PET/CT in a patient with cardiac paraganglioma

Advanced imaging of cardiac Paraganglioma: A systematic review

Background and aims

Cardiac ParaGangliomas (PGLs) are rare extra-adrenal tumours that arise from chromaffin cells of the sympathetic ganglia. PGL are often diagnosed incidentally, with no symptoms or symptoms related to cardiovascular dysfunction.

Methods

Cardiac Computed Tomography (CCT) and Cardiac Magnetic Resonance (CMR) can detect the correct morphology and position of the lesion and provide proper tissue characterization.Nuclear medicine imaging, with Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) with specific radiotracers, can evaluate the functionality of the PGL and to distinguish a secreting from a non-secreting tumour.

Results

In association with biochemical parameters, a multimodal imaging approach, not yet standardized, can be useful both in the diagnosis, in the monitoring and in the treatment planning.

Conclusions

In this systematic review, we aim to investigate the role of diagnostic imaging, in particular CCT, CMR, PET and SPECT in diagnosis, characterization and monitoring of cardiac PGLs.

Clinical Implementation of Total-Body PET in China

Total-body (TB) PET/CT is a groundbreaking tool that has brought about a revolution in both clinical application and scientific research. The transformative impact of TB PET/CT in the realms of clinical practice and scientific exploration has been steadily unfolding since its introduction in 2018, with implications for its implementation within the health care landscape of China. TB PET/CT's exceptional sensitivity enables the acquisition of high-quality images in significantly reduced time frames. Clinical applications have underscored its effectiveness across various scenarios, emphasizing the capacity to personalize dosage, scan duration, and image quality to optimize patient outcomes. TB PET/CT's ability to perform dynamic scans with high temporal and spatial resolution and to perform parametric imaging facilitates the exploration of radiotracer biodistribution and kinetic parameters throughout the body. The comprehensive TB coverage offers opportunities to study interconnections among organs, enhancing our understanding of human physiology and pathology. These insights have the potential to benefit applications requiring holistic TB assessments. The standard topics outlined in The Journal of Nuclear Medicine were used to categorized the reviewed articles into 3 sections: current clinical applications, scan protocol design, and advanced topics. This article delves into the bottleneck that impedes the full use of TB PET in China, accompanied by suggested solutions.

Multimodality Imaging Evaluation of Primary Right Atrial Paraganglioma: A Case Report and Literature Review

Background

Cardiac paraganglioma (CPGL) accounts for 1–3% of cardiac tumors and is usually benign. In total, 35–50% of CPGL lesions secrete catecholamines, causing hypertension, excessive sweating, palpitations, headache, and other symptoms. Preoperative imaging evaluation is important to determine the location of the cardiac mass, its blood supply vessels, and the relationship with surrounding structures. Multimodal imaging techniques combine with morphological and functional information to provide powerful methods for preoperative diagnosis and lesion localization. Furthermore, they can assist to reduce the incidence of intraoperative and postoperative complications and improve patient prognosis.

Case Report

A 67-year-old woman suffered from paroxysmal palpitations with a heart rate of 110 beats per minute 1 month ago. Urine catecholamine and methoxyepinephrine levels were significantly increased. The patient had a 5-year history of hypertension with a maximum blood pressure of 160/100 mmHg. Computed tomography (CT) examination found a soft tissue mass in the right atrium with heterogeneous and significant enhancement, whose blood supply was from the left ileal branch artery. The patient then underwent cardiac magnetic resonance (CMR). The lesion showed inhomogeneous iso signals on the T1-weighted image (T1WI), slightly high signals on the T2 fat-suppression image, inhomogeneous high signals on the diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) images. The mass exhibited heterogeneous and significant enhancement on the first perfusion and delayed scans after intravenous contrast injection. However, abnormal signals were surprisingly found in the patient’s right lung, and the possibility of metastatic lesions could not be excluded. The patient underwent F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) to rule out metastatic lesions. A fluorodeoxyglucose (FDG)-avid soft tissue mass was shown in the right atrium, with the maximum standardized uptake value (SUVmax) at about 15.2, as well as a pathological intake of brown fat throughout the body. Combined with clinical symptoms, CPGL was considered without significant sign of metastasis in 18F-FDG PET/CT. Finally, the patient underwent surgical resection and the post-operative pathology confirmed a CPGL.

Conclusion

The combination of 18F-FDG PET/CT with the CMR containing different image acquisition sequences provides a powerful aid for preoperative non-invasive diagnosis, localization, and staging of CPGL, which helps to reduce intraoperative and postoperative complications and improve patient prognosis.