fdg pet-ct findings of extra-thoracic sarcoid are associated with cardiac sarcoid: a rationale for using fgd pet-ct for cardiac sarcoid evaluation

This retrospective study investigates the relationship between cardiac and extra-thoracic sarcoid findings on fdg pet-ct using a 72-hour pretest high-fat, high-protein, and very low-carbohydrate (hfhpvlc) diet. a total of 196 consecutive fdg pet-ct scans with 72-hour hfhpvlc diet preparation were performed between 2014 and 2015 in known sarcoid patients. of these scans, 5 were excluded for non-adherence to diet preparation or underlying cancer. cardiac and extra-thoracic sarcoid lesions were categorized and measured for radiotracer uptake. a total of 188 patients had 191 eligible fdg pet/ct scans (3 follow-up scans), of which there were 20 (10%) positive, 6 indeterminate (3%), and 165 (86%) negative for cs. among the 20 scans positive for cs, 8 (40%) had findings of both cardiac and extra-thoracic sarcoid. our study shows that 40% of cs patients also have fdg pet-ct findings of extra-thoracic sarcoid. this makes an intriguing case for fdg pet-ct use with pretest diet prep over cardiac mri (cmr) for cardiac sarcoid evaluation, given that cmr is likely to overlook these extra-thoracic sites of disease.