Liraglutide, a glucagon-like peptide 1 (GLP-1) agonist and antidiabetic drug, has shown neuroprotective effects in animal models. In this study, we aimed to evaluate the safety and efficacy of liraglutide in mild to moderate Alzheimer's disease syndrome. 'Evaluating liraglutide in Alzheimer's disease' (ELAD) is a multicenter, randomized, double-blind, placebo-controlled phase 2b trial in 204 participants with mild to moderate Alzheimer's disease syndrome with no diabetes. Participants received daily injections of liraglutide or placebo for 52 weeks. They underwent fluorodeoxyglucose positron emission tomography, magnetic resonance imaging and detailed neuropsychometric evaluations. The primary outcome was a change in cerebral glucose metabolic rate. Secondary outcomes were safety and tolerability and cognitive changes. The primary outcome showed no significant differences in cerebral glucose metabolism (difference = -0.17; 95% confidence interval: -0.39 to 0.06; P = 0.14) between the two groups. The secondary outcome-score on the Alzheimer's Disease Assessment Scale-Executive domain (ADAS-Exec)-performed better in liraglutide-treated patients compared to placebo (0.15; 95% confidence interval: 0.03-0.28; unadjusted P = 0.01). No significant differences were observed in Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) (-0.58; 95% confidence interval: -3.13 to 1.97; unadjusted P = 0.65) or Clinical Dementia Rating-Sum of Boxes (CDR-SoB) (-0.06; 95% confidence interval: -0.57 to 0.44; unadjusted P = 0.81) scores. Liraglutide was generally safe and well tolerated in non-diabetic patients with Alzheimer's disease. ClinicalTrials.gov identifier: NCT01843075 .

Heart transplantation significantly enhances survival and quality of life for patients with end-stage heart failure. Despite advances in surgical and postoperative care, immune-mediated complications, acute graft rejection and cardiac allograft vasculopathy (CAV), remain major barriers to long-term success. Acute rejection predominantly affects early posttransplant survival, whereas CAV becomes a leading cause of mortality in later years. The gold standards for diagnosis, endomyocardial biopsy for rejection and coronary angiography for CAV, are invasive and imperfect. Noninvasive multimodality imaging is increasingly used to complement or, in selected scenarios, defer invasive testing. Echocardiography with strain detects early myocardial dysfunction when ejection fraction is preserved; stress echocardiography provides prognostic information for CAV. Quantitative techniques, positron emission tomography myocardial blood flow/myocardial flow reserve and quantitative cardiac magnetic resonance perfusion, improve detection of diffuse, stage-dependent CAV compared with qualitative assessments. Cardiac magnetic resonance tissue mapping characterizes edema and fibrosis relevant to rejection surveillance; fluorodeoxyglucose-positron emission tomography for inflammation is emerging but remains investigational in most centers. Cardiac computed tomography angiography defines coronary anatomy and plaque with excellent negative predictive value and offers physiologic assessment with computed tomography-myocardial perfusion imaging/computed tomography-derived fractional flow reserve; it is best used strategically rather than as an annually repeated test. This contemporary review synthesizes the strengths, limitations, and practical roles of echocardiography, nuclear imaging, cardiac magnetic resonance, and cardiac computed tomography angiography across adult and pediatric populations; highlights areas where quantitative methods add incremental value; and provides pragmatic, stage-aware surveillance frameworks. Integrating modalities can reduce reliance on invasive procedures, lower procedural risk, and refine therapeutic decision-making benefits that are particularly relevant for children and other patients for whom repeated invasive testing is undesirable.

Multimodal diagnosis and management of prosthetic valve endocarditis: A decade of experience at a tertiary center.

Background: Cardiac sarcoidosis (CS) is a rare, but potentially life-threatening manifestation of systemic sarcoidosis. While both cardiac magnetic resonance imaging (CMRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) are widely used as non-invasive imaging modalities, their relative diagnostic accuracy remains unclear. We aimed to evaluate the diagnostic performance of CMRI compared to FDG-PET for detecting CS. Methods: A systematic literature search was conducted across PubMed, EMBASE, and Cochrane CENTRAL through May 2025 to identify studies evaluating the diagnostic accuracy of CMRI and/or FDG-PET for CS. Studies were included if they reported sufficient data to calculate diagnostic accuracy metrics against a clinical or histological reference standard. A bivariate random-effects model was used to estimate pooled sensitivity, specificity, diagnostic odds ratios (DOR) along with corresponding 95% confidence intervals (CI). The positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), negative likelihood ratio (LR-) and Youden Index were also calculated. A summary receiver operating characteristic (SROC) diagnostic model was used to calculate the area under curve (AUC) and evaluate overall diagnostic performance. A p-value <0.05 was considered significant in all cases. Results: A total of 41 studies were included, out of which 23 reported data for CMRI and 32 for FDG-PET. CMRI demonstrated significantly superior overall diagnostic performance compared to FDG-PET (p = 0.013 for AUC comparison) for the detection of cardiac sarcoidosis. Pooled sensitivity and specificity for CMRI were 0.90 (95% CI: 0.85-0.94) and 0.82 (95% CI: 0.69-0.90) respectively, both higher than FDG-PET, which showed a sensitivity of 0.78 (95% CI: 0.69-0.84) and specificity of 0.78 (0.72-0.84). CMRI also yielded a greater DOR of 41.7 (95% CI: 19.40-89.6) versus 12.50 (95% CI: 7.71-20.30), AUC of 0.92 (95% CI: 0.82-0.91) versus 0.83 (0.74-0.83) and YI of 0.72 (95% CI: 0.59-0.80) versus 0.56 (95% CI: 0.47-0.63) compared to FDG-PET. Conclusion: CMRI demonstrated a significantly greater diagnostic performance for detection of CS compared to FDG-PET with a superior sensitivity, specificity, DOR, AUC and YI, highlighting CMRI as a more robust imaging modality for CS. However, direct comparative studies and standardized diagnostic criteria remain essential to confirm these findings and guide clinical imaging strategies.

Background: 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) is valuable for the diagnosis of cardiac sarcoidosis (CS). Although current guidelines recommend maintaining the initial maximum dose of prednisolone (PSL) for one month after its initiation, the prognostic significance of FDG-PET performed at one month following the initiation of PSL remains unclear. We sought to investigate whether FDG-PET performed at one month after the initiation of PSL was associated with adverse events in patients with CS. Methods: We examined 110 consecutive CS patients performed FDG-PET at diagnosis and one month following the initiation of PSL between January 2010 and January 2025 in a university hospital. All patients were initiated on an initial dose of PSL at 30 mg/day or 1 mg/kg/day, or an equivalent dose. We calculated the change in the maximum standardized uptake value (SUVmax) on FDG-PET from diagnosis to one month after the initiation of PSL. A responder to the maximum dose of prednisolone was defined as a decrease in SUVmax of at least 25%, while a non-responder was defined as a decrease of less than 25% or any increase, in line with previous reports. Patients were classified as either responders (n = 84) or non-responders (n = 26). The primary outcome was a composite of sustained ventricular tachycardia/fibrillation (VT/VF), worsening heart failure (HF), and all-cause death. Results: The median age was 63 ± 11 years, and 87 patients (79.1%) were female. The median left ventricular ejection fraction (LVEF) was 45 (IQR 37–60) %. Patients with non-responder had higher cardiac troponin T levels and lower estimated glomerular filtration rate compared to those with responder. There were no significant differences in age, past history, LVEF, brain natriuretic peptide levels between the groups. During a median follow-up period of 3.3 (IQR 1.1–6.2) years, the primary outcome occurred in 34 patients (30.9%). Patients with non-responder showed significantly higher incidence of primary outcome ( P = 0.006) ( Figure ). In multivariable Cox analyses, non-responder status was significantly associated with the primary outcome, sequentially adjusted for history of VT/VF (HR 2.32, P = 0.022) and then for LVEF (HR 2.15, P = 0.036). Conclusions: FDG-PET performed one month after initiating PSL was associated with adverse events in patients with CS, suggesting its utility in risk stratification and therapeutic decision-making prior to starting PSL tapering.

Introduction:The prevalence of ossification of the posterior longitudinal ligament (OPLL) has been primarily studied in East Asian countries; its prevalence in Western populations remains to be elucidated. We aimed to determine the prevalence of OPLL in a Chilean population aged 60 years and older using fluorine-18 fluorodeoxyglucose positron emission tomography and CT (PET-CT) as screening tool.Methods:We evaluated patients between 60 and 73 years consecutively studied with PET-CT in a University Hospital. We assessed whole-body CT scans in both sagittal and axial views to detect the presence of OPLL. We used the Mann-Whitney test to analyze continuous variables, the Fisher test for categorical variables, and a logistic regression analysis to determine the independent effect of age and sex on the presence of OPLL.Results:We studied 1,009 patients (median age = 66 years); 597 were males (59.17%). Nineteen patients had OPLL, with a prevalence of 1.88% (1.04 to 2.72). OPLL was more prevalent in men (2.68%) than in women (0.73%; P = 0.02). All cases presented cervical involvement; only one had cervical and thoracic OPLL. The median age of patients with OPLL (64 years) and without OPLL (66 years) was not statistically different (P = 0.09). Male sex independently influenced the presence of OPLL (odds ratio = 3.85 [1.11 to 13.33]), age did not (odds ratio = 0.89 [0.78 to 1.02]).Discussion:This is the first study evaluating the prevalence of OPLL in Latin America. It shows a prevalence alike that in non-Asian populations in the United States and lower than the prevalence described in Asian populations.

This systematic review and meta-analysis investigates the diagnostic utility of [18F]Fluorodeoxyglucose (FDG) and Fibroblast activation protein inhibitor (FAPI) positron emission tomography (PET) in Crohn's disease (CD). A comprehensive literature search of Scopus, PubMed, and Web of Science up to April 1, 2025 was performed. Pooled detection rates, sensitivity, specificity, average maximum standardized uptake value (SUVmax), and biomarker correlations were assessed using Stata software. This systematic review evaluates 20 studies (547 patients, 1935 bowel segments) comparing [18F]FDG and FAPI PET tracers in CD. Seven [18F]FDG PET studies (247 patients, 872 segments) demonstrated pooled sensitivity, specificity, and accuracy of 76%, 81%, and 85%. Overall detection rate for CD inflammation was 89%, with SUVmax weighted mean difference (WMD) of 2.9 between inflammatory and non-inflammatory segments (p = 0.0001). [18F]FDG SUVmax correlated strongly with CRP (rho = 0.67, p = 0.001). Four FAPI PET studies (50 patients, 211 segments) showed 92%, 93%, and 96% sensitivity, specificity, and accuracy. Overall, the detection rate for CD fibrosis was 99%, and the WMD in SUVmax between fibrotic and non-fibrotic CD is 7 (p = 0.00001). FAPI SUVmax correlated strongly with histologic fibrosis grading (rho = 0.74, p = 0.0001). Indirect comparisons revealed FAPI's diagnostic effectiveness was twofold greater than FDG (p = 0.03), and has higher overall SUVmax with WMD of 1.3 (p = 0.01). Both PET tracers show promise, with [18F]FDG correlating with CD inflammation, and FAPI with CD fibrosis. FAPI PET imaging demonstrated greater accuracy and higher uptake metrics. Further research is needed to explore diagnostic and predictive utilities in larger studies.

The association of preneoadjuvant maximal standardized uptake value (SUVmax) and postneoadjuvant change in maximal standardized uptake value on 18-fluorodeoxyglucose positron emission tomography with survival after esophagectomy for cancer.

Cervical cancer is the fourth most common gynecologic cancer worldwide and the second most common cancer during pregnancy. Globally, there are high incidence and mortality rates with this cancer, especially in developing countries. The incidence and death rate is not as high within the United States. However, given the preventability of this cancer, attention should be focused on identifying risk factors, prioritizing primary prevention, conducting screening and early detection, and performing tertiary prevention. The most common risk factor is the persistence of high-risk human papillomavirus infection, and vaccination should be encouraged. Cervical cancer screening methods include a cervical cytology test alone, a high-risk human papillomavirus test alone, or a combination of both known as cotesting. When an abnormal result is identified, American Society for Colposcopy and Cervical Pathology guidelines should be followed for management and follow-up. Most general gynecologists are unlikely to manage gynecologic malignancies; therefore, if a malignant lesion is identified, prompt referral to gynecologic oncology is required for management. Magnetic resonance imaging of the pelvis, computed tomography, and 18F-fluorodeoxyglucose positron emission tomography can help identify spread of the malignant lesion with other crucial prognostic factors. Management of cervical cancer depends on the stage of disease and the patient's desire for future fertility. Select patients with appropriate counseling can be candidates for fertility sparing options, if interested in childbearing. Treatment options can include surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy. The 5-year survival rate is approximately 68.0% overall, but it ultimately depends on the cancer's stage. Given the type of treatment that is provided, survivorship care will require a multidisciplinary approach.

In retroperitoneal fibrosis (RPF), glucocorticoids (GC), alone or in combination with immunosuppressive agents, induce remission in 80%-90% of patients but up to two thirds of them relapse. There is limited knowledge on outcome predictors in RPF. We aimed to identify clinical, laboratory and imaging predictors of remission and relapse in RPF. We included consecutive RPF patients treated with 6-9-month courses of GC with/without immunosuppressive agents. Baseline and post-treatment computed tomography, magnetic resonance imaging and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) were assessed. The potential predictive value of the examined parameters as predictors of remission and time-to-relapse was analysed using logistic and Cox regression models. Of 152 patients screened, 115 were included. Of them, 101 (87.8%) achieved remission a median of 4 months (interquartile range 3-5) after starting treatment. At multivariable analysis, smoking (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.11-0.99) and atypical RPF localization (e.g., pelvic) (OR 0.11, 95% CI 0.02-0.52) were negatively associated with remission, whereas pre-treatment 18F-FDG-PET activity was positively associated (OR 11.51, 95% CI 1.35-98.20). A median of 33 months (17-57) after treatment initiation, 42% patients relapsed (median time from remission to relapse, 14 months [8-26]). Thoracic vessel involvement and positive 18F-FDG-PET at the end of treatment independently predicted relapse (hazard ratio [HR] 2.61, 95% CI 1.19-5.68 and HR 3.47, 95% CI 1.54-7.82, respectively). Metabolic activity of RPF at 18F-FDG-PET is an important predictor of remission and relapse. Smoking and atypical localization are negatively associated with remission, whereas thoracic aorta involvement is associated with relapse risk.

Autoimmune encephalitis (AE) is a rapidly evolving topic in both neurology and psychiatry. A recent international consensus article defined criteria for possible, probable, and definite autoimmune psychosis (AP) inspired by the principles established in neurology for the definition of AE. This has stimulated much clinical research on AP but also criticism of the validity of the criteria for possible AP, justifying additional clinical investigations such as lumbar puncture. In clinical practice, it is often difficult to decide how far diagnostic procedures such as lumbar punctures and immunotherapies should go in unclear cases. Against this background, we have 3 aims in this review. First, we summarize and compare the available concepts for the diagnosis of AP in a systematic literature review. Second, we present an overview of typical specific and nonspecific findings that can be obtained in laboratory, electroencephalography, magnetic resonance imaging, cerebrospinal fluid, and [18F]fluorodeoxyglucose positron emission tomography studies in the context of AP. Thirdly, we summarize these findings and present the Neuropsychiatric Checklist for Autoimmune Psychosis as a tool for clinical assessment of the likelihood of AP, with reference to the typical red-flag symptoms and the specific and many unspecific findings that can be identified in additional investigations. We suggest that this instrument may be a useful tool for a comprehensive, possibly uniform, and standardized case assessment in the context of possible AP.

This review covers World Health Organization classification and in-depth imaging of diverse adult and paediatric mesenchymal tumors of the thorax (lungs and pleura), highlighting their key imaging features predominantly on computed tomography (CT) including CT angiography (for intimal sarcoma), and also on other imaging modalities such as ultrasound, magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography CT (FDG PET-CT) wherever necessary. Although rare, it is essential to identify and differentiate these mesenchymal tumors from the common epithelial tumors of lungs on imaging, as their management is entirely different. Mesenchymal tumor should be suspected over epithelial tumor when the CT scan shows a large-sized, well-marginated tumor or a tumor containing fat and calcifications in adults, or a solid-cystic tumor in a relatively younger population. An algorithmic approach to diagnosing these tumors has been presented at the end based on age (children/adult), location (perihilar /intrapulmonary/ peripheral), nature of tumor (solid/solid-cystic), and content (calcification/fat), for the ease of evaluation by the radiologists.

Abstract Background Alzheimer’s disease, a progressive neurological disease, affects an estimated 6.7 million Americans aged 65 and older. Although positron emission tomography (PET) scan is the emerging gold standard for diagnosis of Alzheimer’s disease, Elecsys amyloid beta (Aβ42), total tau (t-Tau) and phosphorylated tau (p-Tau at position 181) in cerebral spinal fluid (CSF) have recently been approved by the FDA as surrogate biomarkers for Alzheimer’s disease. We implemented these Elecsys CSF assays in our laboratory using Cobas e801 analyzer and established a cut-off of > 0.024 for pTau181/Ab 42 ratio for indication of Alzheimer disease. We studied correlation between pTau181/Ab 42 ratio and actual diagnosis of Alzheimer’s ­disease based on PET scan in 143 patients. Materials and Methods All Elecsys assays were obtained from Roche and CSF specimens were collected using specialized Sarstedt tube supplied by Roche. Imaging studies were performed using fluorodeoxyglucose PET scans. Screening for cognitive function (SCF) in these patients was performed using either MOCA (Montreal Cognitive Assessment), SLUMS (Saint Louis University Mental Status Examination), STMS (The Short Test of Mental Status) or MMSE (Mini-Mental State Exam). Results There was no statistically significant difference in age of patients with the CSF biomarker ratio above the cut off limit of 0.024 (80 patients, mean age 71.3 years, SD: 7.9) and ratio below the cut-off (63 patients, mean age 66.3 years, SD :10.0) using Levene’s test. However, older patients were more likely to show an elevated pTau181/Ab 42 ratio. We observed no racial bias (Caucasian, African American, Hispanic and others) in elevated CSF biomarker results or positive PET scans using Chi-Square test. Chi-square analysis also showed a statistically significant association between positive CSF tests and PET scans (p < 0.01). The mean pTau181/Ab42 ratio was 0.055 (SD: 0.05, range: 0.025-0.12) in patients resulted positive for the CSF biomarkers, but the ratio was 0.0138 (SD: 0.0046, range: 0.007-0.024) in patients who tested negative (differences were also statistically significant by t-test). The sensitivity of pTau181/Ab42 was 76.2%, specificity was 84.2% and positive predictive value was 84.2% when compared to PET scan findings. We observed poor correlation between standalone SCF and PET scan result using Chi-Square analysis. For example, MOCA showed a sensitivity of 50.0%, specificity of 66.7% and positive predictive value of only 33.3%. However, binary logistic regression demonstrated a combination of abnormal SCF, and a positive CSF screen significantly predicted a positive imaging result (N = 40, p<.001). Conclusions CSF pTau181/Ab42 ratio is a diagnostic marker for Alzheimer disease correlated well with PET scan compared to various standalone cognitive screening assessment. A negative CSF biomarker test result may help rule out Alzheimer disease. Further, a combination approach inclusive of SCF and CSF biomarkers was significant for positive PET imaging.

18F]FDG-PET provides insights into the liver-brain axis and confirms SUVgluc as a surrogate for MRGlu in a mouse model of liver fibrosis.

Meningiomas are the most common primary central nervous system tumors, arising from arachnoid cap cells and typically following a benign clinical course. However, a minority of cases-particularly higher-grade meningiomas-exhibit aggressive behavior, including local invasion, recurrence, and, in rare instances, extracranial metastasis. Metastatic meningioma, defined as dissemination beyond the cranial and spinal compartments, remains exceptionally uncommon, with reported incidence ranging from 0.1% to 0.76%. Common metastatic sites include the lungs, bone, liver, and lymph nodes, although virtually any organ may be involved. Proposed mechanisms of spread include hematogenous dissemination via venous sinuses, cerebrospinal fluid seeding in high-grade variants, and possibly lymphatic dissemination. Imaging features that suggest metastatic potential include irregular margins, heterogeneous enhancement, prominent peritumoral edema, and bone destruction. Advanced modalities, such as gallium 68 DOTA-Tyr3-octreotide PET/CT and fluorine 18 fluorodeoxyglucose PET, play an increasing role in detecting and characterizing both known and occult metastatic lesions. Molecular alterations, including TERT promoter mutations, CDKN2A/B deletions, and somatostatin receptor 2 overexpression, are increasingly recognized as important markers for risk stratification and targeted therapy selection. Management requires a multimodal approach, including surgery, radiation therapy, and emerging systemic options such as peptide receptor radionuclide therapy and immune checkpoint inhibitors. Given the rarity and clinical complexity of this entity, radiologists must maintain a high index of suspicion, particularly while evaluating in high-grade or recurrent meningiomas. Keywords: Meninges, Brain/Brain Stem, Neuro-oncology, Molecular Imaging, Metastatic Meningioma, DOTATATE, High-Grade Meningioma, Somatostatin Receptor Imaging, SSTR, Peptide Receptor Radionuclide Therapy © RSNA, 2025.

Progressive supranuclear palsy (PSP) is a clinically heterogeneous neurodegenerative disorder with unclear pathophysiology. This study aimed to uncover clinically relevant metabolic networks derived from 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in PSP. FDG and dopaminergic transporter PET data from 72 PSP patients and 70 healthy controls were analyzed, with an independent test set of 24 PSP patients. All patients underwent comprehensive neuropsychiatric assessments. Using spatial independent component analysis, the study identified independent metabolic networks and examined their correlations with clinical features and striatal dopaminergic binding. Three distinct metabolic networks were identified in PSP: The first network demonstrated hypometabolism in dorsomedial thalamus (dmT), medial prefrontal cortex (mPFC) and midbrain, termed the dmT-mPFC network, negatively correlating with disease severity, functional disability and duration, and associating with gait/midline disturbances and ocular dysfunction. The second network displayed posterior cingulate cortex (PCC) and lateral prefrontal hypometabolism (LPFC), named the PCC-LPFC network, linking to disease severity, cognitive impairment, and parkinsonism. The third network exhibited preserved putamen metabolism with ventrolateral thalamus and sensorimotor cortex hypermetabolism, inversely relating to disease duration. Both dmT-mPFC and PCC-LPFC networks strongly correlated with striatal dopaminergic degeneration. The test set showed strong associations between cognitive impairment and the PCC-LPFC network, and between functional disability and the dmT-mPFC network, along with potential trends linking disease severity to these networks. The robust clinical and dopaminergic-related independent metabolic networks offer novel insights into disease pathophysiology, whereas their qualitative weighting offers a potential tool for staging disease severity. © 2025 International Parkinson and Movement Disorder Society.

ObjectiveThis study aimed to develop a machine learning model based on multimodal radiomics features from cerebellar subregions, utilizing the complementarity of cerebellar structural and metabolic imaging data for accurate diagnosis of Alzheimer’s disease (AD).MethodsA total of 164 cognitively normal (CN) subjects and 146 AD patients from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database were included. All participants had 3DT1-weighted magnetic resonance imaging (3DT1W MRI) and [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET) imaging data. The cerebellum was divided into 26 subregions, and radiomics features were extracted from different cerebellar regions of these two modality images, respectively. After feature selection, single-modality ([18F]FDG PET, 3DT1W MRI) and multimodal ([18F]FDG PET + 3DT1W MRI) random forest classification models were constructed. Model performance and clinical value were assessed using area under the curve (AUC), calibration curves, and decision curve analysis (DCA). In addition, we also used Shapley Additive exPlanations (SHAP) to clarify the contributions of features, thereby enhancing the interpretability of the model.ResultsAll three models could effectively diagnose AD, with the multimodal model showing the best performance. In the independent test set, the multimodal model achieved an AUC of 0.903, which was higher than the single-modality models based on [18F]FDG PET (AUC = 0.842) and 3DT1W MRI (AUC = 0.804). The calibration curves and DCA demonstrated that all three models had good calibration and clinical applicability, especially the multimodal model. SHAP analysis of the multimodal model revealed that among the 15 selected features, the top seven features with the highest SHAP values were derived from [18F]FDG PET images, with R_FDG_CER_III_original_firstorder_90Percentile and R_FDG_CER_VI_original_firstorder_Median being the two most important features for distinguishing AD from CN.ConclusionThe multimodal radiomics model based on cerebellar subregions, which integrates [18F]FDG PET and 3DT1W MRI data, can effectively diagnose AD and provide potential biomarkers for clinical applications.

Alzheimer's disease classification based on multimodal consistent distribution and trusted fusion.

18F-fluorodeoxyglucose positron-emission tomography (FDG PET) and whole-body (WB) MRI with diffusion weighted imaging (DWI) are complementary in assessment of multiple myeloma. However, WB DWI suffers from prolonged acquisition times and artifacts. Alternatively, rapid T2-weighted MRI with 2-point Dixon fat-suppression (T2-FS) has demonstrated promise in detection of bone lesions in exam times shorter than DWI. This study evaluated (1) the accuracy of rapid WB T2-FS for multiple myeloma lesion detection and (2) the incremental impact of adding DWI and FDG PET to T2-FS on diagnostic accuracy and patient care management. This retrospective single-center study included patients with clinical WB PET/MRI exams obtained for multiple myeloma. T2-FS, DWI, and PET were reviewed in consensus by 2 readers, each technique reviewed blinded to the other 2 and to other imaging/clinical information. Focal lesions and nonfocal bone marrow disease were recorded. Per-lesion sensitivity and per-patient sensitivity and specificity for each technique were compared with a composite reference standard using McNemar exact test; 95% confidence intervals were calculated, and P<0.05 was considered significant. The incremental impact of adding DWI and PET to T2-FS on diagnostic accuracy and patient care management was recorded. From 34 PET/MRI exams from 34 patients, 3 incomplete exams were excluded. Among the 31 included exams, T2-FS demonstrated a significantly higher per-lesion sensitivity than DWI and PET, at 91.9%, 66.7%, and 44.4%, respectively (P<0.001). T2-FS identified all 21 patients with disease, compared with 85.7% for both DWI and PET; this difference did not reach statistical significance (P>0.050). Adding DWI to T2-FS did not change management in any patient; adding PET to T2-FS changed management in 3 patients. T2-FS was more rapid and more sensitive than DWI for assessment of multiple myeloma. Unlike FDG PET, addition of DWI did not impact clinical management. Larger prospective studies for further validation are needed.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are described as a disease continuum, given their shared clinical, genetic, and pathological characteristics. The comparisons of clinical and biomarker features within ALS and behavioral variant FTD (bvFTD) spectrum, would be of utmost importance for diagnostic and prognostic purposes. This study investigated biomarker differences between patients with ALS cognitively-normal (ALS-cn), ALS-FTD, and bvFTD. Participants, genetically screened for known ALS- and FTD-associated mutations, underwent neuropsychological assessments, CSF analysis, and brain imaging through 18-fluorodeoxyglucose PET ([18F]FDG-PET). Neuropsychological data were analyzed by calculating, for each cognitive domain, a composite score by averaging the rank-transformed z-scores of all tests measuring the same domain. [18F]FDG-PET analysis was performed using a validated voxel-based SPM method at single-subject and group-level. To evaluate the ability of the identified markers to differentiate ALS-cn, ALS-FTD, and bvFTD, machine-learning models-including support vector machine (SVM) and random forest (RF)-were applied, offering a streamlined, data-driven approach to improve diagnostic precision across this spectrum of disorders. 20 ALS-cn, 19 ALS-FTD, and 21 bvFTD patients were included. Neuropsychological composite z-scores revealed significant differences across groups, underlining worse performance in bvFTD regarding memory, visuospatial, language and executive functions. Brain [18F]FDG-PET showed a pattern of hypometabolism increasing from ALS-cn to ALS-FTD and reaching its greatest extent in bvFTD. Specifically, brain hypometabolism was mainly confined to the sensorimotor cortices and the frontobasal regions in the ALS-cn group, whereas in the ALS-FTD group it was extended to the supplementary motor area and the dorsolateral frontal cortex, and in the bvFTD group, a widespread hypometabolism further affected the frontomesial and orbitofrontal cortices. No significant differences in CSF biomarkers were observed. SVM correctly classified 83% of patients, indicating a good level of classification performance, while RF showed perfect accuracy (100%). The two models shared eight to ten most relevant features in the classification system, namely age, disease duration from symptoms onset to diagnosis, total composite z-score, superior frontal gyrus (left), middle frontal gyrus (left), middle frontal gyrus - pars orbitalis (left and right), and anterior cingulate cortex (left). Our study identified significant differences in the biomarkers according to the neurodegenerative clinical groups within the same disease spectrum. These differences were evident in neuropsychological profiles and brain hypometabolism patterns, successfully addressing the study's aim and providing valuable insights for differential diagnosis into ALS-FTD continuum heterogeneity.