Purpose:
@HN To determine the potential of spiral CT as a functional imaging modality of the lung aside from its proven value in morphological depiction.
@HS Materials and Methods:
@HN Spiral CT scan was performed in ten normal female and nine normal male adults(mean age : 39, height : 163cm, weight : 62kg) after single full breath-holding. Three dimensional lung images were reconstructed(minimal threshold value : -1,000
HU<
maximal threshold values : -150, -250, -350, -450HU) to obtain total lung volume(TLV) on a histogram. Total lung volume measured by spiral CT was compared with TLV obtained by spirometry.
@HS Results:
@HN Mean TLV measured by spirometry was 5.62 L and TLV measured by CT at maximal threshold values of -150, -250, -350, and -450HU was 5.53, 5.33, 5. 15, and 4.98 L, respectively. Mean absolute differences between the modalities of 0.17L(3%),
0.32L(5.6%), 0.48L(8.5%), 0.65L(11.5%) were statistically significant(p<0.001). Linear regression coefficients between the modalities were 0.99, 0.97, 0.95, and 0.94 and no statistically significant differences in accuracy of threshold levels in
the
estimation of lung volume(r=0.99, standard error=0.034 L in all) were seen.
@HS Conclusion:
@HN TLV measured by spiral CT closely approximated that measured by spirometry. Spiral CT may be useful as a means of evaluating lung function.
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