RESUMO
AIMS: To test the hypothesis that the improved resolution afforded by 16-detector computed tomography (CT) would translate to better stress fracture detection when compared with skeletal scintigraphy. MATERIALS AND METHODS: Thirty-three cases of suspected stress fractures in 26 patients were investigated using skeletal scintigraphy and 16-detector CT performed on the same day. Planar images of the lower limbs were taken 3h post-injection of 400MBq (99m)Tc-methylene diphosphonate ((99m)Tc-MDP). (99m)Tc-MDP uptake was quantified at suspected fracture sites. CT was performed using a 16-detector multisection machine employing 0.75mm detectors and images reconstructed in 0.5mm increments. Examinations were reported independently and discordant results were compared at follow-up. RESULTS: At initial reporting scintigraphy identified fractures in 13 of the 33 cases and CT identified four of the 33. In one case, on review of the CT images, a fracture was present in the distal fibula that was not initially identified. This resulted in eight scintigraphic-positive CT-negative discordant cases. The (99m)Tc-MDP uptake was significantly lower in the discordant fracture group compared with the concordant group (p<0.01). CONCLUSIONS: Despite technological advances in CT, scintigraphy appeared to detect more stress fractures. As such, multidetector CT should not be used as a routine initial investigation in stress fracture detection. The potential use of (99m)Tc-MDP quantification at fracture sites is of interest and may be worth further investigation.
Assuntos
Fraturas de Estresse/diagnóstico por imagem , Tomografia Computadorizada Espiral/métodos , Adolescente , Adulto , Idoso , Feminino , Fíbula/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Cintilografia , Compostos Radiofarmacêuticos , Medronato de Tecnécio Tc 99m , Fraturas da Tíbia/diagnóstico por imagemRESUMO
Results were evaluated in 81 patients with suspected acute aortic dissection who were examined on a fast CT system capable of a 1 s data acquisition time. 17 patients had Type A and nine had Type B dissections. Radiological assessment provided 78 confident reports and expressed some uncertainty about the diagnosis in three patients. Overall sensitivity for aortic dissection was 96.2% and specificity was 96.4%. When 78 confident reports alone were considered, both sensitivity and specificity reached 100%. Reconstruction of data at 100 ms intervals allowed discrimination between artefacts in the ascending aorta and Type A dissections. CT can often be used as the single investigation prior to surgery for acute Type A dissections.