title: Suspected pulmonary embolism in patients with pulmonary fibrosis: Discordance between ventilation/perfusion SPECT and CT pulmonary angiography.
abstract: Pulmonary embolism (PE) is a common differential diagnosis in patients with pulmonary fibrosis presenting with a clinical deterioration. Both ventilation/perfusion (V/Q)-single photon emission computed tomography (SPECT) and computed tomographic pulmonary angiography (CTPA) are routinely used to detect PE. However, the value of V/Q-SPECT and CTPA in this scenario has not been studied so far. We aimed to investigate the concordance of V/Q-SPECT and CTPA in patients with pulmonary fibrosis and suspicion of pulmonary embolism.
  
  
  
  A total of 22 consecutive patients with pulmonary fibrosis and clinical deterioration who underwent both V/Q-SPECT and CTPA were included in the study and analyzed for the presence of pulmonary embolism.
  
  
  
  Nine of 22 patients (41%) had evidence for pulmonary embolism in V/Q-SPECT, and two of these patients had matching evidence for pulmonary embolism in CTPA. In the other seven patients with positive findings in V/Q-SPECT, no evidence of pulmonary embolism was found in CTPA. None of the 13 patients with a negative V/Q-SPECT had evidence for pulmonary embolism in CTPA.
  
  
  
  In patients with pulmonary fibrosis and suspected pulmonary embolism, pulmonary embolism is detected more frequently by V/Q-SPECT than by CTPA. Thromboembolic disease is identified on CTPA only in a minority of patients with positive findings on V/Q-SPECT. When making treatment decisions, clinicians should be aware of the high rate of discordant findings in V/Q-SPECT and CTPA in this specific patient population.
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Leuschner
authors.affiliation: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Wenter
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Katrin
authors.initials: K
authors.lastname: Milger
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Gregor S
authors.initials: GS
authors.lastname: Zimmermann
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Sandhya
authors.initials: S
authors.lastname: Matthes
authors.affiliation: Institute for Clinical Radiology, University of Munich, Munich, Germany.
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.affiliation: Department of Nuclear Medicine, University of Munich, Munich, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lehner
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Neurohr
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Behr
authors.affiliation: Department of Internal Medicine V, Comprehensive Pneumology Center (CPC-M), Member of the German Center for Lung Research (DZL), Munich, Germany.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Kneidinger
mesh_terms: D000368:Aged; D057186:Comparative Effectiveness Research; D000072226:Computed Tomography Angiography / Q000379:methods*; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000175:diagnosis*; D011658:Pulmonary Fibrosis / Q000175:diagnosis* / Q000503:physiopathology; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
keywords: lung disease; multidetector computed tomography; pulmonary embolism; pulmonary fibrosis; radionuclide imaging