Electrocardiographically Gated Thin-Section CT of the Lung

PURPOSE: To determine whether electrocardiographic (ECG) gating improves image quality of thin-section computed tomographic (CT) scans of the lung obtained with a subsecond CT scanner.

MATERIALS AND METHODS: Thin-section CT was performed in 35 patients by using standard techniques. Three additional sections were obtained in each patient with prospective ECG gating at corresponding levels of the paracardiac lung parenchyma. Non–ECG-gated and ECG-gated sections were then rated in blinded fashion by three experienced radiologists for overall image quality, spatial resolution, and diagnostic value and for different types of respiratory and cardiac motion artifacts.

RESULTS: ECG gating helped significantly reduce artifacts caused by cardiac motion (ie, distortion of pulmonary vessels, double images, or blurring of the cardiac border) (P < .05). ECG gating did not reduce respiratory motion artifacts. In patients with heart rates of less than 76 beats per minute, ECG gating significantly improved overall image quality (P = .041). ECG gating was not perceived to increase the diagnostic value of thin-section CT scans.

CONCLUSION: ECG gating improves image quality of thin-section CT scans of the lung by reducing cardiac motion artifacts that may mimic disease. It must be established whether ECG gating can help increase the diagnostic accuracy of thin-section CT for the evaluation of subtle parenchymal disease.


  • 1 Naidich DP, McCauley DI, Khouri NF, Stitik FP, Siegelman SS. Computed tomography of bronchiectasis. J Comput Assist Tomogr 1982; 6:437-444. Crossref, MedlineGoogle Scholar
  • 2 Naidich DP, Zerhouni EA, Hutchins GM, Genieser NB, McCauley DI, Siegelman SS. Computed tomography of the pulmonary parenchyma. I. Distal air-space disease. J Thorac Imaging 1985; 1:39-53. Google Scholar
  • 3 Zerhouni EA, Naidich DP, Stitik FP, Khouri NF, Siegelman SS. Computed tomography of the pulmonary parenchyma. II. Interstitial disease. J Thorac Imaging 1985; 1:54-64. Crossref, MedlineGoogle Scholar
  • 4 Grenier P, Maurice F, Musset D, Menu Y, Nahum H. Bronchiectasis: assessment by thin-section CT. Radiology 1986; 161:95-99. LinkGoogle Scholar
  • 5 Murata K, Khan A, Herman PG. Pulmonary parenchymal disease: evaluation with high-resolution CT. Radiology 1989; 170:629-635. LinkGoogle Scholar
  • 6 Webb WR, Müller NL, Naidich DP. High-resolution CT of the lung 2nd ed. Philadelphia, Pa: Lippincott-Raven, 1996. Google Scholar
  • 7 Mayo JR. High resolution computed tomography: technical aspects. Radiol Clin North Am 1991; 29:1043-1049. MedlineGoogle Scholar
  • 8 Engeler CE, Tashjian JH, Engeler CM, Geise RA, Holm JC, Ritenour ER. Volumetric high-resolution CT in the diagnosis of interstitial lung disease and bronchiectasis: diagnostic accuracy and radiation dose. AJR 1994; 163:31-35. Crossref, MedlineGoogle Scholar
  • 9 McGuiness G, Naidich DP. Bronchiectasis: CT/clinical correlations. Semin Ultrasound CT MR 1995; 16:395-419. Crossref, MedlineGoogle Scholar
  • 10 Kuhns LR, Borlaza G. The “twinkling star” sign: an aid in differentiating pulmonary vessels from pulmonary nodules on computed tomograms. Radiology 1980; 135:763-764. LinkGoogle Scholar
  • 11 Tarver RD, Conces DJ, Godwin JD. Motion artifacts on CT simulate bronchiectasis. AJR 1988; 151:1117-1119. Crossref, MedlineGoogle Scholar
  • 12 Mayo JR, Webb WR, Gould R, et al. High-resolution CT of the lungs: an optimal approach. Radiology 1987; 163:507-510. LinkGoogle Scholar
  • 13 Mayo JR, Müller NL, Henkelman RM. The double-fissure sign: a motion artifact on thin-section CT scans. Radiology 1987; 165:580-581. LinkGoogle Scholar
  • 14 Ritchie CJ, Godwin JD, Crawford CR, Stanford W, Anno H, Kim Y. Minimum scan speeds for suppression of motion artifacts in CT. Radiology 1992; 185:37-42. LinkGoogle Scholar
  • 15 Lynch DA, Brasch RC, Hardy KA, Webb WR. Pediatric pulmonary disease: assessment with high-resolution ultrafast CT. Radiology 1990; 176:243-248. LinkGoogle Scholar
  • 16 Stanford W, Rumberger JA, eds. Ultrafast computed tomography in cardiac imaging: principles and practice Mount Kisco, NY: Futura, 1992. Google Scholar
  • 17 Hayball MP, Coulden RA, Regn J, Fluhrer M, Clements L, Brown SJ. ECG triggered image acquisition on a sub-second CT system (abstr). Radiology 1998; 206:575. Google Scholar
  • 18 Webb WR. High resolution CT of the lung parenchyma. Radiol Clin North Am 1989; 27:1085-1097. MedlineGoogle Scholar
  • 19 Zerhouni E. Computed tomography of the pulmonary parenchyma: an overview. Chest 1989; 95:901-907. Crossref, MedlineGoogle Scholar

Article History

Published in print: Sept 1999