Diagnosing Heart Disease
Diagnosing heart disease in women—the No. 1 cause of death of women across the globe—is sometimes difficult, but molecular PET and SPECT imaging is beginning to contribute to resolving this problem.
This is quite necessary as women’s cardiac disease is frequently under-diagnosed—for instance, women who suffer a myocardial infarction are more likely to die from it than men with infarctions.
Coronary disease detection using perfusion imaging in women is problematic due to erroneous underestimation of pre-test likelihood. In addition, technical problems such as breast tissue attenuation artifacts complicate image interpretation.
PET/CT’s ability to correct for soft-tissue attenuation, and its excellent spatial and temporal resolution allows it to quantify blood flow in the various regions of the heart in units of ml/g/min. Using this approach, small vessel disease, common in women, can be diagnosed accurately. Quantification of myocardial perfusion, which is possible with PET, but not with SPECT, also provides an advantage for diagnosing multi-vessel disease. Changes in left ventricular ejection fraction from rest to peak stress, another marker of ischemia, can be measured.
With SPECT/CT, appropriate soft-tissue attenuation correction is now possible—reducing the number of false positive findings. High-end CT systems combined with PET or SPECT can be used to assess the coronary morphology non-invasively (CT angiography). For those cardiologists who consider this meaningful, calcium scores also can be obtained.
Thus, PET/CT with imaging probes such as 13N-ammonia or 82Rubidium can be used to accurately survey the coronary system in “at-risk” patients, in women who have traditionally been underserved by myocardial perfusion imaging, and in patients with known coronary artery disease. The effects of life-style or drug interventions can be monitored effectively.
By providing such comprehensive assessments of cardiac function, PET/CT and SPECT/CT will improve the outcome of patients with heart disease.
Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology
Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography
David Geffen School of Medicine at UCLA, Los Angeles, Calif.
This is quite necessary as women’s cardiac disease is frequently under-diagnosed—for instance, women who suffer a myocardial infarction are more likely to die from it than men with infarctions.
Coronary disease detection using perfusion imaging in women is problematic due to erroneous underestimation of pre-test likelihood. In addition, technical problems such as breast tissue attenuation artifacts complicate image interpretation.
PET/CT’s ability to correct for soft-tissue attenuation, and its excellent spatial and temporal resolution allows it to quantify blood flow in the various regions of the heart in units of ml/g/min. Using this approach, small vessel disease, common in women, can be diagnosed accurately. Quantification of myocardial perfusion, which is possible with PET, but not with SPECT, also provides an advantage for diagnosing multi-vessel disease. Changes in left ventricular ejection fraction from rest to peak stress, another marker of ischemia, can be measured.
With SPECT/CT, appropriate soft-tissue attenuation correction is now possible—reducing the number of false positive findings. High-end CT systems combined with PET or SPECT can be used to assess the coronary morphology non-invasively (CT angiography). For those cardiologists who consider this meaningful, calcium scores also can be obtained.
Thus, PET/CT with imaging probes such as 13N-ammonia or 82Rubidium can be used to accurately survey the coronary system in “at-risk” patients, in women who have traditionally been underserved by myocardial perfusion imaging, and in patients with known coronary artery disease. The effects of life-style or drug interventions can be monitored effectively.
By providing such comprehensive assessments of cardiac function, PET/CT and SPECT/CT will improve the outcome of patients with heart disease.
Johannes Czernin, MD
Professor, Molecular & Medical Pharmacology
Director, Nuclear Medicine Clinic, Positron Emission Tomography/Computed Tomography
David Geffen School of Medicine at UCLA, Los Angeles, Calif.