Aligning Coronary Anatomy and Myocardial Perfusion Territories

Abstract

A ppropriate clinical decisions concerning diagnosis and treatment of coronary artery disease rely on the correct integration of data on coronary anatomy and myocardial perfusion.1 Revascularization of coronary stenosis is only justified if it relieves angina complaints and improves patient outcome, which depends on the extent and severity of inducible myocardial ischemia related to the lesion. 2-5 Clinical Perspective on p 595In clinical practice, conventional coronary angiography (CCA) and single-photon emission tomography myocardial perfusion imaging (single-photon emission computed tomography [SPECT]) are the standard imaging methods for detection and quantification of coronary artery stenosis and myocardial perfusion defects. To define a treatment strategy, physicians must mentally create a correlation map, merging the anatomical data from CCA, a projection-imaging method, with the functional data from SPECT, a mix of projection and tomographic imaging methods, overcoming image foreshortening, differences on image-acquisition times, and differences in spatial and temporal resolution between the methods.Myocardial perfusion defects have also been assigned to vascular territories using left ventricular segmentation models. [6][7][8] This approach is usually applied in research settings, where standardization between different imaging methods is attempted. However, standard assumptions about the vascular territory distribution in myocardial perfusion analysis are frequently inaccurate because of morphologic variability in the Background-Appropriate clinical decisions concerning diagnosis and treatment of coronary artery disease rely on correct integration of data on coronary anatomy and myocardial perfusion. The purpose of this article is to introduce a new left ventricular segmentation model for improved alignment of coronary arterial segments and myocardial perfusion territories, designed for the CORE320 study. Methods and Results-CORE320 is a prospective, multicenter study with a primary objective to evaluate the diagnostic accuracy of 320-row detector computed tomography (CT) to detect coronary artery luminal stenosis and corresponding myocardial perfusion deficits in patients with suspected coronary artery disease compared with the gold standard of conventional coronary angiography and single-photon emission CT myocardial perfusion imaging. We describe a 19-coronary segment and 13-myocardial territory alignment model, its application in both standard and CT image data sets, and the adjudication process of the initial cohort of patients recruited for the CORE320 study. Adjudication committees reviewed the images of the first 101 gold standard and 107 CT data sets. On the basis of the presented model and rules, all cases for adjudication were correctly identified. During image review, 6 (5.9%) gold standard and 9 (8.4%) CT data sets needed further realignment not triggered by the algorithm. Conclusions-We present a vascular territory distribution model developed for the CORE320 multicenter study, which acco...

Myocardial Blood Flow and Flow Reserve in Proximal and Mid-to-Distal Lesions of Left Anterior Descending Artery Measured By N-13 Ammonia PET/CT

“…They were divided into two groups by the location of stenosis: three patients with stenoses in proximal LAD (pLAD group), and eight patients with stenoses in mid-to-distal LAD (mdLAD group). The borderline of proximal and mid-to-distal LAD was the origin of the first diagonal branch, as previously suggested [5,13]. The severity of stenosis was >50 % in all cases, and anomaly of coronary arterial origin or course was not observed.…”

“…Myocardial perfusion imaging (MPI) possesses an essential role as a gatekeeper to discriminate those lesions needed to be invasively approached, because unnecessary invasive treatment for coronary stenosis with normal perfusion may lead to unexpected adverse events [1]. In such perspective, many studies to establish the way to find the "culprit" vessel or lesion have been conducted and various assignments of vascular territory to myocardial segments have been introduced [2][3][4][5].…”

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

“…3,6,[13][14][15][16][17] To date, efforts aiming at a more precise characterization of the impact of ischemia extent on prognosis have been limited. [14][15][16][17][18][19][20] Pivotal randomized trials, meta-analyses, and ensuing guidelines have conversely explicitly clarified the importance of angiographically defined LAD disease and multivessel disease in terms of prognosis, but also in terms of incremental benefits if revascularization is preferred over medical therapy. [7][8][9]13 Accordingly, guidelines recommend coronary revascularization in patients with the above features, 8,9,13 with CABG favored whenever disease is diffuse or extensive.…”

Computed Tomographic Perfusion Improves Diagnostic Power of Coronary Computed Tomographic Angiography in Women

“…20 Computed tomographic image acquisition has been previously described in detail. 15,[20][21][22] All CTA and CTP images were reconstructed, processed, and interpreted by 2 blinded core laboratories. 18,19 As previously described, a summed stress score ≥2 for CTP and ≥1 for SPECT was considered positive using a 13-segment myocardial model.…”

“…18,19 As previously described, a summed stress score ≥2 for CTP and ≥1 for SPECT was considered positive using a 13-segment myocardial model. 21,22 Clinically indicated ICA was performed within 60 days of the combined CTA-CTP acquisition, and lesion severity was determined by quantitative coronary angiography methods as previously described. 15 SPECT and ICA images were interpreted in blinded core laboratories using previously described methods.…”