Advancements and challenges in cardiac amyloidosis imaging: A comprehensive review of novel techniques and clinical applications.

Cardiac amyloidosis, characterized by amyloid fibril deposition in the myocardium, leads to restrictive cardiomyopathy and heart failure. This review explores recent advancements in imaging techniques for diagnosing and managing cardiac amyloidosis, highlighting their clinical applications, strengths, and limitations. Echocardiography remains a primary, non-invasive imaging modality but lacks specificity. Cardiac MRI (CMR), with Late Gadolinium Enhancement (LGE) and T1 mapping, offers superior tissue characterization, though at higher costs and limited availability. Scintigraphy with Tc-99m-PYP reliably diagnoses transthyretin (TTR) amyloidosis but is less effective for light chain (AL) amyloidosis, necessitating complementary diagnostics. Amyloid-specific PET tracers, such as florbetapir and flutemetamol, provide precise imaging and quantitative assessment for both TTR and AL amyloidosis. Challenges include differentiating between TTR and AL amyloidosis, early disease detection, and standardizing imaging protocols. Future research should focus on developing novel tracers, integrating multimodality imaging, and leveraging AI to enhance diagnostic accuracy and personalized treatment. Advancements in imaging have improved cardiac amyloidosis management. A multimodal approach, incorporating echocardiography, CMR, scintigraphy, and PET tracers, offers comprehensive assessment. Continued innovation in tracers and AI applications promises further enhancements in diagnosis, early detection, and patient outcomes.

Langerhans Cell Hyperplasia Mimicking Langerhans Cell Histiocytosis: A Rare Complication of COVID-19 Vaccination.

Langerhans cell histiocytosis (LCH) is a rare disorder characterized by the abnormal proliferation of Langerhans cells, a type of immune cell that is normally present in the skin and various other tissues. LCH can affect people of any age but is most commonly diagnosed in children. We report a case of a patient with LCH who developed ipsilateral axillary lymphadenopathology post-COVID-19 vaccination. Lymph node biopsy showed diffuse Langerhans cell hyperplasia which mimicked LCH. Clinically and radiologically, it looked to be a reactive lymph node. The patient was kept on follow up only and after 1 year of follow up the size of lymph nodes regressed confirming to be reactive in nature rather than neoplastic. To the best of our knowledge, this is the second case of Langerhans cell hyperplasia post-COVID-19 vaccination being reported in the literature.

Optimization of BMI-Based Images for Overweight and Obese Patients - Implications on Image Quality, Quantification, and Radiation Dose in Whole Body 18F-FDG PET/CT Imaging.

Purpose: In PET/CT imaging, the activity of the 18F-FDG activity is injected either based on patient body weight (BW) or body mass index (BMI). The purpose of this study was to optimise BMI-based whole body 18F-FDG PET images obtained from overweight and obese patients and assess their image quality, quantitative value and radiation dose in comparison to BW-based images. Methods: The NEMA-IEC-body phantom was scanned using the mCT 128-slice scanner. The spheres and background were filed with F-18 activity. Spheres-to-background ratio was 4:1. Data was reconstructed using the OSEM-TOF-PSF routine reconstruction. The optimization was performed by varying number of iterations and subsets, filter's size and type, and matrix size. The optimized reconstruction was applied to 17 patients' datasets. The optimized BMI-, routine BMI- and the BW-based images were compared visually and using contrast-to-noise ratio (CNR) and standardized uptake values (SUV) measurements. Results: The visual assessment of the optimized phantom images showed better image quality and contrast-recovery-coefficients (CRCs) values compared to the routine reconstruction. Using patient data, the optimized BMI-based images provided better image quality compared to BW-based images in 87.5% of the overweight cases and 66.7% for obese cases. The optimized BMI-based images resulted in more than 50% reduction of radiation dose. No significant differences were found between the three series of images in SUV measurements. Conclusion: The optimized BMI-based approach using 1 iteration, 21 subsets, and 3 mm Hamming filter improves image quality, reduces radiation dose, and provides, at least, similar quantification compared to the BW-based approach for overweight and obese patients.

Durable Response to Pazopanib in a Patient with Fumarate Hydratase-Mutant Tubulocystic Renal Cell Carcinoma.

Tubulocystic carcinoma of the kidney (TC-RCC) is a rare renal tumor and has been recently included as a distinct entity in WHO classification of renal neoplasms. We report the case of a patient with metastatic tubulocystic RCC whose disease progressed through standard of care treatment for nonclear RCC. However, genetic analysis revealed a germline pathogenic variant of fumarate hydratase (FH) gene, and the patient had a sustained and durable response to pazopanib.

Cystic biliary atresia in a neonate with antenatally detected abdominal cyst.

Cystic biliary atresia (BA) is a rare but an important type of BA. An antenatally detected cystic lesion at the porta hepatis raises the suspicion of cystic BA. It is very important to differentiate this from choledochal cyst in infants with cholestasis and cystic lesions. This case report outlines the clinical presentation and radiological findings of an infant who had an antenatally detected intra-abdominal cystic mass, thought to be a choledochal cyst.