Excessive z-axis scan coverage in body CT: frequency and causes


Yar O., ONUR M. R. , İDİLMAN İ. S. , AKPINAR E. , AKATA D.

EUROPEAN RADIOLOGY, 2020 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası:
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1007/s00330-020-07510-4
  • Dergi Adı: EUROPEAN RADIOLOGY

Özet

Objectives The aim of this study was to determine the frequency and causing factors of excessive z-axis coverage in body CT examinations. Methods A total of 2032 body CT examinations performed between 1 March and 1 April 2018 in 1531 patients were included in this study. The over-scanned length values in the z-axis for each CT examination on each patient were determined by calculating the difference between the actual scanned length and optimal scan length in the z-axis. Over-scanning and over-scanning ratios were interrogated in terms of potential underlying factors that can be affected by patient demography, time, the throughput of CT, and the experience of technologists. Results Over-scanned CTs in z-axis were 66% of all CTs performed. CT scans were over-scanned in the cranial side in 18.4% and caudal side in 48.5% of patients. Over-scanning was found to be more frequent in 55-64-year-old age group (74%), thorax CTs (89.2%), patients with consciousness change (88.9%), patients with misleading findings related to lung apex or diaphragm on the scout images (76.6%), CTs performed in day shift (66.8 %), in CT with low daily scan (72.4%), and CT scans performed by less-experienced technologists (75.9%). Conclusions Over-scanning in z-axis in body CT examinations is not infrequently encountered in routine practice. Awareness of causes of over-scanning in z-axis can be helpful to prevent over-scanning in CT and unnecessary ionizing radiation exposure in patients.