OBJECTIVE: This study evaluates the diagnostic value of single photon emission computed tomographic (SPECT)/multislice computed tomographic (MSCT) fusion images compared with planar scintigraphy in children. METHODS: Fifteen children [eight girls, mean age 13 years (range 2-17 years)] who were examined in the SPECT/16-MSCT scanner at the Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet were included. The studies and clinical indications were eight Tc-hydroxymethane diphosphonate bone scintigraphies (three bone abnormalities, three osteomyelitis, two bone tumours), one bone scintigraphy combined with In-labelled leukocyte study (osteomyelitis), three I-meta-iodobenzylguanidine scintigraphies (neuroblastoma), three In-octreotide scintigraphies (two carcinoid tumours, one Langerhans cell histiocytosis) and one Tc-dimercaptosuccinic acid scintigraphy (suspected renal transplant infarction). At the evaluation of the planar scans, the decision to perform a SPECT/16-MSCT scan was taken. A specialist in nuclear medicine read the SPECT scans and the CT scans were, if performed as high resolution or when in doubt, read by the specialist in radiology, followed by a simultaneous reading. We categorized the additional information gained from the SPECT/MSCT scan into three groups: (i) structural information gained from the CT scan, (ii) additional nuclear medicine information gained from the SPECT scan and (iii) information used for biopsy guidance. Use of a CT scan of diagnostic quality was only allowed (n=1) after referral from the clinicians, and read in collaboration with the specialist in radiology. RESULTS: Fourteen of the 15 planar scans gained additional structural information from SPECT/CT. Twelve of 15 planar scans gained additional nuclear medicine information. Six studies gained specific information for biopsy guidance. CONCLUSION: SPECT/CT provided additional information in all cases. SPECT/CT in children seems to be a most valuable tool and it increases the certainty of the diagnostic work-up.