**Congress:**

# Idiopathic Pulmonary Fibrosis :- Correlation of HRCT findings with Pulmonary Function Tests

**ESTI ESCR 2018**

**Poster Number:**

**Type:**

**Keywords:**

**Authors:**

__R. Pothera__

^{1}, C. P. Mathew

^{2}, A. V. Nair

^{3}, S. K. Pullara

^{1}, D. Viswam

^{1}, S. Moorthy

^{1};

^{1}Kochi/IN,

^{2}Kochi, Ke/IN,

^{3}Trivandrum, kerala/IN

**DOI:**

**DOI-Link:**

# Results

**Fig-5**: __Study population__

- In this study, consisting of 30 IPF patients, 13 were female (43%), and 17 were male(57%)
- Mean ageof the study sample was 60.7.

**Fig-6**: __Study population- Age distribution__

**Table-1 :** **HRCT findings in the 30 patients with IPF.**

HRCT findings |
Affected patients |
% |

Reticular abnormality |
30 |
100 |

Honeycombing |
26 |
86 |

Honeycombing , Cysts ↓3mm |
26 |
86 |

Honeycombing , Cysts ↑3mm |
13 |
43 |

Traction bronchiectasis |
29 |
96 |

Associated significant emphysema |
7 |
23 |

- Peripheral distribution /sub pleural predominance of lesions seen in all patients.

**Table-2**: __Mean of physiological indices and HRCT findings__

(FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; FEF25-75 %: forced expiratory flow between 25% and 75%; FEV1: forced expiratory volume in one second; and TID: total interstitial disease score .)

- The higher ratio suggests increased elastic force exerted by the connective tissue abnormally deposited in the parenchyma, keeping airways open.
- In our study group and in the studies of Lopes et al the TID scores correlated positively with FEF25-75 / FVC

**Table 3.
Correlations between HRCT findings & functional indices.**

(FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; FEF25-75 %: forced expiratory flow between 25% and 75%; FEV1: forced expiratory volume in one second; and TID: total interstitial disease score .)

- Karl Pearson coefficient of correlation was used to examine the correlation in the total study group.
- **. Correlation (Corr.) is significant at the 0.01 level.
- Strongest correlation was observed between TID and percentage of predicted DLCO (negative correlation) (p = 0.001).
- No correlation was observed between either the fibrotic score or pulmonary artery diameter (P.A.) and the functional indices.

**Table 4**__.
Correlations between HRCT findings & functional indices.__

(FVC: forced vital capacity; DLCO: diffusing capacity of the lung for carbon monoxide; FEF25-75 %: forced expiratory flow between 25% and 75%; FEV1: forced expiratory volume in one second; and TID: total interstitial disease score)

- Karl Pearson coefficient of correlation was used to examine the correlation in the total study group
- **. Correlation (Corr.) is significant at the 0.01 level.
- Strongest correlation was observed between TID and percentage of predicted DLCO (negative correlation) (p = 0.001).
- No correlation was observed between either the fibrotic score or pulmonary artery diameter (P.A.) and the functional indices.

**Table 5**.**Correlation in the group having no emphysema**

- Analyzed using Spearman’s rank correlation.
- When patients with significant emphysematous changes were excluded, negative correlation between FVC and TID was observed.

**Table 6****.**__Comparison of the overall lung involvement based on DLCO using Independent sample t test__

- After grouping into advanced disease and limited disease based on DLCO17,18,19 (DLCO<39 / DLCO> 40) The two-tailed t test was used to compare the average of TID scores .
- Significant difference was noted in TID values of both groups.
- Correlation is significant at the 0.05 level .

**Fig-7**: __ROC curve__

- From the ROC curve plotted based on the data , we found that a cut off value of six could separate the patients with advanced disease with a sensitivity of 85% and specificity of 65%.

**Study Limitations **

- In the sample evaluated, surgical biopsy was not performed, requiring that clinical, radiological and functional parameters be adopted as inclusion / exclusion criteria.
- Another limitation was the use of semiquantitative scores to evaluate the extent of abnormalities on HRCT scans, although previous studies showed a perfectly acceptable degree of interobserver variation(Collins et al).