Pulmonary ventilation/perfusion single photon emission tomography - Initial experience of a Nuclear Medicine Department

Introduction: lung ventilation/perfusion scintigraphy with planar images (v/qs-planar) is very useful for the diagnosis and follow-up of pulmonary thromboembolism (pte). acquiring tomographic images (v/qs-spect) is a recent development with potential to increase the technique's accuracy. the purpose of this work is to evaluate the added benefits of v/qs-spect studies as opposed to traditional planar imaging. patients and methods: we prospectively revised 53 v/qs-planar and v/qs-spect exams,performed according to the european association of nuclear medicine guidelines. we evaluated the exams independently,by consensus of two nuclear medicine physicians. for both methods,we gave each lung a score expressing the dimension and extension of perfusion defects with normal ventilation. for each lung,we compared the scores with the paired wilcoxon test,estimating the 95% confidence interval (95ci) for the respective difference. results: we performed v/qs-spect exams without technical difficulties. the paired wilcoxon test estimated the score difference to be -0.75 (95ci of -1.0 to -0.5; p-value = 9.6 × 10-7),expressing a statistically significant difference of about 1 subsegmental defect between both methods,with v/qs-spect detecting more defects. discussion: the results demonstrate that v/qs-spect identifies a slightly larger number of perfusion defects than v/qs-planar,suggesting a higher sensitivity of this technique. however,more studies are necessary to evaluate the clinical meaning of this fact. conclusion: v/qs-spect demonstrates a higher capability to identify perfusion defects. this method looks promising,allowing for a greater role of this exam in pulmonary thromboembolism diagnosis and follow-up. © 2015 sociedade portuguesa de pneumologia.