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Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

Ohkubo H, Kanemitsu Y, Uemura T, Takakuwa O, Takemura M, Maeno K, Ito Y, Oguri T, Kazawa N, Mikami R, Niimi A - PLoS ONE (2016)

Bottom Line: NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF.Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

View Article: PubMed Central - PubMed

Affiliation: Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.

ABSTRACT

Background: Although several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.

Objective: The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.

Methods: A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.

Results: CT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).

Conclusion: The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

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Related in: MedlinePlus

ROC curves of NL%.The receiver operating characteristic (ROC) curves of the percentage of the volume of normally attenuated lung in whole lungs from CT imaging (NL%) for clinical composite unit stages of Japanese stage II/III/IV (A), Japanese stage III/IV (B), and GAP stage II/III (C). The values of AUC are 0.864, 0.822, and 0.844, respectively.
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pone.0152505.g004: ROC curves of NL%.The receiver operating characteristic (ROC) curves of the percentage of the volume of normally attenuated lung in whole lungs from CT imaging (NL%) for clinical composite unit stages of Japanese stage II/III/IV (A), Japanese stage III/IV (B), and GAP stage II/III (C). The values of AUC are 0.864, 0.822, and 0.844, respectively.

Mentions: The area under the curve (AUC) values of the ROC curve analysis for the detection of single or composite unit stages in the Japanese and GAP staging systems are shown in Fig 3. The ROC curves of NL% for composite unit stages of Japanese stage II/III/IV (Fig 4A), Japanese stage III/IV (Fig 4B), and GAP stage II/III (Fig 4C) showed that the values of AUC were 0.86, 0.82, and 0.84, respectively. If the cut-off value of NL% was set at 60.4% for detecting Japanese stage II/III/IV, the sensitivity was 62.5%, and the specificity was 100%. If the cut-off value was 63.8% for Japanese stage III/IV, the sensitivity was 75%, and the specificity was 80%. If the cut-off value was 66.0% for GAP stage II/III, the sensitivity was 87%, and the specificity was 75%.


Normal Lung Quantification in Usual Interstitial Pneumonia Pattern: The Impact of Threshold-based Volumetric CT Analysis for the Staging of Idiopathic Pulmonary Fibrosis.

Ohkubo H, Kanemitsu Y, Uemura T, Takakuwa O, Takemura M, Maeno K, Ito Y, Oguri T, Kazawa N, Mikami R, Niimi A - PLoS ONE (2016)

ROC curves of NL%.The receiver operating characteristic (ROC) curves of the percentage of the volume of normally attenuated lung in whole lungs from CT imaging (NL%) for clinical composite unit stages of Japanese stage II/III/IV (A), Japanese stage III/IV (B), and GAP stage II/III (C). The values of AUC are 0.864, 0.822, and 0.844, respectively.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4816297&req=5

pone.0152505.g004: ROC curves of NL%.The receiver operating characteristic (ROC) curves of the percentage of the volume of normally attenuated lung in whole lungs from CT imaging (NL%) for clinical composite unit stages of Japanese stage II/III/IV (A), Japanese stage III/IV (B), and GAP stage II/III (C). The values of AUC are 0.864, 0.822, and 0.844, respectively.
Mentions: The area under the curve (AUC) values of the ROC curve analysis for the detection of single or composite unit stages in the Japanese and GAP staging systems are shown in Fig 3. The ROC curves of NL% for composite unit stages of Japanese stage II/III/IV (Fig 4A), Japanese stage III/IV (Fig 4B), and GAP stage II/III (Fig 4C) showed that the values of AUC were 0.86, 0.82, and 0.84, respectively. If the cut-off value of NL% was set at 60.4% for detecting Japanese stage II/III/IV, the sensitivity was 62.5%, and the specificity was 100%. If the cut-off value was 63.8% for Japanese stage III/IV, the sensitivity was 75%, and the specificity was 80%. If the cut-off value was 66.0% for GAP stage II/III, the sensitivity was 87%, and the specificity was 75%.

Bottom Line: NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF.Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

View Article: PubMed Central - PubMed

Affiliation: Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.

ABSTRACT

Background: Although several computer-aided computed tomography (CT) analysis methods have been reported to objectively assess the disease severity and progression of idiopathic pulmonary fibrosis (IPF), it is unclear which method is most practical. A universal severity classification system has not yet been adopted for IPF.

Objective: The purpose of this study was to test the correlation between quantitative-CT indices and lung physiology variables and to determine the ability of such indices to predict disease severity in IPF.

Methods: A total of 27 IPF patients showing radiological UIP pattern on high-resolution (HR) CT were retrospectively enrolled. Staging of IPF was performed according to two classification systems: the Japanese and GAP (gender, age, and physiology) staging systems. CT images were assessed using a commercially available CT imaging analysis workstation, and the whole-lung mean CT value (MCT), the normally attenuated lung volume as defined from -950 HU to -701 Hounsfield unit (NL), the volume of the whole lung (WL), and the percentage of NL to WL (NL%), were calculated.

Results: CT indices (MCT, WL, and NL) closely correlated with lung physiology variables. Among them, NL strongly correlated with forced vital capacity (FVC) (r = 0.92, P <0.0001). NL% showed a large area under the receiver operating characteristic curve for detecting patients in the moderate or advanced stages of IPF. Multivariable logistic regression analyses showed that NL% is significantly more useful than the percentages of predicted FVC and predicted diffusing capacity of the lungs for carbon monoxide (Japanese stage II/III/IV [odds ratio, 0.73; 95% confidence intervals (CI), 0.48 to 0.92; P < 0.01]; III/IV [odds ratio. 0.80; 95% CI 0.59 to 0.96; P < 0.01]; GAP stage II/III [odds ratio, 0.79; 95% CI, 0.56 to 0.97; P < 0.05]).

Conclusion: The measurement of NL% by threshold-based volumetric CT analysis may help improve IPF staging.

Show MeSH
Related in: MedlinePlus