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Titolo:
A mathematical model of motion of the heart for use in generating source and attenuation maps for simulating emission imaging
Autore:
Pretorius, PH; King, MA; Tsui, BMW; LaCroix, KJ; Xia, WS;
Indirizzi:
Univ Massachusetts, Med Ctr, Dept Nucl Med, Worcester, MA 01655 USA Univ Massachusetts Worcester MA USA 01655 cl Med, Worcester, MA 01655 USA Univ N Carolina, Dept Biomed Engn, Chapel Hill, NC 27599 USA Univ N Carolina Chapel Hill NC USA 27599 Engn, Chapel Hill, NC 27599 USA
Titolo Testata:
MEDICAL PHYSICS
fascicolo: 11, volume: 26, anno: 1999,
pagine: 2323 - 2332
SICI:
0094-2405(199911)26:11<2323:AMMOMO>2.0.ZU;2-V
Fonte:
ISI
Lingua:
ENG
Soggetto:
LEFT-VENTRICULAR FUNCTION; RESPIRATORY MOTION; COMPUTED-TOMOGRAPHY; SPATIAL MODULATION; CARDIAC SPECT; WALL MOTION; RECONSTRUCTION; MAGNETIZATION; SCINTIGRAPHY; RESOLUTION;
Keywords:
cardiac imaging; SPECT; motion artifacts; heart model;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
48
Recensione:
Indirizzi per estratti:
Indirizzo: Pretorius, PH Univ Massachusetts, Med Ctr, Dept Nucl Med, Worcester, MA 01655 USA Univ Massachusetts Worcester MA USA 01655 ter, MA 01655 USA
Citazione:
P.H. Pretorius et al., "A mathematical model of motion of the heart for use in generating source and attenuation maps for simulating emission imaging", MED PHYS, 26(11), 1999, pp. 2323-2332

Abstract

This manuscript documents the alteration of the heart model of the three-dimensional (3D) mathematical cardiac torso (MCAT) phantom to represent cardiac motion. The objective of the inclusion of motion was to develop a digital simulation of the heart such that the impact of cardiac motion on single-photon emission computed tomography (SPECT) imaging could be assessed and methods of quantitating cardiac function could be investigated. The motion of the gated 3D MCAT's (gMCAT) heart is modeled using 128 separate and evenly spaced time samples from a blood volume curve approximating an average heart cycle. Sets of adjacent time samples can he grouped together to represent a single time interval within the heart cycle. Maximum and minimum chamber volumes were selected to be similar to those of a normal healthy personwhile the total heart volume stayed constant during the cardiac cycle. Myocardial mass was conserved during the cardiac cycle and the bases of the ventricles were modeled as moving towards the static apex. The orientation ofthe 3D MCAT heart was changed during contraction to rotate back and forth around the long axis through the center of the left ventricle (LV) using the end systolic time interval as the time point at which to reverse direction. Simple respiratory motion was also introduced by changing the orientation of the long axis of the heart to represent its variation with respiration. Heart models for 24 such orientations spanning the range of motion duringthe respiratory cycle were averaged together for each time sample to represent the blurring of the heart during the acquisition of multiple cardiac cycles. Finally, an option to model apical thinning of the myocardium was included. As an illustration of the application of the gMCAT phantom, the gated heart model was evaluated by measuring myocardial wall thickening. A linear relationship was obtained between maximum myocardial counts and myocardial thickness, similar to published results. Similar results were obtained for full width at half maximum (FWHM) measurements. With the presence of apical thinning, an apparent increase in counts in the apical region comparedto the other heart walls in the absence of attenuation compensation turns into an apparent decrease in counts with attenuation compensation. The apical decrease was more prominent in end systole (ES) than end diastole (ED) due to the change in the partial volume effect. These observations agree with clinical trends. It is concluded that the gMCAT phantom can be used to study the influence of various physical parameters on radionuclide perfusion imaging. (C) 1999 American Association of Physicists in Medicine. [S0094-2405(99)02911-9].

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/20 alle ore 15:42:54