[Abstract] Objective To investigate the imaging manifestations of nonspecific interstitial pneumonia (NSIP) and to evaluate its clinical application value. Methods The clinical and imaging data of 7 cases with confirmed open lung biopsy and 15 cases with clinically comprehensive diagnosis of NSIP were retrospectively analyzed. Results: 14 cases showed mainly single or scattered patchy or lamellar ground glass shadows, while 8 cases were accompanied by solid lobular shadows, and 9 of the 14 cases had mild intralobular interstitial thickening and 2 cases had mild fine bronchial dilatation; 6 cases had both lamellar ground glass shadows and intralobular interstitial thickening and traction fine bronchial dilatation; 2 patients with NSIP mainly showed intralobular interstitial thickening, traction fine bronchial dilatation and localized bronchial dilatation; 2 patients with NSIP mainly showed intralobular interstitial thickening, traction fine bronchial dilatation and localized bronchial dilatation. Of the 22 NSIP lesions, 19 were located in the peripheral parts of the middle and lower lungs, and 1 was located in the posterior segment of the right upper lobe. Conclusion The imaging manifestations of NSIP have certain characteristics, and the combination of clinical information such as medical history, symptoms, signs, pulmonary function and hormone treatment can greatly improve its correct diagnosis. Lei Zhidan, Department of Radiology, Henan Provincial People’s Hospital
[Keywords] Non-specific interstitial pneumonia; open-chest lung biopsy.
Body layer photography, X-ray computer; diagnostic imaging
Imaging Diagnosis of Nonspecific Interstitial Pneumonia
LEI Zhi-dan, JIA Wu-lin, GE Ying-hui, SHI Da-peng, WANG Si-qin,
MA Xi-tao
(Department of Radiology, Henan Provincial People’s Hospital, Zhengzhou, 450003, China)
[Abstract] Objective To investigate imaging features of nonspecific interstitial pneumonia (NSIP), and to discuss it’s clinical value. Methods 22 cases’ NSIP which were proved by open-lung biopsy or clinical comprehensive diagnosis were retrospectively analyzed. 14 cases’ NSIP major showed as ground-glass opacities, which were singly or randomly distributed over the bilateral peripheral zones of Of these 14 cases, 8 cases were accompanied by interlobular consolidation, 9 cases by intralobular septal light thickening, and 2 cases by soft traction bronchus. Six cases were found with ground-glass opacities and accompanied by intralobular septal thickening and traction bronchiocele. Imaging foundings of two NSIP included intralobular septal thickening, traction bronchiocele, and local pulmonary architectural In combination with medical history, subjective and objective symptom,pulmonary function , and curative effect of steroid, the possibility of NSIP’s diagnosis can be raised.
[Key words] Nonspecific interstitial pneumonia; Open-lung biopsy;
Tomography, X-ray computed; Diagnostic imaging
Nonspecific interstitial pneumonia (NSIP) is an independent interstitial pneumonia that was first proposed by Katzenstein and Fiorelli [1] in 1994 and has been the subject of numerous scholarly efforts and consensus. Its clinical, pathological, imaging and pulmonary function changes, especially its response to glucocorticoid therapy and prognosis are significantly different from idiopathic pulmonary fibrosis (IPF). Because of its higher incidence and better prognosis than IPF [2-6], timely and accurate diagnosis is of great value for its treatment and prognosis. By analyzing the clinical and imaging data of 22 cases of NSIP, the author explored the imaging manifestations and the value of clinical application.
1, Data and methods
1. 1 General information
There were 22 cases of NSIP, 13 males and 9 females. Age 41-73 years old, average 52 years old. 7 cases were confirmed by open lung biopsy, 15 cases were confirmed by comprehensive clinical diagnosis. 3 cases had a history of cotton exposure, 10 cases had a history of smoking, 3 cases had a history of pet keeping, 2 cases had a history of dust inhalation, 2 cases had connective tissue disease, and 2 patients had no obvious etiology or causative factors. The main symptoms were cough, chest tightness, shortness of breath, and progressive dyspnea. 22 cases had varying degrees of chest tightness and shortness of breath, 18 cases had progressive motor dyspnea, 16 cases had cough and dry cough or less sputum, 3 cases had mild fever, and 2 cases had cyanosis of the lips. Laboratory tests were not specific in any of the 22 cases. In the pulmonary function tests, all 22 cases had varying degrees of restrictive ventilation disorders, and blood gas analysis showed type I respiratory failure in 18 cases. Signs were mainly Velcro rales, coarse superficial wet rales and hypopnea in the lower and middle lungs. 18 cases had different degrees of wet rales, 12 cases had more obvious Velcro rales, 5 cases had milder Velcro rales and 4 cases had hypopnea. The time between onset and consultation ranged from 3 days to 2 years, with an average of 3 months.
1. 2 Examination methods
All 22 cases had chest plain films, among which 7 cases had more than 3 chest films and 15 cases had more than 2 chest films; 19 cases had CT examinations, among which 13 cases had HRCT examinations.
2, Results
2.1 The imaging manifestations were: patchy and lamellar ground glass shadow in the peripheral part of the middle and lower lungs on one or both sides in 14 cases, with patchy air cavity solid shadow in 11 cases, fine reticular shadow in 9 cases, and slight fine bronchial dilatation in 2 cases (Figure 1, 2); lamellar ground glass shadow, fine reticular shadow, coarse reticular shadow, short striated shadow and fine bronchial dilatation were seen in 6 cases (Figure 3), among which 1 case was located in the posterior segment of the right upper lobe; 2 cases showed The distribution and imaging signs of the 22 cases of NSIP are shown in Table 1 and Table 2, respectively.
Table 1 Distribution characteristics of 22 cases of NSIP (cases)
Upper lung Middle lung Lower lung Subpleural Central
Left lung 0 4 11 15 0
Right lung 1 5 16 20 2
Table 2 Imaging signs of NSIP in 22 cases (cases)
Number of cases Ground glass shadow Fine reticular shadow Coarse reticular shadow Fine bronchial dilatation Distorted lung structures
Cellular type 14 14 9 0 2 0
Mixed type 6 6 6 6 5 4 0
Fibrous type 2 0 2 2 2 2 2
2.2 Pathological manifestations of 7 cases of NSIP: chronic inflammatory cell infiltration with lymphocytes and plasma cells mainly in the alveolar septum and around the fine bronchi, tubular alveolar type II epithelial hyperplasia, dilated fine bronchi, and inflammatory exudate with plasma cells and neutrophils mainly in the alveolar lumen (Figure 5, 6), and significant collagen fiber deposition in the alveolar septum and interstitium around the fine bronchi in 2 cases.
3, Discussion
3.1 Clinical features and pathological manifestations of NSIP
The incidence of NSIP is much higher than that of IPF [4. 6], and although the age of its onset varies in the literature [2. 6.7.8.9], they all tend to be predominantly middle-aged and elderly, with a mean of 51 years in our group, which is basically consistent with the literature. The disease often has a relatively subacute onset, with a few insidious onset, and the average time of presentation in this group was 3 months, thus indicating a shorter course than IPF and significantly longer than acute interstitial pneumonia (AIP). The history of smoking, cotton exposure, pet ownership and other underlying diseases were similar to those reported in the literature [6]. 22 cases had varying degrees of chest tightness and shortness of breath, 18 cases had progressive motor dyspnea and 16 cases had dry cough, indicating that the main symptoms of NSIP were chest tightness, cough and dyspnea, which were similar to other interstitial pneumonia and thus not significantly specific. Pulmonary signs were often localized Velcro rales or coarse superficial wet rales and decreased local breath sounds in the middle and lower lungs. Pulmonary function tests often show restrictive ventilation and blood gas analysis often shows type I respiratory failure.NSIP is often treated with glucocorticoids, which are generally significantly more effective than IPF [3-6].
Initially, NSIP was pathologically divided into three subtypes according to the degree of inflammation and fibrosis: type I is predominantly interstitial inflammation, type II is both inflammation and fibrosis, and type III is predominantly fibrosis. In recent years, it has been classified according to its histological characteristics: ① cellular type, the more it accounts for 50%, mainly manifests as chronic inflammation dominated by lymphocyte and plasma cell infiltration in the alveolar septum or in the peribronchial interstitium, with plasma cells and/or neutrophils in the alveolar lumen and rarely fibrosis. (ii) Mixed type, accounting for approximately 40% of cases, characterized by a large chronic inflammatory cell infiltrate and marked collagen fibrillar deposition in the interstitial lung. (iii) The fibrotic type, accounting for approximately 105%, is characterized by dense collagen fibrous deposits in the interstitium with a mild inflammatory response or lack of inflammation. In addition to this, distended fine bronchial dilatation and type I epithelial hyperplasia are also pathognomonic.
3.2 Imaging features of NSIP
The lesions were located in the peripheral part of the lower and middle lungs (subpleural) in 19 cases, in the central region in 2 cases, and in the posterior segment of the right upper lobe in 1 case, thus indicating that the preferred site is often the peripheral part of the lower and middle lungs; 15 of the 22 patients had lesions in both lungs, indicating that NSIP often develops bilaterally; the lesions in this group were often patchy or lamellar ground glass shadows in 1-4 lobes, accompanied by reticular The majority of the lesions were located in the middle and lower lungs, and none of them formed diffuse lesions in both lungs, thus limiting the extent of NSIP compared with IPF and AIP.
Imaging features: 14 cases of cellular NSIP showed lamellar ground-glass shadow, lobular solid shadow, fine reticular changes in the intralobular septa in 9 cases, slight dilatation of fine bronchi in 2 cases, and no foveal and bronchovascular bundle thickening changes in 1 case, which was consistent with the pathological changes of inflammatory cell infiltration in the alveolar septa and around the fine bronchi (lobular core interstitium) and inflammatory cell filling in the alveolar lumen. 6 cases The mixed type of NSIP showed ground glass shadow, reticular shadow and dilated fine bronchi, indicating both chronic inflammation and fibrosis in the interstitium. 2 cases of fibrosis had a large extent of reticular shadow, dilated fine bronchi, often involving multiple lung lobules, along with fovea and distortion of local lung structures, and these imaging manifestations indicated large deposits of collagen fibers in the interstitium. 22 cases of NSIP lesions Of the 22 NSIP lesions, 20 were confined to the subpleural area, and 8 cases of bronchiectasis involved the terminal bronchi and their distant bronchi, while central bronchi were not dilated or only slightly dilated and interstitial thickening around them was rare, which is consistent with foreign reports [9].
Therefore, the imaging features of NSIP are: (i) the main lesions occur in the peripheral part of the middle and lower lungs, often bilaterally, and the lesions are more limited than those of AIP and IPF, and rarely form diffuse lesions in both lungs. The lesions mainly involve lung tissue at the lobular level and commonly present as ground glass shadow, patchy airspace solid shadow, intralobular interstitial thickening, fibrosis and lobular core abnormalities. (iii) Involved interstitial lung tissue is often intralobular and interlobular core interstitial. ④Distensional bronchial dilatation is often distal to the terminal fine bronchi, while the central bronchi are less frequently involved. (5) The destruction and distortion of lung structures is often limited. (6) Cellular lung is less common.
In summary, a comprehensive analysis of the imaging features of NSIP combined with its etiology or causative factors, disease duration, pulmonary function, the effect of hormonal therapy and prognosis can greatly improve its correct diagnostic rate.