The Study Of Relationship Between Imaging And Common Laboratory Tests In Thoracic Aortic Aneurysm

Introduction and objective:Thoracic aortic disease includes the true aneurysm, pseudoaneurysm,aortic dissection, intramural hematoma, penetrating atherosclerotic ulcers, athero -sclerosis, aortic coarctation and other diseases. The common disease in clinical is the expansion of thoracic aortic lesions,also called the thoracic aortic aneurysm. Etiology of thoracic aortic aneurysm associated with the following factors: hypertension, atherosclerosis, hereditary diseases, syphilitic infection,trauma, cardiac catheterization surgery, pregnancy etc.Most of the thoracic aortic aneurysms occasionally detected by chest X-ray, ultrasound,computed tomographic and magnetic resonance imaging. In the early period there is no symptoms in clinical,and Progressive dilation of arotic may cause dilation of the aortic, with resultant aortic regurgitation.This represents a significant volume overload on the left ventricle, resulting in progressive left ventricular dilation and failure.The thoracic aortic aneurysm may lead to chronic chest pain when it compressed the adjacent structure. However,when the patients have severe chest pain in clinical, it suggests the thoracic aortic aneurysms occur. The clinical manifestations of thoracic and aortic aneurysm are diversity and complexity , in particular aortic dissection has the most mortality rate, and easily missed diagnosis or misdiagnosis. Therefore early diagnosis of thoracic aneurysm becomes more and more important.According to the pathology of thoracic aortic aneurysm,It can be divided into true aortic aneurysm, peudoaneurysm and aortic dissection. In recent years, aortic dissection has been detected several sub-type:1. Classic aortic dissection.aortic dissection is characterized by the presence of an intimal flap that separates between the true and false lumen. This can further be divided into communicating and noncommunicating dissection. 2.Intramural hematoma/hemorrhage:intramural hematoma/hemorrhage may be the result of rupture vasa vasorum and may be the initial lesion in cases of cystic medial degeneration.It often coexists with or progresses to aortic dissection. It is present in 10% to 15% of patients with suspected arotic dissection. 3.Subtle-discrete aortic dissection.This form of dissection is characterized by a stellate or linear intimal tear with the exposure of the underlying media and adventitia but without progression to separation of medial layers.The diagnostic tests failed to diagnose including ultrasound, CT, and MRI.The aortography should be done if dissection is still a highly likely diagnosis. 4.Penetrating aortic ulcer: It refers to an ulceration of an atheromatous plaque that extends deeply through the intima and into the aortic media. It may precipitate an intramedial dissection or may rupture into the adventitia to form a pseudoaneurysm. 5.Traumatic and iatrogenic aortic dissection. Blunt trauma may cause dissection at the level of aortic isthmus. Iatrogenic dissection may be seen after the cardiac catheterization surgery.The current gold standard for diagnosis of thoracic aortic aneurysm is aortic angiography, because of its large contraindications, and it has not three-dimensional to display thoracic aorta.In recent years, both CT and MR examination take its place. However, all the medical imaging are carried on when the doctor doubts the thoracic aortic aneurysms, CT and other examinations are so expensive ,and they are not convenient and simple for diagnosed thoracic aortic aneurysms.It is necessary to bulid a new method for early diagnosis of thoracic aortic aneurysm ,in order to provide new ideas for clinical. Now the international prospective study consider some biological indicators is helpful fo the early detection of aortic dissection [2]. In this project we hope to assess a preliminary of thoracic aortic aneurysm. by diagnosed with CT,and transthoracic echocardiography, as well as some common laboratory markers of peripheral blood.The aim of this study: 1. CT diagnosed different types of thoracic aortic disease, with the clinical common tests in peripheral blood, including leukocytes (WBC) count, high sensitivity C-reactive protein (HS-CRP), Low density lipoprotein cholesterol (LDL-CHOL), Lipoprotein (a) [LP (a)], D-DIMER.These indicators explore the role of the early diagnosis in different types of thoracic aortic diseases.2. On the basis of assessment with laboratory indicators to value different types of thoracic aortic aneurysms, we selected the significance indicator which is helpful in the diagnosis of thoracic aortic aneurysms and it analysis the value in different types of thoracic aortic aneurysm, in addition its detection sensitivity threshold.3. Some special imaging features with CT or transthoracic echocardiography connected with this indicator to assess a preliminary study of for the diagnosis of thoracic aortic aneurysm.It provides the guidance.in clinical.Methods:1. Under the control study of CT,imformation including the clinical history, such as age, gender,etc of 37 patients which suspected aortic lesions,were collected from Jan 2007 to Dec 2010 in our hospital. these patients were divided into four groups which based on the CT results that consist of typical aortic dissection (AD), true thoracic aortic aneurysm(TAA), intramural hematoma (IMH) and control group.2. 37 cases were on examinatons via the transthoracic echocardiography in blind method, and their aortic root diameter were measured by ultrasound3. WBC,HS-CRP,LDL-CHOL,LP (a), D-DIMER are measured in all the individuals 4. Thoracic aortic diseases in different groups were compared with the ultrasound, CT, and common tests of the indicators, and their correlation were analyzed by statistics.Results:1. CT diagnosis:Typical AD group 13 cases, True thoraic aortic aneurysm 11 cases, Intramural hematoma 8 cases, Control group 5 case. The age of onset in TAA and IMH group is older than the typical AD group and control group.Transthoracic echocardiography(TTE): the aortic root diameter(AOD) was measured by ultrasound,in the typical AD group and TAA group AOD≥34mm.2. Laboratory parameters:D-DIMER: In this study compared with control group, serum levels of D-DIMER were statisticaly difference (P<0.05) in the typical AD group, IMH, TAA. Levels of D-DIMER had no significant difference with AD,IMH,and TAA groups. but the these groups'box plot show the minimum median (295ug/l) of D-DIMER,when the level of D-DIMER≥295ug/l, Thoracic aortic aneurysms may be happen. Serum levels of D-DIMER with thrombosis content is higher than the no thrombosis in these three group.Other Laboratory Parameters: Most common cause of aortic aneurysms is at- herosclerosis,and LP (a), LDL-CHOL is atherosclerosis risk factors. HS-CRP is the inflammatory response in the cardiovascular system an important factor. In this study, levels of HS-CRP in our hospital laboratory reference value is 0-3mg/l as the standard. Levels of HS-CRP were significantly different (P <0.05) between control group and typical AD group, IMH or TAA group.But among these three groups above serum levels of HS-CRP did not differ compared with each other. LDL-CHOL in each group Comparative P> 0.05, but not statistically significant. WBC count, LP (a) indicators the typical AD group and IMH are higher than TAA group and control group (P <0.05), while these two indicators have no difference comparing the typical AD with IMH or TAA with the control group. LP (a) indicators are in the reference normal range. The serum level of HS-CRP had a positive correlation with D-DIMER in typical AD,IMH and TAA groups. HS-CRP levels with the D-DIMER increases. Therefore, HS-CRP levels (> 3mg / l) can be combined with levels of D-DIMER increased, as a secondary diagnosis of thoracic aortic aneurysms indicators.3.D-DIMER with CT,and ultrasound correlation analysis:In our hospital D-DIMER reference value (50-285ug/l) as the standard,Serum levels of D-DIMER were divided into>285ug/l compared with the≤285ug/l by CT diagnosis of thoracic aortic aneurysm,which include typical AD group, IMH and TAA group. there were difference among these three groups(p = 0.049 <0.05).For the above three groups, Serum levels of D-DIMER with the signs of thrombosis by CT are higher than the sigh of no thrombosis(P=0.000<0.05).But levels of D-DIMER were associated with the three group above by CT diagnosis (P>0.05).levels of D-DIMER can not distinguish among the type of thoracic aortic aneurysm.Com- pared with aortic root diameter and analysised their correlation,P=0.036 <0.05,R=0.398,AOD has a certain relationship with serum D-DIMER.The correlation between aortic root diameter(AOD) measured by ultrasound and levels of D-DIMER in three groups above of thoracic aortic aneurysms, P = 0.036 <0.05, R = 0.799, AOD and serum D-DIMER in the thoracic aortic aneurysm are possibly related with.Conclusion:1. When levels of D-DIMER≥295ug/l,HS-CRP>3mg/l,the aortic lesions should be considered,furthmer the imaging examionaton should be given.2. When levels of D-DIMER is higher than the reference range(>285ug/l), with AOD≥34mm by the ultrasound, thoracic aortic aneurysm should be consided CT or other examination3. Levels of D-DIMER with the thrombosis group are higher than that of group with no thrombosis.