Search Results (133)

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

Background and Clinical Significance: Renal cell carcinoma (RCC) is the third most common cancer that metastasizes to the oral and maxillofacial region following breast and lung cancers. Metastatic involvement in the oral cavity is rare and can present as a diagnostic challenge due to non-specific clinical features that mimic other benign or malignant conditions. The limited information available regarding oral metastasis of RCC highlights the importance of recognizing this uncommon presentation. Case Presentation: A 50-year-old female presented with a painful swelling in the buccal and palatal mucosa of the right maxilla that progressively enlarged over several months. Initially, this lesion was diagnosed clinically as a pyogenic granuloma. However, given the lesion’s continued growth and unusual presentation, a biopsy was performed. Histopathological examination confirmed the lesion as metastatic renal clear-cell carcinoma (ccRCC), with immunohistochemical analysis verifying the renal origin. Further diagnostic tests, including a computed tomography (CT) urogram, chest CT, and bone scintigraphy, revealed additional metastases in the left adrenal gland, lungs, and bone. Conclusions: This case is notable because the oral lesion was the first visible sign of RCC, making it a rare presentation of metastatic RCC. This underscores the importance of thorough history taking, detailed clinical evaluations, and considering rare metastatic conditions in the differential diagnosis of oral swellings. Additionally, this case reinforces the significance of routine cancer screenings for early detection of undiagnosed cancer. We also updated a previous literature review of metastatic RCC to the head and neck region, covering cases until 2023. Full article

Charcot Neuro-Osteoarthropathy (CNO) is a debilitating complication predominantly affecting individuals with diabetes and peripheral neuropathy. Radiological assessment plays a central role in the diagnosis, staging, and management of CNO. While plain radiographs remain the cornerstone of initial imaging, advanced modalities such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) have significantly enhanced diagnostic accuracy. Nuclear imaging, including bone scintigraphy, radiolabeled leukocyte scans, and FDG-PET/CT, offers additional diagnostic precision in complex cases, especially when differentiating CNO from infections or evaluating patients with metal implants. This review underscores the importance of a multimodal imaging approach suited to the clinical stage and specific diagnostic challenges of CNO. It highlights the critical need for standardized imaging protocols and integrated diagnostic algorithms that combine radiological, clinical, and laboratory findings. Advances in imaging biomarkers and novel techniques such as diffusion-weighted MRI hold promise for improving early detection and monitoring treatment efficacy. In conclusion, the effective management of CNO in diabetic foot patients requires a multidisciplinary approach that integrates advanced imaging technologies with clinical expertise. Timely and accurate diagnosis not only prevents debilitating complications but also facilitates the development of personalized therapeutic strategies, ultimately improving patient outcomes. Full article

Amyloidosis is an infiltrative disease that may cause cardiomyopathy if the precursor protein that misfolds and forms the amyloid is transthyretic or plasma abnormal light chains. Transthyretin amyloid cardiomyopathy has to be diagnosed timely and accurately since there are specific treatment options to support the patients. Multimodality imaging including electrocardiography, echocardiography with strain imaging and cardiac magnetic resonance applying late gadolinium enhancement imaging, native T1 mapping and extracellular volume, raise a high suspicion of the disease and bone scintigraphy set the diagnosis even without the need of biopsy. However, the morbidity and mortality remain high and the need for risk stratification and assessment of the response to treatment are of paramount importance. Cardiac imaging biomarkers offer a thoughtful insight into the prognosis of these patients at diagnosis and after treatment. The current narrative review aims to enlighten the use of multimodality cardiac imaging in transthyretic amyloid cardiomyopathy throughout the disease pathogenesis and evolution from diagnosis to prognosis and response to treatment in a personalized manner. Full article

Background/Objectives: Cardiac amyloidosis (CA) is associated with amyloid infiltration of the extra-cardiac tissue, which may occur in the early stages of the disease. This study evaluates the diagnostic utility of thoracic fat pad biopsy obtained during a pacemaker or ICD implantation as an alternative to the standard diagnostic criteria for systemic amyloidosis. Methods: This exploratory, retrospective study included 27 patients with suspected or diagnosed CA who underwent pacemaker or defibrillator therapy. Results: Of these, 16 patients were confirmed to have CA (15 with technetium-labeled bisphosphonate bone scintigraphy and 1 with protein electrophoresis and echocardiographic findings) while 11 were confirmed to be CA-negative. The thoracic fat pad biopsy demonstrated a specificity of 100% but a sensitivity of only 31%. Among patients with transthyretin (ATTR)-CA, the sensitivity remained similarly low, at 27%. These results are consistent with prior findings on abdominal fat pad biopsy in ATTR-CA, highlighting the limited diagnostic yield of this method. Conclusions: Thoracic fat pad biopsy cannot be recommended as a standard diagnostic tool for CA, particularly in ATTR-CA, due to its poor sensitivity. However, in AL (amyloid light-chain) amyloidosis, this minimally invasive procedure may aid diagnosis without additional invasive interventions. Full article

Background/Objectives: Hereditary transthyretin-mediated amyloidosis (ATTRv) is a rare disease characterized by the deposition of amyloid in the heart and peripheral nerves, particularly affecting small fibers. This study aims to evaluate autonomic cardiac involvement in ATTRv. Methods: Twelve patients with ATTRv and twelve sex- and age-matched healthy subjects underwent ¹²³I-mIBG scintigraphy to evaluate the early and late heart-to-mediastinum ratio (eH/M and lH/M), ^99mTc-HDP bone scan scintigraphy, and neurophysiological assessments. Data were analyzed in relation to functional cardiac and neurologic scales (NYHA and FAP scales). Results: Patients with ATTRv exhibited significant cardiac denervation, as demonstrated by the reduction in early and late H/M ratios compared to the control group (eH/M: 1.48 ± 0.08 vs. 1.89 ± 0.05, p < 0.001; lH/M: 1.39 ± 0.08 vs. 2.01 ± 0.05, p < 0.001). Values of eH/M and lH/M < 1.6 effectively differentiated patients with ATTRv from the healthy controls. Cardiac denervation correlated with interventricular septal thickness and the Perugini score but was not related to neurophysiological assessments or NYHA and FAP scales. Conclusions: Ultimately, ¹²³I-mIBG scintigraphy is an effective tool for assessing cardiac denervation in patients with ATTRv. Full article

Background: ATTRv and ATTRwt cardiac amyloidosis (CA) are underrecognized causes of heart failure with preserved left ventricular ejection fraction. The diagnosis of CA remains challenging due to low diagnostic suspicion and clinical overlap with more common diseases. The aim of this study was to use [^99mTc]-PYP SPECT-CT to perform a volumetric evaluation of bone scintigraphy to overcome the limitations of current practices. Methods: A monocentric prospective study was conducted to evaluate a lot of 22 patients with a mean age of 52.86 ± 13.80 years, diagnosed with hereditary cardiac transthyretin amyloidosis (ATTR). Results: Correlations between the quantitative SPECT-CT, clinical data, and morphological parameters were performed, demonstrating moderate to strong correlation of SUVmaxMyocardium/SUVmaxBone to both ECG low voltage and EchoGLS, SUVmaxMyocardium/SUVmaxLiver to myocardial gadolinium kinetics with T1 mapping MRI, diastolic disfunction, sensory–motor polyneuropathy, and EchoGLS, SUVmaxMyocardium/SUVmeanBone with diastolic disfunction and sensory–motor polyneuropathy, as well as SUVmaxMyocardium/SUVmaxSoft tissue to S II, respectively. Conclusions: The moderate to strong correlations among advanced quantitative SPECT-CT metrics and clinical and paraclinical data create the premises to use these parameters for early diagnosis of cardiac ATTR. Further multicentric studies in a larger patient population are needed to validate the newly identified quantitative SPECT-CT parameters. Full article

The prevalence of cardiac amyloidosis (CA), especially as a cause of heart failure, has significantly increased in recent years. Early detection and accurate assessment of the disease burden are crucial for initiating timely treatment and ensuring precise prognosis. CA primarily results from the infiltration of the myocardium by either immunoglobulin light chain fibrils (AL) or transthyretin fibrils (ATTR), leading to restrictive cardiomyopathy and eventual death if untreated. Over the past decade, advancements in diagnostic imaging and heightened clinical awareness have revealed a substantial presence of CA, particularly ATTR, among the elderly. These diagnostic improvements encompass echocardiography, cardiac computerized tomography scans, magnetic resonance imaging, and radionuclide scintigraphy with bone-avid tracers. Concurrently, significant progress has been made in therapeutic options, with new disease-modifying treatments now available that can dramatically alter the disease trajectory and improve survival rates when administered early. However, despite these advancements, there remains an urgent need for the early and accurate detection of CA to ensure that patients can fully benefit from these emerging therapies. Full article

The image quality index for whole-body bone scintigraphy has traditionally relied on the total count (Total-C) with a threshold of ≥1.5 million counts (MC). However, Total-C measurements are susceptible to variability owing to urine retention. This study aimed to develop a skeletal count (Skel-C)-based index, focusing exclusively on bone regions, to improve the accuracy of image analysis in bone scintigraphy. To determine the optimal Skel-C-based threshold, Skel-C thresholds were set at 0.9, 1.0, 1.1, and 1.2 MC, and Total-C thresholds were set at 1.75, 2.0, and 2.25 MC. Patients were then categorized based on whether their values were above or below these thresholds. The group including all cases was defined as the Total-C 1.5 high group. Sensitivity and specificity were calculated for each group, and receiver operating characteristic analyses and statistical evaluations were conducted. The specificity of the bone scintigraphy image analysis program in the Skel-C < 0.9 MC group was significantly lower than that in the Skel-C ≥ 0.9 MC and Total-C 1.5 high groups. The decrease in specificity was evident only with Skel-C and was not identified based on Total-C levels. These findings highlight the importance of achieving Skel-C ≥ 0.9 MC and suggest that Total-C alone is insufficient for reliable image assessment. Full article

Various imaging methods assist in diagnosing periprosthetic joint infection (PJI). These include radiological techniques such as radiography, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US); as well as advanced nuclear medicine techniques including bone scintigraphy (BS), anti-granulocyte antibody imaging (AGS), leukocyte scintigraphy (LS), and fluorodeoxyglucose positron emission tomography (FDG-PET and FDG-PET/CT). Each imaging technique and radiopharmaceutical has been extensively studied, with unique diagnostic accuracy, limitations, and benefits for PJI diagnosis. This review aims to detail and describe the most commonly used imaging techniques and radiopharmaceuticals for evaluating PJI, focusing particularly on knee and hip arthroplasties. Full article