Original articleHow image quality can be improved: our experience with multidetector computed tomography coronary angiography
Introduction
Coronary artery disease is the leading cause of death in the world [1]. Catheter coronary angiography (CA) is the gold standard in diagnosing coronary artery disease; however, because of its disadvantages (e.g., mortality, morbidity, and cost), noninvasive alternatives are highly needed [2], [3]. Electron beam computed tomography (CT), magnetic resonance imaging, and multidetector CT (MDCT) are noninvasive alternatives that provide direct visualization of the coronary vessels.
The availability of 16-detector row CT with rapid image acquisition and improved temporal and spatial resolutions has allowed for accurate imaging of the heart and coronary vessels. Although CT scanners with more detector rows are now available, 16-detector row CT is more commonly used. Similarly, in this study, 16-detector row CT was used. Because patient selection, patient preparation, speed of contrast agent administration, scanning delay between the start of contrast injection and that of the scan, scanning protocol, and postprocessing have remained to be controversial, this study aimed to define the parameters that may affect the quality of final images by evaluating the quality of the MDCT images of 224 patients.
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Patient selection
The study included 224 consecutive patients (161 men and 63 women; mean age, 52 years; age range, 34–76 years) who were referred to our unit for coronary artery imaging owing to findings of typical or atypical angina pectoris or to abnormal results from noninvasive physiologic tests for ischemia. Multidetector CT angiography was not used on patients with sustained arrhythmia, known allergic reaction to contrast media, deteriorated renal function (serum creatinine >1.5 mg/dl), pregnancy,
Results
Two hundred twenty-four consecutive patients (161 men and 63 women; mean age, 52 years; age range, 34–76 years) were imaged. All CT scans were acquired without any complication.
The HRs of 17 (7.5%) patients were lower than 70 bpm; thus, they did not require metoprolol administration. In the remaining 207 (92.5%) patients, a mean dose of 13.9 mg (range, 5–20 mg) of metoprolol was required. The HRs of 14 (6.7%) patients remained between 70 and 90 bpm despite metoprolol administration of 20 mg.
The
Discussion
It is important to obtain high-quality images across a wide patient spectrum to attain a correct interpretation by coronary artery CT angiography. The quality of an image is a result of a combination of spatial, temporal, and contrast resolutions [5]. The small-sized and mobile coronary arteries place great demands on the spatial resolution that must be achieved for adequate imaging. At present, MDCT systems provide better image quality with higher temporal and spatial resolutions at a shorter
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