title: Assessment of operability by means of CTPA and perfusion SPECT in patients with chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  Chronic thromboembolic pulmonary hypertension (CTEPH) can potentially be cured by pulmonary thrombendarterectomy (PEA), the criteria for differentiation between operable and non-operable patients are not standardized.
  
  
  OBJECTIVE
  To retrospectively evaluate the value of rigidly registered computed tomography pulmonary angiography (CTPA) and single photon emission CT (SPECT) in differentiating for PEA.
  
  
  METHODS
  Forty-nine patients with CTEPH (21 men; age, 58 ± 13 years) were evaluated by an interdisciplinary expert board using all available diagnostic information and their consensus statement as gold standard. For SPECT a lobe based perfusion score was visually assessed using the score of 0 (lack of perfusion) to 1 (normal perfusion) calculating percentage of vascular obstruction (PVO). By CTPA, vascular obstruction index (OI) of central, peripheral, and global PA-bed were determined. The accuracy of the alignment between CTPA and SPECT was determined by fusion score (FS) ranging from 1 (no alignment) to 5 (exact alignment). Angiography provided PA pressure (PAP), pulmonary vascular resistance (PVR), and PA wedge pressure (PAWP). Receiver operating characteristics (ROC) analysis was performed.
  
  
  RESULTS
  Twenty-nine patients were considered surgically amenable, and 20 patients were inoperable. Mean PAP, PVR, and PAWP were 48 ± 11 mmHg, 868 ± 461 dynes*sec*cm(-5), and 11 ± 5 mmHg, without differences between surgical and non-surgical patients (P > 0.5). In all patients accurate registration was reached (FS = 4.1 ± 0.7; range, 2-5). PVO and central OI separated PEA-amenable patients (P ≤ 0.001) resulting in the area under the curve of 0.828 (cutoff for PVO: 37.8% with a sensitivity of 82% and specificity of 79%) and 0.755 (cutoff for central OI: 29% with a sensitivity and specificity of 86.2% and 79%) for operability.
  
  
  CONCLUSIONS
  An accurate interpretation of rigidly registered CTPA and perfusion SPECT may contribute to stratification of operability in patients with CTEPH.
authors.affiliation: Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany aleksandar.grgic@gmx.de.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Grgic
authors.affiliation: Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Miodek
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Saarland University Medical Center, Homburg, Germany.
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Schäfers
authors.affiliation: Medical Mission Hospital, Academic Teaching Hospital, Julius Maximilian University of Wuerzburg, Department of Internal Medicine Wuerzburg, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Held
authors.affiliation: Department of Pulmonology, Respiratory Intensive Care Medicine and Allergology, Saarland University Medical Center, Homburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Kaiser
authors.affiliation: Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany.
authors.forename: Fadi
authors.initials: F
authors.lastname: Khreish
authors.affiliation: Department of Diagnostic and Interventional Radiology, Saarland University Medical Center, Homburg, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Buecker
authors.affiliation: Department of Pulmonology, Respiratory Intensive Care Medicine and Allergology, Saarland University Medical Center, Homburg, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Bals
authors.affiliation: Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany.
authors.forename: Carl-Martin
authors.initials: CM
authors.lastname: Kirsch
authors.affiliation: Department of Pulmonology, Respiratory Intensive Care Medicine and Allergology, Saarland University Medical Center, Homburg, Germany.
authors.forename: Heinrike
authors.initials: H
authors.lastname: Wilkens
mesh_terms: D000792:Angiography / Q000379:methods*; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: Pulmonary hypertension; chronic thromboembolic; multidetector CTPA; operability stratification; perfusion SPECT