scholarly journals Texture-Based Analysis of 18F-Labeled Amyloid PET Brain Images

2021 ◽  
Vol 11 (5) ◽  
pp. 1991
Author(s):  
Alexander P. Seiffert ◽  
Adolfo Gómez-Grande ◽  
Eva Milara ◽  
Sara Llamas-Velasco ◽  
Alberto Villarejo-Galende ◽  
...  
Keyword(s):  
Area Under The Curve ◽  
Standardized Uptake Value ◽  
Texture Features ◽  
Roc Curves ◽  
Significant Feature ◽  
Study Cohort ◽  
Amyloid Pet ◽  
Reference Region ◽  
Brain Images ◽  
Positron Emission

Amyloid positron emission tomography (PET) brain imaging with radiotracers like [18F]florbetapir (FBP) or [18F]flutemetamol (FMM) is frequently used for the diagnosis of Alzheimer’s disease. Quantitative analysis is usually performed with standardized uptake value ratios (SUVR), which are calculated by normalizing to a reference region. However, the reference region could present high variability in longitudinal studies. Texture features based on the grey-level co-occurrence matrix, also called Haralick features (HF), are evaluated in this study to discriminate between amyloid-positive and negative cases. A retrospective study cohort of 66 patients with amyloid PET images (30 [18F]FBP and 36 [18F]FMM) was selected and SUVRs and 6 HFs were extracted from 13 cortical volumes of interest. Mann–Whitney U-tests were performed to analyze differences of the features between amyloid positive and negative cases. Receiver operating characteristic (ROC) curves were computed and their area under the curve (AUC) was calculated to study the discriminatory capability of the features. SUVR proved to be the most significant feature among all tests with AUCs between 0.692 and 0.989. All HFs except correlation also showed good performance. AUCs of up to 0.949 were obtained with the HFs. These results suggest the potential use of texture features for the classification of amyloid PET images.

scholarly journals Concordance in detecting amyloid positivity between 18F-florbetaben and 18F-flutemetamol amyloid PET using quantitative and qualitative assessments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Soo Hyun Cho ◽  
Yeong Sim Choe ◽  
Young Ju Kim ◽  
Byungju Lee ◽  
Hee Jin Kim ◽  
...  
Keyword(s):  
False Positive Rate ◽  
Standardized Uptake Value ◽  
Visual Assessment ◽  
Emission Tomography ◽  
Amyloid Pet ◽  
Reference Region ◽  
Rater Agreement ◽  
High Agreement ◽  
Positron Emission ◽  
Positive Rate

Abstract We aimed to quantitatively and qualitatively assess whether there is a discrepancy in detecting amyloid beta (Aβ) positivity between 18F-florbetaben (FBB) and 18F-flutemetamol (FMM) positron emission tomography (PET). We obtained paired FBB and FMM PET images from 107 participants. Three experts visually quantified the Aβ deposition as positive or negative. Quantitative assessment was performed using global cortical standardized uptake value ratio (SUVR) with the whole cerebellum as the reference region. Inter-rater agreement was excellent for FBB and FMM. The concordance rates between FBB and FMM were 94.4% (101/107) for visual assessment and 98.1% (105/107) for SUVR cut-off categorization. Both FBB and FMM showed high agreement rates between visual assessment and SUVR positive or negative categorization (93.5% in FBB and 91.2% in FMM). When the two ligands were compared based on SUVR cut-off categorization as standard of truth, although not statistically significant, the false-positive rate was higher in FMM (9.1%) than in FBB (1.8%) (p = 0.13). Our findings suggested that both FBB and FMM had excellent agreement when used to quantitatively and qualitatively evaluate Aβ deposits, thus, combining amyloid PET data associated with the use of different ligands from multi-centers is feasible.

scholarly journals Total Aβ42/Aβ40 ratio in plasma predicts amyloid-PET status, independent of clinical AD diagnosis

Neurology ◽  
2020 ◽  
Vol 94 (15) ◽  
pp. e1580-e1591 ◽  
Author(s):  
James D. Doecke ◽  
Virginia Pérez-Grijalba ◽  
Noelia Fandos ◽  
Christopher Fowler ◽  
Victor L. Villemagne ◽  
...  
Keyword(s):  
Area Under The Curve ◽  
Standardized Uptake Value ◽  
Imaging Biomarkers ◽  
Control Group ◽  
Amyloid Pet ◽  
Time Points ◽  
Healthy Control ◽  
Ε4 Allele ◽  
Amyloid Aβ ◽  
Rate Of Failure

ObjectiveTo explore whether the plasma total β-amyloid (Aβ) Aβ42/Aβ40 ratio is a reliable predictor of the amyloid-PET status by exploring the association between these 2 variables in a subset of the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging cohort.MethodsTaking plasma samples at 3 separate time points, month 18 (n = 176), month 36 (n = 169), and month 54 (n = 135), we assessed the total Aβ42/Aβ40 ratio in plasma (TP42/40) with regard to neocortical Aβ burden via PET standardized uptake value ratio (SUVR) and investigated both association with Aβ-PET status and correlation (and agreement) with SUVR.ResultsThe TP42/40 plasma ratio was significantly reduced in amyloid-PET–positive participants at all time points (p < 0.0001). Adjusting for covariates age, gender, APOE ε4 allele status, and clinical classification clearly affects the significance, with p values reduced and only comparisons at 54 months retaining significance (p = 0.006). Correlations with SUVR were similar across each time point, with Spearman ρ reaching −0.64 (p < 0.0001). Area under the curve values were highly reproducible over time points, with values ranging from 0.880 at 36 months to 0.913 at 54 months. In assessments of the healthy control group only, the same relationships were found.ConclusionsThe current study demonstrates reproducibility of the plasma assay to discriminate between amyloid-PET positive and negative over 3 time points, which can help to substantially reducing the screening rate of failure for clinical trials targeting preclinical or prodromal disease.Classification of evidenceThis study provides Class II evidence that plasma total Aβ42/Aβ40 ratio is associated with neocortical amyloid burden as measured by PET SUVR.

scholarly journals The Who, When, Why, and How of PET Amyloid Imaging in Management of Alzheimer’s Disease—Review of Literature and Interesting Images

Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 65 ◽  
Author(s):  
Subapriya Suppiah ◽  
Mellanie-Anne Didier ◽  
Sobhan Vinjamuri
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Area Under The Curve ◽  
Standard Uptake Value ◽  
Amyloid Imaging ◽  
Carrier Status ◽  
Amyloid Pet ◽  
Positron Emission ◽  
Cutoff Points ◽  
Pet Amyloid

Amyloid imaging using positron emission tomography (PET) has an emerging role in the management of Alzheimer’s disease (AD). The basis of this imaging is grounded on the fact that the hallmark of AD is the histological detection of beta amyloid plaques (Aβ) at post mortem autopsy. Currently, there are three FDA approved amyloid radiotracers used in clinical practice. This review aims to take the readers through the array of various indications for performing amyloid PET imaging in the management of AD, particularly using 18F-labelled radiopharmaceuticals. We elaborate on PET amyloid scan interpretation techniques, their limitations and potential improved specificity provided by interpretation done in tandem with genetic data such as apolipiprotein E (APO) 4 carrier status in sporadic cases and molecular information (e.g., cerebral spinal fluid (CSF) amyloid levels). We also describe the quantification methods such as the standard uptake value ratio (SUVr) method that utilizes various cutoff points for improved accuracy of diagnosing AD, such as a threshold of 1.122 (area under the curve 0.894), which has a sensitivity of 92.3% and specificity of 90.5%, whereas the cutoff points may be higher in APOE ε4 carriers (1.489) compared to non-carriers (1.313). Additionally, recommendations for future developments in this field are also provided.

scholarly journals Promising Diagnostic Accuracy of Plasma GFAP and NfL Within The AD Continuum

2021 ◽  
Author(s):  
Tandis Parvizi ◽  
Theresa Koenig ◽  
Raphael Wurm ◽  
Sara Silvaieh ◽  
Patrick Altmann ◽  
...  
Keyword(s):  
Risk Factors ◽  
Single Molecule ◽  
Plasma Concentrations ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Subjective Cognitive Decline ◽  
Amyloid Pet ◽  
Neurofilament Light Chain ◽  
Neurofilament Light ◽  
Visual Rating

Abstract Background: Blood-based biomarkers may add a great benefit in detecting the earliest neuropathological changes in patients with Alzheimer’s disease (AD). We examined the utility of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in plasma and cerebrospinal fluid (CSF) regarding clinical diagnosis and amyloid positivity in an outpatient memory clinic - based cohort. Methods: In this retrospective analysis, we included a total of 185 patients, 141 patients along clinical the AD continuum, i.e. subjective cognitive decline (SCD, n=18), mild cognitive impairment (MCI, n=63), AD (n=60) and 44 age-matched healthy controls (HC). CSF and plasma concentrations of NfL and GFAP were measured with single molecule array (SIMOAâ) technology using the Neurology 2-Plex B kit from Quanterix. Amyloid-PET was performed in 75 patients and graded as amyloid positive and negative by visual rating. To assess the discriminatory potential of different biomarkers, age- and sex-adjusted receiver operating characteristic (ROC) curves were calculated and the area under the curve (AUC) of each model was compared using DeLong’s test for correlated AUC curves.Results: We constructed a panel combining plasma NfL and GFAP with known AD risk factors (age+sex+APOE4+GFAP+NfL panel). Using this panel, AUC was 91.6% for HC vs. AD, 81.7% for HC vs. MCI, 85% for SCD vs. AD, 81.3% for SCD vs. MCI, 77.7% for HC vs. SCD and 72.3% for MCI vs. AD. In terms of predicting amyloid PET status, we computed an AUC of 88.4%. Conclusion: The combination of plasma GFAP and NfL with well-established risk factors could contribute crucially to the identification of patients at risk, and thereby facilitate inclusion of patients in clinical trials for disease modifying therapies.

scholarly journals Concordance in Detecting Amyloid Positivity Between 18F-florbetaben and 18F-flutemetamol Amyloid PET Using Quantitative and Qualitative Assessments

2020 ◽  
Author(s):  
Soo Hyun Cho ◽  
Yeong Sim Choe ◽  
Young Ju Kim ◽  
Byungju Lee ◽  
Hee Jin Kim ◽  
...  
Keyword(s):  
Visual Analysis ◽  
False Positive Rate ◽  
Temporal Cortex ◽  
Standardized Uptake Value ◽  
Occipital Lobe ◽  
Visual Assessment ◽  
Future Research ◽  
Amyloid Pet ◽  
Positron Emission ◽  
Positive Rate

Abstract Background In the present study, the discrepancy in detecting amyloid beta (Aβ) positivity between 18F-florbetaben (FBB) and 18F-flutemetamol (FMM) positron emission tomography (PET) was quantitatively and qualitatively assessed.Methods Paired FBB and FMM PET images were obtained on separate days from 107 participants. Three experts visually quantified the scans as positive or negative for Aβ deposition. Quantitative assessment was performed using global cortical standardized uptake value ratio (SUVR) with the whole cerebellum (WC) as a reference region.Results Inter-rater agreement was excellent for FBB (Fleiss k = 0.86) and FMM (Fleiss k = 0.78). The concordance rates between FBB and FMM were 94.4% (101/107) for visual assessment and 98.1% (105/107) for SUVR cut-off categorisation. Both FBB and FMM showed high agreement rates between visual assessment and SUVR positive or negative categorisation (93.5% in FBB and 91.2% in FMM). When the two ligands were compared based on SUVR cut-off categorisation as standard of truth, although not statistically significant, the false-positive rate (visual assessment-positive, SUVR-negative) was higher in FMM (9.1%) than in FBB (1.8%) (P = 0.13). In those cases, assessing uptakes in the lateral temporal cortex was often more problematic than in other regions in visual analysis, especially near the border with the occipital lobe.Conclusion Our findings suggested that both FBB and FMM had excellent agreement when used to quantitatively and qualitatively evaluate Aβ deposits, thus, combining amyloid PET data associated with the use of different ligands from multi-centers can be useful in future research.

scholarly journals Spill-in counts in the quantification of 18F-florbetapir on Aβ-negative subjects: the effect of including white matter in the reference region

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Francisco Javier López-González ◽  
◽  
Alexis Moscoso ◽  
Nikos Efthimiou ◽  
Anxo Fernández-Ferreiro ◽  
...  
Keyword(s):  
White Matter ◽  
Standardized Uptake Value ◽  
Patient Data ◽  
Reference Region ◽  
Cognitively Normal ◽  
Positron Emission ◽  
Linear Fit ◽  
Mc Simulation ◽  
Analytical Correction ◽  
The Impact

Abstract Background We aim to provide a systematic study of the impact of white matter (WM) spill-in on the calculation of standardized uptake value ratios (SUVRs) on Aβ-negative subjects, and we study the effect of including WM in the reference region as a compensation. In addition, different partial volume correction (PVC) methods are applied and evaluated. Methods We evaluated magnetic resonance imaging and 18F-AV-45 positron emission tomography data from 122 cognitively normal (CN) patients recruited at the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Cortex SUVRs were obtained by using the cerebellar grey matter (CGM) (SUVRCGM) and the whole cerebellum (SUVRWC) as reference regions. The correlations between the different SUVRs and the WM uptake (WM-SUVRCGM) were studied in patients, and in a well-controlled framework based on Monte Carlo (MC) simulation. Activity maps for the MC simulation were derived from ADNI patients by using a voxel-wise iterative process (BrainViset). Ten WM uptakes covering the spectrum of WM values obtained from patient data were simulated for different patients. Three different PVC methods were tested (a) the regional voxel-based (RBV), (b) the iterative Yang (iY), and (c) a simplified analytical correction derived from our MC simulation. Results WM-SUVRCGM followed a normal distribution with an average of 1.79 and a standard deviation of 0.243 (13.6%). SUVRCGM was linearly correlated to WM-SUVRCGM (r = 0.82, linear fit slope = 0.28). SUVRWC was linearly correlated to WM-SUVRCGM (r = 0.64, linear fit slope = 0.13). Our MC results showed that these correlations are compatible with those produced by isolated spill-in effect (slopes of 0.23 and 0.11). The impact of the spill-in was mitigated by using PVC for SUVRCGM (slopes of 0.06 and 0.07 for iY and RBV), while SUVRWC showed a negative correlation with SUVRCGM after PVC. The proposed analytical correction also reduced the observed correlations when applied to patient data (r = 0.27 for SUVRCGM, r = 0.18 for SUVRWC). Conclusions There is a high correlation between WM uptake and the measured SUVR due to spill-in effect, and that this effect is reduced when including WM in the reference region. We also evaluated the performance of PVC, and we proposed an analytical correction that can be applied to preprocessed data.

scholarly journals Medial temporal tau can be a predictor for amyloid-ß positivity in mild cognitive impairment

2020 ◽  
Author(s):  
Hanna Cho ◽  
Min Seok Baek ◽  
Hye Sun Lee ◽  
Jae Yong Choi ◽  
Jae Hoon Lee ◽  
...  
Keyword(s):  
Area Under The Curve ◽  
Standardized Uptake Value ◽  
Visual Assessment ◽  
Parahippocampal Cortex ◽  
Positron Emission ◽  
Auc Value ◽  
Tau Pet ◽  
Sensitivity Specificity ◽  
Post Hoc ◽  
Pet Scans

Abstract Introduction Although both amyloid-ß (Aß) and tau positron emission tomography (PET) are important for the assessment of Alzheimer’s disease pathology, obtaining two PET scans can be challenging in clinical practice. We sought to determine whether Aß-positivity in MCI patients can be predicted with only a single tau PET scan. Methods We prospectively recruited 105 MCI patients and performed two PET scans with 18 F-florbetaben and 18 F-flortaucipir with all patients. Regional 18 F-flortaucipir standardized uptake value ratios (SUVR) were measured using FreeSurfer-generated volumes-of-interest and with the cerebellar crus median as a reference. Results We classified 49 (46.7%) MCI patients as Aß-positive using visual assessment. In 12 regions showing greater tau uptake in the MCI-Aβ+ patients compared to the MCI-Aβ- patients, tau uptake in the entorhinal cortex showed the greatest area under the curve (AUC) value (AUC = 0.835, sensitivity/specificity = 73.5% /85.7%) for discriminating Aß-positivity. The second and third largest AUCs were obtained with tau uptake in the amygdala (AUC = 0.814, sensitivity/specificity = 65.3%/94.6%) and the parahippocampal cortex (AUC = 0.802, sensitivity/specificity = 67.4%/91.1%). However, post-hoc analyses revealed no statistical differences between the three regions. Conclusions Single tau PET scans may be helpful in the evaluation of disease state and stage at the same time in MCI patients.

scholarly journals Anomaly Analysis of Alzheimer’s Disease in PET Images Using an Unsupervised Adversarial Deep Learning Model

2021 ◽  
Vol 11 (5) ◽  
pp. 2187
Author(s):  
Husnu Baris Baydargil ◽  
Jang-Sik Park ◽  
Do-Young Kang
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Area Under The Curve ◽  
Qualitative Evaluation ◽  
Input Image ◽  
Normal Brain ◽  
Brain Images ◽  
Positron Emission ◽  
Proposed Model ◽  
Anomaly Analysis

In this study, the anomaly analysis of Alzheimer’s disease using positron emission tomography (PET) images using an unsupervised proposed adversarial model is investigated. The model consists of three parts: a parallel-network encoder, which is comprised of a convolutional pipeline and a dilated convolutional pipeline that extracts global and local features and concatenates them, a decoder that reconstructs the input image from the obtained feature vector, and a discriminator that distinguishes if the input image image is real or fake. The hypothesis is that if the proposed model is trained with only normal brain images, the corresponding construction loss for normal images should be minimal. However, if the input image belongs to a class that is designated as an anomaly that which the model is not trained with, then the construction loss will be high. This will reflect during the anomaly score comparison between the normal and the anomalous image. A multi-case analysis is performed for three major classes using the Alzheimer’s Disease Neuroimaging Initiative dataset, Alzheimer’s disease, mild cognitive impairment, and normal control. The base parallel-encoder network shows better classification accuracy than the benchmark models, and the proposed model that is built on the parallel model outperforms the benchmark anomaly detection models. The proposed model gave out 96.03% and 75.21% in classification and area under the curve score, respectively. Additionally, a qualitative evaluation done by using Fréchet inception distance gave a better score than the state-of-the-art by three points.

scholarly journals Posterior acetabular uptake on 18F-fluoride positron emission tomography/computed tomography reveals a putative contrecoup region in patients with femoroacetabular impingement

2019 ◽  
Vol 27 (3) ◽  
pp. 230949901986892
Author(s):  
Takayuki Oishi ◽  
Naomi Kobayashi ◽  
Hyonmin Choe ◽  
Taro Tezuka ◽  
Daigo Kobayashi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Positron Emission Tomography ◽  
Standardized Uptake Value ◽  
Emission Tomography ◽  
Study Cohort ◽  
Entire Study ◽  
Positron Emission ◽  
Pet Ct ◽  
The Mean ◽  
Cam Morphology

Background and purpose: The pathology of the posterior acetabular lesions, so-called “contrecoup regions”, in femorocacetabular impingement (FAI) has not been elucidated fully. 18F-fluoride positron emission tomography/computed tomography (PET/CT) can visualize abnormal uptake caused by impingement. Therefore, we aimed to evaluate posterior acetabular uptake on PET/CT in FAI patients. Patients and methods: Patients with FAI who underwent 18F-fluoride PET/CT between October 2014 and October 2016 were retrospectively evaluated. The maximum standardized uptake value (SUVmax) in the posterior acetabulum was evaluated. The mean SUVmax of FAI with cam morphology (the cam group) was compared with that of FAI with pincer morphology (the pincer group). In addition, the numbers of cases with SUVmax ≥ 6 and SUVmax < 6 in each group were evaluated. The entire study cohort was also grouped according to SUVmax, and the mean α and center edge angles were evaluated. Results: In total, 41 hips were analyzed (34 hips in the cam group and 7 in the pincer group). The mean SUVmax of the cam group (11.2 ± 7.4) was significantly higher than that of the pincer group (4.9 ± 1.9) ( p < 0.01). The incidence of cases with SUVmax ≥ 6 in the cam group was significantly high ( p < 0.01). In the overall cohort, the mean α angle of the SUVmax ≥ 6 group was significantly higher than that of the SUVmax < 6 group ( p < 0.01). Conclusion: Evaluation of posterior acetabular uptake suggests an association between cam morphology and increased posterior acetabular uptake.

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