Subtraction Coronary CT Angiography for the Evaluation of Severely Calcified Lesions Using a 320-Detector Row Scanner
One of the major challenges in coronary computed tomography (CT) is the presence of severe calcification, which may interfere with the assessment of lesions and may reduce diagnostic accuracy. However, such calcifications may potentially be eliminated by subtracting precontrast CT image data from contrast-enhanced coronary CT angiography data. Such examinations require perfect alignment and can be performed in two ways: 1) the “single breath-hold method,” in which both precontrast and postcontrast CT data are acquired during a breath-hold, and 2) the “two breath-hold method,” in which the calcium scoring data are used as the precontrast CT data. Misregistration artifacts must be corrected manually based on visual assessment, which results in long image processing times. Although a number of challenges remain to be overcome, subtraction coronary CT angiography might improve the diagnostic accuracy of coronary CT angiography in patients with severe calcification in the future.
KeywordsComputed tomography 320-detector row computed tomography Wide-area computed tomography Angiography Coronary artery Coronary artery disease Calcification Subtraction Imaging
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