title: Region of interest-based versus whole-lung segmentation-based approach for MR lung perfusion quantification in 2-year-old children after congenital diaphragmatic hernia repair.
abstract: OBJECTIVE
  With a region of interest (ROI)-based approach 2-year-old children after congenital diaphragmatic hernia (CDH) show reduced MR lung perfusion values on the ipsilateral side compared to the contralateral. This study evaluates whether results can be reproduced by segmentation of whole-lung and whether there are differences between the ROI-based and whole-lung measurements.
  
  
  METHODS
  Using dynamic contrast-enhanced (DCE) MRI, pulmonary blood flow (PBF), pulmonary blood volume (PBV) and mean transit time (MTT) were quantified in 30 children after CDH repair. Quantification results of an ROI-based (six cylindrical ROIs generated of five adjacent slices per lung-side) and a whole-lung segmentation approach were compared.
  
  
  RESULTS
  In both approaches PBF and PBV were significantly reduced on the ipsilateral side (p always <0.0001). In ipsilateral lungs, PBF of the ROI-based and the whole-lung segmentation-based approach was equal (p=0.50). In contralateral lungs, the ROI-based approach significantly overestimated PBF in comparison to the whole-lung segmentation approach by approximately 9.5 % (p=0.0013).
  
  
  CONCLUSIONS
  MR lung perfusion in 2-year-old children after CDH is significantly reduced ipsilaterally. In the contralateral lung, the ROI-based approach significantly overestimates perfusion, which can be explained by exclusion of the most ventral parts of the lung. Therefore whole-lung segmentation should be preferred.
  
  
  CONCLUSIONS
  • Ipsilaterally, absolute lung perfusion after CDH is reduced in whole-lung analysis. • Ipsilaterally, the ROI- and whole-lung-based approaches generate identical results. • Contralaterally, the ROI-based approach significantly overestimates perfusion results. • Whole lung should be analysed in MR lung perfusion imaging. • MR lung perfusion measurement is a radiation-free parameter of lung function.
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany. Meike.Weis@medma.uni-heidelberg.de.
authors.forename: M
authors.initials: M
authors.lastname: Weis
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Sommer
authors.affiliation: Computer Assisted Clinical Medicine, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: F G
authors.initials: FG
authors.lastname: Zöllner
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hagelstein
authors.affiliation: Department of Paediatric Surgery, University Medical Center Mannheim, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Zahn
authors.affiliation: Department of Paediatrics, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Schaible
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany.
authors.forename: S O
authors.initials: SO
authors.lastname: Schoenberg
authors.affiliation: Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, Medical Faculty Mannheim, Heidelberg University, Theodor-Kutzer Ufer 1-3, 68167, Mannheim, Germany.
authors.forename: K W
authors.initials: KW
authors.lastname: Neff
mesh_terms: D001810:Blood Volume; D002675:Child, Preschool; D003287:Contrast Media; D005260:Female; D065630:Hernias, Diaphragmatic, Congenital / Q000601:surgery*; D006801:Humans; D007089:Image Enhancement; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011182:Postoperative Care / Q000379:methods*; D012039:Regional Blood Flow / Q000502:physiology*; D015203:Reproducibility of Results
chemical_list: D003287:Contrast Media
keywords: Congenital diaphragmatic hernia; Dynamic contrast-enhanced MRI; Lung perfusion; Lung segmentation; MR perfusion imaging