The Diagnostic and Prognostic Value of
ECG-Gated SPECT Myocardial Perfusion Imaging
Vanessa Go, MD; Mehul R. Bhatt, MD; and Robert C. Hendel, MD
Section of Cardiology, Department of Medicine, Rush University Medical Center, Chicago, Illinois
Since the development of gated SPECT imaging approximately
10 y ago, this technique is now almost universally used as an
adjunct for radionuclide perfusion imaging, enabling the assess-
ment of perfusion along with determination of regional and
global left ventricular function in the same examination. The
gated SPECT determination of the left ventricular ejection frac-
tion and volumes has been extensively validated. Additionally,
this method allows for the improved identification of soft-tissue
artifacts and enhances the detection of multivessel coronary
artery disease. Furthermore, gated SPECT provides powerful
information for the risk assessment of patients with known or
suspected coronary artery disease and aids in the assessment
of myocardial viability. Gated SPECT imaging has clearly be-
come an integral part of radionuclide myocardial perfusion
J Nucl Med 2004; 45:912–921
Electrocardiographically (ECG)-gated myocardial per-
fusion SPECT was developed in the late 1980s and has
rapidly evolved into a standard for myocardial perfusion
imaging in the United States. The American Society of
Nuclear Cardiology in its position paper from March 1999
recommended the routine incorporation of ECG gating dur-
ing SPECT cardiac perfusion scintigraphy (1,2). Gated
SPECT studies allow simultaneous assessment of perfusion
and function in a single-injection, single-acquisition se-
The development of new radioisotopes and improve-
ments in imaging hardware and computer technology have
contributed significantly to the growth of gated SPECT. The
99mTc-based perfusion tracers, because of their higher count
rates and stable myocardial distribution with time, permit
evaluation of regional myocardial wall motion and wall
thickening throughout the cardiac cycle. The development
of automated algorithms to quantitatively measure left ven-
tricular (LV) volume and ejection fraction (EF), and even
regional myocardial wall motion and thickening from gated
SPECT, rapidly and accurately, and with minimal operator
interaction, has also contributed to its widespread use.
These innovations have made SPECT imaging a premier
method of noninvasive evaluation of myocardial blood flow
and cardiac function in a variety of clinical situations (3).
GATED SPECT ACQUISITION AND PROCESSING
In a gated acquisition, a 3-lead ECG provides the R wave
trigger to the acquisition computer, with 2 successive R
wave peaks on the ECG defining a cardiac cycle. Counts
from each phase of the cardiac cycle are associated with a
temporal frame within the computer (4). Gating of myocar-
dial perfusion is usually performed at 8 frames per R–R
interval per projection, although most manufacturers have
the capability to acquire 16 frames per R–R interval. The
acquired data are then reconstructed and displayed in a
cinematic or multiframe format, allowing the reader to
assess wall motion in all areas of the myocardium, including
the left and right ventricles (Fig. 1) (5).
Changes in heart rate due to a variety of factors can result
in temporal blurring—that is, mixing of counts from adja-
cent frames. To minimize temporal blurring, a beat rejection
Received Jun. 23, 2003; revision accepted Jan. 7, 2004.
For correspondence or reprints contact: Robert C. Hendel, MD, Section of
Cardiology, Department of Medicine, Rush-Presbyterian-St. Luke’s Medical
Center, 1725 W. Harrison St., Suite 020, Chicago, IL 60612-3864.
frames corresponding to different phases of cardiac cycle are
acquired for each angular projection. Perfusion images are ob-
tained from summation of individual frames. (Reprinted with
permission of (5).)
ECG-gated SPECT acquisition. Separate temporal
THE JOURNAL OF NUCLEAR MEDICINE • Vol. 45 • No. 5 • May 2004
window is set by specifying the acceptable deviation of each
R–R interval from the expected value. A 20% window has
historically been applied, although in patients with highly
variable heart rates, up to a 100% acceptance window can
be set. In patients with arrhythmias, it is important to check
for gating errors, as it has been demonstrated that EF
fluctuations, perfusion differences, and, in particular, wall
thickening discordance may occur with arrhythmias (6).
Thus, in cases of extreme variation in heart rate or rhythm,
an ungated SPECT study may be the most appropriate test.
There are a variety of single-day and 2-d protocols that
may be used in conjunction with gated SPECT. Either201Tl
or99mTc perfusion tracers may be used. Most commonly
used is the high-dose technetium stress study because of its
superior myocardial count density.
vides more reproducible volume and LVEF measurements
201Tl (7). In addition, when low- versus high-dose
technetium was compared there was less variability of
LVEF in the high-dosage cohort (8).
Either or both of the acquisitions composing the stress/
rest or rest/stress sequence can be gated. Although the
common practice is to gate only the poststress image, a
small study by Johnson et al. reports that, in 36% of patients
with reversible perfusion defects, the poststress LVEF was
?5% lower than at rest (9). This implies that global and
regional LV function obtained from poststress gated acqui-
sitions are not representative of basal LV function in pa-
tients with stress-induced ischemia and that perhaps both
rest and stress images should be gated routinely, as long as
counts are sufficient.
Overall ventricular function and regional cardiac function
(myocardial wall motion and thickening) are calculated
separately using computer software requiring minimal op-
erator input (Fig. 2). Most of these programs use an edge
Cedars-Sinai). (A) Myocardial contours displaying endocardial and epicardial surfaces overlying end-diastolic (ED) and end-systolic
(ES) frames display 3 short-axis images, a midcavity horizontal image, and a midcavity vertical long-axis image. (B) Quantitative
polar plots measuring regional myocardial wall perfusion (B1, B2), motion (B3), and wall thickening (B4) from gated SPECT. (C)
Three-dimensional display of endocardial (solid) and epicardial (grid) LV surfaces calculated by automatic algorithm. (D) Endocardial
time–volume curve and calculated LVEF from end-systolic and end diastolic volumes.
Quantification of EF, regional myocardial wall motion, and thickening from gated myocardial perfusion SPECT (QPS;
CLINICAL VALUE OF GATED SPECT • Go et al.
echocardiography for predicting function recovery after revascularization. Am J
60. Nakajima K, Taki J, Kawano M, et al. Diastolic dysfunction in patients with
systemic sclerosis detected by gated myocardial perfusion SPECT: an early sign
of cardiac involvement. J Nucl Med. 2001;42:183–188.
61. Soudry G, Dibos PE. Gated myocardial perfusion scan leading to diagnosis of
unsuspected massive pulmonary embolism [letter]. Ann Intern Med. 2000;132:
62. Ioannidis JP, Trikalinos TA, Danias PG. Electrocardiogram-gated single-photon
emission computed tomography versus cardiac magnetic resonance imaging for
the assessment of left ventricular volumes and ejection fraction: a meta-analysis.
J Am Coll Cardiol. 2002;39:2059–2068.
63. Baba A, Hano T, Ohmori H, et al. Assessment of left ventricular function by
thallium-201 quantitative gated cardiac SPECT. Kaku Igaku. 2002;39:21–27.
64. Itti E, Rosso J, Damien P, Auffret M, Thirion JP, Meignan M. Assessment of
ejection fraction with Tl-201 gated SPECT in myocardial infarction: precision in
a rest-redistribution study and accuracy versus planar angiography. J Nucl Car-
65. Vourvouri EC, Poldermans D, Bax JJ, et al. Evaluation of left ventricular function
and volumes in patients with ischaemic cardiomyopathy: gated single-photon
emission computed tomography versus two-dimensional echocardiography. Eur
J Nucl Med. 2001;28:1610–1615.
66. Higuchi T, Nakajima K, Taki J, Kinuya S, Bunko H, Tonami N. Assessment of
left ventricular systolic and diastolic function based on the edge detection method
with myocardial ECG-gated SPET. Eur J Nucl Med. 2001;28:1512–1516.
67. Faber TL, Cooke CD, Folks RD, et al. Left ventricular function and perfusion
from gated SPECT perfusion images: an integrated method. J Nucl Med. 1999;
68. Tadamura E, Kudoh T, Motooka M, et al. Use of technetium-99m sestamibi
ECG-gated single-photon emission tomography for the evaluation of left ven-
tricular function following coronary artery bypass graft: comparison with three-
dimensional magnetic resonance imaging. Eur J Nucl Med. 1999;26:705–712.
69. Yoshioka J, Hasegawa S, Yamaguchi H, Tokita N, Paul AK, Xiulu M. Left
ventricular volumes and ejection fraction calculated from quantitative electrocar-
diographic-gated99mTc-tetrofosmin myocardial SPECT. J Nucl Med. 1999;40:
70. Nichols K, Tamis J, DePuey EG, Mieres J, Malhotra S, Rozanski A. Relationship
of gated SPECT ventricular function parameters to angiographic measurements.
J Nucl Cardiol. 1998;5:295–303.
71. Nichols K, DePuey EG, Rozanski A, Salensky H, Friedman MI. Image enhance-
ment of severely hypoperfused myocardia for computation of tomographic ejec-
tion fraction. J Nucl Med. 1997;38:1411–1417.
72. Atsma DE, Bavelaar-Croon CD, Germano G, et al. Good correlation between
gated single photon emission computed myocardial tomography and contrast
ventriculography in the assessment of global and regional left ventricular func-
tion. Int J Card Imaging. 2000;16:447–453.
73. Wright GA, McDade M, Keeble W, Martin W, Hutton I. Quantitative gated
SPECT myocardial perfusion imaging with201Tl: an assessment of the limita-
tions. Nucl Med Commun. 2000;21:1147–1151.
74. Bax JJ, Lamb H, Dibbets P, et al. Comparison of gated single-photon emission
computed tomography with magnetic resonance imaging for evaluation of left
ventricular function in ischemic cardiomyopathy. Am J Cardiol. 2000;86:1299–
75. Bavelaar-Croon CD, Kayser HW, van der Wall EE, et al. Left ventricular
function: correlation of quantitative gated SPECT and MR imaging over a wide
range of values. Radiology. 2000;217:572–575.
76. Cwajg E, Cwajg J, Keng F, He ZX, Nagueh S, Verani MS. Comparison of global
and regional left ventricular function assessed by gated-SPECT and 2-D echo-
cardiography. Rev Port Cardiol. 2000;19(suppl 1):I39–I46.
77. Nichols K, Lefkowitz D, Faber T, et al. Echocardiographic validation of gated
SPECT ventricular function measurements. J Nucl Med. 2000;41:1308–1314.
78. He ZX, Cwajg E, Preslar JS, Mahmarian JJ, Verani MS. Accuracy of left
ventricular ejection fraction determined by gated myocardial perfusion SPECT
with Tl-201 and Tc-99m sestamibi: comparison with first-pass radionuclide
angiography. J Nucl Cardiol. 1999;6:412–417.
79. Vaduganathan P, He ZX, Vick GW 3rd, Mahmarian JJ, Verani MS. Evaluation
of left ventricular wall motion, volumes, and ejection fraction by gated myocar-
dial tomography with technetium 99m-labeled tetrofosmin: a comparison with
cine magnetic resonance imaging. J Nucl Cardiol. 1999;6:3–10.
80. Inubushi M, Tadamura E, Kudoh T, et al. Simultaneous assessment of myocardial
free fatty acid utilization and left ventricular function using123I-BMIPP-gated
SPECT. J Nucl Med. 1999;40:1840–1847.
81. Nichols K, DePuey EG, Rozanski A. Automation of gated tomographic left
ventricular ejection fraction. J Nucl Cardiol. 1996;3:475–482.
82. Everaert H, Bossuyt A, Franken PR. Left ventricular ejection fraction and
volumes from gated single photon emission tomographic myocardial perfusion
images: comparison between two algorithms working in three-dimensional space.
J Nucl Cardiol. 1997;4:472–476.
83. Chua T, Yin LC, Thiang TH, Choo TB, Ping DZ, Leng LY. Accuracy of the
automated assessment of left ventricular function with gated perfusion SPECT in
the presence of perfusion defects and left ventricular dysfunction: correlation
with equilibrium radionuclide ventriculography and echocardiography. J Nucl
84. Abe M, Kazatani Y, Fukuda H, Tatsuno H, Habara H, Shinbata H. Left ventric-
ular volumes, ejection fraction, and regional wall motion calculated with gated
technetium-99m tetrofosmin SPECT in reperfused acute myocardial infarction at
super-acute phase: comparison with left ventriculography. J Nucl Cardiol. 2000;
85. Manrique A, Koning R, Cribier A, Vera P. Effect of temporal sampling on
evaluation of left ventricular ejection fraction by means of thallium-201 gated
SPET: comparison of 16- and 8-interval gating, with reference to equilibrium
radionuclide angiography. Eur J Nucl Med. 2000;27:694–699.
86. Williams KA, Taillon LA. Left ventricular function in patients with coronary
artery disease assessed by gated tomographic myocardial perfusion images:
comparison with assessment by contrast ventriculography and first-pass radionu-
clide angiography. J Am Coll Cardiol. 1996;27:173–181.
87. Rozanski A, Nichols K, Yao SS, Malholtra S, Cohen R, DePuey EG. Develop-
ment and application of normal limits for left ventricular ejection fraction and
volume measurements from99mTc-sestamibi myocardial perfusion gates SPECT.
J Nucl Med. 2000;41:1445–1450.
CLINICAL VALUE OF GATED SPECT • Go et al.