Presentation
Patient undergoes FDG PET-CT for assessment of multiple myeloma.
Patient Data
MIP from FDG PET-CT shows an enlarged heart with intense FDG avidity. Remainder of the FDG activity is physiologic.
Axial attenuation corrected PET and fused PET-CT images show the intense FDG avidity to localize to the right ventricle.
CT shows cardiomegaly. Lytic lesions are present throughout the osseous structures, without significant FDG avidity, consistent with known multiple myeloma in remission.
Review of patient records showed a history of pulmonary hypertension and right heart strain. A right heart catheterization 2 weeks prior to PET-CT demonstrated an enlarged right ventricle with septal flattening consistent with pressure overload. Pressures were elevated with right sided filling pressure of 12 mmHg (normal 3-7), pulmonary artery systolic pressure of 70 mmHg with a mean of 25 mmHg (normal less than 25 and 15 respectively), and an elevated pulmonary capillary wedge pressure (PCWP) of 18 mmHg (normal 4-12).
Case Discussion
Chronic increased pressure or volume overload has been shown to alter the metabolism of ventricular myocardium, increasing glucose uptake and decreasing free fatty acid consumption. In advanced cases, such as this, it can present with intense FDG avidity throughout the free wall as well as the septum.
It can be helpful to be aware of this phenomenon and if encountered, suggest the possibility of right heart strain and the need to consider further investigation.