Modern tools in cardiac imaging to assess myocardial inflammation and infection

Development of Novel 99mTc-Labeled Hydrazinoicotinamide-Modified Ubiquicidin 29-41 Complexes with Improved Target-to-Nontarget Ratios for Bacterial Infection Imaging

To develop novel 99mTc-labeled ubiquicidin 29-41 derivatives for bacterial infection SPECT imaging aiming at achieving a high target-to-nontarget ratio and lower nontarget organ uptake, a novel 6-hydrazinoicotinamide (HYNIC) ubiquicidin 29-41 derivative (HYNIC-UBI 29-41) was designed and synthesized. It was then radiolabeled with ternary ligands, including TPPTS, PDA, 2,6-PDA, NIC, ISONIC, PSA, 4-PSA, and PES, to obtain eight 99mTc-labeled HYNIC-UBI 29-41 complexes. All the complexes demonstrated hydrophilicity, exhibited good in vitro stability, and specifically bound Staphylococcus aureus in vitro. Biodistribution studies in mice with bacterial infection demonstrated that [99mTc]Tc-tricine/TPPTS-HYNIC-UBI 29-41 resulted in increased abscess-to-muscle and abscess-to-blood ratios as well as decreased nontarget organ uptake. Furthermore, it was able to distinguish between bacterial infection and sterile inflammation. Single-photon emission computed tomography (SPECT) imaging studies in mice with bacterial infection revealed visible accumulation at the site of infection, indicating that [99mTc]Tc-tricine/TPPTS-HYNIC-UBI 29-41 is a potential radiotracer for imaging bacterial infection.

A Review of Photon-Counting Computed Tomography (PCCT) in the Diagnosis of Cardiovascular Diseases

Photon-counting computed tomography (PCCT) is an innovative mechanism used for imaging and provides higher spatial resolution and contrast sensitivity in comparison with the orthodox energy-integrating detectors (EIDs). Unlike EID-based CT systems, which indirectly convert X-ray photons to electrical signals, PCCT directly counts and quantifies each photon's energy, enhancing image quality and material separation. With all of these features, PCCT is especially useful for cardiovascular imaging, where it is essential to precisely observe cardiac tissues, vascular structures, and coronary arteries. Around the globe, cardiovascular diseases (CVDs) continue to be the primary cause of morbidity and death, and early, precise diagnosis is essential for effective management. This review examines the role of PCCT in diagnosing CVDs, highlighting its enhanced capabilities in improving the precision in diagnosis as well as patient outcomes compared to conventional CT methods. While current evidence supports PCCT's advantages, further research is necessary to validate these findings and facilitate its broader clinical adoption.

Diagnostic and management strategies in cardiac sarcoidosis

Cardiac sarcoidosis (CS) is increasingly recognized in the context of with otherwise unexplained electrical or structural heart disease due to improved diagnostic tools and awareness. Therefore, clinicians require improved understanding of this rare but fatal disease to care for these patients. The cardinal features of CS, include arrhythmias, atrio-ventricular conduction delay and cardiomyopathy. In addition to treatments tailored to these cardiac manifestations, immunosuppression plays a key role in active CS management. However, clinical trial and consensus guidelines are limited to guide the use of immunosuppression in these patients. This review aims to provide a practical overview to the current diagnostic challenges, treatment approach, and future opportunities in the field of CS.

Manifestations of Prosthetic Valve Endocarditis: Lessons From Multimodality Imaging and Pathological Correlation

Heart valve replacement has steadily increased over the past decades due to improved surgical mortality, an aging population, and the increasing use of transcatheter valve technology. With these developments, prosthetic valve complications, including prosthetic valve endocarditis, are increasingly encountered. In this review, we aim to characterize the manifestations of prosthetic valve endocarditis using representative case studies from our institution to highlight the advances and contributions of modern multimodality imaging techniques.