The relationship between stress-induced myocardial ischemia and coronary artery atherosclerosis measured by hybrid SPECT/CT camera

Abstract

Objective: The coronary artery calcium (CAC) score and myocardial perfusion imaging can now be detected simultaneously using a hybrid SPECT/CT camera. However, there has been little evaluation on the relationship between stress-induced ischemia and coronary artery calcification in a Japanese population. The aim of this study was to investigate the relationship between these parameters and to elucidate the diagnostic value of the CAC score as an adjunct to myocardial perfusion imaging (MPI) for the assessment of coronary artery disease (CAD) in an intermediate-risk population.Methods: We retrospectively analyzed 105 patients (63% men, mean age 71 years) with CAD or suspected CAD who underwent MPI using SPECT/CT. CAC scanning was performed by using a SPECT/CT camera. Results: There was a significant difference in the CAC score between patients with ischemia (n=42) and those without ischemia

Clinical Implications of the Coronary Artery Calcium Score in Japanese Patients

“…Our previous study showed that the prevalence of obstructive CAD in subjects with stenosis of ＞50% in diameter on coronary angiography increases across increasing CAC categories (CAC score = 0, 5%; 1-99, 36%; 100-399, 78%; 400-999, 80%; and ≥ 1,000, 94%) 26) . In addition, a previous study using a hybrid single photon emission computed tomography (SPECT)/CT camera showed that the extent of myocardial perfusion defects tends to worsen as the degree of coronary calcification increases 31) . Furthermore, in a study of 92 patients with 819 segments who underwent invasive CT angiography, the accuracy of a CAC score of 0 was excellent (93%) and a higher number of stenosed vessels was found to be associated with a higher CAC score 32) .…”

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

“…4 In patients with NSTEACS the management approach is of course altogether different, but discrepancies are evident also on the diagnostic approach. [1][2][3] Indeed, in NSTEACS, at odds with stable CAD, pre-test probability of CAD receives much lesser emphasis.…”

“…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.…”

Nuclear myocardial perfusion imaging using thallium-201 with a novel multifocal collimator SPECT/CT: IQ-SPECT versus conventional protocols in normal subjects

“…The study protocol is illustrated in Figure 1. Acquisition was performed using large-field measurements on Symbia T6 dual-head hybrid SPECT/CT cameras (Siemens Medical Solutions, Munich, Germany) equipped with a conventional gamma camera system (Siemens ECAM) or with a multifocal collimator called IQ-SPECT [13]. ECG-gated SPECT images were acquired with a 64x64 matrix, 6˚ step, and 360˚ rotation.…”

“…SPECT/CT allowed acquisition of MPI imaging and a CT scan, and fusion and registration of the two images. Complementary information such as calcium scoring could be obtained with SPECT/CT [13], although Symbia T6 cannot perform CT coronary angiography for fusion imaging between CT and MPI [14]. Attenuation correction could be successfully achieved with a CT attenuation map, and this method is more patient-specific to compensate for attenuation [17].…”