| Part 1Value of computed tomography angiography in the assessment of disease activity in TakayasuObjective:To investigate the value of CT angiography in assessment of disease activity in patients with Takayasu Arteritis(TA).Methods:We retrospectively analyzed data on 162 aortic CT angiography from 140 TA patients.They were divided into an active group(n=65)and an inactive group(n=97)according to the National Institutes of Health(NIH)criteria,which define clinical status on the basis of 4 elements:systemic features,elevated ESR or CRP,vascular ischemia,and angiographic changes.The active phase is defined as new onset or worsening of 2 or more of these features.CT angiography abnormalities were compared between the two groups.Clinical characteristics(sex,onset age,age at diagnosis,disease duration and body mass index),symptoms,information from a physical examination were recorded.Laboratory tests included CRP and ESR.CT analysis was focused on the evaluation of imaging in the following parameters.Involved segments,wall thickness and enhancement;luminal abnormalities,including stenosis,occlusion lesions,and dilatation;positive remodeling and low-attenuation ring.Results:The active patients were younger(median 41 vs 29 years)and had shorter disease duration(median 12 vs 2 years)than the inactive patients.Hypertension was the most common presenting feature in TA patients presented in 51.9%patients,and more frequently seen in inactive patients(30.7%vs.66%,p<0.001).Left subclavian artery was the most frequent involved segment,presented in 61.7%of patients,and followed by descending thoracic aorta(60.5%),aortic arch(59.3%),left common carotid artery(58%),abdominal aorta(58%),innominate artery(52.5%),right common carotid artery(55.6%)and right subclavian artery(36.4%).Involvement of renal artery,celiac trunk,and superior mesenteric artery was less commonly,presenting in 30.9%(right renal artery),30.2%(left renal artery),25.9%and 19.1%of patients,respectively.Pulmonary.artery and coronary artery involvement were identified in 6.2%and 20.4%of the patients respectively.Luminal narrowing and occlusion were the two most frequent lesions.Dilatation or aneurysm was less common seen compared with stenosis and occlusion lesions.Arterial wall thickness of active TA was thicker than that in inactive patients(5.2±2.4 mm vs.2.5±0.8 mm,p<0.001).The ratio of mural CT attenuation over that of the paravertebral muscle was higher in active patients(1.5±0.3 vs.1.1±0.2,p<0.001).Given a thickness cutoff of 3.3 mm,sensitivity for active-phase TA was 83.1%,specificity 89.7%,positive predictive value 84.4%,and negative predictive value 88.8%.With enhancement ratio cutoff of 1.2,sensitivity for active-phase TA was 89.2%,specificity 76.3%,positive predictive value 71.6%,and negative predictive value 91.3%.In receiver-operating characteristic curves comparison,wall thickness and enhancement ratio were superior to C-reactive protein and erythrocyte sedimentation rate(p<0.05).Aortic positive remodeling,low-attenuation ring were only observed in active TA patients.Mural calcifications were more commonly seen in inactive patients.Conclusion:Arterial wall thickness and enhancement ratio have a high sensitivity and specificity for detecting TA activity,superior to both ESR and CRP,with statistical significance.CT angiography may be a useful tool to assess disease activity by depicting distinctive mural and luminal changes in TA patients.Part 2Application of PET/CT and CT angiography in the assessment of disease activity in Takayasu arteriesObjective:To explore the diagnostic yield of CT angiography and 18F-fluorodeoxyglucose positron emission tomography(18F-FDG PET)in disease activity assessment of takayasu arteries(TA),and investigate the relationship between thickened wall thickness measured by CT angiography and uptake measured by PET/CT.Methods:Forty-seven patients with TA who had undergone CT angiography and PET/CT were enrolled.Clinical disease activity was assessed using the National Institutes of Health criteria.The CT images were analyzed by two cardiovascular imaging physicians to measure the thickness of the thickest wall and assess the patient’s disease activity by CT.The PET/CT images were analyzed by two nuclear medicine imaging physicians to measure the SUVmax at the thickest part of the arterial wall and assess the patient’s disease activity by PET/CT.CT analysis was focused on the evaluation of imaging in the following parameters:Involved segments,wall thickness and enhancement;luminal abnormalities,including stenosis,occlusion lesions,dilatation,positive remodeling and low-attenuation ring;Periarterial changes;Pericardial effusion and pleural effusion.Arterial wall thickness>3mm,wall enhancement ratio>1.2,low density ring,positive remodeling,irregular wall and increased periarteral fat density are the manifestations of active stage.Pericardial effusion and pleural effusion are also considered to be signs of active inflammation.Full thickness calcification and severe stenosis were considered to be signs of inactive inflammation.PET/CT images were analyzed using four scores:0,no uptake present;1+,low-grade uptake(uptake present but lower than liver uptake);2+,intermediate-grade uptake(similar to liver uptake);3+,high-grade uptake(between liver uptake and cerebral uptake or similar to the uptake in the cerebral cortex).One segment of the artery with 2+or 3+resulting in a positive result.ROI was set at the thicknest segment and SUVmax was calculated by the software.Receiver operator characteristics analysis was applied to determine the diagnostic accuracy of CTA and PET for detecting clinically active disease.The relationship between arterial wall thickness and SUVmax was analyzed by spearman correlation.Results:Fifty-three examinations in 47 patients were analyzed and 25 were performed to evaluate the condition before treatment,28 were to monitor the situation after treatment.Twenty-one cases were finally classified as clinically active and 32 as clinically inactive according to the NIH criteria.Overall,the areas under the curves of CTA,PET/CT,C-reactive protein(CRP)and erythrocyte sedimentation rate(ESR)were 0.764(95%CI:0.627-0.870),0.804(95%CI:0.671-0.900),0.660(95%CI:0.517-0.784)and 0.644(95%CI:0.500-0.770),respectively,in the activity detection.PET/CT and CTA were greater than CRP and ESR.Among the 25 newly diagnosed patients,14 were in an active stage and 11 in an inactive stage.The areas under the curve of CTA,PET/CT,CRP and ESR were 0.929(95%CI:0.751-0.993),0.964(95%CI:0.803-0.999),0.776(95%CI:0.566-0.917)and 0.705(95%CI:0.490-0.868),respectively.PET/CT and CTA were superior to CRP and ESR,and the difference between PET/CT and CTA was not statistically significant.Among the 28 patients diagnosed with TA,7 were in an active phase and 21 were in an inactive phase according to the National Institutes of Health criteria.The areas under the curve of CTA,PET/CT,CRP and ESR were 0.643(95%CI:0.441-0.814),0.667(95%CI:0.464-0.832),0.524(95%CI:0.328-0.715)and 0.524(95%CI:0.328-0.715),respectively.The efficiency of CTA,PET/CT,CRP and ESR in evaluating the disease activity was not so good.CTA and PET/CT were more sensitive to mild inflammation,and false positive results were obtained when NIH criteria was used as the standard.In the analysis of 53 individuals,the SUVmax at the thickest point of the artery was correlated with the wall thickness and ESR,with correlation coefficients of 0.362 and 0.383,respectively,and no correlation with CRP.The ratio of SUVmax and liver SUVmax was significantly correlated with the wall thickness,CRP and ESR,and the correlation coefficients were 0.455,0.420 and 0.45,respectively.In patients with uptake in PET/CT,the SUVmax and its ratio to liver SUVmax at the thickest part of the wall were significantly correlated with the wall thickness,with correlation coefficients of 0.416 and 0.507,respectively.Conclusion:CTA and PET/CT were valuable in the assessment of disease acticity in TA,and PET/CT is more sensitive to mild inflammation.There was a positive correlation between wall thickness and SUVmax and SUVmax/SUVliver.The thickness of the artery wall partly reflects the severity of the inflammation.Part 3Value of CT angiography in the analysis of prognostic indicators in Takayasu arteriesObjective:It is difficult to predict the prognosis and complications of Takayasu arteritis(TA)due to its wide variation in the long course.The aim of this study was to investigate the value of CT angiography in the analysis of prognostic indicators in Takayasu arteries(TA).Methods:We retrospectively analyzed the CT angiography images and clinical characteristics from 464 TA patients.The evaluation of CT images include the involvement of the segments including ascending aorta,aortic arch,descending thoracic aorta,abdominal aorta,innominate artery,proximal common carotid artery,subclavian artery,celiac trunk,superior mesenteric artery,renal artery,coronary artery and pulmonary artery.Involvement is considered when the lumen is moderately or severely narrowed,dilated,or aneurysmal.Patients were followed-up regarding the occurrence of disease-related death,cardiac failure,aortic dissection,cerebral hemorrhage,blindness and other related complications and disease recurrence.Follow-up information was gathered by clinical visits or telephone contacts.Cardiac involvement is considered when mitral valve and tricuspid valve have medium or large amount of regurgitation,the heart is obviously enlarged or pericardial effusion is present.Relapse is defined as the change of disease state from the stable or remission stage to active stage again,and the corresponding treatment needs to be changed.Kaplan-Meier analysis was used to screen the risk factors and Cox proportional multivariate analysis was used to analyze the risk factors affecting the prognosis.Results:Finally,456 patients(mean age 39.1 ± 12.5 years)were enrolled in the study,including 390 females(85.5%)with an average age of 39.1 ± 12.5 years.The median and quartile follow-up time was 3.6(2-5.5)years,and 153 patients had disease recurrence.Forty patients died in this study and 32 were females.The average age at death was 41 ± 13.5 years and an average duration of disease was 16.6± 11.2 years.Compared with the non-death group,patients in the death group had a longer disease duration(16.6±11.2 vs.11.8±9.2).Of the 40 deaths,25 died from heart failure,3 from cerebral hemorrhage,2 from stroke,3 from myocardial infarction,1 from aortic dissection,1 from pulmonary infection in a blind patient and 1 from postoperative complications.Two cases died suddenly and 3 died of unknown causes.Kaplan Meier analysis showed that the involvements of ascending aorta and aortic arch and descending aorta thoracic segments,pulmonary artery,heart coronary artery,renal artery and recurrence were factors affecting the prognosis when death was defined as the events.Multi-variable Cox regression analysis showed that involvements of aortic arch,thoracic descending aorta,pulmonary artery,cardiac involvement and recurrence are independent poor survival predictors.Conclusion:CTA was valuable in the evaluation of clinical severity and prognosis analysis in TA.Involvement of aortic arch,thoracic aorta,pulmonary artery and cardic involvement and the recurrence were risk factors affecting prognosis.Involvement of thoracic aorta,pulmonary artery,cardiac involvement and recurrence are independent poor survival predictors. |
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