ABSTRACT
Summary The new technology of PET/MRI is a prototype of hybrid imaging, allowing for the combination of molecular data from PET scanning and morphofunctional information derived from MRI scanning. Recent advances regarding the technical aspects of this device, especially after the development of MRI-compatible silicon photomultipliers of PET, permitted an increase in the diagnostic performance of PET/MRI translated into dose reduction and higher imaging quality. Among several clinical applications, PET/MRI gains ground initially in oncology, where MRI per se plays an essential role in the assessment of primary tumors (which is limited in the case of PET/CT), including prostate, rectal and gynecological tumors. On the other hand, the evaluation of the lungs remains an enigma although new MRI sequences are being designed to overcome this. More clinical indications of PET/MRI are seen in the fields of neurology, cardiology and inflammatory processes, and the use of PET/MRI also opens perspectives for pediatric populations as it involves very low radiation exposure. Our review aimed to highlight the current indications of PET/MRI and discuss the challenges and perspectives of PET/MRI at HC-FMUSP.
Resumo A nova tecnologia PET/RM é o protótipo de diagnóstico por imagem híbrido e permite combinar dados moleculares obtidos da tomografia PET e informações morfofuncionais derivadas da ressonância magnética. Avanços recentes relativos a aspectos técnicos desse dispositivo, principalmente após o desenvolvimento de fotomultiplicadores de silício compatíveis com RM, permitiram uma melhora do desempenho diagnóstico da PET/RM traduzida em redução da dose e qualidade superior das imagens. Entre diversas aplicações clínicas, a PET/RM ganha espaço inicialmente no campo da oncologia, onde a RM tem papel essencial na avaliação de tumores primários (limitado no caso da PET/TC), incluindo tumores de próstata, reto e ginecológicos. Por outro lado, a avaliação dos pulmões ainda é um enigma, a despeito de novas sequências de RM que estão sendo criadas para tentar resolver essa questão. Outras indicações clínicas da PET/RM são encontradas no âmbito da neurologia, cardiologia e de processos inflamatórios, nos quais a técnica também abre perspectivas para pacientes pediátricos, já que envolve uma exposição baixíssima à radiação. Nossa revisão teve como objetivo destacar as indicações atuais da PET/RM e discutir os desafios e perspectivas da aplicação dessa técnica no Hospital das Clínicas da FMUSP.
Subject(s)
Humans , Male , Female , Magnetic Resonance Imaging/methods , Tomography, X-Ray Computed/methods , Positron-Emission Tomography/methods , Multimodal Imaging/methods , Positron Emission Tomography Computed Tomography/methods , Neoplasms/diagnostic imaging , Medical Oncology/instrumentation , Neoplasms/classificationABSTRACT
Prostate cancer imaging has become an important diagnostic modality for tumor evaluation. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) has been extensively studied, and the results are robust and promising. The advent of the PET/magnetic resonance imaging (MRI) has added morphofunctional information from the standard of reference MRI to highly accurate molecular information from PET. Different PSMA ligands have been used for this purpose including 68gallium and 18fluorine-labeled PET probes, which have particular features including spatial resolution, imaging quality and tracer biodistribution. The use of PSMA PET imaging is well established for evaluating biochemical recurrence, even at low prostate-specific antigen (PSA) levels, but has also shown interesting applications for tumor detection, primary staging, assessment of therapeutic responses and treatment planning. This review will outline the potential role of PSMA PET/MRI for the clinical assessment of PCa.