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V/Q scan

V/Q scan is the recommended screening test for CTEPH

Ventilation/perfusion (V/Q) scan is the preferred and recommended screening test for chronic thromboembolic disease in patients with pulmonary hypertension (PH). V/Q scan has been shown to effectively exclude CTEPH and have higher sensitivity and specificity than computed tomography pulmonary angiogram (CTPA) in screening for CTEPH1


  • The V/Q method uses scintigraphy and medical isotopes to evaluate the circulation of air and blood in the lungs2

  • The ventilation scan detects radioactive gas inhaled by the patient and shows the distribution of ventilation2

  • The perfusion scan detects radioactive albumin (intravenously injected prior to the scan) and shows the distribution of pulmonary perfusion2

  • Both scans are usually performed together during a single visit2


V/Q scan image

Let image courtesy of G Heresi-Davila, Cleveland Clinic PTE Program; right image courtesy of the PTE Program at University of California, San Diego

V/Q is more sensitive than CTPA

  • As the 6th World Symposium on PH reported in 2018, V/Q scanning the preferred screening test for CTEPH because of its high sensitivity and specificity1

    • A normal V/Q scan effectively excludes CTEPH with a sensitivity of 90%-100% and a specificity of 94%-100%1

    • Although Tunariu et al. (2007) had previously reported a CTPA sensitivity for detecting CTEPH of 51% vs 96% with V/Q scan, more recent studies have found this difference has narrowed with the advancement of CT technology and interpretation1,3

    • A more recent study in 2012 showed that V/Q scan had 100% sensitivity, 93.7% specificity, and 96.5% accuracy and CTPA had 96.1% sensitivity, 95.2% specificity, and 95.6% accuracy for detecting CTEPH1

    • However, V/Q scan still remains the preferred initial imaging test for CTEPH screening1

    • A normal V/Q scan can rule out CTEPH3

    • An abnormal V/Q scan is suggestive of CTEPH—even when a CT scan is negative3

  • Despite widespread and consistent recommendations that V/Q scanning be used to screen for CTEPH: “Underutilization of V/Q scans in screening PH invites potential misdiagnosis of PAH”1

  • A positive V/Q scan should be followed by further diagnostic studies consistent with the diagnostic algorithm4

  • The V/Q scan is also an important diagnostic test for patients with suspected PH or pulmonary embolism (PE) patients who are still symptomatic after 3 months of anticoagulation5

If a V/Q scan suggests CTEPH, the patient should be referred to a specialized center with expertise in the treatment of this condition.1


Abnormal V/Q Scan


V/Q and RHC

Watch to see William R. Auger, MD, of Temple University Hospital, discuss the use of V/Q scanning and right heart catheterization in diagnosing CTEPH.


1. Kim NH, Delcroix M, Jais X, et al. Chronic thromboembolic pulmonary hypertension. Eur Respir J. 2019;53:1801915. 2. Medline Plus website. Pulmonary ventilation/perfusion scan. Accessed September 2019. 3. Tunariu N, Gibbs SJR, Win Z, et al. Ventilation–perfusion scintigraphy is more sensitive than multidetector CTPA in detecting chronic thromboembolic pulmonary disease as a treatable cause of pulmonary hypertension. J Nucl Med. 2007;48(5):680-684. 4. Jenkins D, Mayer E, Screaton N, Madani M. State-of-the-art chronic thromboembolic pulmonary hypertension diagnosis and management. Eur Respir Rev. 2012;21(123):32-39. 5. Fedullo P, Kerr KM, Kim NH, Auger WR. Chronic thromboembolic pulmonary hypertension. Am J Respir Crit Care Med. 2011;183(12):1605-1613.