Application of model-free analysis in the MR assessment of pulmonary perfusion dynamics.
Dynamic contrast-enhanced (DCE) MRI has been used to quantitatively evaluate pulmonary perfusion based on the assumption of a gamma-variate function and an arterial input function (AIF) for deconvolution. However, these assumptions may be too simplistic and may not be valid in pathological conditions, especially in patients with complex inflow patterns (such as in congenital heart disease). Exploratory data analysis methods make minimal assumptions on the data and could overcome these pitfalls. In this work, two temporal clustering methods--Kohonen clustering network (KCN) and Fuzzy C-Means (FCM)--were concatenated to identify pixel time-course patterns. The results from seven normal volunteers show that this technique is superior for discriminating vessels and compartments in the pulmonary circulation. Patient studies with five cases of acquired or congenital pulmonary perfusion disorders demonstrate that pathologies can be highlighted in a concise map that combines information of the mean transit time (MTT) and pulmonary blood volume (PBV). The method was found to provide greater insight into the perfusion dynamics that might be overlooked by current model-based analyses, and may serve as a basis for optimal hemodynamic quantitative modeling of the interrogated perfusion compartments.
Chuang
Kai-Hsiang
KH
Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ROC.
Wu
Ming-Ting
MT
Lin
Yi-Ru
YR
Hsieh
Kai-Sheng
KS
Wu
Ming-Long
ML
Tsai
Shang-Yueh
SY
Ko
Cheng-Wen
CW
Chung
Hsiao-Wen
HW
D000328:Adult; D002675:Child, Preschool; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D008168:Lung / Q000098:blood supply*; D008171:Lung Diseases / Q000503:physiopathology*; D008297:Male; D011652:Pulmonary Circulation / Q000502:physiology*
D003287:Contrast Media; D019786:Gadolinium DTPA