A ventilation/perfusion lung scan, also called a V/Q lung scan, or ventilation/perfusion scintigraphy, is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient's lungs,[1][2] in order to determine the ventilation/perfusion ratio. The ventilation part of the test looks at the ability of air to reach all parts of the lungs, while the perfusion part evaluates how well blood circulates within the lungs. As Q in physiology is the letter used to describe bloodflow the term V/Q scan emerged.
Ventilation/perfusion scan
Normal pulmonary ventilation and perfusion (V/Q) scan. The nuclear medicine V/Q scan is useful in the evaluation of pulmonary embolism.
Ventilation-perfusion scintigraphy in a woman taking oral contraceptives and valdecoxib with a pulmonary embolism. (A) After inhalation of 20 mCi of Xenon-133 gas, scintigraphic images were obtained in the posterior projection, showing uniform ventilation to lungs.. (B) After intravenous injection of 4.1 mCi of Technetium-99m-labeled macroaggregated albumin, scintigraphic images were obtained, shown here in the posterior projection. This and other views showed decreased activity in the following regions: apical segment of right upper lobe, anterior segment of right upper lobe, superior segment of right lower lobe, posterior basal segment of right lower lobe, anteromedial basal segment of left lower lobe, and lateral basal segment of left lower lobe.
V/Q Scan Interpretation
Result
Interpretation
Significance
Normal
No perfusion deficit
Excludes pulmonary thromboembolism
Low probability
Perfusion deficit with matched ventilation deficit
< 20% probability of PE
Intermediate probability
Perfusion deficit that corresponds to parenchymal abnormality on chest x-ray
20% - 80% probability of PE
High probability
Multiple segmental perfusion deficits with normal ventilation
> 80% probability of PE
Decreased uptake of the inhaled radioisotope may indicate an impaired ability to breathe, airway obstruction, or possible pneumonia.
Decreased circulation of the injected MAA indicates a problem with blood flow into or within the lungs. A localized area of decreased uptake, usually in a wedge shaped (or pie shaped) configuration with normal ventilation images (mismatched defect) suggests a pulmonary embolus or blood clot in the lungs, which leads to reduced perfusion beyond the obstruction.
Risksedit
Although this test uses radioactive materials, the total amount of radiation exposure is low. Typical effective doses for a V/Q scan range from 1-5 mSv.[7][8] In order to decrease the radiation exposure in pregnant patients, the total radioactivity administered may be decreased or the ventilation phase omitted. A CT pulmonary angiogram (CTPA) with radiocontrast can alternatively be performed, although this can result in a greater radiation dose to the patient.[9]
Procedureedit
The ventilation and perfusion phases of a V/Q lung scan are performed together and may include a chest X-ray for comparison or to look for other causes of lung disease. A defect in the perfusion images requires a mismatched ventilation defect to indicate pulmonary embolism.[8]
In the ventilation phase of the test, a gaseous radionuclides such as xenon-133, krypton-81m, or technetium-99mDTPA in an aerosol form is inhaled by the patient through a mouthpiece or mask that covers the nose and mouth.[10] Ventilation imaging can also be performed using a Technegas machine which produces an aerosol of radioactive nanoparticles, specifically carbon nanoparticles containing technetium-99m.[11] The perfusion phase of the test involves the intravenous injection of radioactive technetium macro aggregated albumin (Tc99m-MAA). A gamma camera acquires the images for both phases of the study.[12] A SPECT image can also be taken following an injection of Technetium labelled MAA. SPECT is often skipped if the patient has pulmonary hypertension.
It is also possible to perform the scan with positron emission tomography (PET) rather than conventional gamma camera scintigraphy.[13] This has been performed with Gallium-68 labelled carbon nanoparticles (Galligas) using a conventional Technegas machine for ventilation images, and with Gallium-68 labelled MAA (Ga68-MAA) for perfusion images. PET has multiple potential advantages including superior resolution, speed and quantification.[14][15]
^Nigel Key; Michael Makris; Denise O'Shaughnessy; David Lillicrap (3 July 2009). Practical Hemostasis and Thrombosis. John Wiley and Sons. pp. 140–. ISBN978-1-4051-8460-1. Retrieved 14 November 2010.
^Mason, Robert J.; Broaddus, V. Courtney; Martin, Thomas R.; King, Talmadge E.; Schraufnagel, Dean; Murray, John F.; Nadel, Jay A. (2010). Murray and Nadel's Textbook of Respiratory Medicine. Elsevier Health Sciences. p. 477. ISBN978-1437735536.
^Parker, J. A.; Coleman, R. E.; Grady, E.; Royal, H. D.; Siegel, B. A.; Stabin, M. G.; Sostman, H. D.; Hilson, A. J. W. (26 January 2012). "SNM Practice Guideline for Lung Scintigraphy 4.0". Journal of Nuclear Medicine Technology. 40 (1): 57–65. doi:10.2967/jnmt.111.101386. PMID 22282651.
^ abBajc, M.; Neilly, J. B.; Miniati, M.; Schuemichen, C.; Meignan, M.; Jonson, B. (27 June 2009). "EANM guidelines for ventilation/perfusion scintigraphy". European Journal of Nuclear Medicine and Molecular Imaging. 36 (8): 1356–1370. doi:10.1007/s00259-009-1170-5. hdl:2158/774307. PMID 19562336.
^Anderson, David R.; Kahn, Susan R.; Rodger, Marc A.; Kovacs, Michael J.; Morris, Tim; Hirsch, Andrew; Lang, Eddy; Stiell, Ian; Kovacs, George; Dreyer, Jon; Dennie, Carol; Cartier, Yannick; Barnes, David; Burton, Erica; Pleasance, Susan; Skedgel, Chris; O’Rouke, Keith; Wells, Philip S. (19 December 2007). "Computed Tomographic Pulmonary Angiography vs Ventilation-Perfusion Lung Scanning in Patients With Suspected Pulmonary Embolism". JAMA. 298 (23): 2743–53. doi:10.1001/jama.298.23.2743. PMID 18165667.
^Fogelman, Ignac; Clarke, Susan; Cook, Gary; Gnanasegaran, Gopinath (2014). Atlas of Clinical Nuclear Medicine (3rd ed.). CRC Press. p. 1075. ISBN9781841847528.
^Lobov, Sergei A.; King, David W.; Knox, Karen J.; Senden, Tim J.; Stephens, Ross W. (February 2013). "Cationised radiolabelled nanoparticles for perfusion imaging of the lungs". Biomaterials. 34 (6): 1732–1738. doi:10.1016/j.biomaterials.2012.11.022. PMID 23218595.
^Waxman, AD; Bajc, M; Brown, M; Fahey, FH; Freeman, LM; Haramati, LB; Julien, P; Le Gal, G; Neilly, B; Rabin, J; Soudry, G; Tapson, V; Torbati, S; Kauffman, J; Ahuja, S; Donohoe, K (May 2017). "Appropriate Use Criteria for Ventilation-Perfusion Imaging in Pulmonary Embolism: Summary and Excerpts" (PDF). Journal of Nuclear Medicine. 58 (5): 13N–15N. PMID 28461589.
^Hofman, M. S.; Beauregard, J. -M.; Barber, T. W.; Neels, O. C.; Eu, P.; Hicks, R. J. (2011). "68Ga PET/CT Ventilation-Perfusion Imaging for Pulmonary Embolism: A Pilot Study with Comparison to Conventional Scintigraphy". Journal of Nuclear Medicine. 52 (10): 1513–1519. doi:10.2967/jnumed.111.093344. PMID 21908388.
^Bailey, Dale L.; Eslick, Enid M.; Schembri, Geoffrey P.; Roach, Paul J. (September 2016). "68Ga PET Ventilation and Perfusion Lung Imaging—Current Status and Future Challenges". Seminars in Nuclear Medicine. 46 (5): 428–435. doi:10.1053/j.semnuclmed.2016.04.007. PMID 27553468.
ventilation, perfusion, scan, ventilation, perfusion, lung, scan, also, called, lung, scan, ventilation, perfusion, scintigraphy, type, medical, imaging, using, scintigraphy, medical, isotopes, evaluate, circulation, blood, within, patient, lungs, order, deter. A ventilation perfusion lung scan also called a V Q lung scan or ventilation perfusion scintigraphy is a type of medical imaging using scintigraphy and medical isotopes to evaluate the circulation of air and blood within a patient s lungs 1 2 in order to determine the ventilation perfusion ratio The ventilation part of the test looks at the ability of air to reach all parts of the lungs while the perfusion part evaluates how well blood circulates within the lungs As Q in physiology is the letter used to describe bloodflow the term V Q scan emerged Ventilation perfusion scanNormal pulmonary ventilation and perfusion V Q scan The nuclear medicine V Q scan is useful in the evaluation of pulmonary embolism OPS 301 code3 703 2 edit on Wikidata Contents 1 Uses 1 1 Significance of results 2 Risks 3 Procedure 4 See also 5 ReferencesUses editThis test is most commonly done in order to check for the presence of a blood clot or abnormal blood flow inside the lungs such as a pulmonary embolism PE although computed tomography with radiocontrast is now more commonly used for this purpose 3 4 The V Q scan may be used in some circumstances where radiocontrast would be inappropriate as in allergy to contrast agent or kidney failure 5 A V Q lung scan may be performed in the case of serious lung disorders such as chronic obstructive pulmonary disease COPD or pneumonia as well as a lung performance quantification tool pre and post lung lobectomy surgery 6 Significance of results edit nbsp Ventilation perfusion scintigraphy in a woman taking oral contraceptives and valdecoxib with a pulmonary embolism A After inhalation of 20 mCi of Xenon 133 gas scintigraphic images were obtained in the posterior projection showing uniform ventilation to lungs B After intravenous injection of 4 1 mCi of Technetium 99m labeled macroaggregated albumin scintigraphic images were obtained shown here in the posterior projection This and other views showed decreased activity in the following regions apical segment of right upper lobe anterior segment of right upper lobe superior segment of right lower lobe posterior basal segment of right lower lobe anteromedial basal segment of left lower lobe and lateral basal segment of left lower lobe V Q Scan Interpretation Result Interpretation Significance Normal No perfusion deficit Excludes pulmonary thromboembolism Low probability Perfusion deficit with matched ventilation deficit lt 20 probability of PE Intermediate probability Perfusion deficit that corresponds to parenchymal abnormality on chest x ray 20 80 probability of PE High probability Multiple segmental perfusion deficits with normal ventilation gt 80 probability of PE Decreased uptake of the inhaled radioisotope may indicate an impaired ability to breathe airway obstruction or possible pneumonia Decreased circulation of the injected MAA indicates a problem with blood flow into or within the lungs A localized area of decreased uptake usually in a wedge shaped or pie shaped configuration with normal ventilation images mismatched defect suggests a pulmonary embolus or blood clot in the lungs which leads to reduced perfusion beyond the obstruction Risks editAlthough this test uses radioactive materials the total amount of radiation exposure is low Typical effective doses for a V Q scan range from 1 5 mSv 7 8 In order to decrease the radiation exposure in pregnant patients the total radioactivity administered may be decreased or the ventilation phase omitted A CT pulmonary angiogram CTPA with radiocontrast can alternatively be performed although this can result in a greater radiation dose to the patient 9 Procedure editThe ventilation and perfusion phases of a V Q lung scan are performed together and may include a chest X ray for comparison or to look for other causes of lung disease A defect in the perfusion images requires a mismatched ventilation defect to indicate pulmonary embolism 8 In the ventilation phase of the test a gaseous radionuclides such as xenon 133 krypton 81m or technetium 99m DTPA in an aerosol form is inhaled by the patient through a mouthpiece or mask that covers the nose and mouth 10 Ventilation imaging can also be performed using a Technegas machine which produces an aerosol of radioactive nanoparticles specifically carbon nanoparticles containing technetium 99m 11 The perfusion phase of the test involves the intravenous injection of radioactive technetium macro aggregated albumin Tc99m MAA A gamma camera acquires the images for both phases of the study 12 A SPECT image can also be taken following an injection of Technetium labelled MAA SPECT is often skipped if the patient has pulmonary hypertension It is also possible to perform the scan with positron emission tomography PET rather than conventional gamma camera scintigraphy 13 This has been performed with Gallium 68 labelled carbon nanoparticles Galligas using a conventional Technegas machine for ventilation images and with Gallium 68 labelled MAA Ga68 MAA for perfusion images PET has multiple potential advantages including superior resolution speed and quantification 14 15 See also editVentilation perfusion ratioReferences edit Pulmonary ventilation perfusion scan University of Maryland Medical Center Retrieved 3 January 2018 Mortensen Jann Berg Ronan M G 1 January 2019 Lung Scintigraphy in COPD Seminars in Nuclear Medicine 49 1 16 21 doi 10 1053 j semnuclmed 2018 10 010 PMID 30545511 S2CID 56486118 Retrieved 4 July 2021 Konstantinides Stavros V Torbicki Adam Agnelli Giancarlo Danchin Nicolas Fitzmaurice David Galie Nazzareno Gibbs J Simon R Huisman Menno V Humbert Marc Kucher Nils Lang Irene Lankeit Mareike Lekakis John Maack Christoph Mayer Eckhard Meneveau Nicolas Perrier Arnaud Pruszczyk Piotr Rasmussen Lars H Schindler Thomas H Svitil Pavel Vonk Noordegraaf Anton Zamorano Jose Luis Zompatori Maurizio Zamorano Jose Luis Achenbach Stephan Baumgartner Helmut Bax Jeroen J Bueno Hector et al 14 November 2014 2014 ESC Guidelines on the diagnosis and management of acute pulmonary embolism PDF European Heart Journal 35 43 3033 3073 doi 10 1093 eurheartj ehu283 PMID 25173341 Managing suspected pulmonary embolism NICE National Institute for Health and Care Excellence January 2015 Nigel Key Michael Makris Denise O Shaughnessy David Lillicrap 3 July 2009 Practical Hemostasis and Thrombosis John Wiley and Sons pp 140 ISBN 978 1 4051 8460 1 Retrieved 14 November 2010 Mason Robert J Broaddus V Courtney Martin Thomas R King Talmadge E Schraufnagel Dean Murray John F Nadel Jay A 2010 Murray and Nadel s Textbook of Respiratory Medicine Elsevier Health Sciences p 477 ISBN 978 1437735536 Parker J A Coleman R E Grady E Royal H D Siegel B A Stabin M G Sostman H D Hilson A J W 26 January 2012 SNM Practice Guideline for Lung Scintigraphy 4 0 Journal of Nuclear Medicine Technology 40 1 57 65 doi 10 2967 jnmt 111 101386 PMID 22282651 a b Bajc M Neilly J B Miniati M Schuemichen C Meignan M Jonson B 27 June 2009 EANM guidelines for ventilation perfusion scintigraphy European Journal of Nuclear Medicine and Molecular Imaging 36 8 1356 1370 doi 10 1007 s00259 009 1170 5 hdl 2158 774307 PMID 19562336 Anderson David R Kahn Susan R Rodger Marc A Kovacs Michael J Morris Tim Hirsch Andrew Lang Eddy Stiell Ian Kovacs George Dreyer Jon Dennie Carol Cartier Yannick Barnes David Burton Erica Pleasance Susan Skedgel Chris O Rouke Keith Wells Philip S 19 December 2007 Computed Tomographic Pulmonary Angiography vs Ventilation Perfusion Lung Scanning in Patients With Suspected Pulmonary Embolism JAMA 298 23 2743 53 doi 10 1001 jama 298 23 2743 PMID 18165667 Fogelman Ignac Clarke Susan Cook Gary Gnanasegaran Gopinath 2014 Atlas of Clinical Nuclear Medicine 3rd ed CRC Press p 1075 ISBN 9781841847528 Lobov Sergei A King David W Knox Karen J Senden Tim J Stephens Ross W February 2013 Cationised radiolabelled nanoparticles for perfusion imaging of the lungs Biomaterials 34 6 1732 1738 doi 10 1016 j biomaterials 2012 11 022 PMID 23218595 Waxman AD Bajc M Brown M Fahey FH Freeman LM Haramati LB Julien P Le Gal G Neilly B Rabin J Soudry G Tapson V Torbati S Kauffman J Ahuja S Donohoe K May 2017 Appropriate Use Criteria for Ventilation Perfusion Imaging in Pulmonary Embolism Summary and Excerpts PDF Journal of Nuclear Medicine 58 5 13N 15N PMID 28461589 Hofman M S Beauregard J M Barber T W Neels O C Eu P Hicks R J 2011 68Ga PET CT Ventilation Perfusion Imaging for Pulmonary Embolism A Pilot Study with Comparison to Conventional Scintigraphy Journal of Nuclear Medicine 52 10 1513 1519 doi 10 2967 jnumed 111 093344 PMID 21908388 Bailey Dale L Eslick Enid M Schembri Geoffrey P Roach Paul J September 2016 68Ga PET Ventilation and Perfusion Lung Imaging Current Status and Future Challenges Seminars in Nuclear Medicine 46 5 428 435 doi 10 1053 j semnuclmed 2016 04 007 PMID 27553468 Velikyan Irina 2014 Prospective of Ga Radiopharmaceutical Development Theranostics 4 1 47 80 doi 10 7150 thno 7447 PMC 3881227 PMID 24396515 Retrieved from https en wikipedia org w index php title Ventilation perfusion scan amp oldid 1222495034, wikipedia, wiki, book, books, library,
