Objective: To determine the prevalence of abdominal involvement, distribution pattern and evaluate role of hybrid molecular imaging in patients with abdominal sarcoidosis. Methods: Between January 2010 and December 2011, 98 patients with chronic sarcoidosis and presence of prolonged symptoms or other findings suggestive of active disease were referred to FDG PET/CT examination. Active disease was found in 82 patients, and they all were screened for presence of abdominal sarcoidosis on FDG PET/CT. All patients also underwent MDCT and assessment of serum ACE level. Follow up FDG PET/CT examination was done 12.3±5.4 months after the baseline. Results: Abdominal sarcoidosis was present in 31 /82 patients with active sarcoidosis. FDG uptake was present in: retroperitoneal lymph nodes (77%), liver (26%), spleen (23%), adrenal gland(3%). Majority of patients had more than two locations of disease. Usually thoracic disease was spread into the extrathoracic localizations, while isolated abdominal sarcoidosis was present in 10% of patients. After first FDG PET/CT examination therapy was changed in all patients. Eleven patients came to the follow up examination where SUV max significantly decreased in majority of them. Three patients had total remission, three had absence of abdominal disease but discrete findings in thorax and others had less spread disease. ACE levels did not correlate with SUV max level. Conclusion: FDG PET/CT can be a useful tool for detection of abdominal sarcoidosis and in the evaluation of therapy response in these patients. Awareness of the presence of intra-abdominal sarcoidosis is important in order to prevent long-standing unrecognized disease.

To determine the prevalence of head and neck sarcoidosis (HNS) and evaluate the role of hybrid molecular imaging in HNS. Between 2010 and 2018, 222 patients with chronic sarcoidosis and presence of prolonged symptoms of active disease were referred to FDG PET/CT. Active disease was found in 169 patients, and they were all screened for the presence of HNS. All patients underwent MDCT and assessment of the serum ACE level. Follow-up FDG PET/CT examination was done 19.84 ± 8.98 months after the baseline. HNS was present in 38 out of 169 patients. FDG uptake was present in: cervical lymph nodes (38/38), submandibular glands (2/38), cerebrum (2/38), and bone (1/38). The majority of patients had more than two locations of disease. After FDG PET/CT examination, therapy was changed in most patients. Fourteen patients returned to follow-up FDG PET/CT examination in order to assess the therapy response. PET/CT revealed active disease in 12 patients and complete remission in two patients. Follow-up ACE levels had no correlation with follow-up SUVmax level (ρ = −0.18, p = 0.77). FDG PET/CT can be useful in the detection of HNS and in the evaluation of the therapy response. It may replace the use of non-purposive mounds of insufficiently informative laboratory and radiological procedures.