Integrated cardio-thoracic imaging with ECG-Gated 64-slice multidetector-row CT: initial findings in 133 patients

Abstract

The purpose of this study was to investigate the possibility of assessing the underlying respiratory disease as well as cardiac function during ECG-gated CT angiography of the chest with 64-slice multidetector-row CT (MDCT). One hundred thirty-three consecutive patients in sinus rhythm with known or suspected ventricular dysfunction underwent an ECG-gated CT angiographic examination of the chest without beta-blockers using the following parameters: (1) collimation: 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices (Sensation 64; Siemens); rotation time: 0.33 s; pitch: 0.3; 120 kV; 200 mAs; ECG-controlled dose modulation (ECG-pulsing) and (2) 120 ml of a 35% contrast agent. Data were reconstructed: (1) to evaluate the underlying respiratory disease (1-mm thick lung and mediastinal scans reconstructed at 55% of the R-R interval; i.e., "morphologic scans") and (2) to determine right (RVEF) and left (LVEF) ventricular ejection fractions (short-axis systolic and diastolic images; Argus software; i.e., "functional scans"). The mean heart rate was 73 bpm (range: 42-120) and the mean scan time was 18.11 +/- 2.67 s (range: 10-27). A total of 123 examinations (92%) had both lung and mediastinal images rated as diagnostic scans, whereas 10 examinations (8%) had non-diagnostic images altered by the presence of respiratory-motion artifacts (n = 4) or cyclic artifacts related to the use of a pitch value of 0.3 in patients with a very low heart rate during data acquisition (n = 6). Assessment of right and left ventricular function was achievable in 124 patients (93%, 95% CI: 88-97%). For these 124 examinations, the mean RVEF was 46.10% (+/- 9.5; range: 20-72) and the mean LVEF was 58.23% (+/- 10.88; range: 20-83). In the remaining nine patients, an imprecise segmentation of the right and left ventricular cavities was considered as a limiting factor for precise calculation of end-systolic and end-diastolic ventricular volumes. The mean (+/- SD) DLP value of the examinations was 279.86 (+/- 117.50) mGy.cm. Assessment of underlying respiratory disease and cardiac function from the same data set was achievable in 92% of the patients with ECG-gated 64-slice MDCT.

Coronary imaging quality in routine ECG-gated multidetector CT examinations of the entire thorax: preliminary experience with a 64-slice CT system in 133 patients

“…The mean duration of data acquisition was 18.11±2.67 s (range: [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. In our study group, 127 patients (95%) had coronary arteries that could be partially or totally assessed; coronary artery imaging failed in six patients (5%), due to a poor level of enhancement achieved within coronary arteries in five patients (i.e., attenuation values below 200 HU) and alteration of image quality by interpolation artefacts in one patient with a heart rate of 45 bpm.…”

“…In the studied population, CT was indicated for the management of bronchopulmonary (n=102) or pulmonary vascular (n=31) diseases. Detailed description of the studied population and scanning parameters have been reported in a separate study [12]. In the same group of patients who did not receive β-blockers prior to CT scanning, the objective of the present study was to investigate the assessability of coronary arteries acquired by a routine ECG-gated MDCT examination of the chest.…”

Screening for coronary artery disease in respiratory patients: comparison of single- and dual-source CT in patients with a heart rate above 70 bpm

“…Apart from coronary imaging, ECG-gated examinations of the chest can also provide cardiac functional information, of great interest in respiratory patients. Investigating 133 patients with a regular sinus rhythm who did not receive betablockers, Salem et al found that both morphological and functional information could be obtained from the same data set in 92% of the population studied with singlesource MDCT [41]. These recent experiences suggest that respiratory patients can now benefit from cardiothoracic imaging, a concept worth considering in the management of patients with chronic obstructive pulmonary disease (COPD) in whom coronary arteries represent a well-known target of systemic inflammation [42][43][44].…”

Prevelance of aortic root dilation in patients with cta of the aorta

“…without compromising image quality (7,8). Depending on the thoracic dimensions, the scanning time varied between three and four seconds.…”