4) ◽  
pp. 535-541 ◽  
Author(s):  
Jörg Schwarz-Dose ◽  
Michael Untch ◽  
Reinhold Tiling ◽  
Stefanie Sassen ◽  
Sven Mahner ◽  
...  

Purpose To evaluate positron emission tomography (PET) using [18F]fluorodeoxyglucose (FDG) for prediction of histopathologic response early during primary systemic therapy of large or locally advanced breast cancer. Patients and Methods In a prospective multicenter trial, 272 FDG-PET scans were performed in 104 patients at baseline (n = 104) and after the first (n = 87) and second cycle (n = 81) of chemotherapy. The level and relative changes in standardized uptake value (SUV) of FDG uptake were assessed regarding their ability to predict histopathologic response. All patients underwent surgery after chemotherapy, and histopathologic response defined as minimal residual disease or gross residual disease served as the reference standard. Results Seventeen (16%) of 104 patients were histopathologic responders and 87 were (84%) nonresponders. All patients for whom baseline SUV was less than 3.0 (n = 24) did not achieve a histopathologic response. SUV decreased by 51% ± 18% after the first cycle of chemotherapy in histopathologic responders (n = 15), compared with 37% ± 21% in nonresponders (n = 54; P = .01). A threshold of 45% decrease in SUV correctly identified 11 of 15 responders, and histopathologic nonresponders were identified with a negative predictive value of 90%. Similar results were found after the second cycle when using a threshold of 55% relative decrease in SUV. Conclusion FDG-PET allows for prediction of treatment response by the level of FDG uptake in terms of SUV at baseline and after each cycle of chemotherapy. Moreover, relative changes in SUV after the first and second cycle are a strong predictor of response. Thus, FDG-PET may be helpful for individual treatment stratification in breast cancer patients.


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