Myocardial perfusion imaging using adenosine-induced stress dual-energy computed tomography of the heart: comparison with cardiac magnetic resonance imaging and conventional coronary angiography.
ABSTRACT To evaluate the feasibility and diagnostic accuracy of adenosine-stress dual-energy computed tomography (DECT) for detecting haemodynamically significant stenosis causing reversible myocardial perfusion defect (PD) compared with stress perfusion magnetic resonance imaging (SP-MRI) and conventional coronary angiography (CCA).
Fifty patients with known coronary artery disease (CAD) detected by dual-source CT (DSCT) were investigated by contrast-enhanced, stress DECT with high- and low-energy x-ray spectra settings during adenosine infusion. A colour-coded iodine map was used for evaluation of myocardial PDs compared with rest DSCT perfusion images. Reversible myocardial PDs according to the stress DECT/rest DSCT were compared with SP-MRI on a segmental basis and CCA on a vascular territorial basis.
A total of 697 myocardial segments and 123 vascular territories of 41 patients were analysed. Three hundred one segments and 72 vascular territories in 38 patients showed reversible PDs on stress DECT. Stress DECT had 89% sensitivity, 78% specificity and 82% accuracy for detecting segments with reversible PDs seen on SP-MRI (n=28). Compared with CCA (n=41), stress DECT had 89% sensitivity, 76% specificity and 83% accuracy for the detection of vascular territories with reversible myocardial PDs that had haemodynamically relevant CAD.
Adenosine stress DECT can identify stress-induced myocardial PD in patients with CAD.
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ABSTRACT: We assessed the diagnostic performance of stress- and rest-dual-energy computed tomography (DECT) and their incremental value when used with coronary CT angiography (CCTA) compared with combined invasive coronary angiography (ICA)/cardiovascular magnetic resonance (CMR) for detecting hemodynamically significant stenosis causing a myocardial perfusion defect. Forty patients (30 men; mean age, 63.4 ± 8.8 years) with known or suspected coronary artery disease detected by CCTA underwent stress- and rest-DECT, CMR, and ICA. DECT iodine maps were compared with CMR on a per-segment and per-vessel basis. Diagnostic value of CCTA was assessed on a per-vessel basis before and after stress- and rest-DECT and compared to that of ICA/CMR. Compared to CMR, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of rest-DECT for detecting segment (vessel)-based perfusion defects were 29 % (46 %), 88 % (79 %), 56 % (61 %), and 70 % (67 %), respectively. Corresponding values using stress-DECT were 73 % (94 %), 83 % (74 %), 70 % (72 %), and 85 % (95 %), respectively. There was fair (κ = 0.39) agreement between rest- and stress-DECT iodine maps in identifying segments with perfusion defects. Compared with the ICA/CMR for identifying hemodynamically significant stenoses, per-vessel territory sensitivity, specificity, PPV, and NPV of CCTA were 91, 56, 55, and 91 %, respectively; those using CCTA/rest-DECT were 42, 83, 59, and 70 %, respectively; and those using CCTA/stress-DECT were 87, 79, 71, and 91 %, respectively. The area under the receiver operating characteristic curve decreased from 0.74 to 0.62 (P = 0.06) using CCTA/rest-DECT but increased to 0.83 (P = 0.02) using CCTA/stress-DECT. Stress-DECT has incremental value when used with CCTA for detecting hemodynamically significant stenoses.The international journal of cardiovascular imaging 04/2014; · 2.15 Impact Factor
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ABSTRACT: Computed tomographic (CT) coronary angiography is a well-established, noninvasive imaging modality for detection of coronary stenosis, but it has limited accuracy in demonstrating whether a coronary stenosis is hemodynamically significant. An additional functional test is often required because both anatomic and functional information is needed for guiding patient care. Recent developments in CT technology allow CT evaluation of myocardial perfusion during vasodilator stress, thereby providing information about myocardial ischemia. Investigators in several single-center studies have established the feasibility of performing stress myocardial perfusion CT imaging in small groups of patients and have shown that stress myocardial perfusion CT in combination with CT coronary angiography improved the diagnostic accuracy in comparison with CT coronary angiography alone. However, CT perfusion acquisition protocols must be optimized in terms of acquisition and reconstruction parameters, contrast material protocol injections, and radiation dose. Further research is needed to establish the clinical usefulness of this novel technique. The purpose of this review is to (a) provide an overview of the physiology of coronary circulation and myocardial perfusion; (b) describe the technical prerequisites, challenges, and mathematic modeling related to CT perfusion imaging; (c) note recent advances in CT scanners and CT perfusion protocols; and (d) discuss the interpretation of CT perfusion images. Finally, a review and summary of the current literature are provided, and future directions for research are discussed. © RSNA, 2014.Radiology 01/2014; 270(1):25-46. · 6.34 Impact Factor
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ABSTRACT: To determine the effect of reduced 80-kV tube voltage with increased 370-mAs tube current on radiation dose, image quality and estimated myocardial blood flow (MBF) of dynamic CT stress myocardial perfusion imaging (CTP) in patients with a normal body mass index (BMI) compared with a 100-kV and 300-mAs protocol. Thirty patients with a normal BMI (<25 kg/m(2)) with known or suspected coronary artery disease underwent adenosine-stress dual-source dynamic CTP. Patients were randomised to 80-kV/370-mAs (n = 15) or 100-kV/300-mAs (n = 15) imaging. Maximal enhancement and noise of the left ventricular (LV) cavity, contrast-to-noise ratio (CNR) and MBF of the two groups were compared. Imaging with 80-kV/370-mAs instead of 100-kV/300-mAs was associated with 40 % lower radiation dose (mean dose-length product, 359 ± 66 vs 628 ± 112 mGy[Symbol: see text]cm; P < 0.001 ) with no significant difference in CNR (34.5 ± 13.4 vs 33.5 ± 10.4; P = 0.81) or MBF in non-ischaemic myocardium (0.95 ± 0.20 vs 0.99 ± 0.25 ml/min/g; P = 0.66). Studies obtained using 80-kV/370-mAs were associated with 30.9 % higher maximal enhancement (804 ± 204 vs 614 ± 115 HU; P < 0.005), and 31.2 % greater noise (22.7 ± 3.5 vs 17.4 ± 2.6; P < 0.001). Dynamic CTP using 80-kV/370-mA instead of 100-kV/300-mAs allowed 40 % dose reduction without compromising image quality or MBF. Tube voltage of 80-kV should be considered for individuals with a normal BMI. • CT stress perfusion imaging (CTP) is increasingly used to assess myocardial function. • Dynamic CTP is feasible at 80-kV in patients with normal BMI. • An 80-kV/370-mAs protocol allows 40 % dose reduction compared with 100-kV/300-mAs. • Contrast-to-noise ratio and myocardial blood flow of the two protocols were comparable.European Radiology 11/2013; · 4.34 Impact Factor