Search Results (599)

Infective endocarditis (IE) is an uncommon but life-threatening condition characterized by infection and inflammation of the endocardial surface of the heart, most commonly affecting native or prosthetic valves. Recent data indicate in-hospital mortality rates ranging from 15% to 25%, with evidence of increasing mortality even in high-income countries. Beyond its fatal potential, IE poses a major public health burden, accounting for over 1.7 million disability-adjusted life years (DALYs) globally in 2019. This review aims to discuss recent advancements in the diagnosis and management of IE given the shifting epidemiology and pathogen profile of the disease. There is a rising incidence of healthcare-associated IE and an expanding population of vulnerable patients, including the elderly and those with prosthetic material or indwelling catheters. Diagnostic capabilities have rapidly advanced with the adoption of modalities such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), cardiac CT, and cardiac magnetic resonance (CMR), particularly in patients with prosthetic valve endocarditis or culture-negative presentations. Additionally, the expanding indications for surgical intervention and increasing antimicrobial resistance have added complexity to management decisions. These developments underscore the need for a comprehensive review to support healthcare providers in navigating the modern diagnostic and therapeutic landscape of IE. Full article

Background: Dual-tracer positron emission tomography/magnetic resonance imaging (PET/MRI) using [¹⁸F]-fluorodeoxyglucose (¹⁸F-FDG) and [¹⁸F]-fluoroethylcholine (¹⁸F-FEC) may reveal complementary aspects of hepatocellular carcinoma (HCC) biology. This retrospective study evaluates whether PET parameters obtained from ¹⁸F-FDG and ¹⁸F-FEC correlate with MRI enhancement parameters, tumor histological grade, and survival in patients with HCC. Methods: We retrospectively evaluated 25 patients who underwent integrated PET/MRI. Lesions were analyzed on pre-contrast MRI and at early (3–5 min) and late (20–30 min) post-contrast phases. For ¹⁸F-FDG and ¹⁸F-FEC, standardized uptake values (SUV maximum, mean, and peak) and metabolic tumor volume were measured, along with lesion size, MRI enhancement ratios, AFP levels, and survival. For patient-level imaging analyses, the largest lesion per patient was defined as the index lesion. Correlation analysis using Spearman’s rank correlation coefficient, Kaplan–Meier analysis, log-rank testing, and exploratory Cox proportional hazards models were performed. Results:¹⁸F-FDG SUVmean (index lesion) showed the strongest inverse association with survival (r = −0.61, p = 0.003), followed by SUVpeak (r = −0.50, p = 0.012). ¹⁸F-FDG SUVmean differed across tumor grades (G1–G3; p = 0.040), without a consistent trend. In Cox regression, ¹⁸F-FDG SUVpeak was significantly associated with shorter overall survival (HR 1.22, 95% CI 1.05–1.42, p = 0.01), whereas SUVmean showed only a borderline association (p = 0.07). When split at the median, SUVmean was also significantly associated with shorter survival (p < 0.001; HR 10.39, 95% CI 2.75–39.3). ¹⁸F-FEC parameters were not associated with survival but showed a moderate correlation with AFP levels (r = 0.41, p = 0.01). Dynamic MRI early and delayed enhancement of the index lesion were strongly correlated (r = 0.70, p < 0.001) but not associated with survival. Conclusions: In HCC, ¹⁸F-FDG uptake provides prognostic information beyond MRI enhancement and histology, reflecting tumor aggressiveness and independently predicting survival. While ¹⁸F-FEC-PET complements lesion characterization and correlates with AFP, it does not show meaningful prognostic value. MRI enhancement parameters were not associated with survival in this cohort. ¹⁸F-FDG-based metabolic imaging may improve pre-treatment risk stratification, whereas dual-tracer PET/MRI should be considered a selective, exploratory approach rather than routine imaging. Full article

Butyrate, a short-chain fatty acid produced by the fermentation of soluble dietary fiber by gut bacteria, also functions as a histone deacetylase inhibitor known to induce apoptosis and promote differentiation in colon tumor cells. During tumorigenesis, cancer cells undergo metabolic reprogramming to meet energetic and biosynthetic demands, increasing glycolytic metabolism and reducing oxidative metabolism—a phenomenon known as the Warburg effect. This study aimed to evaluate the impact of butyrate on the aggressiveness-related metabolic phenotype of three colon cancer cell lines (LS1034, C2BBe1, and WiDr). Butyrate’s effects were assessed through fluorine-18 fluorodeoxyglucose ([¹⁸F]FDG) uptake, flow cytometry analysis of cytoplasmic and membrane expression of glucose transporters (GLUT1, GLUT3, GLUT5, and GLUT12), lactate production, and analysis of Krebs cycle turnover and glycolysis–Krebs cycle coupling using nuclear magnetic resonance isotopomer profiling. [¹⁸F]FDG uptake decreased in C2BBe1 and WiDr cells, whereas an opposite response was observed in LS1034 cells, which also exhibited reduced GLUT5 expression. These uptake patterns were consistent with lactate production measurements, and an enhancement of oxidative metabolism was detected in C2BBe1 and WiDr cells. Although butyrate was consumed by all three cell lines, its metabolic handling appeared to differ in LS1034 cells, possibly reflecting cytotoxic stress and/or distinct metabolic regulation mechanisms. Overall, these findings indicate that butyrate exerts cell-line-dependent metabolic effects in colorectal cancer cells. In C2BBe1 and WiDr cells, butyrate exposure was broadly consistent with the attenuation of glycolytic/Warburg-associated features, whereas LS1034 cells displayed a divergent response and were interpreted separately. These data support further investigation of butyrate as a modulator of colorectal cancer cell metabolism, while highlighting the heterogeneity of metabolic responses across tumor models. Full article

¹⁸F-fluorodeoxyglucose (FDG) PET/CT is widely used for the evaluation of pulmonary lesions but lacks specificity, as increased FDG uptake is frequently observed in inflammatory and reparative processes. This limitation may lead to false-positive interpretations and unnecessary surgical resections. This study aimed to evaluate the immunohistochemical expression of integrin α_vβ₆ in 18 surgically resected pulmonary lesions that were falsely classified as malignant on FDG PET/CT, in order to find out if ⁶⁸Ga-Trivehexin PET/CT could have superior preoperative diagnostic specificity. Histopathological examination classified all lesions as non-neoplastic inflammatory processes of varying etiologies. Integrin α_vβ₆ expression was detected in all immunohistochemically examined tissue specimens (18/18 cases (100%)), with moderate membranous overexpression in 2/18 cases (11.11%) and strong membranous overexpression in 16/18 cases (88.89%) observed in the alveolar and bronchial epithelium of inflammatory lung lesions. Our findings indicate that integrin α_vβ₆ is upregulated not only in neoplastic lung tissue but also in inflammatory lesions, suggesting that integrin α_vβ₆ may have limited specificity for distinguishing primary neoplastic from inflammatory pulmonary lesions when used alone. Its interpretation requires integration with other clinical imaging modalities and histopathological data. Full article

Introduction: The majority of progressive multifocal leukoencephalopathy (PML) cases is still represented by patients affected by acquired immunodeficiency syndrome (AIDS). Diagnosis of PML relies on histopathological findings or by the combination of clinical signs, radiological evidence, and molecular positivity of the JC virus in cerebrospinal fluid. However, AIDS status predisposes to various diseases involving the brain, testing the diagnostic ability of the clinician. Case description: We describe a PML case in a patient with AIDS, in whom lumbar puncture was initially impossible for severe thrombocytopenia and magnetic resonance showed an hyperintense lesion and was unable to distinguish between PML and lymphoma. In this case, [¹⁸F]-fluorodeoxyglucose (FDG)-PET imaging showing a hypometabolism of the lesion helped to initially orient toward PML, as diagnosis was later confirmed by lumbar puncture. We collected 21 cases in the literature in which [¹⁸F]-FDG-PET was helpful in cases of PML. Discussion and Conclusions: PET imaging is not considered a standard diagnostic tool for PML. However, in selected cases, it may provide valuable information to direct the diagnosis towards PML. Full article

Alzheimer’s disease (AD) is characterized by significant reductions in glucose metabolism, reflecting underlying synaptic dysfunction, correlating with cognitive decline. We aimed to explore the impact of dietary patterns on the change in glucose metabolism. Methods: This longitudinal, prospective study included 132 community-dwelling older adults without a diagnosed dementia history enrolled in the Western Australian Memory Study (WAMS). Participants completed a food frequency questionnaire at baseline and underwent [¹⁸F]-Fluorodeoxyglucose positron emission tomography (FDG-PET) imaging at baseline and at up to two follow-up assessments scheduled approximately 18 months apart, over a maximum follow-up period of 43 months. Principal component analysis yielded two dietary patterns—named Western Diet and Prudent Diet. Linear mixed-effect models evaluated the association between dietary adherence and glucose metabolism, including potential confounders. Analysis was repeated stratified by sex. Results: Adherence to a Western Diet, characterized by high sugars and saturated fats, was associated with faster decline in glucose metabolism in the left fusiform gyrus (β = −0.00062; SE = 0.00025; FDR-adjusted p = 0.043), neocortex (β = −0.00063; SE = 0.00026; FDR-adjusted p = 0.047), left ventrolateral prefrontal (β = −0.00083; SE = 0.00032; FDR-adjusted p = 0.045 and inferior parietal region (β = −0.00344; SE = 0.00129; FDR-adjusted p = 0.033) in females. A Prudent Diet, characterized by a high intake of fruits, vegetables, and whole grains, showed no significant effects. Conclusions: Our study highlights the following: (a) The potential detrimental impact of a Western Diet on brain glucose metabolism, particularly for females, who are at higher risk for AD. The decline was observed in regions essential for cognitive functions, including visual processing and facial recognition, emphasizing the role of diet in brain health. (b) No significant associations were observed between adherence to a Prudent dietary pattern and changes in glucose metabolism. Full article

Background/Objectives: Novel hotspot displacement radiomic features (normalized hotspot-to-centroid distance [NHOC]/normalized hotspot-to-perimeter distance [NHOP]) are robust against image resampling and spatial resolution variations. However, their reproducibility under respiratory motion remains unvalidated. This study aimed to evaluate the reproducibility, reliability, and survival prognostic value of NHOC/NHOP features in thoracic ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) images with and without respiratory motion correction and to determine whether these features maintain stability and predictive performance for overall survival (OS) compared with respiratory-stable reference features. Methods: We analyzed 138 patients (203 lesions) who underwent ¹⁸F-FDG PET/CT with and without data-driven respiratory gating. Reproducibility and reliability were assessed using the coefficient of variation (CoV) and intraclass correlation coefficient (ICC), respectively. OS prediction was evaluated using Cox regression and concordance index (c-index) analyses. Results: Except for NHOCmax and NHOPpeak, which showed ICC values of 0.782 and 0.93, respectively, the novel morphological features generally exhibited poor reproducibility and moderate reliability (CoV > 20% and ICC < 0.75). In contrast, reference features (entropy-based and sphericity) demonstrated excellent robustness. Motion-corrected NHOCmax showed significant OS prediction for both spatially resampled and non-resampled images. No significant differences in c-indices were observed between motion-corrected and non-corrected features. Conclusions: The marked sensitivity of novel hotspot-displacement features to respiratory motion substantially limits their clinical applicability in thoracic disease. To ensure reproducibility and generalizability in future research, prioritizing inherently robust radiomic parameters, such as entropy-based features, is strongly recommended. Full article

Cardiac sarcoidosis (CS) is a critical and frequently underdiagnosed phenotype of sarcoidosis, characterized by non-caseating granulomatous infiltration of the myocardium. This review synthesizes current knowledge regarding the pathogenesis, diagnosis, and management of CS. The disease manifests with a heterogeneous clinical spectrum ranging from asymptomatic conduction abnormalities to life-threatening ventricular arrhythmias and heart failure. Diagnosis remains challenging due to the patchy distribution of granulomas, which limits the sensitivity of endomyocardial biopsy. Consequently, a multimodal diagnostic approach is essential, integrating advanced imaging modalities such as cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) and ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET). These tools not only facilitate detection but also enable the differentiation of active inflammation from chronic fibrosis. Histopathological assessment, supported by specific immunophenotyping and electron microscopy, remains the gold standard for confirming diagnosis and excluding mimics like giant cell myocarditis or infectious granulomatous diseases. Management requires a multidisciplinary strategy combining immunosuppressive therapy, primarily corticosteroids and steroid-sparing agents, with guideline-directed cardiac care, including implantable cardioverter-defibrillators for arrhythmia risk stratification. Emerging biomarkers and artificial intelligence-driven imaging analysis promise to further refine risk stratification and therapeutic monitoring, advancing precision medicine in this complex disorder. Full article

Background and Clinical Significance: Diffuse Large B-Cell Lymphoma (DLBCL) is a morphologically and molecularly heterogeneous lymphoproliferative disorder that originates from a clonal B-cell ancestor. Patients usually present with rapidly enlarging lymph nodes or mass(es) at single or multiple sites. Generally, 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET-CT) is performed post-treatment to evaluate remission status, especially in radiologically residual tumors. Myofibroblastoma (MFB) is a benign mesenchymal tumor of the mammary stroma composed of fibroblasts and myofibroblasts. These entities do not often present concurrently. Case presentation: The patient was an 80-year-old man with a history of stage IV-BS Diffuse Large B-Cell Lymphoma (DLBCL) with a high-risk International Prognostic Index (IPI). The patient underwent treatment with a six-cycle R-CHOP regimen. Immediately after the last cycle, an 18F-Fluorodeoxyglucose (18F-FDG) positron emission tomography with computed tomography (PET-CT) scan revealed a nodular solid lesion with a faintly increased metabolic standardized uptake value (SUVmax) of 3 in the upper outer quadrant of his left breast. A biopsy of the breast lesion was performed, and it revealed a benign mesenchymal tumor, specifically a Myofibroblastoma. The patient has not presented any symptoms or complications since surgery (12 months) and remains in complete remission (CR). Conclusions: Given the potential diagnostic pitfalls and therapeutic implications of residual tumors in the context of DLBCL, a conscientious evaluation by a multidisciplinary team (MDT) is highly recommended. Full article

Background: Plasma cell granuloma is generally considered a pseudotumor formed by reactive, polyclonal plasma cells. Although most cases can show polyclonal gammaglobulin production, quite a minority may exhibit monoclonal gammopathy, which mimics plasma cell neoplasms such as multiple myeloma or plasmacytoma. Because of this overlap, distinguishing reactive monoclonal proliferation from true malignancy is clinically essential. Case report: A 79-year-old man was presented with an anterior chest wall mass that had grown during investigation for fever of unknown origin. ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) revealed a sternal bone mass (SUVmax 9.04), aortic uptake of bifurcation (SUVmax 7.08), and Th7/8 soft tissue mass (SUVmax 5.32). Results from the FDG-PET revealed infectious reactions. A chest wall biopsy revealed high degree proliferation of plasma cells. Hematologists suspected plasmacytoma. The pathologist did not diagnose plasmacytoma; thus, there remains a possibility of reactive granuloma lesion. Lastly, the patient’s vertebral soft tissue mass culture yielded Staphylococcus aureus. The patient was treated with antimicrobials and responded well. Discussion: In the presented case, FDG-PET revealed an aortic mass with an aortic aneurysm, a sternal mass, and a vertebral mass, as multiple lesions. The abscess lesions that initially resembled multiple plasmacytomas were identified as plasma cell granuloma. The final diagnosis required demonstrating biopsy and definitive monoclonality. Light-chain restriction or monoclonal protein should be considered in the clinical context. Ultimately, this case highlights the diagnostic value of FDG-PET and the importance of differentiating reactive plasma cell granuloma from true plasma cell neoplasm to guide appropriate management. In conclusion, a reactive plasma cell granuloma associated with infectious aortitis can exhibit monoclonal gammopathy, mimicking plasma cell neoplasm. Careful pathological and clinical evaluation is essential to avoid misdiagnosis and ensure proper treatment. Full article

The short half-life of positron emission tomography (PET) radioisotopes makes transport time a critical factor in medical logistics. While drones have demonstrated advantages in short-range medical deliveries, the feasibility and benefits of long-distance drone transport remain largely unexplored. In a comparative simulation-based modelling framework, this study explores whether long-range drone transport (117–376 km) can improve delivery performance of fluorodeoxyglucose-18 ([¹⁸F]FDG) PET isotopes compared with two existing ground-only routes (146 km and 348 km) and two combined car–airplane routes (532 km and 546 km). Simulated transport times, radioactive decay losses, and economic implications were estimated using drone speeds of 150, 200, and 250 km/h. Hourly weather data from 2023–2024 were incorporated to model flight feasibility and weather-related no-fly conditions. Time savings were translated into preserved radioactive activity and analyzed together with break-even transport costs. A drone speed of 150 km/h provided limited benefit, whereas speeds of 200–250 km/h preserved activity corresponding to a reduction from the current total use of 118 GBq to 72 and 65 GBq, respectively. Weather constraints reduced feasible winter flights by up to 30%. Estimated break-even drone costs ranged from EUR 3–18/km and increased to EUR 14–20/km when accounting for preserved isotopes, corresponding to annual economic gains of EUR 1.0–1.7 million. These results suggest that long-range drone transport could reduce isotope losses and improve diagnostic capacity, although feasibility depends on drone costs, weather resilience, and integration into clinical logistics systems. Full article

Background/Objectives: 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is used in oncology but has limited specificity due to uptake in infectious and inflammatory conditions. This study evaluated the diagnostic value of 18F-FDG PET/CT in patients with infectious, inflammatory, and malignant lesions and its role in guiding histopathological biopsy decisions in an infectious disease setting. Methods: A retrospective cohort study included 186 adult patients who underwent 18F-FDG PET/CT between 2018 and 2023 for diagnostic evaluation at a tertiary care hospital. Clinical indications were fever of unknown origin (FUO), inflammation of unknown origin (IUO), lymphadenopathy of unknown origin, and suspected solid mass. Diagnostic yield, biopsy decisions, and factors associated with biopsy were analyzed. Results: The diagnostic yield of 18F-FDG PET/CT was 58.6%, with higher in malignant conditions (hematologic malignancy 85.7%, solid organ malignancy 88.9%) and lower in autoimmune/inflammatory diseases (20.8%) and mycobacterial infections. PET/CT showed moderate sensitivity (59.8%) and high specificity (98.7%) for infection detection, improving to 67.8% sensitivity after excluding mycobacterial infections. Biopsy was performed more in patients with lymphadenopathy, higher SUVmax (>7.4), and PET/CT findings not suggestive of infection. Analysis identified lymphadenopathy (aOR = 2.77), PET/CT not suggestive of infection (aOR = 4.73), and SUVmax > 7.4 (aOR = 4.98) as predictors of biopsy. Conclusions: 18F-FDG PET/CT provides moderate diagnostic value across infectious, inflammatory, and malignant diseases and guides biopsies effectively, particularly in patients with lymphadenopathy, elevated SUVmax, and non-infectious findings. Its limited performance in mycobacterial and autoimmune diseases requires cautious interpretation. Overall, 18F-FDG PET/CT supports clinical decisions in complex diagnostic scenarios. Full article

Isolated pelvic nodal metastasis from carcinoma of unknown primary origin (CUP) is rare. Evaluation should prioritize gynecological and anorectal sites based on pelvic lymphatic drainage. Although spontaneous regression of these primary lesions is exceptional, regressed lesions can present as CUP, necessitating diagnostic caution. Here, we report the case of a 40-year-old woman with a solitary, intensely fluorodeoxyglucose F-18 avid left obturator lymph node and a subtle endocervical abnormality on pelvic magnetic resonance imaging. Loop electrosurgical excision revealed a Nabothian cyst only. Excisional nodal biopsy by polymerase chain reaction revealed metastatic squamous cell carcinoma with diffuse block-type p16 and human papillomavirus (HPV) 16. Considering the potential for a primary cervical tumor along the obturator drainage pathway, the patient underwent hysterectomy with pelvic lymph node dissection. No residual invasive carcinoma was found; however, HPV16 was detected in the cervix with a low-grade squamous intraepithelial lesion, supporting a regressed cervical focus. She received adjuvant cisplatin-based chemoradiotherapy and has remained disease-free for 56 months. This case highlights the diagnostic value of integrating lymphatic anatomy with the molecular profile of HPV. Cervical squamous cell carcinoma rarely regresses and presents solely as an isolated nodal disease. Full article

Background/Objectives: Spread through air spaces (STAS) represents an aggressive invasion pattern in lung cancer and is associated with unfavorable oncologic outcomes. As STAS is currently identifiable only on postoperative pathology, reliable preoperative, noninvasive prediction remains a clinical challenge. This study aimed to evaluate the feasibility of predicting STAS using ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT)-derived radiomic and clinicoradiomic models. Methods: In this retrospective study, patients who underwent surgical resection for lung cancer with available preoperative ¹⁸F-FDG PET/CT imaging were analyzed. Radiomic features were extracted from intratumoral and peritumoral regions. Clinical, radiomic-only, and combined clinicoradiomic models were developed using LASSO-based feature selection and multivariable logistic regression. Model performance was evaluated using nested cross-validation, receiver operating characteristic analysis, calibration assessment, and decision curve analysis. Results: Radiomic features reflecting intratumoral metabolic characteristics and peritumoral tissue heterogeneity were significantly associated with STAS. The combined clinicoradiomic model demonstrated superior discriminative performance compared with the clinical and radiomic-only models (mean AUC ≈ 0.75), along with favorable calibration (Brier score = 0.20) and improved clinical net benefit across relevant threshold probabilities. Lower eosinophil count, lower SUVmin_tumor, and lower intratumoral SUV skewness emerged as independent predictors of STAS. Conclusions: Preoperative prediction of STAS in lung cancer is feasible using PET/CT-based radiomic analysis integrating intratumoral, peritumoral, and clinical features. This noninvasive approach provides biologically relevant information beyond conventional anatomical assessment and warrants further validation in prospective, multicenter cohorts. Full article

Background/Objectives: This prospective study aimed to investigate asymptomatic microscopic changes in the myocardium following postoperative radiation therapy (RT) in patients with left breast cancer using multi-medical assessment techniques. Methods: This study included 16 left-sided breast cancer patients who received postoperative RT between January 2021 and December 2022 at our institution. Cardiac examinations were performed before RT and at 1, 12, 24, and 48 weeks after RT. We conducted comparative analyses between pre-RT and various post-RT time points, exploring correlations between changes in hematologic biomarkers, global longitudinal strain (GLS), and myocardial metabolism. Results: Inflammatory biomarkers such as the neutrophil–lymphocyte, platelet–lymphocyte, and lymphocyte–monocyte ratios changed between the pre- and post-RT periods but returned to normal levels after several months. However, troponin T and soluble suppression of tumorigenicity 2 showed sustained changes during the 1-year follow-up period. Among echocardiographic parameters, GLS_LAX showed a significant difference between pre-RT and post-RT assessments. Additionally, irradiated and non-irradiated myocardial metabolic ratios on ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography differed between pre-RT and post-RT and remained altered up to one year after treatment. Conclusions: These findings suggest that subclinical myocardial changes may persist following RT, although the clinical significance of subclinical myocardial changes remains uncertain and warrants further investigation. Full article