title: Estimation of pulmonary motion in healthy subjects and patients with intrathoracic tumors using 3D-dynamic MRI: initial results.
abstract: OBJECTIVE
  To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors.
  
  
  METHODS
  Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM).
  
  
  RESULTS
  The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved significantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 +/- 0.5 versus 3.4 L +/- 0.6, FEV1 0.9 +/- 0.2 versus 1.4 +/- 0.2 L) after CHT, but this improvement was not significant.
  
  
  CONCLUSIONS
  A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases).
authors.affiliation: Department of Radiology, German Cancer Research Center Heidelberg, Germany. christian.plathow@uniklinikfreiburg.de
authors.forename: Christian
authors.initials: C
authors.lastname: Plathow
authors.forename: Max
authors.initials: M
authors.lastname: Schoebinger
authors.forename: Felix
authors.initials: F
authors.lastname: Herth
authors.forename: Siegfried
authors.initials: S
authors.lastname: Tuengerthal
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Meinzer
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
mesh_terms: D002289:Carcinoma, Non-Small-Cell Lung / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008175:Lung Neoplasms / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008654:Mesothelioma / Q000503:physiopathology*; D008875:Middle Aged; D009068:Movement / Q000502:physiology*