Search Results (142)

Brown tumors (BTs) are rare osteolytic lesions that typically occur in association with primary or secondary hyperparathyroidism (PHP and SHP). Excessive secretion of parathyroid hormone induces increased bone resorption, resulting in lesions characterized by fibrosis, vascularization, and hemosiderin deposition. The most common sites include the jaws, ribs, pelvis, and long bones. Clinical manifestations may involve pain, swelling, or pathological fractures. We present the case of a mandibular BT in a 48-year-old female with chronic renal failure and secondary hyperparathyroidism. The patient exhibited progressive mandibular swelling with radiological features resembling an aggressive odontogenic or malignant lesion. Laboratory analysis confirmed markedly elevated parathyroid hormone levels, while scintigraphy demonstrated increased focal uptake in the mandible and ribs. Histopathological evaluation revealed multinucleated giant cells within a fibrous stroma, consistent with BT. Despite initiation of systemic endocrine therapy, the lesion continued to enlarge, necessitating complete surgical excision of the mandibular mass. This case underscores the diagnostic dilemmas of mandibular BT, which may closely mimic aggressive jaw pathologies. Importantly, while many BTs regress after systemic management of hyperparathyroidism, this case illustrates that surgical excision may be unavoidable in patients with unstable systemic status or progressive local disease. Comprehensive clinical, radiological, laboratory, and histopathological evaluation remains essential to ensure timely diagnosis and appropriate treatment. Full article

Primary bone tumors encompass a heterogeneous spectrum ranging from benign entities to highly aggressive sarcomas. This review aims to summarize the current role and future perspectives of nuclear medicine in the diagnosis, staging, and management of primary bone tumors. Accurate diagnosis and staging are critical yet challenging due to histologic heterogeneity and overlapping imaging features. While radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) remain essential, nuclear medicine provides a complementary functional perspective by assessing bone turnover, vascularity, and glucose metabolism. Bone scintigraphy is highly sensitive for skeletal lesions and useful for detecting skip lesions or multifocal disease, although its specificity is limited. Hybrid single-photon emission computed tomography (SPECT)/CT enhances diagnostic confidence through precise anatomic localization and quantitation. [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) positron emission tomography (PET)/CT, by directly visualizing tumor metabolism, has become a cornerstone in osteosarcoma and Ewing sarcoma management, demonstrating superiority over bone scintigraphy for detecting skeletal metastases. In chondrosarcoma, [¹⁸F]FDG uptake correlates with histologic grade, although overlap with benign cartilage tumors complicates interpretation. Future directions include the integration of quantitative SPECT, artificial intelligence, and novel tracers such as [¹⁸F]sodium fluoride and [⁶⁸Ga]Ga-fibroblast activation protein inhibitor (FAPI). Collectively, nuclear medicine imaging is becoming a key element in musculoskeletal oncology, offering unique biological insights that complement anatomic imaging and contribute to improved patient management. Full article

Background: Wild-type transthyretin cardiac amyloidosis (ATTRwt-CM) is a frequent but underdiagnosed cause of heart failure with preserved ejection fraction (HFpEF) and left ventricular hypertrophy (LVH). Early identification is essential given the availability of disease-modifying therapies. The T-Amylo and Davies scores are non-invasive tools for estimating ATTR CM probability, but their comparative performance in the same real-world population is not well defined. Objectives: To compare the diagnostic accuracy of T-Amylo and Davies scores in consecutive patients referred for suspected cardiac amyloidosis. Methods: We retrospectively analyzed 81 patients (mean age 76.8 ± 8.3 years, 74% male) who underwent a standardized work-up: ECG, echocardiography with strain, NT-proBNP and troponin, bone scintigraphy, and immunofixation. ATTR CM was diagnosed according to established non-biopsy criteria. Both scores were calculated retrospectively, and sensitivity, specificity, predictive values, accuracy, and agreement were assessed. Results: ATTR CM was confirmed in 28 patients (34.5%). T-Amylo showed higher sensitivity (91.2% vs. 73.5%) and NPV (89.7% vs. 79.1%), while Davies had greater specificity (85.0% vs. 65.0%) and PPV (80.5% vs. 70.8%). Overall accuracy was comparable (T-Amylo 77.0% vs. Davies 79.7%). Agreement between scores was moderate (κ = 0.59). Conclusions: T-Amylo is best suited as a screening tool for suspected ATTR CM, while Davies offers confirmatory value in high-probability cases. Combining these tools in a sequential strategy may optimize diagnostic efficiency, reduce unnecessary testing, and expedite initiation of disease-modifying therapy. Full article

Background: Hypophosphatemia is a frequently underestimated metabolic disorder, yet it can be one of the first biochemical findings in primary hyperparathyroidism (PHPT). Current diagnostic and surgical criteria for PHPT do not include serum phosphate, despite its potential value as an early marker. Methods: We report the case of a 79-year-old woman with type 2 diabetes mellitus, hypertension and osteoarthritis, followed since 2015 for persistent hypophosphatemia (0.8 mg/dL) and stress fractures. Results: Initial calcium and vitamin D levels were normal, but PTH was elevated. Bone scintigraphy revealed multiple stress fractures, while ultrasound and sestamibi scan were inconclusive. Despite cholecalciferol and calcitriol supplementation, hypophosphatemia persisted. From 2023, progressive hypercalcemia developed (10.9 mg/dL), with sustained hypophosphatemia (1.7 mg/dL), persistently high PTH (121 pg/mL) and markedly elevated FGF-23 (1694 kRU/L). Renal phosphate wasting was demonstrated, with reduced tubular reabsorption. An 18F-fluorocholine PET-CT performed in 2024 identified two right parathyroid adenomas, establishing the diagnosis of PHPT. The patient was referred for parathyroidectomy. Conclusions: Hypophosphatemia may serve as a complementary biomarker in the diagnostic and therapeutic approach to PHPT, but only after other potential causes of low phosphate levels have been excluded, as illustrated in this case. Its consideration could facilitate the early identification of PHPT and improve clinical decision-making, particularly in patients who do not meet classical surgical indications. Full article

Background: Cardiac amyloidosis (CA) is an increasingly recognized but historically underdiagnosed cause of restrictive cardiomyopathy and heart failure with preserved ejection fraction (HFpEF). It results from the extracellular deposition of misfolded protein fibrils, most commonly transthyretin (ATTR) or immunoglobulin light chains (AL), leading to progressive myocardial dysfunction and multi-organ involvement. Objective: This review provides a comprehensive, cardiology-centered overview of cardiac amyloidosis, with an emphasis on early recognition, diagnostic strategies, subtype differentiation, and the evolving therapies. Content: We summarize the epidemiology, pathophysiology, and clinical manifestations of both ATTR and AL subtypes. Key diagnostic tools, including echocardiography, cardiac magnetic resonance imaging, bone scintigraphy, monoclonal protein screening, and endomyocardial biopsy, are reviewed in the context of a stepwise diagnostic approach. Special attention is given to clinical presentation, electrocardiographic and imaging “red flags,” and to differentiating CA from mimickers such as hypertrophic cardiomyopathy, hypertension-induced left ventricular hypertrophy, and aortic stenosis. Staging systems are detailed, highlighting the prognostic role of cardiac biomarkers. Therapeutic strategies are explored, including subtype-specific regimens (e.g., daratumumab-based therapy for AL; tafamidis and gene silencers for ATTR), the judicious use of conventional heart failure medications, and emerging therapies such as CRISPR-based gene editing. Conclusions: Timely recognition and accurate diagnosis of cardiac amyloidosis are critical to improving outcomes. As diagnostic tools and disease-modifying therapies evolve rapidly, cardiologists must remain at the forefront of multidisciplinary care. A structured biomarker- and imaging-guided approach can enhance diagnostic yield, inform prognosis, and optimize patient-specific management. Full article

Background and clinical significance: Paget’s disease of bone involves anomalies of the bone metabolism; however, the presence of tumor-derivate abnormal parathyroid hormone (PTH) levels does not represent one of these disturbances. To our best knowledge, the association with normocalcemic variant of primary hyperparathyroidism has been limitedly reported, and here we introduce such an unusual overlap in a male suffering from osteoporosis. Case presentation: A 71-year-old, non-smoker man was hospitalized for mild, nonspecific dysphagia, asthenia, decreased appetite, and mild weight loss during the latest 2 months. His medical history included cardiovascular conditions and an abnormal PTH level with normal serum calcium under daily cholecalciferol supplements (tested twice during latest 12 months). The lab findings pointed out a normocalcemic primary hyperparathyroidism (PTH of maximum 163 pg/mL, and total calcium of 9.3 mg/dL) caused by a right parathyroid tumor of 1.2 cm, as confirmed by computed tomography (CT). Additionally, CT showed a left humerus lesion suggestive of Paget’s disease of bone, a confirmation that also came from the whole-body bone scintigraphy. The subject presented increased P1NP and osteocalcin, CrossLaps as bone formation, and resorption markers, with normal total alkaline phosphatase. CT scan also detected multiple vertebral fractures and small kidney stones. Zoledronate i.v. (3 mg, adjusted for creatinine clearance) was administered, taking into consideration all three bone ailments (Paget’s disease, high PTH/calcium, and osteoporosis) with further follow-up. Conclusions: This case highlights the following technical notes based on a real-life setting: 1. Despite the mentioned bone diseases, no bone pain was present. Loss of appetite, dysphagia, and asthenia may be a consequence of mineral metabolism disturbances. 2. The panel of blood bone turnover markers levels might be related to both hyperparathyroidism and Paget’s disease; notably, rare cases of Paget’s disease with normal alkaline phosphatase were prior reported. 3. A meticulous differentiation between secondary and primary hyperparathyroidism is required. In this instance, lack of hypocalcaemia and vitamin D deficiency was suggestive of the diagnosis of a primary variant. 4. Kidney stones, osteoporosis, and osteoporotic fractures may be correlated with both conditions, as well, while a dual perspective of the therapy, since the patient was not a parathyroid surgery candidate, included a first dose of zoledronate with consecutive long-term follow-up. To our best knowledge, the co-presence of normocalcemic variant of primary hyperparathyroidism represents an exceptional finding in a patient synchronously diagnosed with Pagetic lesions and osteoporosis complicated with vertebral fractures. Full article

Background: Spinal metastasis is the third most common site for metastatic localization, following the lung and liver. Manual detection through imaging modalities such as CT, MRI, PET, and bone scintigraphy can be costly and inefficient. Preliminary artificial intelligence (AI) techniques and computer-aided detection (CAD) systems have attempted to improve lesion detection, segmentation, and treatment response in oncological imaging. The objective of this review is to evaluate the current applications of AI across multimodal imaging techniques in the diagnosis of spinal metastasis. Methods: Databases like PubMed, Scopus, Web of Science Advance, Cochrane, and Embase (Ovid) were searched using specific keywords like ‘spine metastases’, ‘artificial intelligence’, ‘machine learning’, ‘deep learning’, and ‘diagnosis’. The screening of studies adhered to the PRISMA guidelines. Relevant variables were extracted from each of the included articles such as the primary tumor type, cohort size, and prediction model performance metrics: area under the receiver operating curve (AUC), accuracy, sensitivity, specificity, internal validation and external validation. A random-effects meta-analysis model was used to account for variability between the studies. Quality assessment was performed using the PROBAST tool. Results: This review included 39 studies published between 2007 and 2024, encompassing a total of 6267 patients. The three most common primary tumors were lung cancer (56.4%), breast cancer (51.3%), and prostate cancer (41.0%). Four studies reported AUC values for model training, 16 for internal validation, and five for external validation. The weighted average AUCs were 0.971 (training), 0.947 (internal validation), and 0.819 (external validation). The risk of bias was the highest in the analysis domain, with 22 studies (56%) rated high risk, primarily due to inadequate external validation and overfitting. Conclusions: AI-based approaches show promise for enhancing the detection, segmentation, and characterization of spinal metastatic lesions across multiple imaging modalities. Future research should focus on developing more generalizable models through larger and more diverse training datasets, integrating clinical and imaging data, and conducting prospective validation studies to demonstrate meaningful clinical impact. Full article

The jaw bones can manifest various cysts and tumors of different origins and etiologies. Any bone lesions lacking any potential odontogenic origin might require more accurate diagnostics, adequate investigation, and careful patient anamnesis. In cases of sharply demarcated radiolucency or mixed radiolucent–radiopaque radiological appearance lesions, they can sometimes extend between the displaced tooth roots or cause their resorption. The scope of cortical bone in radiographic studies might have a different status, and lesions can spread outside of the bone. If no odontogenic feature is present, an additional blood examination for bone markers and calcium–phosphate markers is useful to establish any endocrine-related pathologies. In the primary hyperparathyroidism (PHP), bone blood markers and bone scintigraphy are very useful to establish the possible occurrence of brown tumor. On the other hand, in central giant cell granuloma (CGCG), only a direct tumor lesion biopsy might confirm the diagnosis, where in microscopic evaluation, mostly fibroblasts and secondary cells have multinucleated giant cells along with some accessory cells like macrophages, dendrocytes, and other endothelial cells. Because both lesions can have similar clinical and radiological appearances and unclear borders, with different shapes, sizes, and symptoms, it is quite important to compare both clinical and radiological patient characteristics. The authors aim to present how radiological studies alone can easily lead to lesion misdiagnosis. They also aim to emphasize how local treatment methods without advanced microsurgical reconstruction can, in some cases, improve patient outcomes. Full article

Background/Objectives: In patients with metastatic castration-resistant prostate cancer (mCRPC) and osseous metastases only, ²²³Radium therapy represents a valuable therapeutic option. Bone scintigraphy (BS) is typically performed to assess metastasis load, with the BS-derived automated bone scan index (aBSI) used for response assessment. This study aimed to evaluate the prognostic value of aBSI in patients receiving three or six cycles of ²²³Ra therapy. Methods: We included patients that were diagnosed with extensive osseous tumor load on BS, had no visceral or nodal metastases, had undergone ²²³Ra therapy. The aBSI prior to and following three or six cycles of therapy, total tumor volume (TTV), SUV_max, and overall survival were analyzed. Results: This study included 49 mCRPC patients (mean age: 70 ± 9 years) with 42 (85.7%) receiving six and 7 (14.3%) receiving three cycles. After three cycles, the mean aBSI (p = 0.369), TTV (p = 0.902), and SUV_max (p = 0.149) remained unchanged. After six cycles, the mean aBSI (p = 0.247) and TTV (p = 0.784) were unchanged, while SUV_max decreased significantly (p = 0.001). The aBSI did not significantly correlate with the mean aBSI (six cycles: χ² = 1.823, p = 0.177; three cycles: χ² = 0.308, p = 0.579). Conclusions: Although quantitative changes in TTV and aBSI did not significantly correlate with each other, their respective absolute values consistently indicated stable disease burden under therapy. This highlights its potential as a useful tool for monitoring disease burden while indicating that aBSI alone is insufficient for predicting overall survival. Full article

Objective: This study proposes a novel deep learning approach for enhancing low-dose bone scintigraphy images using an Enhanced Convolutional Autoencoder (ECAE), aiming to reduce patient radiation exposure while preserving diagnostic quality, as assessed by both expert-based quantitative image metrics and qualitative evaluation. Methods: A supervised learning framework was developed using real-world paired low- and full-dose images from 105 patients. Data were acquired using standard clinical gamma cameras at the Nuclear Medicine Department of the University General Hospital of Alexandroupolis. The ECAE architecture integrates multiscale feature extraction, channel attention mechanisms, and efficient residual blocks to reconstruct high-quality images from low-dose inputs. The model was trained and validated using quantitative metrics—Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index (SSIM)—alongside qualitative assessments by nuclear medicine experts. Results: The model achieved significant improvements in both PSNR and SSIM across all tested dose levels, particularly between 30% and 70% of the full dose. Expert evaluation confirmed enhanced visibility of anatomical structures, noise reduction, and preservation of diagnostic detail in denoised images. In blinded evaluations, denoised images were preferred over the original full-dose scans in 66% of all cases, and in 61% of cases within the 30–70% dose range. Conclusion: The proposed ECAE model effectively reconstructs high-quality bone scintigraphy images from substantially reduced-dose acquisitions. This approach supports dose reduction in nuclear medicine imaging while maintaining—or even enhancing—diagnostic confidence, offering practical benefits in patient safety, workflow efficiency, and environmental impact. Full article

Background/Objectives: In the surgical treatment of benign bone tumors, bone substitutes are widely used. However, each of them has its advantages and disadvantages. We decided to study the novel bioactive and osseoconductive HAP/β–glucan bone substitute. Methods: We qualified eight patients with enchondroma of the lower limbs for this study, who underwent marginal resection of the lesion with the use of a bone substitute—FlexiOss^®. During the 12-month follow-up, a series of X-rays and bone scintigraphy were performed. Bone remodeling was assessed using the modified Neer scale (MNS), while functional results were assessed using the MSTS scale. Results: Very good functional results were noted in all patients—MSTS = 27–30. In the MNS, Score I was recorded in six cases, and Score II was recorded in two cases. Among the complications in the two patients, a clear serous discharge from the wound was observed. Conclusions: The use of the new HAP/β–glucan composite in the treatment of enchondroma initially shows good treatment results. Full article

Background: Bisphosphonate scintigraphy (BS) is a recognized tool for diagnosing amyloid transthyretin cardiomyopathy (ATTR-CA). However, its sensitivity for rare transthyretin (TTR) variants, like Glu54Gln, remains underexplored. Methods: This was a retrospective descriptive study including all known patients with the Glu54Gln variant diagnosed between 2017 and 2023 in Romania, aiming to evaluate the diagnostic performance of BS in Glu54Gln ATTR–CA. Results: All symptomatic patients (n = 22) with histologically confirmed ATTR-CA had positive BS results (100% sensitivity). No false negatives were observed in asymptomatic carriers (n = 4). The Perugini visual score correlated with disease severity, with grade 3 scores associated with advanced cardiac involvement. We proposed a new parameter, heart-to-liver-uptake (H/L) ratio, which proved a strong positive correlation with both the heart-to-contralateral-uptake (H/CL) ratio (R² = 0.768, p < 0.001) and interventricular septum thickness (R² = 0.584, p < 0.001) and a weak correlation with the global longitudinal strain (R² = 0.212, p = 0.023). Conclusions: BS demonstrates high diagnostic accuracy for Glu54GlnATTR-CA, underscoring its utility in early diagnosis and clinical management. The H/L ratio presents a novel approach to semiquantitative analysis of bisphosphonate uptake in cardiac amyloidosis, potentially addressing key limitations of the traditional H/CL ratio. Full article

Background/Objectives: A 43-year-old male presented with neurological symptoms and asymptomatic cardiac dysfunction, left ventricular hypertrophy, and impaired global longitudinal strain with apical sparing, associated with elevated NT-proBNP. Methods: Multimodality imaging (bone scintigraphy and cardiac magnetic resonance) revealed cardiac amyloid deposition. Genetic testing confirmed variant transthyretin amyloidosis (ATTR) with mixed phenotype. Results: Treatment with tafamidis 20 mg for stage I polyneuropathy, available at that moment, was initiated with good neurological outcome. Three years later, cardiac function deteriorated, following a moderate COVID-19 infection, with heart failure symptoms and reduced ventricular and atrial functions. For progressive ATTR cardiomyopathy, we intensified therapy to tafamidis free acid 61 mg, associated with SGLT2 inhibitor, spironolactone, and furosemide with subsequent improvements of symptoms and stabilization of imaging findings. Conclusions: This case emphasizes the importance of multimodal imaging in early detection, monitoring, and guiding individualized management in ATTR cardiomyopathy. Full article

Background/Objectives: Transthyretin cardiac amyloidosis (ATTR-CA) is an infiltrative cardiomyopathy caused by transthyretin (TTR) amyloid deposition in the myocardium, increasingly recognized in patients with aortic stenosis (AS). This study aims to investigate the diagnostic challenges and therapeutic strategies for patients with both conditions, focusing on shared pathophysiological mechanisms and key diagnostic indicators. Methods: A multimodal diagnostic approach was applied, utilizing cardiac magnetic resonance (CMR) and bone scintigraphy with technetium-99m-labeled tracers to assess AS patients with suspected ATTR-CA. Clinical signs, such as disproportionate heart failure symptoms, conduction abnormalities, and low-flow, low-gradient AS, were evaluated. Electrocardiographic findings, including low-voltage QRS complexes and pseudo-infarction patterns, were also assessed. Treatment options, including transcatheter aortic valve replacement (TAVR) and emerging pharmacotherapies for ATTR-CA, were analyzed. Results: The study found that ATTR-CA is increasingly prevalent in AS patients, with shared mechanisms like oxidative stress and amyloid-induced tissue remodeling. Key diagnostic signs include disproportionate heart failure symptoms, conduction abnormalities, and specific electrocardiographic patterns. TAVR was effective in both isolated AS and AS with ATTR-CA, although patients with both conditions had a higher risk of heart failure hospitalization and persistent symptoms. Emerging pharmacotherapies, such as TTR stabilizers and gene-silencing agents, showed promise in slowing disease progression. Conclusions: A multimodal diagnostic approach is essential for the early detection of ATTR-CA in AS patients. Combining TAVR with emerging pharmacotherapies may improve long-term outcomes for this high-risk group, enhancing patient care in those with both conditions. Full article

Unilateral condylar hyperplasia (UCH) is one of the causes of facial asymmetry, and it is characterized by increased growth in one of the mandibular condyles. In UCH, it is important to determine whether the metabolic activity of the hyperplastic condyle is still active. Fractal dimension (FD) analysis could be a non-invasive method to identify active metabolic activity. The aim of this study is to compare the FD of the hyperplastic condyle with the contralateral one in patients with facial asymmetry and positive bone scintigraphy and to compare the FD of the right and left condyles in symmetrical patients. A cross-sectional retrospective study of fifteen patients with facial asymmetry and positive bone scintigraphy and fifteen symmetrical patients was conducted. Clinical data and scintigraphy results were collected from medical records, and CBCT scans were used for the application of FD by pre-processing the images according to White and Rudolph and using ImageJ^® (1.54p) software and the box-counting method. Wilcoxon’s t test was used to analyze the differences in FD between the hyperplastic and contralateral condyles in patients with UCH and between the right and left condyles in symmetrical patients. A p-value of <0.05 was considered statistically significant. The FD of the hyperplastic condyles was significantly higher than the contralateral one in the axial and coronal plane (p = 0.001). The analysis of FD of the mandibular condyle can be a useful non-invasive method to identify active UCH in patients with facial asymmetry. Full article