Korean J Radiol.  2019 Dec;20(12):1583-1596. 10.3348/kjr.2019.0327.

Clinical Applications of Wide-Detector CT Scanners for Cardiothoracic Imaging: An Update

• Kang EJ

• KMID: 2471672
• DOI: http://doi.org/10.3348/kjr.2019.0327

Abstract

Technical developments in multidetector computed tomography (CT) have increased the number of detector rows on the z-axis, and 16-cm wide-area-coverage CT scanners have enabled volumetric scanning of the entire heart. Beyond coronary arterial imaging, such innovations offer several advantages during clinical imaging in the cardiothoracic area. The wide-detector CT scanner markedly reduces the image acquisition time to less than 1 second for coronary CT angiography, thereby decreasing the volume of contrast material and radiation dose required for the examination. It also eliminates stair-step artifacts, allowing robust improvements in myocardial function and perfusion imaging. Additionally, new imaging techniques for the cardiothoracic area, including subtraction imaging and free-breathing scans, have been developed and further improved by using the wide-detector CT scanner. This article investigates the technical developments in wide-detector CT scanners, summarizes their clinical applications in the cardiothoracic area, and provides a review of the recent literature.

Keyword

Multidetector computed tomography; Wide-area detector; Coronary artery disease; Imaging; Technology

MeSH Terms

Angiography
Artifacts
Coronary Artery Disease
Heart
Multidetector Computed Tomography
Perfusion Imaging

Figure

• 

  Fig. 1 Representative images of abnormal TAG in LAD of 55-year-old man with nonspecific chest pain.A. Coronary CT angiography showed LAD with significant dense calcified plaque burden that was suspicious for severe obstructive lesion (arrows). B. Invasive coronary angiography showed severe luminal narrowing of LAD (arrows). C. TAG of LAD measured with semi-automated method by using dedicated computer software (Canon Medical Systems). Mean luminal radiologic attenuation (HU) was measured at 1-mm intervals, from ostium to distal level (cross-sectional area < 2 mm2). TAG was −24.98, which indicates significantly low value (generally accepted cutoff value: −15 to −18). CT = computed tomography, HU = Hounsfield units, LAD = left anterior descending coronary artery, TAG = transluminal attenuation gradient

• 

  Fig. 2 Triple-rule-out scan using wide-volume scan method in 40-year-old woman diagnosed with acute pulmonary arterial thromboembolism.A. Detector width is set at 14–16 cm to cover half of entire thorax, and whole chest is covered with two axial volume scan acquisitions. B. Whole-chest CT scan acquired using two axial volume scans that are automatically stitched immediately after reconstruction. C. Data from second scan are separately reconstructed for coronary angiography. Multifocal low-density filling defects in both lobar and segmental pulmonary arteries suggesting pulmonary arterial thromboembolism (arrows in B). No definite abnormality is observed in thoracic aorta and coronary arteries. RCA = right coronary artery

• 

  Fig. 3 Thoracic CT images of 4-month-old boy with repaired tracheoesophageal fistula.Images are obtained using conventional helical acquisition method with sedation (A) and single-axial volume scan method without sedation (B) using 16-cm wide-detector CT scanner. A. Helical mode images show severe motion artifacts with blurring (arrowheads), especially near diaphragm (arrows). B. Axial volume scan images show relatively good image quality with few respiratory motion artifacts near diaphragm (arrows) and more clearly defined lung parenchymal structures, bronchi (arrowheads), vessels, and lung fissures.

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