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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 Scan

Learn why a V/Q scan is the best practice used to diagnose CTEPH.

Compensated by Bayer for video.


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.