PET MPI Statistics

PET Myocardial Perfusion Image Quality ChartImage Quality

PET Myocardial Perfusion provides excellent spatial resolution and attenuation correction. The enhanced image quality for PET MPI vs. SPECT is due to:

  • Higher count rates (240% increase over SPECT)
  • Improved spatial resolution
  • Routine and robust attenuation correction on all scans
  • Images can be sliced at 3mm (PET MPI) instead of 6mm (SPECT) to better detect multi-vessel disease

Diagnostic Accuracy

PET myocardial perfusion has a 95% sensitivity and 95% specificity for detecting coronary artery disease, while SPECT myocardial perfusion has an 87% sensitivity and 73% specificity for detection.

Diagnostic Accuracy by Gender

P=0.55 (MEN); P=0.009 (WOMEN)

Diagnostic Accuracy Chart by Gender

Diagnostic Accuracy by BMI

P=0.05 (BMI<30); P=0.02 (BMI>30)

Diagnostic Accuracy by BMI Chart

MVD Sensitivity

P=0.03

MVD Sensitivity Chart

Degrees of Interpretive Certainty

Interpretive Certainty

Better images means greater diagnostic confidence. The literature suggests that PET Myocardial Perfusion images can be read with 96% interpretive certainty vs. 82% with SPECT.

Interpretive Certainty Chart

Prognostic Value

Obese patients who are often difficult to image with SPECT had excellent outcomes using PET MPI with Rb-82. The graph below has a curve that shows the difference between survival, free from any cardiac events, for patients with a normal vs. an abnormal PET MPI scan. This study also went on to show that for hard cardiac events (cardiac death & MI), patients with a normal PET scan had a 0% annualized event rate, which is quite impressive.

Prognostic Value Chart One

The graph below depicts the prognostic value in all patient types using Rb-82 PET MPI, which is ultimately useful in making patient management decisions.

Prognostic Value Chart Two

Rubidium-82

Half life is 75 seconds; dose range is 20-60 mCi. Rb-82 has a high myocardial extraction fraction at peak stress flow; tracer uptake is more proportional to myocardial blood flow and facilitates better detection of disease.

Pharmacokinetics

PET MPI uses higher energy tracers 511keV v. 140KeV for SPECT; this leads to higher count rates and improved image quality.

Artifacts

PET MPI offers attenuation correction on all scans, reduces ambiguity, enhances interpretive certainty

Scan Time Efficiency

30 minutes for PET MPI for gated rest/stress v. 2.5-4 hours for SPECT

PET MPI v. SPECT

Characteristics of SPECT vs. PET MPI
PET SPECT
Availability Limited Wide
Attenuation correction Accurate Less accurate
Spatial resolution 5–7 mm 12–15 mm
Protocol < 1 hour 2 days
Radiation < 10 mSv > 10 mSv
Images Quantitative Qualitative
Hybrid with CT Yes Yes

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