The Imaging And Pathology Control Study On Subtype Of Idiopathic Interstitial Pneumonia

Purpose:To investigate the HRCT features of usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP) and pathology control study on the usual interstitial pneumonia (UIP) and nonspecific interstitial pneumonia (NSIP).Methods: The HRCT , pathological and clinical date of 20 cases with UIP and36 cases with NSIP confirmed by open or video-assisted thoracoscopic lung biopsy were reviewed retrospectively. The patient was always supine, and scans were obtained from the lung apex to the base using 1～1.5mm collimation and a 10～15 mm slice interval .Reconstruction were performed with a bone algorithm. The lung was evenly divided into three parts from the apex to below the right diaphragm , and these parts were denoted as the upper, middle ,and lower zones. Each part was evaluated by the observers. The observers appraised the areas of ground-glass opacity ,intralobular reticular opacities, interlobular reticular opacities, the extent of traction bronchiectasis and the extent of opacity. HRCT and pathology control study was done on all cases. Results: UIP occurred more often in males over 50 years of age. Clinical findings included progressive shortness of breath, cough, sputum and crackles over both lung fields. HRCT showed ground-glass opacity(35%,7/20),Interlobular reticular opacities and Intralobular reticular opacities (80%,16/20),in middle and lower lung fields predominantly(100%,20/20). Traction bronchiectasis was present in 15 cases (75%,15/20).Honeycombing was found in 16 patients (80%,16/20). There was fair agreement among the radiologists for the diagnosis (k=0.51 P<0.05) and good agreement among the radiologists and pathologists for the diagnosis (k=0.51 P<0.05) Histologically, UIP was characterized by scattered fibrotic foci, frbrosis (often associated with honeycombing) and pulmonary architectural destruction. It had a heterogeneous appearance, with alternating areas of normal lung ,interstitial inflammation, fibrosis, and honeycomb changes. NSIP occurred more in female (male: female 1:3,9/27) ,and the patient's average age was 48years.The manifestation was progressive dyspnea ,cough and sputum, crackles over both lungs and restrictive ventilation abnormalities. On HRCT, areas with ground-glass opacity were present in all 36 patients(100%,36/36). Intralobular reticular opacities and Interlobular reticular opacities were seen in 32 patients(88.9%,32/36). Traction bronchiectasis was present in 32 cases (88.9%,32/36). Honeycombing was seen in 6 cases (16.7%,6/36) . HRCT of 30 patients(83.3%,30/36) showed diseases in lower lobes predominantly and HRCT 2 patients (5.6%,2/36) showed diseases in upper, middle or lower lobes randomly. There was fair agreement among the radiologists for the diagnosis (k=0.671 P<0.05) and good agreement among the radiologists and pathologists for the diagnosis (k=0.671 P<0.05).Conclusion: The predominant HRCT findings of UIP consisted of areas of ground-glass opacity, reticular opacity and honeycombing involved the basal and subpleural regions predominantly. Honeycombing is the important features of UIP on HRCT.The HRCT features of NSIP is characterized by basal-predominant ground-glass opacity ,often associated with Intralobular reticular opacities , interlobular reticular opacities and traction bronchiectasis. Honeycombing was seen in fibrosing pattern. HRCT findings of NSIP and UIP correlated closely with the pathological features. It is useful for performing HRCT to diagnosis NSIP and UIP.