PLoS ONE (Jan 2013)

Semi-automatic quantification of subsolid pulmonary nodules: comparison with manual measurements.

  • Ernst Th Scholten,
  • Bartjan de Hoop,
  • Colin Jacobs,
  • Saskia van Amelsvoort-van de Vorst,
  • Rob J van Klaveren,
  • Matthijs Oudkerk,
  • Rozemarijn Vliegenthart,
  • Harry J de Koning,
  • Carlijn M van der Aalst,
  • Willem Th M Mali,
  • Hester A Gietema,
  • Mathias Prokop,
  • Bram van Ginneken,
  • Pim A de Jong

DOI
https://doi.org/10.1371/journal.pone.0080249
Journal volume & issue
Vol. 8, no. 11
p. e80249

Abstract

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RATIONALE: Accurate measurement of subsolid pulmonary nodules (SSN) is becoming increasingly important in the management of these nodules. SSNs were previously quantified with time-consuming manual measurements. The aim of the present study is to test the feasibility of semi-automatic SSNs measurements and to compare the results to the manual measurements. METHODS: In 33 lung cancer screening participants with 33 SSNs, the nodules were previously quantified by two observers manually. In the present study two observers quantified these nodules by using semi-automated nodule volumetry software. Nodules were quantified for effective diameter, volume and mass. The manual and semi-automatic measurements were compared using Bland-Altman plots and paired T tests. Observer agreement was calculated as an intraclass correlation coefficient. Data are presented as mean (SD). RESULTS: Semi-automated measurements were feasible in all 33 nodules. Nodule diameter, volume and mass were 11.2 (3.3) mm, 935 (691) ml and 379 (311) milligrams for observer 1 and 11.1 (3.7) mm, 986 (797) ml and 399 (344) milligrams for observer 2, respectively. Agreement between observers and within observer 1 for the semi-automatic measurements was good with an intraclass correlation coefficient >0.89. For observer 1 and observer 2, measured diameter was 8.8% and 10.3% larger (p<0.001), measured volume was 24.3% and 26.5% larger (p<0.001) and measured mass was 10.6% and 12.0% larger (p<0.001) with the semi-automatic program compared to the manual measurements. CONCLUSION: Semi-automated measurement of the diameter, volume and mass of SSNs is feasible with good observer agreement. Semi-automated measurement makes quantification of mass and volume feasible in daily practice.