A novel clinically relevant segmentation method and corresponding maximal ischemia score to risk-stratify patients undergoing myocardial perfusion scintigraphy

Abstract

Our novel segmentation method and corresponding MIS efficiently yield satisfactory prognostic information.

Prognostic impact of location and extent of vessel-related ischemia at myocardial perfusion scintigraphy in patients with or at risk for coronary artery disease

“…1 Stress/rest myocardial perfusion scintigraphy (MPS) is particularly useful in this setting, as it can combine exercise testing (or pharmacologic stress) with accompanying ECG analysis to detailed multiparametric imaging aimed at quantifying the severity, location, and extent of reversible (i.e., myocardial ischemia) as well as irreversible deficits (i.e., necrosis), enabling a precise three-dimensional characterization of myocardial pathophysiology. 2 Indeed, the prognostic impact of moderate or severe ischemia at MPS is well established, [2][3][4] and the same applies to extent of ischemia. 5,6 Demonstration at coronary angiography of a significant stenosis involving the left anterior descending (LAD) has a key impact on prognosis and ensuing management strategy.…”

Cadmium-zinc-telluride myocardial perfusion imaging: The dream of a single test gets nearer

“…[1][2][3] Myocardial perfusion imaging (MPI) with singlephoton emission computed tomography (SPECT) embodies the key strengths of non-invasive functional cardiovascular tests, by combining the physiologic details provided by stress testing (exercise or pharmacologic) with accurate information on myocardial perfusion, viability, and contractility, thus justifying its historically prominent role in cardiovascular imaging. 1,[4][5][6] The traditional acquisition technology for SPECT is the Anger camera, which has good diagnostic and excellent prognostic accuracy, as demonstrated by several studies with large sample size, despite its evident limitations in terms of spatial and energy resolution, as well as acquisition times. 7 The recent introduction of the cadmium-zinc-telluride (CZT) cameras for SPECT has purportedly revolutionized MPI, thanks to their superior spatial and energy resolution.…”

“…18 Focusing on positive tests, the expected pros of CZT are a more correct classification of ischemic patients in terms of ischemia severity (e.g., in keeping with the Maximal Ischemia Score [MIS], distinguishing minimal, mild, moderate or severe ischemia), extension, and involvement of the corresponding coronary vessel, in particular, the left anterior descending (e.g., single-vessel-related ischemia [VRI] versus multiple VRI, with or without left anterior descending involvement). 4,5 Accordingly, we may more accurately proceed with risk stratification and choice of subsequent clinical management. Focusing on the evaluation of end-diastolic perfusion, another advantage of CZT is the possibility of significantly reducing false-positive results in patients with left bundle branch block (Figure 1), who typically display a perfusion abnormality which is more severe in the endsystolic phase than in the end-diastolic phase, at odds with ischemic patients (Figure 2).…”

Bridging the Atlantic gap in clinical guidelines for non-ST-elevation acute coronary syndromes

“…For instance, MPI scoring systems enable a more detailed characterization of the patient, but are more demanding. 6 Some differences regarding the use of diagnostic tests between American and European guidelines can be explained by the fact that access to invasive angiography is easier and more proactive in the US, resulting in fewer noninvasive imaging tests. 3 The same explanation may apply to the stronger recommendations favoring CT and anatomic details in American guidelines.…”

“…4,7 For instance, CT-derived anatomic imaging, which provides for instance details on lesion location, plaque features, vessel remodeling, calcium score, and stenosis severity can be seamlessly combined with MPI-derived functional imaging, which yields several functional parameters provided by MPI, including, most recently, coronary flow reserve. 6,[13][14][15] Thus, hybrid imaging provides many important results which are complementarily associated with pre-test and stress features, enabling the best clustering of the patient into a low-risk group, or otherwise prompting expedited invasive assessment, or guiding postdischarge management and follow-up.…”