Stress and Rest Dynamic Myocardial Perfusion Imaging by Evaluation of Complete Time-Attenuation Curves With Dual-Source CT

Abstract

Vasodilator-stress CT MPI may be feasible in human subjects at a radiation dose similar to NMPI. It identifies areas of abnormal flow reserve and infarction with a high degree of correlation to NMPI as well as to stenoses detected in CTA and ICA.

Infarct characterization using CT

“…The accuracy in the detection of ischemia was investigated by several studies which compared stressrest CCT with SPECT and CMR demonstrating a good agreement and similar sensitivity and specificity (30)(31)(32)(51)(52)(53)(91)(92)(93)(94). In particular, stress perfusion CCT may refine the diagnostic accuracy of CCT alone (52), with increased sensitivity from 83% to 91% and specificity from 71% to 91%.…”

Myocardial perfusion with single-photon emission computed tomography, multidetector computed tomography, or neither?

“…Nonetheless, the importance of an abnormality in myocardial blood flow and tissue perfusion over mere anatomy has been reinforced in invasive clinical trials 1,2 The significance of tissue perfusion has therefore promoted an interest in developing CT protocols that may allow a ''one stop shop'' assessment of anatomical severity and physiological significance of obstructive CAD. [3][4][5][6][7] The assessment of myocardial ischemia with computed tomography is based on a comparison of myocardial enhancement after the infusion of a vasodilator agent, such as adenosine, to myocardial enhancement during rest. This concept is therefore similar to myocardial perfusion imaging with scintigraphy, although the applicable mechanisms are substantially different; transit of iodinated contrast vs extraction of a tracer via a molecular mechanism.…”

Evaluation of Myocardial Ischemia by Multiple Detector Computed Tomography

“…Nos tomógrafos dual source de segunda geração, a aquisição prospectiva axial ou aquisição espiral em high pitch (flash mode) foram utilizadas no lugar da aquisição retrospectiva dos aparelhos de primeira geração. A aquisição dinâmica em "vai e volta" -shuttle mode (movimentação rápida da mesa do tomógrafo entre duas posições com cobertura de todo o coração) 28,30,32,39,[41][42][43] é uma alternativa em crescente investigação. Adicionalmente, sistemas com dual source permitem a realização da dupla energia (dual energy CT) para avaliação dos defeitos de perfusão miocárdica 27,34,40 , com um tubo adquirindo as imagens em 140 kV e outro com 80 kV 34,40 .…”

“…Todos os defeitos são analisados em múltiplas fases para determinar se é um defeito de perfusão real ou artefato 33 . 21,28,[30][31][32][33]36,41,44,[48][49][50][51] . A sensibilidade oscila entre 79% e 97%, e a especificidade, de 72% a 98%, dependendo do equipamento utilizado, padrão de referência, população estudada, e se a análise é por paciente, segmento ou território coronariano.…”