Uptake In Ganglia Research Articles

Intra-Individual Comparison of Physiologic [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 Uptake in Ganglia in Patients with Prostate Cancer: A Retrospective, Monocentric Analysis.

Several studies indicate, particularly in the case of [18F]PSMA-1007, a relatively high rate of detection of ganglia in PSMA PET imaging. Ganglia are an integral part of the sympathetic portion of the autonomous nervous system. To date, no studies have directly compared [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 ganglionic uptake intra-individually and analyzed the underlying molecular and physical mechanisms of different detection rates. With this monocentric retrospective study, we sought to evaluate the intra-individual physiological ganglion uptake of these different PSMA ligands in evidence-based imaging for prostate cancer. Our cohort consists of 19 male patients (median age 72 ± 9 with a range of 56-85) with biochemical recurrence of prostate cancer who underwent both [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 PET/CT in our clinic on the same scanner per standard care between March 2015 and March 2022. Tracer uptake was quantified according to maximum standardized uptake value (SUVmax) for both [68Ga]Ga-PSMA-11 and [18F]PSMA-1007 PET/CT scans. Ganglia-to-background ratios (GBRs) were determined to quantify the image contrast through dividing the SUVmax of the ganglia by the background value (SUVmax of blood pool in the descending aorta, fatty tissue, and skeletal muscle in gluteal region). We used descriptive analyses for demographics and tumor characteristics and performed two-way repeated-measures ANOVA (analysis of variance) for SUV metrics including GBR measurements. In total, we examined 101 ganglia with [18F]PSMA-1007 scanning, localized mostly in pairs as stellate, coeliac, and sacral, of which 76 were also detected with [68Ga]Ga-PSMA-11 PET/CT scanning. There was no statistically significant difference in PSMA uptake in terms of SUVmax between [18F]PSMA-1007 and [68Ga]Ga-PSMA-11 (p value: 0.052). In contrast, the comparison of GBRs revealed a higher detectability rate of ganglia with [18F]PSMA-1007 imaging (p < 0.001). Furthermore, a separate comparison of ganglia with respect to their anatomical location also demonstrated statistically significant differences both within and between [18F]PSMA-1007 and [68Ga]Ga-PSMA-11 PET/CT scans. Given the impression of more accentuated [18F]PSMA-1007 uptake in ganglia compared with 68Ga-labelled counterparts, our study demonstrated that the better detectability of ganglia is not due to more intense [18F]PSMA-1007 uptake by these small structures but to much more favorable physical properties of the radionuclide 18F. The most relevant limitations of our study are its retrospective design and the small patient cohort.

PSMA-1007 Uptake in Ganglia of the Sympathetic Trunk and Its Intra-individual Reproducibility

Aim/Purpose18F-labeled PSMA ligands offer various advantages as PET tracers over 68Ga-labeled PSMA counterparts. Especially, an improved spatial resolution leads to improved detection rates of smaller prostate cancer (PCa) lesions. However, physiological PSMA uptake of ganglia of the sympathetic trunk can be quickly misinterpreted as possible PSMA-positive lymph node metastases. The aim of this retrospective study is to investigate [18F]PSMA-1007 uptake and its intra-individual reproducibility in ganglia of the sympathetic trunk.MethodsWe retrospectively included 28 consecutive patients (median age 69 ± 9 with a range of 49–90) with biochemical recurrence of PCa who underwent [18F]PSMA-1007 PET/CT scan and, accordingly, a follow-up examination between August 2018 and August 2021. Cervical, coeliac, and sacral ganglia were identified on the iterative PET reconstructions and correlated with CT component. Tracer uptake of ganglia was determined by measuring SUVmax and SUVmean values. Anatomical position of the ganglia in relation to adjacent vertebral bodies were noted. Statistical analyses were conducted using two-way repeated measures ANOVA and descriptive statistics.ResultsThe highest [18F]PSMA-1007 uptake was found in coeliac ganglia followed by cervical and sacral ganglia. The SUVmax in coeliac ganglia was 3.13 ± 0.85 (follow-up scan 3.11 ± 0.93), in cervical ganglia 2.73 ± 0.69 (follow-up scan 2.67 ± 0.74), and in sacral ganglia 1.67 ± 0.50 (follow-up scan 1.64 ± 0.52). The SUVmean in coeliac ganglia was 2.28 ± 0.64 (follow-up scan 2.28 ± 0.66), in cervical ganglia 1.62 ± 0.43 (follow-up scan 1.61 ± 0.43) and in sacral ganglia 1.15 ± 0.33 (follow-up scan 1.12 ± 0.34). In a given ganglion station, there was no statistically significant difference of SUVmax or SUVmean values between baseline and follow-up scans.ConclusionsThe first systematically described physiological [18F]PSMA-1007 uptake in ganglia of the sympathetic trunk showed a low variability of SUVmax or SUVmean and a good intra-individual reproducibility of [18F]PSMA-1007 uptake in follow-up scans. These findings might improve and guide the differentiation of ganglia from possible malignant lesions.

The Heterogeneous Metabolic Patterns of Ganglia in 68Ga-PSMA, 11C-choline, and 18F-FDG PET/CT in Prostate Cancer Patients.

PurposeStudies have indicated that PSMA-positive ganglia represent a diagnostic pitfall for nuclear medicine physicians. No studies have described choline and FDG uptake in ganglia, which may be a source of misdiagnosis. Herein, we described the percentage and uptake pattern of 68Ga-PSMA, 11C-choline and 18F-FDG PET/CT in ganglia and evaluated the heterogeneous metabolic patterns of ganglia to differentiate from lymph node metastases (LNM).MethodsThirty-nine patients who underwent 11C-choline PET/CT and 120 patients who underwent 68Ga-PSMA PET/CT and 18F-FDG PET/CT were retrospectively analyzed. The prevalence of PSMA-positive, choline-positive and FDG-positive ganglia was determined, the SUVmax of ganglia in different locations were measured, and the configuration was described. The SUVmax cutoff of PSMA-PET, choline-PET and FDG-PET was determined by ROC curve analysis to differentiate ganglia from LNM.Results329 PSMA-positive ganglia were identified in 120 patients, 95 choline-positive ganglia were identified in 39 patients, and 39 FDG-positive ganglia were identified in 34 patients. PSMA-positive uptake was observed in 98.3%, 95.8%, and 80.0% of cervical, coeliac, and sacral ganglia, respectively. Choline-positive uptake was observed in 84.6%, 97.4%, and 61.5% of cervical, coeliac, and sacral ganglia, respectively. FDG-positive uptake was observed in 16.7%, 13.3%, and 2.5% of cervical, coeliac, and sacral ganglia, respectively. Cervical and coeliac ganglia had a higher rate of PSMA-positive uptake than sacral ganglia. Choline uptake was highest in coeliac ganglia followed by cervical and sacral ganglia. PSMA, choline or FDG uptake in LNM was all significantly higher than ganglia. ROC curve analysis revealed that at a 4.1 SUVmax cutoff of PSMA-PET, the sensitivity, specificity and accuracy of LNM identification was 88.4%, 97.9% and 96.2%, respectively. ROC curve analysis revealed that at a 2.35 SUVmax cutoff for choline-PET, the sensitivity, specificity, and accuracy of LNM identification was 95.0%, 92.6% and 93.0%, respectively. ROC curve analysis revealed that at a 2.55 SUVmax cutoff for FDG-PET, the sensitivity, specificity, and accuracy of LNM identification was 77.3%, 87.2%, and 81.9%, respectively. PSMA-, Choline- and FDG-positive ganglia are mainly band-shaped; most LNMs exhibited nodular and teardrop-shaped configuration.Conclusion 68Ga-PSMA and 11C-choline uptake in ganglia was common, and FDG-positive ganglia were observed at lower frequency. Using 68Ga-PSMA, 11C-choline and 18F-FDG uptake and anatomic location and configuration, the differentiation of ganglia from adjacent LNM is feasible.

Intra-patient comparison of physiologic 68Ga-PSMA-11 and 18F-DCFPyL PET/CT uptake in ganglia in prostate cancer patients: a pictorial essay

BackgroundRecent studies reported metabolic uptake in at least one of the evaluated ganglia in 98.5% of patients undergoing 68Ga -PSMA-11 and in 96.9% of patients undergoing 18F-DCFPyL PET/CT examination. We have observed different patterns of ganglion visualization with 18F-DCFPyL compared to 68Ga-PSMA-11. This includes more frequent visualization of cervical and sacral ganglia, which may be attributable to better imaging characteristics with 18F PET imaging.Case presentationThis pictorial essay is to illustrate and compare, in the same patient, various representative cases of 68Ga-PSMA-11 and 18F-DCFPyL PET/CT uptake in ganglia at different anatomic locations, with different patterns and distribution of metabolic activity.ConclusionReading physicians should be aware of the frequently encountered and occasionally different physiologic uptake of 68Ga-PSMA-11 and 18F DCFPyL in different ganglia.

18F-AV-1451 positron emission tomography in neuropathological substrates of corticobasal syndrome.

Multiple neuropathological processes can manifest in life as a corticobasal syndrome. We sought to relate retention of the tau-PET tracer 18F-AV-1451 and structural magnetic resonance measures of regional atrophy to clinical features in clinically diagnosed and neuropathologically confirmed cases of corticobasal syndrome and to determine whether these vary with the underlying neuropathological changes. In this observational, cross-sectional study, 11 subjects (eight female and three male, median age 72 years) with corticobasal syndrome underwent structural MRI, tau-PET with 18F-AV-1451, amyloid-PET with 11C-Pittsburgh compound B, detailed clinical examinations and neuropsychological testing. Of the 11, three had evidence of high amyloid burden consistent with Alzheimer's disease while eight did not. Neuropathological evaluations were acquired in six cases. Mixed effects general linear models were used to compare 18F-AV-1451 retention and atrophy in amyloid-negative corticobasal syndrome cases to 32 age-matched healthy control subjects and to relate cortical and subcortical 18F-AV-1451 retention and atrophy to clinical features. Subjects without amyloid, including three with pathologically confirmed corticobasal degeneration, showed greater regional 18F-AV-1451 retention and associated regional atrophy in areas commonly associated with corticobasal degeneration pathology than healthy control subjects [retention was higher compared to healthy controls (P = 0.0011), driven especially by the precentral gyrus (P = 0.011) and pallidum (P < 0.0001), and greater atrophy was seen in subjects compared to control subjects (P = 0.0004)]. Both 18F-AV-1451 retention and atrophy were greater in the clinically more affected hemisphere [on average, retention was 0.173 standardized uptake value ratio units higher on the more affected side (95% confidence interval, CI 0.11-0.24, P < 0.0001), and volume was 0.719 lower on the more affected side (95% CI 0.35-1.08, P = 0.0001)]. 18F-AV-1451 retention was greater in subcortical than in cortical regions, P < 0.0001. In contrast to these findings, subjects with amyloid-positive corticobasal syndrome, including two neuropathologically confirmed cases of Alzheimer's disease, demonstrated greater and more widespread 18F-AV-1451 retention and regional atrophy than observed in the amyloid-negative cases. There was thalamic 18F-AV-1451 retention but minimal cortical and basal ganglia uptake in a single corticobasal syndrome subject without neuropathological evidence of tau pathology, likely representing non-specific signal. Asymmetric cortical and basal ganglia 18F-AV-1451 retention consonant with the clinical manifestations characterize corticobasal syndrome due to corticobasal degeneration, whereas the cortical retention in cases associated with Alzheimer's disease is greater and more diffuse.

Peripheral ganglia in healthy rats as target structures for the evaluation of PSMA imaging agents

BackgroundThe recent implementation of PET with prostate specific membrane antigen (PSMA)-specific radiotracers into the clinical practice has resulted in the significant improvement of accuracy in the detection of prostate carcinoma (PCa). PSMA-expression in ganglia has been regarded as an important pitfall in prostate carcinoma-PET diagnostics but has not found any practical use for diagnosis or therapy.MethodsWe explored this phenomenon and demonstrated the applicability of peripheral ganglia in healthy rats as surrogates for small PSMA positive lesions for the preclinical evaluation of diagnostic PCa PET probes. Healthy rats were measured with PET/CT using the tracers [18F]DCFPyL, [Al18F]PSMA-11 and [68Ga]PSMA-11. Sections of ganglia were stained with an anti-PSMA antibody. [18F]DCFPyL uptake in ganglia was compared to that in LNCaP tumor xenografts in mice.ResultsWhereas [18F]DCFPyL and [68Ga]PSMA-11 were stable in vivo and accumulated in peripheral ganglia, [Al18F]PSMA-11 suffered from fast in vivo deflourination resulting in high bone uptake. Ganglionic PSMA expression was confirmed by immunohistochemistry. [18F]DCFPyL uptake and signal-to-noise ratio in the superior cervical ganglion was not significantly different from LNCaP xenografts.ConclusionsOur results demonstrated the non-inferiority of the novel model compared to conventionally used tumor xenografts in immune compromised rodents with regard to reproducibility and stability of the PSMA signal. Furthermore, the model involves less expense and efforts while it is permanently available and avoids tumor-growth associated animal morbidity and distress. To the best of our knowledge, this is the first tumor-free model suitable for the in vivo evaluation of tumor imaging agents.

PET in brain tumors

The aim of this Pictorial Essay is to illustrate the metabolic aspect of PET (positron emission tomography) imaging in relation to conventional and advanced MR (magnetic resonance) of brain neoplasms. 10 patients, who performed PET–CT with amino acid tracers and/or FDG were selected from a series of more than 250 cases from a single institution. The selection was made to illustrate and discuss each of the indications reported in the European guidelines. Fusion imaging was obtained merging PET–CT with MR T1-CE (contrast enhanced) and/or T2/FLAIR sequences. The SUVmax of the lesion and the SUVmax lesion to SUVmax background ratio were evaluated. The lesion uptake was also assessed using a five-point visual scale with a range from − 2 to + 2 in relation to basal ganglia uptake. The Hospital Information System (HIS) and the proton therapy data archives have been used for clinical history. For each case, the critical issues were described and the physiopathological correlations were provided to explain the imaging findings. The complexity of illustrated cases demonstrates the need for a multidisciplinary board evaluation to reach a more accurate diagnosis.

68Ga-PSMA-HBED-CC Uptake in Cervical, Celiac, and Sacral Ganglia as an Important Pitfall in Prostate Cancer PET Imaging.

The study aims to investigate the presence of physiologic prostate-specific membrane antigen (68Ga-PSMA)-ligand uptake on PET in cervical, celiac, and sacral ganglia of the sympathetic trunk as a pitfall for lymph node metastases in prostate cancer imaging. Methods: Four hundred seven patients who underwent Glu-NH-CO-NH-Lys radiolabeled with 68Ga-gallium N,N-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N-diacetic acid (68Ga-PSMA-HBED-CC) PET (combined with a diagnostic CT) were retrospectively analyzed. The number of 68Ga-PSMA PET-positive cervical, celiac, and sacral ganglia was determined, and the configuration and SUVmax of each ganglion were measured. In addition, the configuration and SUVmax of adjacent lymph node metastases in the respective region (cervical, celiac, or sacral) were determined. Results:68Ga-PSMA-ligand uptake above background was detected in 401 (98.5%) patients in any peripheral ganglia, in 369 (92%) patients in cervical ganglia, in 363 (89%) patients in celiac ganglia, and in 183 (46%) patients in sacral ganglia. The 68Ga-PSMA-ligand uptake was highest in celiac (mean SUVmax, 2.9 ± 0.8 vs. cervical mean SUVmax, 2.4 ± 0.6) and sacral (mean SUVmax 1.7 ± 0.5; both P < 0.0001) ganglia. Intraindividually there was a statistically significant but weak to moderate correlation between the 68Ga-PSMA-ligand uptake in cervical versus celiac ganglia (R = 0.34, P < 0.0001), cervical versus sacral (R = 0.52, P < 0.0001), and celiac versus sacral (R = 0.16, P < 0.05). The 68Ga-PSMA-ligand uptake was significantly more intense in adjacent lymph node metastases than the respective ganglia (cervical: 18.0 ± 16.2 vs. 2.4 ± 0.6, P < 0.0001; celiac: 13.5 ± 12.3 vs. 2.9 ± 0.8, P < 0.0001; sacral: 13.4 ± 11.6 vs. 1.7 ± 0.5, P < 0.0001). Furthermore, ganglia predominantly exhibit a band-shaped configuration (71.2%), followed by a teardrop (26.8%) and only rarely a nodular configuration (2.0%). Conversely, lymph node metastases are only rarely band-shaped (1.1%), but more often show teardrop (40.3%) or nodular appearance (58.6%) (P < 0.00001). Conclusion:68Ga-PSMA-ligand uptake in ganglia along the sympathetic trunk as assessed by 68Ga-PSMA-HBED-CC PET represents an important pitfall in prostate cancer PET imaging. The 68Ga-PSMA-ligand uptake is higher in celiac ganglia than cervical or sacral ganglia, and the level of 68Ga-PSMA-ligand uptake seems to be patient-related. For the differentiation between lymph node metastases and sympathetic ganglia, both intensity of 68Ga-PSMA-ligand uptake and exact localization and configuration of the respective lesion should be examined carefully.

Basal ganglia uptake of 64Cu in Parkinson’s disease patients compared to healthy subjects

Basal ganglia uptake of 64Cu in Parkinson’s disease patients compared to healthy subjects

Uptake in sympathetic ganglia on 68 Ga-PSMA-HBED PET/CT: A potential pitfall in scan interpretation.

The aim of this study was to assess the frequency of PSMA-HBED uptake in coeliac and stellate ganglia in patients presenting for PSMA-HBED PET/CT scan. Prostate-specific membrane antigen-HBED PET/CT scans of 100 consecutive patients were analysed. Coeliac and stellate ganglia were identified by their anatomical location. PSMA-HBED uptake in these ganglia was recorded as either present or absent. If present, the SUVmax value for each ganglion was measured and compared to SUVmax of mediastinal blood pool. Of the 100 patients, 45 had PSMA-HBED uptake in the right coeliac ganglion and 81 had PSMA-HBED uptake in the left coeliac ganglion. The mean SUVmax for the right coeliac ganglion was 2.6 (range 1.2-4.0) and for the left, 2.7 (range 1.2-6.5). An SUVmax 1.5 times greater than that of mediastinal blood pool activity was found in 25 of right and 47 of left coeliac ganglia. Stellate ganglion uptake of PSMA-HBED was identified in 54 of right and 74 of left stellate ganglia. The mean SUVmax for the right and left stellate ganglia were 2.2 (range 1.6-3.6) and 2.4 (range 1.4-4.2) respectively. An SUVmax 1.5 times greater than that of mediastinal blood pool activity was found in 12 of right and 32 of left coeliac ganglia. Uptake in coeliac and stellate ganglia is a frequent finding on PSMA-HBED PET/CT imaging. Often this uptake can be sufficiently high to cause potential diagnostic confusion. It is important to be aware of this physiologic uptake to avoid incorrect diagnosis of metastatic prostate carcinoma.

Regional brain metabolism in schizophrenia

Schizophrenia has been associated with a plethora of metabolic changes in the brain that vary with duration and type of psychoses. Additionally, it has been observed that antipsychotics can further alter cerebral glucose metabolism. These changes resulting from antipsychotics have been postulated to be reflective of the duration and mechanism of action of the medication. We aimed to examine the influence of antipsychotics on brain metabolism in individuals with schizophrenia in a naturalistic setting. A cross-sectional study was carried out by the psychiatry department of a tertiary care hospital in collaboration with the Radiation Medicine Centre. Eighteen male patients with schizophrenia in different phases of treatment underwent an 18F-deoxyglucose positron emission tomography scan in a resting state 12 hours after the last dose of antipsychotic. The types and duration of treatment were then compared with the regional glucose uptake in 14 predetermined regions of interest. The relative Uptake Values were further compared using SPSS 11.0. An immediate increase followed by a decrease in cortical uptake was noted while the basal ganglia uptake remained high, albeit with a decreasing trend. Typical antipsychotics were associated with lower frontal cortical and higher basal ganglia and cerebellar uptake as compared to atypical antipsychotics. The differential influence of the type and duration of antipsychotic on glucose uptake suggests a possible trend towards long-term side effects with typical medications that were not noted on clinical examination. This however needs to be confirmed with larger, controlled studies.

Neuroimaging of Acupuncture in Patients with Chronic Pain

Acupuncture is an ancient therapeutic technique that has been extensively used in China for analgesia as well as for treatment of a variety of medical disorders. In this paper, we describe the potential use of various functional brain imaging techniques in the study of the effects of acupuncture. Five subjects with chronic pain had measures of cerebral blood flow obtained using single photon emission computed tomography (SPECT) both before (baseline) and after acupuncture. The baseline scans revealed asymmetric uptake in the thalami in all five cases. In four cases, the asymmetry was marked (three with right greater than left, and one left greater than right), while the last case revealed a bilateral increase in the thalami. In two patients, basal ganglia uptake was asymmetric with one patient having an increase in the left putamen and the other in the right caudate. The post-acupuncture scans revealed marked increases in the brainstem uptake and a tendency for normalization of the asymmetric thalamic and...

Single‐Photon Emission Computed Tomography of the Brain in Acute Mania and Schizophrenia

Single-photon emission computed tomography (SPECT) imaging with n-isopropyliodoamphetamine (IMP) was performed on 11 patients with bipolar mania, 21 acute schizophrenics, and 15 healthy control subjects. Subjects were evaluated with neuropsychological tests and psychiatric rating scales. SPECT brain studies were blindly evaluated to assess the degree of radiopharmaceutical uptake in three neuroanatomical regions of interest in each hemisphere. All the control subjects, 1 manic patient, and 1 schizophrenic patient had normal brain SPECT uptake patterns. The scans of all others were read as abnormal. Hypofrontality was noted in some schizophrenics and maniacs. A significant increase in tracer uptake in temporal lobes was observed in both patient groups, more prominently in the manic patients. Increased and decreased basal ganglia uptake was also observed in patients. Both manic and schizophrenic patients showed cortical tracer heterogeneity of varying degree. The patterns of cerebral SPECT uptake seen in these acute psychoses were not specific for a diagnosis, but may be associated with dimensions of psychopathology. Because the patterns are different from those seen in cerebrovascular disease and the dementias, they may prove to be helpful in differential diagnosis.

The scintigraphic evaluation of Huntington's disease and other movement disorders using single photon emission computed tomography perfusion brain scans

The increasing availability of single-photon emission computed tomography (SPECT) perfusion brain scans has led to the investigation of a variety of neuropsychiatric conditions including the movement disorders such as Huntington's and Parkinson's disease. In general, observers have noted that Huntington patients have bilaterally decreased uptake of technetium 99m HM-PAO and iodine 123 IMP in the basal ganglia regions involving the heads of the caudate nucleic and adjacent structure, which reflects decreased neuronal function. These functional changes precede the morphological changes due to caudate nucleus atrophy that are observed on computed tomography and magnetic resonance imaging. Cortical changes occur in severely diseased Huntington's patients but are more nonspecific. Prediction of individuals at risk for Huntington's disease using SPECT scans should be done with caution and in association with other clinical data. In contrast, in Parkinson's disease mild diffusely decreased perfusion is commonly noted throughout the cerebral structures, except for the cerebellum. In Parkinson's disease, there is less agreement among observers as to whether the basal ganglia are abnormal. Some observers report that there are no specific basal ganglia perfusion defects in excess of those changes seen elsewhere in the brain. Others report diminished basal ganglia uptake associated with L-dopa therapy in some Parkinson's patients, and in patients with hemi-parkinsonism there have been perfusion deficits reported in the contralateral basal ganglia. In some Parkinson patients, bilateral Alzheimer's-like posterior temporoparietal cortical perfusion defects have been observed in association with progressive dementia. Basal ganglia and cortical perfusion changes also have been reported in a few patients with a variety of other less common movement disorders.

The use of technetium-99m-HM-PAO in the assessment of patients with dementia and other neuropsychiatric conditions.

One hundred fourteen patients suffering from neuropsychiatric conditions have been studied using 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) and single photon emission computed tomography (SPECT). Ninety-one patients had a firm clinical diagnosis while 23 were examined without knowledge of the clinical diagnosis. Of the 91 patients, 51 were suffering from dementia, 25 multi-infarct type and 26 Alzheimer's disease. In 19 of the Alzheimer's patients, a characteristic pattern of decreased perfusion in the parieto-occipital regions was demonstrated while those with multi-infarct type showed varying degrees of irregular uptake in the cerebral cortex. These appearances are similar to those shown with positron emission tomography (PET) and we believe that HM-PAO will provide a widely available method for identifying patients with Alzheimer's disease. Twenty-nine patients were suffering from diseases involving the basal ganglia. Fifteen patients with Parkinson's disease showed no significant abnormality in basal ganglia uptake, while 7 or 8 patients with Huntington's disease who had full examinations showed decreased uptake in the caudate nuclei. Similarly, four of six patients with other basal ganglia diseases showed impaired uptake by basal ganglia, and it is concluded that HM-PAO may be useful for the diagnosis and management of this type of patient. Twenty-three patients received HM-PAO imaging as part of their diagnostic work-up; in 19 of them, detailed follow-up was obtained, which indicated that in 7 cases the result of the HM-PAO scan altered the clinical diagnosis and in 9 cases resulted in a change in management. In the remaining 13 cases, the study was found to be helpful in confirming the diagnosis.

Belated Diagnosis of Hashimoto's Disease

<b>978</b> <h3><b>Objectives:</b></h3> 1. To recognize patterns of uptake in different ganglia which may mimic lymph node metastases in different anatomic locations 2. To understand the role of CT characterization and localization in the differentiation of benign uptake in ganglia versus metastatic lymph nodes. 3. How to interpret these findings and direct further evaluation or recommendation if needed. <b>Abstract:</b> Several recent studies revealed accurate staging of primary prostate cancer (PC) and restaging after biochemical recurrence with ⁶⁸Ga -PSMA PET/CT. However, ⁶⁸Ga -PSMA uptake is not completely specific to PC. Recent study showed relatively high PSMA uptake in coeliac ganglia in most patients which may mimic lymph node metastases in this area in PC patients undergoing ⁶⁸Ga -PSMA PET/CT examination for staging or restaging¹. We will demonstrate in a large collection of cases varieties of findings with different patterns of PSMA uptake which would include unilateral and bilateral uptake, mild and moderate uptake, focal and diffuse uptake, isolated ganglion uptake and multiple ganglia uptake in same patient. Also, correct and careful of interpretation of the CT scan as part of the ⁶⁸Ga-PSMA PET/CT examination is of special importance in differentiating PSMA uptake in a ganglia versus in lymph nodes. Associated CT findings and characterization of ganglia in the ⁶⁸Ga-PSMA PET/CT would be demonstrated at different location including stellate ganglia in the cervicothoracic region, coeliac and superior mesenteric in the abdomen and inferior mesenteric in the pelvic region. We will also show the appearance of some of these findings by other imaging modalities for further characterization. Reading physician should be aware of the frequently encountered physiologic uptake of 68Ga-labelled PSMA ligand in different ganglia in order to avoid false positive interpretation.