Learning objectives
To recognize the imaging findings on high-resolution CT (HRCT) that are necessarily present to diagnose the usual interstitial pneumonia (UIP) pattern and its associated pitfalls.
To identify the critical imaging findings to be evaluated in follow-up HRCT of idiopathic pulmonary fibrosis (IPF) patients treated with antifibrotic drugs.
Background
IPF is currently an underdiagnosed disease due to difficulties in the interpretation of HRCT findings and also due to the initially silent clinic. It is a progressive, irreversible, fatal, fibrosing lung disease of unknown cause, that carries with a survival rate lower than some cancer types.
Current hypothesis to the emergence of IPF:
An endogenous/environmental stimulus disrupts the balance of alveolar epithelial cells, resulting in cellular activation and anomalous epithelial repair
The exposure of a susceptible person to a specific agent may lead to alveolar...
Findings and procedure details
UIP Pattern
Histologically, it is characterized by the presence of a heterogeneous pattern with different parts of the biopsy showing normal lung, interstitial fibrosis, fibroblast proliferation, and honeycombing. They each represent a different stage in the temporal evolution of fibrosis, reflecting spatial and temporal heterogeneity, typical of UIP.
Definite UIP Pattern
Subpleural, basal predominance
Reticular changes
Honeycombing with/without traction bronchiectasis
Absence of characteristics considered inconsistent with the UIP pattern
Findingsconsidered inconsistent with UIP pattern
• Upper/middle lobe predominance
• Peribroncovascular predominance
• More extensive ground-glass...
Conclusion
The early identification of IPF features on imaging results in the potential early initiation of innovative drugs with significant improvement in the patient's quality of life.
The thorough evaluation of each imaging feature on follow-up HRCT examinations of these patients may have implications on the patients. This may prove to be particularly important in patients with severe IPF that may not perform pulmonary functional tests, thus benefiting from CT as a supplementary tool to evaluate the response to treatment.
Personal information and conflict of interest
F. Matos; Viseu/PT - nothing to disclose S. G. Teixeira; Viseu/PT - nothing to disclose P. M. R. C. Patrão; Viseu/PT - nothing to disclose P. G. J. Magalhaes; Viseu/PT - nothing to disclose P. Cruz; Viseu/PT - nothing to disclose D. Silva; Viseu/PT - nothing to disclose
References
1. Balestro, E., Cocconcelli, E., Giraudo, C., Polverosi, R., Biondini, D., & Lacedonia, D. et al. (2019). High-Resolution CT Change over Time in Patients with Idiopathic Pulmonary Fibrosis on Antifibrotic Treatment.Journal Of Clinical Medicine,8(9), 1469. doi: 10.3390/jcm8091469
2. Chung, J., Cox, C., Montner, S., et al. CT Features of the Usual Interstitial Pneumonia Pattern: Differentiating Connective Tissue Disease–Associated Interstitial Lung Disease From Idiopathic Pulmonary Fibrosis.American Journal of Roentgenology 2018, 210(2), pp.307-313.
3. Egashira, R., Jacob, J., Kokosi, M., Brun, A., Rice, A., & Nicholson, A....