title: Non-invasive quantitative pulmonary V/Q imaging using Fourier decomposition MRI at 1.5T.
abstract: OBJECTIVE
  Techniques for quantitative pulmonary perfusion and ventilation using the Fourier Decomposition method were recently demonstrated. We combine these two techniques and show that ventilation-perfusion (V/Q) imaging is possible using only a single MR acquisition of less than thirty seconds.
  
  
  METHODS
  The Fourier Decomposition method is used in combination with two quantification techniques, which extract baselines from within the images themselves and thus allows quantification. For the perfusion, a region assumed to consist of 100% blood is utilized, while for the ventilation the zero-frequency component is used. V/Q-imaging is then done by dividing the quantified ventilation map with the quantified perfusion map. The techniques were used on ten healthy volunteers and fifteen patients diagnosed with lung cancer.
  
  
  RESULTS
  A mean V/Q-ratio of 1.15 ± 0.22 was found for the healthy volunteers and a mean V/Q-ratio of 1.93 ± 0.83 for the non-afflicted lung in the patients. Mean V/Q-ratio in the afflicted (tumor-bearing) lung was found to be 1.61 ± 1.06. Functional defects were clearly visible in many of the patient images, but 5 of 15 patient images had to be excluded due to artifacts or low SNR, indicating a lack of robustness.
  
  
  CONCLUSIONS
  Non-invasive, quantitative V/Q-imaging is possible using Fourier Decomposition MRI. The method requires only a single acquisition of less than 30 seconds, but robustness in patients remains an issue.
authors: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany. Electronic address: Asmund.Kjorstad@medma.uni-heidelberg.de.
authors: Åsmund
authors: Å
authors: Kjørstad
authors: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany.
authors: Dominique M R
authors: DMR
authors: Corteville
authors: Institute of Clinical Radiology and Nuclear Medicine, Medical Faculty Mannheim, Heidelberg University, Germany.
authors: Thomas
authors: T
authors: Henzler
authors: Interdisciplinary Thoracic Oncology, Department of Surgery, Medical Faculty Mannheim, Heidelberg University, Germany.
authors: Gerald
authors: G
authors: Schmid-Bindert
authors: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany.
authors: Frank G
authors: FG
authors: Zöllner
authors: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Germany.
authors: Lothar R
authors: LR
authors: Schad
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008168:Lung / Q000503:physiopathology*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012129:Respiratory Function Tests / Q000379:methods; D012680:Sensitivity and Specificity; D014692:Ventilation-Perfusion Ratio; D055815:Young Adult
keywords: Fourier-Decomposition; Lung MRI; Lungen-MRT; Perfusion; V/Q; Ventilation; fourier decomposition; perfusion; ventilation