title: Quantification of myocardial blood flow using model based analysis of first-pass perfusion MRI: extraction fraction of Gd-DTPA varies with myocardial blood flow in human myocardium.
abstract: For the absolute quantification of myocardial blood flow (MBF), Patlak plot-derived K1 need to be converted to MBF by using the relation between the extraction fraction of gadolinium contrast agent and MBF. This study was conducted to determine the relation between extraction fraction of Gd-DTPA and MBF in human heart at rest and during stress. Thirty-four patients (19 men, mean age of 66.5 ± 11.0 years) with normal coronary arteries and no myocardial infarction were retrospectively evaluated. First-pass myocardial perfusion MRI during adenosine triphosphate stress and at rest was performed using a dual bolus approach to correct for saturation of the blood signal. Myocardial K1 was quantified by Patlak plot method. Mean MBF was determined from coronary sinus flow measured by phase contrast cine MRI and left ventricle mass measured by cine MRI. The extraction fraction of Gd-DTPA was calculated as the K1 divided by the mean MBF. The extraction fraction of Gd-DTPA was 0.46 ± 0.22 at rest and 0.32 ± 0.13 during stress (P < 0.001). The relationship between extraction fraction (E) and MBF in human myocardium can be approximated as E = 1 - exp(-(0.14 × MBF + 0.56)/MBF). The current results indicate that MBF can be accurately quantified by Patlak plot method of first-pass myocardial perfusion MRI by performing a correction of extraction fraction.
authors.affiliation: Department of Radiology, Mie University Hospital, Tsu, Mie, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Ishida
authors.forename: Takashi
authors.initials: T
authors.lastname: Ichihara
authors.forename: Motonori
authors.initials: M
authors.lastname: Nagata
authors.forename: Nanaka
authors.initials: N
authors.lastname: Ishida
authors.forename: Shinichi
authors.initials: S
authors.lastname: Takase
authors.forename: Tairo
authors.initials: T
authors.lastname: Kurita
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ito
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
authors.forename: Hajime
authors.initials: H
authors.lastname: Sakuma
mesh_terms: D000368:Aged; D003287:Contrast Media; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000502:physiology*; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008962:Models, Theoretical; D012146:Rest / Q000502:physiology; D012189:Retrospective Studies; D013312:Stress, Physiological / Q000502:physiology
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA