Pediatric CT of the Lung: Influences on Image Quality

Enno Stranzinger, Sebastian Tobias Schindera, Jennifer Larissa Cullmann, Ralph Herrmann, Shu-Fang Hsu Schmitz, Rainer Wolf

Department of Diagnostic, Interventional and Pediatric Radiology, Bern University Hospital, Bern, Switzerland.
Institute of Mathematical Statistics and Actuarial Science, University of Bern, Bern, Switzerland.

DOI: 10.4236/ojrad.2013.31007                

Abstract

Objective: To assess influential factors of CT on image quality of the lung in children. Materials and methods: Retrospective evaluation of 82 consecutive chest-CT-scans in 50 children (1-16 years, 17 females and 33 males). Two pediatric radiologists evaluated in consensus the subjective image quality on lung windows using a 4-point scale (1 = very good, 2 = good, 3 = moderate, 4 = poor). Ventilation, motion artifacts and beam hardening artifact were included in this score. The effects of the following factors were evaluated: 1) CT-settings (tube energy, tube current); 2) Patient’s age, weight, chest size, ventilation; 3) Artifacts of devices, tubes and lines; 4) Combination MRI of the abdomen prior to CT of the chest with the same sedation/anesthesia in oncological patients. Results: The odds of having a better image quality increase with patient’s age, weight and chest diameter in a multiple-factor model. There was no difference between tube current protocols. In infants (<15 kg) subjective image quality was good in only 1 (8%), moderate in 8 (67%) and poor in 3 (25%) scans. In childhood and adolescence (15 - 90 kg) 25 (36%) scans were very good, 28 (40%) good, 15 (21%) moderate and 2 (3%) poor. Artifacts of tubes and lines have no statistical significant influence on image quality. Lower lung densities were related to better ventilation and older children. Conclusion: Increasing dose parameters may not increase necessarily subjective image quality in infants (<15 kg), rather than good ventilation, optimal preparation and avoiding artifacts. A possible explanation of the rather moderate image quality in infants may be the alveolar stage of the lung. Up to two years of age the lung has a high specific lung volume per kg and a low total lung volume with a low alveolar surface.

Keywords

CT; Lung; Image Quality; Children

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W. A. Hudson, “Normal and Abnormal Structural Development of the Lung in Polin RA,” Fetal and Neonatal Physiology, 2nd Edition, W. B. Saunders, Philadelphia, 1988, p. 1037.
[2]	A. Paterson, D. P. Frush and L. F. Donnelly, “Helical CT of the Body: Are Settings Adjusted for Pediatric Patients?” American Journal of Roentgenology, Vol. 176, No. 2, 2001, pp. 297-301.
[3]	K. J. Strauss, M. J. Goske, S. C. Kaste, et al., “Image Gently: Ten Steps You Can Take to Optimize Image Quality and Lower CT Dose for Pediatric Patients,” American Journal of Roentgenology, Vol. 194, No. 4, 2010, pp. 868-873. doi:10.2214/AJR.09.4091
[4]	T. L. Slovis, “The ALARA (as Low as Reasonably Achievable) Concept in Pediatric CT Intelligent Dose Reduction,” Multidisciplinary Conference Organized by the Society of Pediatric Radiology, Pediatric Radiology, Vol. 32, No. 4, 2010, pp. 217-313.
[5]	A. Paterson and D. P. Frush, “Dose Reduction in Paediatric MDCT: General Principles,” Clinical Radiology, Vol. 62, No. 6, 2007, pp. 507-517. doi:10.1016/j.crad.2006.12.004
[6]	P. Vock, “CT Radiation in Children: Consequences of the American Discussion for Europe,” Radiologe, Vol. 42, No. 9, 2002, pp. 697-702. doi:10.1007/s00117-002-0812-4
[7]	E. Y. Lee, M. J. Siegel, C. F. Hildebolt, F. R. Gutierrez, S. Bhalla and J. H. Fallah, “MDCT Evaluation of Thoracic Aortic Anomalies in Pediatric Patients and Young Adults: Comparison of Axial, Multiplanar, and 3D Images,”American Journal of Roentgenology, Vol. 182, No. 3, 2004, pp. 777-784.
[8]	M. J. Siegel, “Multiplanar and Three-Dimensional Multi Detector Row CT of Thoracic Vessels and Airways in the Pediatric Population,” Radiology, Vol. 229, 2003, pp. 641-650. doi:10.1148/radiol.2293020999
[9]	D. D. Cody, D. M. Moxley, K. T. Krugh, J. C. O’Daniel, L. K. Wagner and F. Eftekhari, “Strategies for Formulating Appropriate MDCT Techniques When Imaging the Chest, Abdomen, and Pelvis in Pediatric Patients,” American Journal of Roentgenology, Vol. 182, No. 4, 2004, pp. 849-859.
[10]	P. Rogalla, B. St?ver, et al., “Low-Dose Spiral CT: Applicability to Paediatric Chest Imaging,” Pediatric Radiology, Vol. 29, No. 8, 1999, pp. 565-569. doi:10.1007/s002470050648
[11]	B. St?ver and P. Rogalla, “CT Examinations in Children,” Der Radiologe, Vol. 48, No. 3, 2008, pp. 243-248. doi:10.1007/s00117-007-1600-y