THE SENSITIVITY OF HIGH-RESOLUTION CT IN DETECTING IDIOPATHIC PULMONARY FIBROSIS PROVED BY OPEN LUNG-BIOPSY - A PROSPECTIVE-STUDY

Objectives: To assess the sensitivity of high-resolution chest compute d tomography (HRCT) in detecting idiopathic pulmonary fibrosis proved by biopsy specimen. To determine the degree of physiologic and patholo gic abnormalities in patients with idiopathic pulmonary fibrosis who h ave a false-negative HRCT. Design: Prospective 2-year study. Setting: Tertiary care university hospital. Patients: All patients with dyspnea and suspected interstitial lung disease referred to the University of Michigan for enrollment in the Idiopathic Pulmonary Fibrosis Speciali zed Center of Research (SCOR) protocol were included; 25 underwent ope n lung biopsy and formed the final study group. Measurements: All pati ents underwent physiologic (pulmonary function, gas exchange, and exer cise testing), radiologic (chest x-ray film and HRCT), and pathologic assessments (bronchoscopic and open lung biopsy). The results of HRCT were prospectively compared with results of standard pulmonary functio n tests, cardiopulmonary exercise testing, and open lung biopsy. Resul ts: Of 25 patients who had both HRCT and open lung biopsy, 3 patients (12%) had HRCTs that demonstrated no evidence of interstitial lung dis ease. These three patients had less severe disease based on clinical, radiographic, and physiologic (CRP) scores, gas exchange abnormalities , and pathologic scoring of open lung biopsy specimens, compared with those with an abnormal HRCT. Conclusion: We conclude that in the evalu ation of patients with dyspnea and abnormal results of pulmonary funct ion studies, a normal HRCT does not exclude early and clinically signi ficant interstitial lung disease. In our patient population, physiolog ic testing was more sensitive than HRCT in detecting mild abnormalitie s in patients with idiopathic pulmonary fibrosis proved by biopsy spec imen.