High-speed Myocardial Perfusion Imaging Research Articles

Diagnostic value of stress thallium-201/rest technetium-99m-sestamibi sequential dual isotope high-speed myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

BackgroundThe aim of this study was to determine the diagnostic accuracy of stress thallium-201/rest technetium-99m-sestamibi sequential dual-isotope high-speed myocardial perfusion imaging (DI-HS-MPI) against invasively determined fractional flow reserve (FFR). MethodsFifty-four consecutive patients prospectively underwent DI-HS-MPI before invasive coronary angiography. Perfusion was scored visually by summed stress score on a patient and coronary territory basis. Significant coronary artery disease (CAD) was defined by the presence of ≥ 90% stenosis/occlusion or fractional flow reserve ≤ 0.80 for coronary stenosis ≥ 50%. ResultsFFR was measured in 69 of 162 coronary vessels, with 1.28 ± 0.56 vessels assessed/patient. Sensitivity, specificity, and diagnostic accuracy of MPI for the detection of significant CAD were 92.8%, 69.2%, and 81.4%, on a patient basis, and 83.7%, 90.4%, and 88.8% by coronary territory. ConclusionsDI-HS-MPI accurately detects functionally significant CAD as defined by using FFR.

0054: Validation of stress thallium-201/rest technetium-99m sequential dual isotope high-speed myocardial perfusion imaging against fractional flow reserve for the detection of the extent of ischemia

The aim of this study was to determine the diagnostic accuracy of stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging (DI-HS-MPI) against invasively determined fractional flow reserve (FFR) and to establish the correlation between myocardium at risk defined by using the invasive BARI-score and DI-HS-MPI. Relatively few studies have compared the diagnostic performance of new Cadmium Zinc Telluride - cameras versus FFR. Fifty-four patients referred for angiography underwent DI-HSMPI. Perfusion was scored visually by summed stress score (SSS) on a patient and coronary territory basis, and ischemic burden was calculated by quantitative segmentation of the extent of ischemia. Significant coronary artery disease (CAD) was defined by the presence of ≥90% stenosis/occlusion or fractional flow reserve ≤0.80 in vessels >2mm. The relation between FFR and perfusion was determined for each vascular zone. The BARI-score was calculated from the coronary angiograms to quantify the myocardium at risk. FFR was measured in 70 of 162 coronary vessels; Vessels FFR measured per patient was 1.3±0.57. Sensitivity, specificity, and diagnostic accuracy of MPI for the detection of significant CAD were 92%, 88%, and 90% by coronary territory and 87%, 93%, and 92%, on a patient basis. The area under the summary receiver-operating characteristic at the patient level was 0.94 (95% CI: 0.88 to 1) and 0.90 (95% CI: 0.83 to 0.97) at the artery and territory levels, respectively. The mean ischemic burden for MPI and BARI-score showed a strong correlation between techniques (r=0.71, P<0.0001). Stress thallium-201/rest technetium-99m sequential DI-HSMPI accurately detects functionally significant CAD as defined by using FFR and provides an assessment of ischemic burden in agreement with the invasive BARI-score.

Rapid Fire Abstract session: usefulness of CT and radionuclide imaging in different clinical scenarios378Improving the cost-effectiveness of chest pain investigations using single photon emission computed tomography379Is autonomic nervous dysfunction severity associated to less benefit from cardiac resynchronization therapy?380Validation of stress Thallium-201/Rest Technetium-99m sequential dual isotope high-speed myocardial perfusion imaging against fractional flow reserve for the detection of the extent of

Rapid Fire Abstract session: usefulness of CT and radionuclide imaging in different clinical scenarios378Improving the cost-effectiveness of chest pain investigations using single photon emission computed tomography379Is autonomic nervous dysfunction severity associated to less benefit from cardiac resynchronization therapy?380Validation of stress Thallium-201/Rest Technetium-99m sequential dual isotope high-speed myocardial perfusion imaging against fractional flow reserve for the detection of the extent of

Stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging validation versus invasive coronary angiography

BackgroundRecent advances in nuclear myocardial perfusion imaging (MPI) have made it possible to develop a dual-isotope protocol for high-speed acquisition with image quality and radiation delivery comparable to that obtained with conventional single isotope protocols. So far, no study has compared dual-isotope high-speed MPI to invasive coronary angiography (ICA) in a large cohort using a Cadmium-zinc-telluride SPECT system. MethodsOver a 1-year period (May 2011 to April 2012), 1366 patients underwent dual-isotope high-speed MPI. Patients with ICA within 3 months after dual-isotope high-speed MPI were included together with patients with a low likelihood of coronary artery disease (CAD) in order to assess normalcy rate. Global summed stress score (SSS) and summed rest score (SRS) were calculated, and ICA results were analyzed independently. The main end point was a patient-based assessment of the diagnostic performance of dual-isotope high-speed MPI in detecting or ruling out significant CAD (>70% reduction in lumen diameter). ResultsInclusion criteria were fulfilled for 214 patients (143 men; age 60 ± 14 years; ICA, n = 104; low likelihood for CAD, n = 110). An exercise stress test was performed in 62% of patients and a pharmacological stress test was performed with either dipyridamole (32%) or dobutamine (6%). Average examination duration was 22.4 ± 4.5 minutes. Mean SSS, SRS, and SDS were 8.0 ± 4.9, 3.1 ± 4.3, and 5.0 ± 3.2, respectively. Prevalence of angiographic CAD was 75%. ICA detected stenosis in the left main trunk, left anterior descending artery, left circumflex artery, and right coronary artery in 4, 33, 31, and 42 patients, respectively. Sensitivity of dual-isotope high-speed MPI was 94%, normalcy rate was 92%, and accuracy was 83% for detecting CAD. ConclusionDual-isotope high-speed MPI is reliable at detecting or ruling out CAD. NCT01785589

Initial multicentre experience of high-speed myocardial perfusion imaging: comparison between high-speed and conventional single-photon emission computed tomography with angiographic validation

High-speed (HS) single-photon emission computed tomography (SPECT) with a recently developed solid-state camera shows comparable myocardial perfusion abnormalities to those seen in conventional SPECT. We aimed to compare HS and conventional SPECT images from multiple centres with coronary angiographic findings. The study included 50 patients who had sequential conventional SPECT and HS SPECT myocardial perfusion studies and coronary angiography within 3 months. Stress and rest perfusion images were visually analysed and scored semiquantitatively using a 17-segment model by two experienced blinded readers. Global and coronary territorial summed stress scores (SSS) and summed rest scores (SRS) were calculated. Global SSS ≥3 or coronary territorial SSS ≥2 was considered abnormal. In addition the total perfusion deficit (TPD) was automatically derived. TPD >5% and coronary territorial TPD ≥3% were defined as abnormal. Coronary angiograms were analysed for site and severity of coronary stenosis; ≥50% was considered significant. Of the 50 patients, 13 (26%) had no stenosis, 22 (44%) had single-vessel disease, 6 (12%) had double-vessel disease and 9 (18%) had triple-vessel disease. There was a good linear correlation between the visual global SSS and SRS (Spearman's ρ 0.897 and 0.866, respectively; p < 0.001). In relation to coronary angiography, the sensitivities, specificities and accuracies of HS SPECT and conventional SPECT by visual assessment were 92% (35/38), 83% (10/12) and 90% (45/50) vs. 84% (32/38), 50% (6/12) and 76% (38/50), respectively (p < 0.001). The sensitivities, specificities and accuracies of HS SPECT and conventional SPECT in relation to automated TPD assessment were 89% (31/35), 57% (8/14) and 80% (39/49) vs. 86% (31/36), 77% (10/13) and 84% (41/49), respectively. HS SPECT allows fast acquisition of myocardial perfusion images that correlate well with angiographic findings with overall accuracy by visual assessment better than conventional SPECT. Further assessment in a larger patient population may be needed to confirm this observation.

117: Direct comparison of stress Thallium-201/Rest Technetium-99m dual isotope perfusion imaging with Cadmium-Zinc-Telluride detector versus standard dual detector camera

Recent advances in nuclear myocardial perfusion imaging (MPI) have provided opportunity for improved image information with an important reduction of exam time and radiation. This technology can be used to explore novel protocols (dual isotope high-speed MPI). Today, two devices exist: D-SPECT and Discovery NM 530c (DNM) camera. With D-SPECT, it was showed that rapid stress Tl-201/rest Tc-99m protocol for use with high-speed MPI has offered the superior qualities of Tl-201 for stress imaging and of the Tc-99m agents for rest imaging can be preserved. However, no study has evaluated the same dual-isotope protocol with the other system. A total of 38 consecutive patients underwent simultaneous dual-radionuclide (stress thallium-201/rest technetium-99m) perfusion imaging with a DNM camera and standard dual dectector camera (S-SPECT) during the month of May 2011. All patients successfully underwent stress/rest MPI with both cameras. In 38 patients (50%) pharmacological stress was induced with dipyridamole. DNM SPECT SSS and SRS correlated linearly with conventional S-SPECT respective scores (r=0.84, p<0.0001 for SSS, and r=0.94, p<0.0001 for SRS). On Bland-Altman analysis there was good agreement between the two imaging methods with a shift for both SSS and SRS (mean difference = 1, 95% confidence interval = −3.74 – 5.74 for SSS; mean difference = −3.0, 95% confidence interval = −3.13 – 3.91 for SRS). The analyze revealed a perfusion defect in both the S-SPECT and DNM scans but systematically perfusionnels defects or scars were more extensive with the DNM-camera. Overall image quality was good to excellent. Our study showed a clinical agreement of 96% between the DNM camera and S-SPECT MPI. The effective dose was 11.9 mSv for the study protocol, with 9.7 mSv coming from the Tl-201. The DNM camera such as D-SPECT camera provides clinical information equivalent to conventional standard SPECT MPI.

Prognostic value of quantitative high-speed myocardial perfusion imaging

BackgroundWe studied the prognostic value of fully automated quantitative analysis software applied to new solid-state, high-speed (HS) SPECT-myocardial perfusion imaging (MPI). Methods1,613 consecutive patients undergoing exercise or adenosine HS-MPI were followed for 2.6 ± 0.5 years for all-cause mortality (ACM). Automated quantitative software was used to compute stress total perfusion deficit (sTPD) and was compared to semi-quantitative visual analysis. MPI was characterized as 0% (normal), 1%-4% (minimal perfusion defect), 5%-10% (mildly abnormal), and >10% (moderately/severely abnormal). ResultsDuring follow-up, 79 patients died (4.9%). Annualized ACM increased with progressively increasing sTPD; 0% (0.87%), 1%-4% (1.94%), 5%-10% (3.10%), and >10% (5.33%) (log-rank P < .0001). While similar overall findings were observed with visual analysis, only sTPD demonstrated increased risk in patients with minimal perfusion defects. In multivariable analysis, sTPD > 10% was a mortality predictor (HR 3.03, 95% CI 1.30-7.09, P = .01). Adjusted mortality rate was substantial in adenosine MPI, but low in exercise MPI (9.0% vs 1.0%, P < .0001). ConclusionsBy quantitative analysis, ACM increases with increasing perfusion abnormality among patients undergoing stress HS-MPI. These findings confirm previous results obtained with visual analysis using conventional Anger camera imaging systems.

Stress Thallium-201/Rest Technetium-99m Sequential Dual Isotope High-Speed Myocardial Perfusion Imaging

Our purpose was to describe a novel, rapid stress thallium-201 (Tl-201)/rest technetium-99m (Tc-99m) agent myocardial perfusion imaging (MPI) protocol (Tl/Tc) with a high-speed MPI scanner and to compare this protocol with a standard rest/stress Tc-99m agent protocol (Tc/Tc) with respect to image quality and radiation dosimetry. Recent advances in gamma camera technology have provided opportunity for improved SPECT MPI protocols. A rapid Tl/Tc protocol that could improve image information while maintaining a low radiation burden for the patient would be desirable. We compared high-speed SPECT MPI studies in 374 consecutive patients undergoing exercise or pharmacologic Tl/Tc protocol to those of 262 patients undergoing rest/stress Tc/Tc protocol. Tl/Tc imaging was accomplished in <20 min. Overall image quality was good to excellent in 96% and 98% of patients with the Tl/Tc and the Tc/Tc protocols, respectively (p = ns). Beginning rest imaging within 2 min after rest injection with the Tl/Tc protocol did not result in reduced confidence in image interpretation. Early rest Tc images of the Tl/Tc protocol showed less extracardiac activity than was observed on standard rest imaging used in the Tc/Tc protocol (84% vs. 61%), respectively (p < 0.01). The normalcy rate was high in both groups (100% vs. 92%). Radiation burden was similar between the Tl/Tc and Tc/Tc protocols. A rapid stress Tl-201/rest Tc-99m protocol for use with high-speed SPECT MPI has image quality and radiation dosimetry similar to those observed with a conventional rest/stress Tc-99m protocol. The Tl/Tc protocol offers promise as an efficient and relatively low radiation dose method, in which the superior qualities of Tl-201 for stress imaging and of the Tc-99m agents for rest imaging can be preserved. The findings also suggest that with rapid imaging rest MPI immediately after Tc-99m agent injection may be superior to standard delayed image initiation.

Abstract 5818: Stress Thallium-201/Rest Tc-99m Sequential Dual Isotope High-Speed Myocardial Perfusion Imaging

Recent advances in gamma camera technology are providing opportunities for novel high-speed myocardial perfusion imaging (HS-MPI) protocols. We aimed to develop and evaluate a stress thallium-201 (Tl-201) and rest Tc-99m sestamibi or tetrofosmin imaging protocol that could reduce imaging time and radiation burden. Methods: We studied 410 consecutive patients undergoing exercise or pharmacologic low-dose stress Tl-201 HS-MPI (4 min/acquisition) in the semi-upright and supine positions (D-SPECT, Spectrum-Dynamics) followed by rest Tc-99m sestamibi (n= 139) or tetrofosmin (n= 271) with immediate post-injection rest imaging. Of 330 patients with no known coronary artery disease (CAD), 29 patients also underwent invasive coronary angiography (ICA) or coronary computed tomography angiography (CCTA) within a three month period and 36 had a &lt; 5% pre-test likelihood of CAD (LLk). Despite low injected doses [Tl-201 (2.2± 0.3 mCi) and Tc-99m sestamibi or tetrofosmin (8.9± 2.4 mCi), the 3 acquisition MPI protocol (2 stress/1 rest) was accomplished &lt; 20 minutes. The quality of stress and resting image was good to excellent in &gt;96% of cases; importantly, no or minor extracardiac activity was seen on 99% of stress and 93% of rest images. HS-MPI was nondiagnostic or uninterpretable in only 2/410 patients. In the 29 patients with CCTA or ICA, the sensitivity and specificity for the detection of ≥70% stenosis were 73% and 89%, respectively, and in 15 patients with ICA, the sensitivity was 89%. The normalcy rate in the LLk group was 100%. A fast stress Tl-201/rest Tc-99m HS-MPI protocol offers promise as a time-efficient, low radiation dose method, in which the superior qualities of Tl-201 for stress imaging and of Tc-99m agents for rest imaging can be utilized.

2.09: Validation of quantitative analysis of high-speed myocardial perfusion imaging: Comparison to conventional SPECT imaging

2.09: Validation of quantitative analysis of high-speed myocardial perfusion imaging: Comparison to conventional SPECT imaging

High-Speed Myocardial Perfusion Imaging: Initial Clinical Comparison With Conventional Dual Detector Anger Camera Imaging

The purpose of this study was to compare myocardial perfusion imaging (MPI) with high-speed single-photon emission computed tomography (SPECT) with conventional SPECT imaging for the evaluation of myocardial perfusion in patients with known or suspected coronary artery disease. A novel technology has been developed for high-speed SPECT MPI by employing a bank of independently controlled detector columns with large-hole tungsten collimators and multiple cadmium zinc telluride crystal arrays. A total of 44 patients (39 men) underwent same-day Tc-99m sestamibi stress/rest MPI. High-speed SPECT images were performed within 30 min after conventional SPECT. Stress and rest acquisition times were 16 and 12 min for conventional imaging and 4 and 2 min for high-speed SPECT, respectively. Myocardial counts/min (cpm) were calculated for both conventional SPECT and high-speed SPECT. Images were visually analyzed, and the summed stress score (SSS) and summed rest score (SRS) were calculated. Image quality and diagnostic confidence were qualitatively assessed. High-speed SPECT SSS and SRS correlated linearly with conventional SPECT respective scores (r = 0.93, p < 0.0001 for SSS, and r = 0.93, p < 0.0001 for SRS). Image quality was rated good and higher in 17 (94%) cases for high-speed SPECT and 16 (89%) cases for conventional SPECT. Of the 44 patients studied, 36 (81.8%) and 35 (79.5%) were diagnosed definitely normal or abnormal by conventional and high-speed SPECT, respectively (p = NS). Myocardial count rate was significantly higher in high-speed versus conventional SPECT (384 x 10(-3) +/- 134 x 10(-3) cpm/min vs. 47 x 10(-3) +/- 14 x 10(-3) cpm/min, respectively, p < 0.0001) for stress and (962 x 10(-3) +/- 426 x 10(-3) cpm/min vs. 136 x 10(-3) +/- 37 x 10(-3) cpm/min, respectively, p < 0.001) for rest. High-speed SPECT provides fast MPI with high image quality and up to 8 times increased system sensitivity. The amount of perfusion abnormality visualized by high-speed SPECT is highly correlated to conventional SPECT, with an equivalent level of diagnostic confidence.