tellurium and Myocardial-Ischemia

Whether estimates of myocardial perfusion reserve (MPR) stemming from new-generation cadmium-zinc-telluride (CZT) cameras are accurate remains unclear.. We queried our institutional database for patients undergoing MPR with CZT cameras. The primary goal was appraising the incremental diagnostic yield of MPR on top or at odds of maximal ischemia score (MIS).. A total of 66 subjects were included. When distinguishing patients according to normal vs abnormal MPR (cut-off 2.1 mL/min/g) and normal vs abnormal MIS, 4 groups could be identified: 12 (18.1%) individuals with normal MPR and MIS, 12 (18.1%) with normal MPR and abnormal MIS, 16 (24.2%) with abnormal MPR and normal MIS, and 26 (39.4%) with abnormal MPR and MIS. MIS was significantly associated with several baseline features, whereas MPR did not. There was no significant association between MPR and MIS, nor with regional perfusion. Clinical outcomes were uncommon and not significantly associated with MPR or MIS, whereas angiographically significant coronary artery disease (CAD) was associated solely with MIS (P < 0.05), and not with MPR.. There is limited agreement between CZT-derived MPR and baseline risk, perfusion and angiography results. Whether such discrepancies may still prove incrementally beneficial for the diagnosis or prognosis of CAD remains unclear.

Topics: Aged; Aged, 80 and over; Cadmium; Female; Fractional Flow Reserve, Myocardial; Gamma Cameras; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Predictive Value of Tests; Retrospective Studies; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

Topics: Cadmium; Fractional Flow Reserve, Myocardial; Gamma Cameras; Humans; Myocardial Ischemia; Myocardial Perfusion Imaging; Predictive Value of Tests; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

The aim of this study was to compare the diagnostic performances for the detection of myocardial ischemia of 82-Rb-PET-MPS and 99m-Tc-SPECT-MPS in overweight individuals and women.. Men with BMI ≥ 25 and women referred for MPS were considered for inclusion. All individuals underwent 99m-Tc-SPECT-MPS with CZT cameras and 82-Rb-PET-MPS in 3D-mode. Individuals with at least one positive MPS were referred for coronary angiography (CA) with FFR measurements. A criterion for positivity was a composite endpoint including significant stenosis on CA or, in the absence of CA, the occurrence of acute coronary event during the following year. 313 patients (46% women) with mean BMI of 31.8 ± 6.5 were included. Sensitivity for the detection of myocardial ischemia was higher with 82-Rb-PET-MPS compared with 99m-Tc-SPECT-MPS (85% vs. 57%, P < .05); specificity was equally high with both imaging techniques (93% vs. 94%, P > .05). 82-Rb-PET allowed for a more accurate detection of patients with a high-risk coronary artery disease (HR-CAD) than 99m-Tc-SPECT-MPS (AUC = 0.86 vs. 0.75, respectively; P = .04).. In women and overweight individuals, 82-Rb-PET-MPS provides higher sensitivity for the detection of myocardial ischemia than 99m-Tc-SPECT-MPS thanks to a better image quality and an improved detection of HR-CAD.

Topics: Aged; Area Under Curve; Body Mass Index; Cadmium; Coronary Artery Disease; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Overweight; Positron-Emission Tomography; Reproducibility of Results; Risk Factors; Rubidium; Sensitivity and Specificity; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

Upper reference limits for transient ischemic dilation (TID) have not been rigorously established for cadmium-zinc-telluride (CZT) camera systems. We aimed to derive TID limits for common myocardial perfusion imaging protocols utilizing a large, multicenter registry (REFINE SPECT).. One thousand six hundred and seventy-two patients with low likelihood of coronary artery disease with normal perfusion findings were identified. Images were processed with Quantitative Perfusion SPECT software (Cedars-Sinai Medical Center, Los Angeles, CA). Non-attenuation-corrected, camera-, radiotracer-, and stress protocol-specific TID limits in supine position were derived from 97.5th percentile and mean + 2 standard deviations (SD). Reference limits were compared for different solid-state cameras (D-SPECT vs. Discovery), radiotracers (technetium-99m-sestamibi vs. tetrofosmin), different types of stress (exercise vs. four different vasodilator-based protocols), and different vasodilator-based protocols.. TID measurements did not follow Gaussian distribution in six out of eight subgroups. TID limits ranged from 1.18 to 1.52 (97.5th percentile) and 1.18 to 1.39 (mean + 2SD). No difference was noted between D-SPECT and Discovery cameras (P = 0.71) while differences between exercise and vasodilator-based protocols (adenosine, regadenoson, or regadenoson-walk) were noted (all P < 0.05).. We used a multicenter registry to establish camera-, radiotracer-, and protocol-specific upper reference limits of TID for supine position on CZT camera systems. Reference limits did not differ between D-SPECT and Discovery camera.

Topics: Adult; Aged; Cadmium; Female; Gamma Cameras; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Registries; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

The aim of this study was to compare CZT-SPECT (CZT SPECT) to conventional SPECT (C-SPECT) in the assessment of left ventricular myocardial scar, contractile function, and mechanical synchrony in patients with heart failure (HF).. There was a good correlation between CZT SPECT and C-SPECT for SRS and TPD. CZT SPECT tended to underestimate SRS and TPD compared to C-SPECT. CZT-SPECT and C-SPECT showed excellent agreement in assessing the perfusion/metabolism pattern though a small proportion of normal segments (6.6%) identified by CZT/PET exhibited mismatch pattern on C-SPECT/PET. CZT SPECT also showed excellent correlation with C-SPECT in measuring EDV, ESV, and EF. Finally, BW and SD measured by CZT SPECT correlated well with C-SPECT but CZT SPECT tended to overestimate BW and SD compared to C-SPECT.. CZT SPECT provided comparable data to C-SPECT for measuring LV scar, function and synchrony at a considerable reduction in imaging time. CZT SPECT holds a promise for comprehensive evaluation of myocardial performance in patients with HF.

Topics: Adult; Aged; Automation; Cadmium; Cicatrix; Female; Heart Failure; Heart Ventricles; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Myocardium; Semiconductors; Software; Stroke Volume; Technetium Tc 99m Sestamibi; Tellurium; Tomography, Emission-Computed, Single-Photon; Ventricular Function, Left; Zinc

In myocardial perfusion imaging (MPI), single-photon emission tomography (SPECT) soft-tissue attenuation by the abdomen, breasts, and lateral chest wall may create artifacts that mimic true perfusion defects. This may cause misdiagnosis of myocardial perfusion. The aim of the present study was to compare the localization, extent, and depth of attenuation artifacts in MPI SPECT for a multi-pinhole cadmium zinc telluride (CZT) camera vs a conventional gamma camera.. Phantom and patient measurements were performed using a CZT camera (GE NM 530c) and a conventional gamma camera (GE Ventri). All images were attenuation corrected with externally acquired low-dose computed tomography. The localization, extent, and depth of the attenuation artifact were quantified by comparing attenuation-corrected and non-attenuation-corrected images.. Attenuation artifacts were shifted from the inferolateral wall to the lateral wall using the CZT camera compared to a conventional camera in both the patient and the phantom. The extent of the attenuation artifact was significantly larger for the CZT camera compared to the conventional camera (23 ± 5% vs 15 ± 5%, P < .001) for patients and the result was similar for the phantom (28% vs 19%). Furthermore, the depth of the attenuation artifact (percent of maximum counts) was less pronounced for the CZT camera than for the conventional camera, both for phantom measurements (73% vs 67%) and patients (72 ± 3% vs 68 ± 4%, P < .001).. Attenuation artifacts are found in different locations to different extents and depths when using a CZT camera vs a conventional gamma camera for MPI SPECT. This should be taken into consideration when evaluating MPI SPECT studies to avoid misinterpretation of myocardial perfusion distribution.

Topics: Aged; Aged, 80 and over; Artifacts; Cadmium; Female; Gamma Cameras; Heart; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Myocardium; Perfusion; Phantoms, Imaging; Tellurium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Zinc

The purpose of this study was to assess the prognostic value of ultra-low dose thallium myocardial perfusion imaging. Three hundred and sixty-six patients (245 men) underwent ultra-low dose stress-redistribution imaging on CZT SPECT camera GE Discovery NM 530c. The stress test was performed by bicycle ergometry or regadenoson injection. The activity of 0.5 MBq (0.014 mCi) Tl-201 chloride per kilogram of body weight was administered. The stress images were acquired immediately and redistribution images were taken after 3 h. Patient follow-up was focused on combined end-point (death, myocardial infarction, unstable angina, revascularization and hospitalization for heart failure). Data analysis was performed from hospital database, with a mean period 23 months. Patients with revascularization within 1 month after SPECT was excluded as revascularization for diagnosis. Ischaemia on SPECT was found in 72 patients, 294 patients were without ischaemia. In patients with ischaemia there were 21 (29.2%) subjects with cardiac events, and 23 (7.9%) in patients without ischaemia (HR 4.15, 95% CI 2.30-7.51, p < 0.0001). Ultra-low dose thallium perfusion imaging using CZT camera provides very good prognostic results in assessment of myocardial ischaemia.

Topics: Aged; Cadmium; Coronary Circulation; Disease Progression; Equipment Design; Exercise Test; Female; Gamma Cameras; Humans; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Pilot Projects; Predictive Value of Tests; Prognosis; Purines; Pyrazoles; Radiation Dosage; Radiation Exposure; Radiopharmaceuticals; Reproducibility of Results; Tellurium; Thallium Radioisotopes; Time Factors; Tomography, Emission-Computed, Single-Photon; Vasodilator Agents; Zinc

Attenuation correction (AC) improves the diagnostic outcome of stress-only myocardial perfusion imaging (MPI) using conventional SPECT. Our aim was to determine the value of AC using a cadmium zinc telluride-based (CZT)-SPECT camera.. We retrospectively included 107 consecutive patients who underwent stress-optional rest MPI CZT-SPECT/CT. Next, we created three types of images for each patient; (1) only displaying reconstructed data without the CT-based AC (NC), (2) only displaying AC, and (3) with both NC and AC (NC + AC). Next, two experienced physicians visually interpreted these 321 randomized images as normal, equivocal, or abnormal. Image outcome was compared with all hard events over a mean follow-up time of 47.7 ± 9.8 months. The percentage of images interpreted as normal increased from 45% using the NC images to 72% using AC and to 67% using NC + AC images (P < .001). Hard event hazard ratios for images interpreted as normal were not different between using NC and AC (1.01, P = .99), or NC and NC + AC images (0.97, P = .97).. AC lowers the need for additional rest imaging in stress-first MPI using CZT-SPECT, while long-term patient outcome remained identical. Use of AC reduces the need for additional rest imaging, decreasing the mean effective dose by up to 1.2 mSv.

Topics: Algorithms; Artifacts; Cadmium; Equipment Design; Equipment Failure Analysis; Exercise Test; Humans; Image Enhancement; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Netherlands; Observer Variation; Prevalence; Prognosis; Radionuclide Imaging; Reproducibility of Results; Sensitivity and Specificity; Survival Rate; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc

The aim of this study was to evaluate the possible impact of stress-induced left ventricular (LV) diastolic dysfunction at cadmium-zinc-telluride (CZT) imaging, on the detection of significant coronary artery disease (CAD).. Four hundred and twenty-five consecutive patients underwent myocardial perfusion imaging at rest and after stress with a low-dose CZT protocol and the evaluation of coronary anatomy by invasive or computed coronary angiography. The summed difference score (SDS) was calculated in every patient. Left ventricular ejection fraction and peak filling rate (PFR) at baseline and after stress were derived from gated CZT images and the '% stress-to-rest' PFR difference, as an indicator of stress-induced diastolic dysfunction, determined. In the study population, the mean SDS was 5 ± 4, while mean stress PFR and rest PFR were 2.5 ± 0.8 end-diastolic volumes (EDV)/s and 2.5 ± 0.7 EDV/s, respectively. There was a strict correlation between the presence and extent of CAD and both myocardial SDS and '% stress-to-rest' PFR (P < 0.001 for both). Interestingly, while myocardial SDS and '% stress-to-rest' PFR were significantly correlated (P < 0.001), they resulted independent predictors of the presence of significant CAD (P < 0.001 and P < 0.032, respectively). Of note, at receiving operating characteristic analysis, a '% stress-to-rest' PFR ≤3 showed 71% sensitivity in unmasking the presence of significant coronary luminal narrowings.. The present study shows that the assessment of stress-induced diastolic dysfunction with an ultrafast scintigraphic protocol can improve the accuracy in detection of significant ischaemic heart disease.

Topics: Aged; Aged, 80 and over; Cadmium; Cohort Studies; Confidence Intervals; Coronary Angiography; Coronary Artery Disease; Disease Progression; Exercise Test; Female; Follow-Up Studies; Humans; Logistic Models; Male; Middle Aged; Myocardial Ischemia; Myocardial Perfusion Imaging; Odds Ratio; Retrospective Studies; ROC Curve; Sensitivity and Specificity; Severity of Illness Index; Stroke Volume; Tellurium; Tomography, X-Ray Computed; Ventricular Dysfunction, Left; Zinc

The new multipinhole cardiac single photon emission computed tomography/computed tomography (SPECT/CT) cameras with cadmium-zinc-telluride (CZT) detectors are highly sensitive and produce images of high quality but rely on complex dedicated reconstruction algorithms. The aim of this study was to determine the impact of various processing steps on image formation and in the detection of ischaemia in CZT-SPECT/CT both with and without attenuation correction (AC).. Data on 20 consecutive patients who underwent a 1-day protocol stress-rest SPECT/CT using 99mTc-tetrofosmin were processed twice by three experienced operators, yielding 120 AC and 120 noncorrected (NC) data sets. Processing steps included selection and determination of myocardial axes, manual SPECT/CT coregistration for AC and myocardial masking. Using the 17-segment cardiac model, differences between stress and rest segmental uptake (%) were calculated for NC and AC image sets. Both interoperator and intraoperator variations were considered significant for the diagnosis of ischaemia when greater than 5%.. The mean interoperator variations were 2.4±1.4% (NC) and 3.8±1.9% (AC) (P<0.01). In 6% (NC) and 23% (AC) of the 120 processed cases, operator variation was larger than 5% and therefore potentially clinically interfering with the diagnosis of ischaemia. Differences between interoperator and intraoperator variations were nonsignificant.. Operator variations in the processing of myocardial perfusion image data using CZT-SPECT/CT are significant and may influence the diagnosis of ischaemia, especially when AC is applied. Clearer guidelines for image processing are necessary to improve the reproducibility of the studies and to obtain a more reliable diagnosis of ischaemia.

Topics: Adult; Aged; Cadmium; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Multimodal Imaging; Myocardial Ischemia; Myocardial Perfusion Imaging; Observer Variation; Tellurium; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Zinc

To investigate the relationships between regional adrenergic innervation heterogeneity, myocardial perfusion, and contractile function obtained by means of a low-dose imaging protocol with a cadmium-zinc-telluride (CZT) dedicated camera.. Twenty-eight patients with or without ischaemic heart disease underwent (123)I-metaiodobenzylguanidine (MIBG) planar scintigraphic and CZT early and delayed evaluations followed by (99m)Tc-tetrofosmin rest gated CZT with a single-day protocol. The heart-to-mediastinum ratio and the washout rate were computed from planar (123)I-MIBG images. The summed (123)I-MIBG defect scores (SS-MIBG) were semi-quantitatively assessed from CZT images. The summed rest score (SRS), summed motion score (SMS), and summed thickening score (STS) were quantitated from (99m)Tc-tetrofosmin images.. Sixteen patients showed a depressed left ventricular systolic function [ejection fraction (EF)<50%]. They presented higher SRS (P = 0.007), SMS (P < 0.001), STS (P < 0.001), and early SS-MIBG (P = 0.007) values than those with normal contractile function. Interestingly, higher early SS-MIBG values, index of regional sympathetic innervation heterogeneity, clustered with more elevated SRS (P = 0.023), and more impaired measures of regional and global left ventricle systolic function, i.e. SMS (P = 0.046), STS (P = 0.014), and EF (P = 0.027). At multivariate analysis, a higher SRS (P = 0.039) remained the only independent predictor of more elevated early SS-MIBG values. In the 20 of 28 ischaemic patients, the correlations between early SS-MIBG and SMS (P = 0.017) and also STS (P = 0.036) were further confirmed. The effective dose of the investigation was 4.2 ± 0.72 mSv.. An altered early SS-MIBG, assessed with a low-dose imaging protocol and a CZT cardiac camera, identifies patients with more impaired myocardial perfusion and contractile function.

Topics: 3-Iodobenzylguanidine; Adrenergic Neurons; Aged; Cadmium; Female; Heart; Humans; Male; Middle Aged; Myocardial Ischemia; Organophosphorus Compounds; Organotechnetium Compounds; Radiographic Image Interpretation, Computer-Assisted; Radiopharmaceuticals; Tellurium; Tomography, Emission-Computed, Single-Photon; Zinc