Figure 1 - available via license: CC BY-NC
Content may be subject to copyright.
Source publication
The evaluation of stress-induced myocardial perfusion defects by non-invasive myocardial perfusion imaging (MPI) modalities has a leading role in the identification of coronary artery disease, and has excellent diagnostic and prognostic value. Non-invasive MPI can be performed using conventional and novel gamma cameras or by PET/CT. New software ha...
Context in source publication
Context 1
... gated SPECT allows 2D and 3D LV geometry to be evaluated, providing remodelling parameters, such as eccentricity and the end-diastolic and end-systolic LV shape index (LVSI), which are automatically generated by QGS software (QGIS Development Team). 16 Specifically, eccentricity is a measure of the elongation of the LV, and varies from 0 (sphere) to 1 (line); it is calculated from the major and the minor axes of the ellipsoid that best fits the mid-myocardial surface, while LVSI is calculated as the ratio of the maximum 3D short-and long-axis LV dimension, at end-diastole and at end-systole by applying the algorithm proposed by Abidov et al. 17 The closer the dimensions of the axes are, the more the ellipsoid takes the shape of a sphere (Figure 1). These parameters are highly repeatable and have been shown to have clinical utility in identifying not only patients with an exacerbation of cardiac heart failure but also early LV remodelling in patients with diabetes, demonstrating a prognostic value, even in the presence of normal myocardial perfusion. ...
Similar publications
Citations
... The prognostic value of stress myocardial perfusion single-photon emission computed tomography (MPS) has been widely demonstrated. [1][2][3] Mostly according to clinical status, patients referred to stress-MPS may undergo physical exercise or pharmacological test. For similar levels of coronary atherosclerotic impairment, patients able to exercise demonstrate a better outcome as compared to those undergoing pharmacological stress test due to a number of factors expressing an overall frailty. ...
Background
Chronotropic incompetence is common in patients with cardiovascular disease and is associated with increased risk of adverse events. We assessed the incremental prognostic value of heart rate reserve (HRR) over stress myocardial perfusion single-photon emission computed tomography (MPS) findings in patients with suspected coronary artery disease (CAD).
Methods
We studied 866 patients with suspected CAD undergoing exercise stress-MPS as part of their diagnostic program. The primary study endpoint was all-cause mortality. All patients were followed for at least 5 years. HRR was calculated as the difference between peak exercise and resting HR, divided by the difference of age-predicted maximal and resting HR and expressed as percentage.
Results
During 7 years follow-up, 61 deaths occurred, with a 7% cumulative event rate. Patients experiencing death were older ( P < .001), and had a higher prevalence of male gender ( P < .001) and diabetes ( P < .05). Patients with event also had lower values of HRR (65% ± 27% vs 73% ± 18%, P < .0001) and higher prevalence of stress-induced myocardial ischemia (25% vs 8%, P < .0001). Male gender, HRR and stress-induced ischemia were independent predictors of all-cause mortality (all P < .01). HRR improved the prognostic power of a model including clinical data and MPS findings, increasing the global χ ² from 66 to 82 ( P < .005).
Conclusions
Chronotropic incompetence has independent and incremental prognostic value in predicting all-cause mortality in patients with suspected CAD undergoing exercise stress-MPS. Hence, the evaluation of HRR may further improve patients’ risk stratification.
... 5 Moreover, SPECT perfusion imaging provides other useful information with diagnostic and prognostic value such as regional wall motion and thickening, ejection fraction and left ventricular geometry indices. [6][7][8] Another tracer that can be used in the evaluation of AAR and of the extent of myocardial salvage is the 123 Ib-methyliodo-phenyl pentadecanoic acid ( 123 I-BMIPP). Rest imaging of 123 I-BMIPP is related to its metabolism in the mitochondria. ...
Objectives. In this work, we proposed a deep-learning segmentation algorithm for cardiac magnetic resonance imaging to aid in contouring of the left ventricle, right ventricle, and Myocardium (Myo). Approach. We proposed a shifted window multilayer perceptron (Swin-MLP) mixer network which is built upon a 3D U-shaped symmetric encoder-decoder structure. We evaluated our proposed network using public data from 100 individuals. The network performance was quantitatively evaluated using 3D volume similarity between the ground truth contours and the predictions using Dice score coefficient, sensitivity, and precision as well as 2D surface similarity using Hausdorff distance (HD), mean surface distance (MSD) and residual mean square distance (RMSD). We benchmarked the performance against two other current leading edge networks known as Dynamic UNet and Swin-UNetr on the same public dataset. Results. The proposed network achieved the following volume similarity metrics when averaged over three cardiac segments: Dice = 0.952 ± 0.017, precision = 0.948 ± 0.016, sensitivity = 0.956 ± 0.022. The average surface similarities were HD = 1.521 ± 0.121 mm, MSD = 0.266 ± 0.075 mm, and RMSD = 0.668 ± 0.288 mm. The network shows statistically significant improvement in comparison to the Dynamic UNet and Swin-UNetr algorithms for most volumetric and surface metrics with p-value less than 0.05. Overall, the proposed Swin-MLP mixer network demonstrates better or comparable performance than competing methods. Significance. The proposed Swin-MLP mixer network demonstrates more accurate segmentation performance compared to current leading edge methods. This robust method demonstrates the potential to streamline clinical workflows for multiple applications.
Coronary artery disease (CAD) is one of the most common causes of mortality both in Russia and worldwide, which necessitates the development of diagnostic methods for detecting and localizing pathology in coronary vessels at the earliest stages. Among the non-invasive diagnostic methods, one of the most common and effective is myocardial perfusion imaging using single-photon emission computed tomography (SPECT), which, however, only allows for semi-quantitative assessment. Quantitative assessment is possible using positron emission tomography combined with computed tomography (PET/CT), including the use of 82Rb-chloride as a tracer. The aim of this study was to evaluate the feasibility of applying the SPECT technique proposed by Ansheles et al. in 2015, for the detection of early perfusion abnormalities, analyze the results obtained, and determine the differences in the use of the 15-segment and 17-segment myocardial division schemes in PET with rubidium-82 chloride. Materials and methods: PET studies with rubidium-82 chloride were conducted on 10 patients with symptoms of CAD but without coronary artery stenosis according to coronary angiography. Perfusion severity indices and perfusion heterogeneity indices were calculated for each patient using both the standard 17-segment model and the previously proposed 15-segment model. Results: Statistically significant differences between the 17-segment and 15-segment models were only observed when assessing the heterogeneity index at rest; in other cases, no statistically significant differences were found between the two models, indicating the possibility of using the 15-segment model for calculating quantitative parameters. Both models showed a lack of correlation between perfusion severity indices during rest and stress studies, which may allow for the use of this index in evaluating the presence of microvascular abnormalities. No statistically significant differences were found between men and women in the analysis of these indices...
