Evaluation of the Prognostic Value of PET/MRI in Cardiac Sarcoidosis

Inclusion Criteria:

• Age ≥ 18 years

• Sarcoidosis defined according to ATS/ERS/WASOG criteria

• Suspicion of cardiac involvement in sarcoidosis:

• Clinical manifestations (syncope, lipothymia, persistent palpitations, signs ofheart failure) and/or

• Cardiac rhythm or conduction disorder (Mobitz type 2 atrioventricular block (AVB), AVB 3, right or left bundle branch block, Q wave in at least 2 leads,ventricular arrhythmia (ventricular mono/polymorphic complexes> 1000 per 24 h,ventricular tachycardia, ventricular fibrillation), unexplained sustained VT orepsilon wave) and/or

• Compatible cardiac ultrasound abnormality: left ventricular dilatation, septalthickening or wall thinning (especially basal), segmental kinetic disorder andwall aneurysm without coronary anomaly, altered left ventricular ejectionfraction, altered diastolic function, altered right ventricular systolicfunction.

• Informed patient consent

• Membership of a social security scheme

Exclusion Criteria:

• Psychiatric illness not controlled by treatment

• Claustrophobia

• Known pregnancy or breast-feeding patient

• Unbalanced diabetes (influence on carbohydrate metabolism for PET)

• Previous infarction or known coronary disease

• Known allergy to gadolinium and fluoro-desoxyglucose and their excipients

• Renal insufficiency (Clairance < 30 mL/min/1.73m2)

• Implanted pacemaker not compatible with a 3 Teslas magnetic field

• Patients with ocular metallic foreign bodies, pacemakers, neurostimulators, cochlearimplants, metallic heart valves, vascular clips formerly implanted on cranialaneurysms and, in general, any non-removably implanted electronic medical equipment

• Inability or refusal to follow a low-carbohydrate diet for 24 hours, followed by a 6-hour fast required prior to the examination

• Patient unable to hold a 10-second apnea.

• Patient deprived of liberty by judicial or administrative decision

• Patient under legal protection (guardianship, curatorship)

• Participation in other interventional research involving the human person or beingin the exclusion period following previous research involving the human person

• Patients under AME

Exclusion criteria (post signature of consent) for women of reproductive age :

• Positive pregnancy test result after inclusion