Is SPECT/CT with a hybrid camera useful to improve scintigraphic imaging interpretation?

Objectives To assess the usefulness of a hybrid imaging system (single-photon emission computed tomography/ computed tomography, SPECT/CT) for functional anatomical mapping (FAM) using various radiotracers and the additional value of fused SPECT/CT images compared with SPECT alone. Methods Eighty-one consecutive patients studied for various clinical situations were evaluated: 10 with In-111-pentetreotide, four with I-123-meta-iodobenzylguanidine (I-123-MIBG), five with Tc-99m-labelled red blood cells, two with Tc-99m-antigranulocyte antibodies, four with Tc-99m-nanocolloids, 10 with Ga-67, seven with Tc-99m-methylene diphosphonate (Tc-99m-MDP), nine with Tc-99m-sestamibi, 21 with Tc-99m-tetrofosmin, two with Tl-201, three with Tc-99m-ethylcysteinate dimer (ECD), one with Tc-99m-hexamethylpropyleneamine oxime (Tc-99m-HMPAO) and three with I-123-N-w-fluoropropyl-2-beta-carbomethoxy-3-beta-(4-iodophenyl) nortropanel (FPCIT). The acquisition of both anatomical (CT) and functional (SPECT) data was performed during a single session. SPECT data were first interpreted alone and then re-evaluated with the addition of FAM. Results Transmission anatomical maps allowed for the precise anatomical localization of SPECT images in 79 of the 81 cases. SPECT/CT had a significant impact on the results in 33 (40.7%) of the 81 patients: FAM provided the correct localization of SPECT findings in 23 cases, allowed the definition of the functional significance of CT lesions in two and enabled the exclusion of disease in sites of physiological tracer uptake in eight. Conclusions SPECT/CT with this hybrid system is a feasible technique yielding co-registered dual-modality images. FAM allows a more precise interpretation of scintigraphic studies in several cases and fused images can improve the diagnostic accuracy of SPECT in various clinical situations. (C) 2004 Lippincott Williams Wilkins.