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Gated Myocardial Perfusion SPECT: Basic Principles, Technical Aspects, and Clinical Applications

Asit K. Paul and Hani A. Nabi
Journal of Nuclear Medicine Technology December 2004, 32 (4) 179-187;

Article Figures & Data

Figures

  • FIGURE 1.
    FIGURE 1.

    Principle of ECG-gated acquisition. R–R interval on ECG, representing 1 cardiac cycle, is typically divided into 8 frames of equal duration (A). Image data from each frame are acquired over multiple cardiac cycles and stored separately in specific locations (“bin”) of computer memory (B). When all data in a bin are added together, image represents a specific phase of cardiac cycle. Typically, a volume curve is obtained, which represents endocardial volume for each of 8 frames (C). ED = end-diastole; ES = end-systole.

  • FIGURE 2.
    FIGURE 2.

    Same-day GSPECT protocols with 99mTc-sestamibi or 99mTc-tetrofosmin. Myocardial perfusion imaging can be gated either at rest or after exercise–stress in stress–rest (A) or rest–stress (B) sequence.

  • FIGURE 3.
    FIGURE 3.

    Assessment of LV regional function by GSPECT. RWM is assessed by inward excursion of endocardial wall (A) and SWT is assessed by myocardial brightening (arrow) from end-diastole to end-systole (B). ED = end-diastole; ES = end-systole; SEPT = septal; ANT = anterior; LAT = lateral.

  • FIGURE 4.
    FIGURE 4.

    Comparison of LVEF between GSPECT and contrast left ventrioculography (LVG) in a patient. ISE = base; ANT = anterior; SEPT = septal; INF = inferior.

  • FIGURE 5.
    FIGURE 5.

    GSPECT shows preserved SWT of anterior wall of LV, suggesting presence of attenuation artifact rather than true infarct.

Tables

  • TABLE 1

    Acquisition Parameters for GSPECT with 99mTc-Perfusion Tracers

    ParameterCharacteristic
    γ-CameraDual or triple detector
    CollimatorLow energy, high resolution
    Orbit180° (dual detector) or 360° (triple detector)
    Projections32∼64
    Acquisition time/projection>25 s
    Matrix64 × 64
    Framing8∼16/R–R interval
    Beat acceptance±20%
    Total acquisition time∼20–30 min
  • TABLE 2

    Repeatability of Gated SPECT Measurements

    ReferenceParameterNo. of patientsMeasurementAgreement
    YearAuthor
    1997Johnson et al. (23)LVEF15Consecutive daysr = 0.98, SD = 2.6%
    1998Berman et al. (24)LVEF180Proner = 0.93, SD = 3.2%
    EDV180Supiner = 0.97, SD = 2.6 mL
    ESV180Same-day consecutive scansr = 0.98, SD = 4.8 mL
    2001Paeng et al. (25)RWM31Same-day consecutive scansr = 0.95 (quantitative); 79%*, κ = 0.81 (visual)
    SWT31Same-day consecutive scansr = 0.88 (quantitative); 71%*, κ = 0.71 (visual)

    • ↵* Exact segmental agreement.

    • κ = Cohen’s κ.

    • Measurements were performed using QGS software (18,19).

  • TABLE 3

    Validation of LV Volumes and EF Measurements Obtained by GSPECT

    ReferenceStudy patientsNo. of patientsModality of comparisonr with GSPECT measurements
    YearAuthorEDVESVLVEF
    1999Vaduganathan et al. (26)Recent MI25MRI0.810.920.93
    1999Tadamura et al. (27)CAD20MRI0.920.970.94
    2000Bavelaar-Croon et al. (28)CAD21MRI0.940.950.85
    2000Bax et al. (29)CAD with LV dysfunction25MRI0.840.870.90
    1998Nichols et al. (30)CAD58LVG0.870.910.86
    1999Yoshioka et al. (31)Mixed21LVG0.730.830.87
    1999Cwajg et al. (32)Mixed109Echo0.870.860.72
    2001Vourvouri et al. (33)CAD with LV dysfunction32Echo0.940.960.83
    2000Paul et al. (34)Mixed15ERNA (tomographic)0.990.990.97
    2000Chua et al. (35)CAD with large defect62ERNA (planar)0.880.950.94

    • MI = myocardial infarction; LVG = contrast left ventriculography; Echo = echocardiography.

  • TABLE 4

    Validation of LV Regional Function Obtained by GSPECT

    ReferencePatientsNo. of patientsNo. of segmentsGSPECT evaluationModality of comparisonExact agreement, κ value
    YearAuthorRWMSWT
    1997Gunning et al. (38)Mixed28252Visual, SQMRI78%, 0.6678%, 0.62
    1999Tadamura et al. (27)CAD20180Visual, SQMRI84%, 0.7387%, 0.76
    1999Tadamura et al. (39)After CABG16128Visual, SQMRINA76%, 0.62
    2001Wahba et al. (40)CAD21273Visual, SQMRI84%, 0.7286%, 0.77
    1994Chua et al. (41)CAD40640Visual, SQEcho91%, 0.6890%, 0.62
    1997Germano et al. (19)Mixed791,580QuantitativeVisual, SQ GSPECT73%, 0.4375%, 0.41
    2000Sharir et al. (58)Mixed1002,000QuantitativeVisual, SQ GSPECT80%, 0.7186%, 0.68

    • κ = Cohen’s κ; SQ = semiquantitative; CABG = coronary artery bypass graft; NA = not available; Echo = echocardiography.

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