IJCS | Volume 32, Nº2, May/June 2019

308 1. National Heart, Lung, and Blood. U.S. Department of Health andHuman Services - National Institutes of Health. 2011. [Cited in 2018 May 10]. Available from: https://www.nhibi.nih.gov 2. Leung AN, Bull TM, Jaeschke R, Lockwood CJ, Boiselle PM, Hurwitz LM,; ATS/STR Committee on Pulmonary Embolism in Pregnancy. American Thoracic Society documents: an official American Thoracic Society/Society of Thoracic Radiology Clinical Practice Guideline-- Evaluation of Suspected Pulmonary Embolism in Pregnancy. Radiology. 2012;262(2):635-46. 3. Ciofetta G, Piepsz A, Roca I, Fisher S, Hahn K, Sixt R, et al. Guidelines for lungscintigraphyinchildren.EurJNuclMedMolImaging.2007;34:1518-26. 4. Bajc M, Neilly JB, Miniati M, Schuemichen C, Meignan M, Jonson B, et al. EANM guidelines for ventilation/perfusion scintigraphy: Part 1. Pulmonary imaging with ventilation/perfusion single photon emission tomography. Eur J Nucl Med Mol Imaging. 2009;36(8):1356-70. 5. Parker JA, Coleman RE, Grady E, Royal HD, Siegel BA, StabinMG, et al. SNM practice guideline for lung scintigraphy 4.0. J Nucl Med Technol. 2012;40(1):57-65. 6. Wells PS, Anderson DR, Rodger M, Stiell I, Dreyer JF, Barnes D, et al. Excluding pulmonary embolism at the bedside without diagnostic imaging: management of patients with suspected pulmonary embolism presenting to the emergency department by using a simple clinical model and d-dimer. Ann Inter Med. 2001;135(2):98-107. 7. Jögi J, Jonson B, Ekberg M, Bajc M. Ventilation-perfusion SPECT with 99m Tc-DTPA versus Technegas: a head-to-head study in obstructive and nonobstructive disease. J Nucl Med. 2010;51(5):735-41. References control to ensure that the labeling efficiency is greater than 90%. Due to the presence of free Tc-99m pertechnetate. It should be remembered that visual analysis is always paramount and the presence of tracer in the brain and in renal cortex should be verified. Perform differential analysis of lung function prior to surgical procedure: The aim of this indication is to help predict the lung function reduction in the postoperative period following lung resection (e.g. lung cancer). This is particularly important in those patients who already have a reduced function in the preoperative period. The differential function is calculated by drawing ROIs on each lung in the anterior and posterior views. The lung can also be divided into three equal rectangular ROI: top, middle, and bottom. Alternatively, posterior oblique views can be used to assess lobar segmentation, assisting in cases of segmentectomy or lobectomy. 20 Postoperative evaluation of lung transplantation Evaluate the feasibility of vascular anastomosis. It is also possible to assess rejection, when there are matched defects suggestive of obstructive lung disease or changes in the perfusion between both lungs (in the case of unilateral transplantation). Important observations There may be hot spots on perfusion images, in case blood coagulation occurs in the syringe during injection of the tracer, which may occur when blood is aspirated into the syringe during injection. The acquisition of images with the patient in different positions (dorsal decubitus or supine position) may hinder the comparability of the studies. The unilateral absence of one of the lungs in the perfusion imaging, with normal ventilation, is not an indicative of PE. In these cases, the chest CT scan must be assessed in order to look for tumors, aortic aneurysm, vascular defects or other pathologies. Author contributions Conception and design of the research: Rigolon MY, Amorim BJ. Acquisition of data: Rigolon MY. Analysis and interpretation of the data: Rigolon MY, Mesquita CT, Amorim BJ. Writing of the manuscript: Rigolon MY. Critical revision of the manuscript for intellectual content: Mesquita CT, Amorim BJ. Supervision / as the major investigador: Amorim BJ. Potential Conflict of Interest No potential conflict of interest relevant to this article was reported. Sources of Funding There were no external funding sources for this study. Study Association This study is not associated with any thesis or dissertation work. Rigolon et al. Guideline for lung scintigraphy Int J Cardiovasc Sci. 2019;32(3)302-309 Guideline