TITLE:
Pediatric CT of the Lung: Influences on Image Quality
AUTHORS:
Enno Stranzinger, Sebastian Tobias Schindera, Jennifer Larissa Cullmann, Ralph Herrmann, Shu-Fang Hsu Schmitz, Rainer Wolf
KEYWORDS:
CT; Lung; Image Quality; Children
JOURNAL NAME:
Open Journal of Radiology,
Vol.3 No.1,
March
19,
2013
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.