Biopsy-proved Idiopathic Pulmonary Fibrosis: Spectrum of Nondiagnostic Thin-Section CT Diagnoses

Radiology: Volume 254: Number 3 March 2010

Dr Fabrício Maia Torres AlvesClínica São Judas Tadeu

Objetivo

• Documentar a espectro da falha do diagnóstico da TC de alta resolução em pacientes com fibrose pulmonar idiopática (FPI) diagnosticadas por biópsia

• Diagnóstico de FPI

– Histológico ou padrão de TC

– Dados clínicos

Padrão TC FPI

• Padrão reticular

• Faveolamento

• Distribuição basal e subpleural

• Ausente em 30% dos pacientes

• Estudo retrospectivo• Aprovação institucional• Sem termo de consentimento• Royal Brompton Hospital (London, England) e

Morgagni Hospital (Forlì, Italy) entre janeiro de 2003 e dezembro de 2006.

• Grupo de estudo com 55 pacientes com diagnóstico clínico-radiológico-patológico de FPI

• 20 pacientes com diagnóstico clínico-radiológico de FPI

• 48 pacientes com doenças intersticiais e pulmonares crônicas – NSIP, sarcoidose, PH crônica, pneumonia intersticial descamativa, histiocitose de Langerhans , organizing pneumonia, associação de NSIP e organizing pneumonia e pneumonia intersticial linfóide

• Exclusão – Doença ocupacional– Doença do tecido conjuntivo– Insuficiência cardíaca– Infecção– Exacerbação da doença de base

• Diagnóstico histológico em consenso por dois patologistas

Protocolo de TC

• Cortes de 1,0 – 1,5 mm e intervalo de 10 mm

• Volumétrico, com colimador de 0,6 – 1,0 mm e recontrução de 1,0 mm

• WW, 1500–1600 UH; WL, −500 to −600 UH

• 03 radiologistas torácicos independentes

• Sem dados clínicos

• Não sabiam o propósito do estudo

• Listar diagnósticos diferencais com probabilidades

Avaliação do diagnóstico

• Individual – diagnóstico de FPI– 36%– 23%– 16%

• Observação combinada (55 pacientes)– Probabilidade alta – 27%– Probabilidade intermediária – 11%• NSIP, PH

– Probabilidade baixa – 62%

Thin-section CT pattern was thought to be consistent with IPF by two observers, who scored UIP with 60% and NSIP with 40% probability. Conversely, the third observer scored NSIP with 60% and UIP with 40% probability. Transverse CT section through the lower zones shows a peripheral reticular pattern with traction bronchiectasis but no honeycombing .

High-probability (70%) NSIP by all three observers. Transverse thin-section CT scan obtained through the lower lungs shows a basilar peripheral predominant reticular pattern with ground-glass opacity and traction bronchiectasis.

High-probability chronic HP by all three observers. Transverse thin-section CT scans at levels of (a) aortic arch and (b) lung bases show bilateral patchy areas of ground-glass opacity superimposed on fine reticulation with minimal subpleural honeycombing (curved arrow). Some lobules appear to be of relatively decreased attenuation, suggesting air trapping (straight arrows).

Two of three observers diagnosed sarcoidosis with 100% probability, whereas the other observer split the diagnosis between chronic HP (55% probability) and NSIP (45% probability). Transverse thin-section CT scans at levels of (a) trachea and (b) bronchus intermedius show reticular pattern composed of irregular intralobular lines and subpleural nodularity (straight arrows) and some patchy honeycombing (curved arrow). (c) Transverse section through lung bases demonstrates relative sparing of lower zones with limited subpleural reticulation and patchy ground-glass opacity.

Was interpreted by the three observers as 60%, 70%, and 80% probability for organizing pneumonia. (a) Transverse thin-section CT scan at level of bronchus intermedius shows patchy subpleural consolidation (straight arrows) with peripheral reticular opacity and honeycombing (curved arrow). (b) Transverse scan at lung bases shows focal consolidation on the right (straight arrow) on a background of ground-glass opacity with some microcystic honeycombing (curved arrow).

Discussão

• Não se pode excluir o diagnóstico de FPI com base apenas na TC de alta resolução

• NSIP e PH crônica • Sarcoidose• Organizing pneumonia• 62% tiveram diagnósticos alternativos• FPI típica e atípica: queda da função pulmonar

em 12 meses

Conclusão

• O diagnóstico de FPI não pode ser excluído quando TC de alta resolução apresenta características mais sugestivas de PH crônica, sarcoidose e NSIP

EUROPEAN RESPIRATORY REVIEW, 2008;17: 108-115

Idiopathic Interstitial Pneumonias: CT FeaturesRadiology, 2005; 236: 10 - 21

IIP: idiopathic interstitial pneumonias; IPF: idiopathic pulmonary fibrosis; BAL: bronchoalveolar lavage; TBB: transbronchial biopsy; DPLD: diffuse parenchymal lung diseases; PLCH: pulmonary Langerhans cell histiocytosis; DIP: desquamative interstitial pneumonia; RB-ILD: respiratory bronchiolitis-associated interstitial lung disease; AIP: acute interstitial pneumonia; COP: cryptogenic organising pneumonia; NSIP: nonspecific interstitial pneumonia; LIP: lymphoid interstitial pneumonia.