The HRCT Diagnosis And Evaluation For Interstitial Lung Diseases Associated With Connective Tissue Diseases

1. The Value of High Resolution Computed Tomography in Systematic Connective Tissue Disease-Interstitial Lung DiseaseObjective:Interstitial lung disease (ILD) is one of the common complications of connective tissue diseases (CTD) and affects the patients’ life quality and death rate. Diagnosing CTD-ILD at early stage and identifying its pathologic type of ILD play an important role in successful treatment and outcome predicting. High resolution computed tomography (HRCT) has become the main approach to diagnose CTD-ILD. Although the HRCT appearance of different type of CTD-ILD has some overlap, the typical appearance of each disease can be the distinguishing feature. The objective of this research was to identify different types of CTD-ILD by HRCT appearance, and advance the knowledge of the diagnosis of this disease.Materials and methods:From October 2011 to March 2014, a total of 197 patients (129 female and 68 male) aged between 21 and 82 years (mean age,57.61 years) were diagnosed with CTD by clinical symptom and laboratory examination, and examined by HRCT. High-definition Discovery CT750 HDCT and 64-slice VCT (GE Healthcare, Wisconsin, USA) were used. The parameters were as follows:layer thickness,5-10 mm; reconstruction layer thickness,0.625mm; thread pitch,1.375; rotational speed,0.5s per rotation; voltage,120-140kV; and electric current,600 mA. The HRCT appearance was observed at axial, coronal and sagittal images. Data were analyzed using Stata 10.0 (Stata Corp., USA). The Mest and rank-sum test was used to analyze the appearance between different types of CTD-ILD. P<0.05 was considered to be statistically significant.Results:Among 197 CTD patients,53 cases (34 female and 18 male) were confirmed combined with ILD using HRCT, and the incidence rate was 26.9%. Fifteen patients were diagnosed with SLE (28.3%), and eight RA (15.1%), twelve PM/DM (22.6%), nine SS (17.0%),8 SSc (15.1%) and one BD patient 1.9%). There showed no statistical difference of age, progression of disease and symptom of respiratory system between every types of CTD (P>0.05). The most common HRCT appearance of CTD-ILD was ground glass opacity (41/53,77.4%). Other appearances were consolidation (28/53,53.8%), contractive bronchiectasis (21/53,39.6%), reticular opacity (16/53,30.2%), honeycomb shade (9/53,17.0%), and subpleural line (9/53, 17.0%) successively.Construction:The HRCT signs of CTD-ILD are appeared before clinical symptoms and abnormalities of pulmonary function test. HRCT is valuable for identifying different types of CTD-ILD, which can be a routine method to assess the disease.2. Quantitative Analysis And Therapeutic evaluation of Connective Tissue Disease-Interstitial Lung Disease With High Resolution Computed TomographyObjective:Interstitial lungdisease (ILD) is one of the common complications of connective tissue diseases (CTD) and affects the outcome of treatment. ILD at early stage is curable, while is irreversible in advanced stage. So diagnosis and assessment of CTD-ILD at early stage is the key to successful treatment. The golden standard of confirming CTD-ILD is biopsy, but it is invasive and is not without risk. High resolution computed tomography (HRCT) has become the main approach to diagnose CTD-ILD, and makes it possible to assess the extent of disease quantitatively. The objective of this research is to evaluate the potential of HRCT to quantitative assess the extent and therapeutic outcome of CTD-ILD.Materials and Methods:From October2011 to March2014, a total of 52 patients (34 female and 18 male) were diagnosed with CTD-ILD by rheumatologists and radiologists. Fifteen patients is diagnosed with SLE (28.8%), and eight RA (15.4%), twelve PM/DM (23.1%), nine SS (17.3%) and 8 SSc patients (15.4%). The course of disease is 27 days to 18 years, and 37months on average. High-definition Discovery CT750 HDCT and 64-slice VCT (GE Healthcare, Wisconsin, USA) were used. The parameters were as follows:layer thickness,5-10 mm; reconstruction layer thickness, 0.625mm; thread pitch,1.375; rotational speed,0.5s per rotation; voltage,120-140kV; and electric current,600 mA.The extent of ILD is quantitative analyzed by Gay’s scoring system, and divided disease into four stages according to Qiu’s staging methods. All the patients were underwent HRCT examination before and after the therapy within three days, and follow up by HRCT. Compared the follow up imaging data with the baseline CT images, the therapeutic outcomes were assessed subjectively as completely absorbed, mostly absorbed, mildly absorbed, and no absorption. Data was analyzed using Stata 10.0 (Statacorp, USA). The five-years survival rate is estimated using Kaplan-Meier methods, and the diffidence of outcomes were compared by Spearman χ2 test. P<0.05 was considered to be statistically significant.Results:There are 16 patients were at stage Ⅰ (31.0%),17 were at stage Ⅱ (32.7%), and 19 were at stage Ⅲ (36.5%). The most common HRCT appearance of CTD-ILD was ground glass opacity (41/52,78.8%). Other appearances were consolidation (28/52,53.8%), interlobular septal thickening (27/52,51.9%), nodules (22/52,42.3%), contractive bronchiectasis (19/52,36.5%), reticular opacity (16/52,30.8%), honeycomb shade (9/52,17.3%), and subpleural line (9/52,17.3%) successively. The alveolar score (CT-alv) of SLE, RA, SS, PM/DM and SSc were 0.8±0.7,1.1±0.7, 0.8±0.7, 1.1±0.8, and 1.3±0.7 respectively, which showed no statistically difference (P>0.05). The fibrosis score (CT-fib) of SSc is significantly higher than CT-alv (P<0.05). The follow up period is 2.4 years on average, and 4 patients were lost because of hyoxemia and respiratory failure. The five-year survival rate is 65.3% (27.2-78.6%)。In stage Ⅰ patients,13 cases (13/16,81.3%) underwent HRCT examination after therapy, and the lesion was completely absorbed in 8 (61.5%) cases, and mostly absorbed in 5 (38.5%) cases. Images data were available in 16 (94.1%) patients at stage Ⅱ, and 6 (37.5%) lesion were mostly absorbed,10 (62.5%) were mildly absorbed. All the 19 patients at stage Ⅲ gained the images data after therapy, the lesion of 4 (21.1%) cases were mildly absorbed, and the rest (15/19,78.9%) showed no absorption. The therapeutic outcome was statisticallydifferent between three stages (P<0.05).Conclusions:Quantitative analysis with HRCT can assess the extent and stage of CTD-ILD precisely, and is valuable in making clinical decision and predicting therapeutic outcomes.