Related Experiment Video
Updated: May 22, 2026
Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Assessment of transient ischemic dilation (TID) ratio in gated SPECT myocardial perfusion imaging (MPI) using
1Department of Medicine, Beth Israel Medical Center, Manhattan Campus of the Albert Einstein College of Medicine, New York, NY, USA. jkatz@chpnet.org
Insights
Transient ischemic dilation (TID) ratio abnormalities correlate with coronary artery disease (CAD) severity. This study found TID levels in gated single-photon emission computed tomography myocardial perfusion imaging (MPI) are associated with the extent of CAD detected via angiography.
Area of Science:
- Cardiology
- Nuclear Medicine
- Radiology
Background:
- Abnormal transient ischemic dilation (TID) ratios indicate severe and extensive coronary artery disease (CAD).
- Regadenoson gated single-photon emission computed tomography myocardial perfusion imaging (MPI) assesses ventricular volumes at rest and during stress.
Purpose of the Study:
- To establish the relationship between the TID ratio, derived from regadenoson gated SPECT MPI, and the extent of CAD identified through coronary angiography.
- To evaluate TID as a potential non-invasive marker for CAD severity.
Main Methods:
- Analysis of 195 patients who underwent dual isotope MPI with regadenoson and coronary angiography.
- Calculation of TID ratios using Emory Cardiac Toolbox software.
- Comparison of mean TID values across different CAD classifications (non-obstructive, single-vessel, multi-vessel disease).
Main Results:
- The mean TID ratio for non-obstructive CAD was 1.09 (SD 0.15).
- Patients with multi-vessel CAD showed a higher mean TID ratio (1.19, SD 0.26).
- An abnormal TID ratio was significantly associated with multi-vessel disease (OR 3.4).
Conclusions:
- The TID ratio in regadenoson gated SPECT MPI is linked to the degree of CAD.
- A TID threshold of 1.39 demonstrated 95% specificity for identifying multi-vessel CAD.
- TID analysis during MPI can aid in assessing CAD extent.
Background:
Abnormal values of the transient ischemic dilation (TID) ratio are associated with severe and extensive coronary artery disease (CAD). The objective of this study was to determine the relationship between TID, determined from stress and rest ventricular volumes during regadenoson gated single-photon emission computed tomography myocardial perfusion imaging (MPI) dual isotope studies, and the extent of CAD found during coronary angiography.
Methods:
195 patients who underwent dual isotope MPI with regadenoson and cardiac angiography between March 2009 and February 2010 were analyzed. TID was calculated using commercially available software, Emory Cardiac Toolbox. Mean TID values were compared across disease types. A threshold for abnormal TID was determined by adding two standard deviations (SDs) to the mean TID of the "non-obstructive CAD" subgroup.
Results:
In the 195-patient group analyzed, the mean TID ratio for non-obstructive CAD (n = 104) was found to be 1.09 with a SD of 0.15. In a subgroup of patients whose angiogram was within 3 months of MPI (n = 155), the mean TIDs for non-obstructive disease (n = 81), single-vessel disease (n = 35), and multi-vessel disease (n = 39) were 1.09, 1.15, and 1.19 with SDs of 0.16, 0.19, and 0.26, respectively. Those with an abnormal TID had a crude and adjusted odds ratio of 3.4 for multi-vessel disease which was statistically significant. History of diabetes was not found to be a significant confounder, effect modifier, or mediator of the relationship between the TID and the vessel disease.
Conclusion:
The mean TID ratio in patients with multi-vessel disease was 1.19. The threshold for an abnormal TID was 1.39 with specificity of 95% and sensitivity of 15% for determining multi-vessel CAD status. We conclude that the level of TID in gated SPECT MPI using regadenoson is associated with the degree of CAD on angiography.
Related Concept Videos
01:13Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...
01:21Imaging Studies for Cardiovascular System IV: CMRI
01:30Acute Coronary Syndrome III: Diagnostic Studies