title: Nonmassive acute pulmonary embolism: evaluation of the impact of pulmonary arterial wall distensibility on the assessment of the CT obstruction score.
abstract: OBJECTIVE
  To evaluate the impact of pulmonary arterial wall distensibility on the assessment of a computed tomography (CT) score in patients with nonmassive pulmonary embolism (PE) (ie, Mastora score).
  
  
  METHODS
  The arterial wall distensibility of five central pulmonary arteries (pulmonary artery trunk, right and left main pulmonary arteries, right and left interlobar pulmonary arteries) was studied on ECG-gated CT angiographic studies of the chest in 15 patients with no pulmonary arterial hypertension (group 1; mean pulmonary artery pressure: 17.2 mm Hg) and 9 patients with nonmassive PE (group 2), using 2D reconstructions at every 10% of the R-R interval.
  
  
  RESULTS
  The systolic and diastolic reconstruction time windows of the examined arteries were identical in the 2 groups, obtained at 20% and 80% of the R-R interval, respectively. No statistically significant difference was observed between the mean values of the pulmonary arterial wall distensibility between the 2 groups, varying between 20.5% and 24% in group 1 and between 23.3% and 25.9% in group 2. The coefficients of variation of the average arterial surfaces were found to vary between 4.30% and 6.50% in group 1 and 4.2% and 8.4% in group 2. Except the pulmonary artery trunk in group 2, all the intraclass correlation coefficients were around 0.8 or greater than 0.8, that is the cutoff for good homogeneity of measurements.
  
  
  CONCLUSIONS
  The pulmonary arterial wall systolic-diastolic distensibility does not interfere with the assessment of a CT obstruction score in the setting of nonmassive PE.
authors.affiliation: Department of Thoracic Imaging, Hospital Calmette, University Center of Lille, Boulevard Jules Leclercq, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Bigot
authors.forename: Martine
authors.initials: M
authors.lastname: Rémy-Jardin
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Andréi-Bogdan
authors.initials: AB
authors.lastname: Gorgos
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Faivre
authors.forename: Jacques
authors.initials: J
authors.lastname: Rémy
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003287:Contrast Media; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007472:Iohexol; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011856:Radiographic Image Enhancement / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol