title: Quantification of lung perfusion blood volume (lung PBV) by dual-energy CT in patients with chronic thromboembolic pulmonary hypertension (CTEPH) before and after balloon pulmonary angioplasty (BPA): Preliminary results.
abstract: OBJECTIVE
  Balloon pulmonary angioplasty (BPA) is a treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Its effect on pulmonary perfusion has not been quantified; we examined the clinical significance of pulmonary blood volume (PBV) using dual-energy computed tomography (DECT) in patients with CTEPH undergoing BPA.
  
  
  METHODS
  In this retrospective study of 16 BPAs in eight female patients with CTEPH, we evaluated both-lung (n=16), right- or left-lung (n=32), and three right- or left-segment (upper, middle, and lower) (n=96) PBVs before and after BPA, using DECT. We evaluated the relationships between improvement in lung PBV and pulmonary artery (PA) pressure (PAP), cardiac index (CI), pulmonary vascular resistance (PVR), and 6-min walking distance. We measured PA enhancement (PAenh) on DECT images and calculated lung PBV/PAenh to adjust timing.
  
  
  RESULTS
  Pre- and post-BPA 6-segment lung PBV/PAenh were 0.067±0.021 and 0.077±0.019, respectively, in the treated segment (p<0.0001). There were significant positive correlations between pre- to post-BPA improvements in both-lung PBV/PAenh and PAP (R=0.69, p=0.005), PVR (R=0.56, p=0.03), and 6-min walking distance (R=0.67, p=0.01).
  
  
  CONCLUSIONS
  Improved PBV after BPA, reflecting increased lung perfusion, was positively correlated with PAP, PVR, and 6-min walking distance. Lung PBV may be an indicator of BPA treatment effect.
authors: Department of Radiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: kei16231623@gmail.com.
authors: Hirofumi
authors: H
authors: Koike
authors: Department of Radiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: sueyo@nagasaki-u.ac.jp.
authors: Eijun
authors: E
authors: Sueyoshi
authors: Department of Radiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: ichiro-s@nagasaki-u.ac.jp.
authors: Ichiro
authors: I
authors: Sakamoto
authors: Department of Radiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: uetani@nagasaki-u.ac.jp.
authors: Masataka
authors: M
authors: Uetani
authors: Department of Cardiovascular medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: t-nakata@nagasaki-u.ac.jp.
authors: Tomoo
authors: T
authors: Nakata
authors: Department of Cardiovascular medicine, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. Electronic address: maemura@nagasaki-u.ac.jp.
authors: Kouji
authors: K
authors: Maemura
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000379:methods; D001810:Blood Volume; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D007564:Japan; D011652:Pulmonary Circulation; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods; D014655:Vascular Resistance
keywords: Balloon pulmonary angioplasty (BPA); Chronic thromboembolic pulmonary hypertension (CETPH); Dual-energy computed tomography (DECT); Pulmonary blood volume (PBV); Pulmonary perfusion