Hybrid SPECT/CT for Attenuation Correction of Stress Myocardial Perfusion Imaging

Abstract

Attenuation correction using Hybrid SPECT/CT improved specificity in the right coronary artery, but decreased specificity in the left anterior descending. This technique is likely to be more useful in men than in women.

Diagnostic performance of myocardial perfusion single-photon emission computed tomography with attenuation correction

“…An improved detection rate of the left anterior descending CAD was also reported by Shotwell et al [5] Improvement of specificity the detection of stenosed LAD observed in our study indicates that AC did not introduce additional artefacts in the anterior wall of myocardium, an argument that is raised by authors against application of AC [17]. Several authors have reported such artefacts [18,19], including recently Huang et al [10], who observed a reduction of specificity in anterior wall as an effect of AC. Such artefacts are thought to be the effect of overcorrection of the inferior wall [18,19], causing a relative reduction of counts in anterior wall, leading to induction of false perfusion defects.…”

“…This inconsistency of results should be attributed to the high complexity of the method and several sources of variability: the geometry, the kind of transmission source, the software applied for tomographic reconstruction of a study, the structure of the studied group of patients (percentage of patients with negative results of coronary angiography or low probability of CAD), and the methods applied for interpretation of studies. Moreover, many authors use only AC [1,4,9,10,12] while others also apply scatter correction [2,5,13,14] and resolution recovery [13]. In this multitude of factors affecting results of clinical studies it is very difficult to determine the real effect of AC on diagnostic efficacy of detection of CAD.…”

“…Nonetheless, in the results of those studies some trends can be observed. Attenuation correction usually improves normalcy rate or specificity of the study (the latter holds true only if the percentage of patients with negative results of coronary angiography in the whole studied material is high enough) [2,10,15]. Improvement of accuracy can usually be observed as an effect of enhanced specificity, without [5] or with marked decline of sensitivity of the study [9,12].…”

“…Although coronary angiography is not an ideal reference method for myocardial perfusion imaging, it is still used by many authors as a gold standard [5,9,10,12] because no better method of verification of myocardial perfusion study results is available. The prognostic value of this study, treated as a verification method, takes a long time to be determined.…”

“…This results mostly from diverse results of studies applying this correction. As well as studies demonstrating a significant improvement in diagnostic efficacy after AC [1][2][3][4][5], communications on its proper effects only in parts of patients with lack of improvement or even deterioration of diagnostic efficacy in the remaining ones can also be found [6][7][8][9][10]. The present publication is intended to add a point to this debate by determining whether visual, semi-quantitative analysis of AC myocardial perfusion imaging provides an advantage over a non-corrected study.…”