scholarly journals Quantitative Myocardial Perfusion with 2D and 3D Sequences Alternating Every Heartbeat

Author(s):  
Qi Huang ◽  
Ye Tian ◽  
Jason Mendes ◽  
Ravi Ranjan ◽  
Ganesh Adluru ◽  
...  

Abstract PurposeTo evaluate a myocardial perfusion acquisition that alternates 2D simultaneous multi-slice (SMS) and 3D stack-of-stars (SoS) acquisitions each heartbeat. MethodsA hybrid saturation recovery radial 2D SMS and a saturation recovery 3D SoS sequence were created for the quantification of myocardial blood flow (MBF). Initial studies were done to study the effects of using only every other beat for the 2D SMS in two subjects, and for the 3D SoS in two subjects. Alternating heartbeat 2D SMS and 3D SoS were then performed in ten dog studies at rest, four dog studies at adenosine stress, and two human resting studies. 2D SMS acquisition acquired three slices and 3D SoS acquired six slices. An arterial input function (AIF) for 2D SMS was obtained using the first 24 rays. For 3D, the AIF was obtained in a 2D slice prior to each 3D SoS readout. Quantitative MBF analysis was performed for 2D SMS and 3D SoS separately, using a two-compartment model. ResultsAcquiring every-other-beat data resulted in 5-20% perfusion changes at rest for both 2D SMS and 3D SoS methods. For alternating acquisitions, 2D SMS and 3D SoS quantitative perfusion values were comparable for both the twelve rest studies (2D SMS: 0.68±0.15 vs 3D: 0.69±0.15 ml/g/min, p=0.85) and the four stress studies (2D SMS: 1.28±0.22 vs 3D: 1.30±0.24 ml/g/min, p=0.66).ConclusionEvery-other-beat acquisition changed estimated perfusion values relatively little for both sequences. 2D SMS and 3D SoS gave similar quantitative perfusion estimates when used in an alternating every-other-heartbeat acquisition. Such an approach allows consideration of more diverse perfusion acquisitions that could have complementary features, although testing in a cardiac disease population is needed.

2011 ◽  
Vol 32 (3) ◽  
pp. 548-559 ◽  
Author(s):  
Bernard Lanz ◽  
Kai Uffmann ◽  
Matthias T Wyss ◽  
Bruno Weber ◽  
Alfred Buck ◽  
...  

The purpose of this study was to develop a two-compartment metabolic model of brain metabolism to assess oxidative metabolism from [1-11C] acetate radiotracer experiments, using an approach previously applied in 13C magnetic resonance spectroscopy (MRS), and compared with an one-tissue compartment model previously used in brain [1-11C] acetate studies. Compared with 13C MRS studies, 11C radiotracer measurements provide a single uptake curve representing the sum of all labeled metabolites, without chemical differentiation, but with higher temporal resolution. The reliability of the adjusted metabolic fluxes was analyzed with Monte-Carlo simulations using synthetic 11C uptake curves, based on a typical arterial input function and previously published values of the neuroglial fluxes Vtcag, Vx, Vnt, and Vtcan measured in dynamic 13C MRS experiments. Assuming Vxg=10 × Vtcag and Vxn= Vtcan, it was possible to assess the composite glial tricarboxylic acid (TCA) cycle flux Vgtg ( Vgtg= Vxg × Vtcag/( Vxg+ Vtcag)) and the neurotransmission flux Vnt from 11C tissue-activity curves obtained within 30 minutes in the rat cortex with a beta-probe after a bolus infusion of [1-11C] acetate ( n=9), resulting in Vgtg=0.136±0.042 and Vnt=0.170±0.103 μmol/g per minute (mean±s.d. of the group), in good agreement with 13C MRS measurements.


2005 ◽  
Vol 21 (4) ◽  
pp. 354-359 ◽  
Author(s):  
Andrew G. Elkington ◽  
Taigang He ◽  
Peter D. Gatehouse ◽  
Sanjay K. Prasad ◽  
David N. Firmin ◽  
...  

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Regine Schmidt ◽  
Dirk Graafen ◽  
Stefan Weber ◽  
Laura M. Schreiber

Contrast-enhanced first-pass magnetic resonance imaging (MRI) in combination with a tracer kinetic model, for example, MMID4, can be used to determine myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). Typically, the arterial input function (AIF) required for this methodology is estimated from the left ventricle (LV). Dispersion of the contrast agent bolus might occur between the LV and the myocardial tissue. Negligence of bolus dispersion could cause an error in MBF determination. The aim of this study was to investigate the influence of bolus dispersion in a simplified coronary bifurcation geometry including one healthy and one stenotic branch on the quantification of MBF and MPR. Computational fluid dynamics (CFD) simulations were combined with MMID4. Different inlet boundary conditions describing pulsatile and constant flows for rest and hyperemia and differing outflow conditions have been investigated. In the bifurcation region, the increase of the dispersion was smaller than inside the straight vessels. A systematic underestimation of MBF values up to −16.1% for pulsatile flow and an overestimation of MPR up to 7.5% were found. It was shown that, under the conditions considered in this study, bolus dispersion can significantly influence the results of quantitative myocardial MR-perfusion measurements.


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