Application Of Gemstone Spectral CT In Unstable Angina Pectoris Coronary Atherosclerotic Plaque

Objective:1.The composition and distribution of different types of coronary plaques in 70 patients with unstable angina pectoris,as well as the relationship between various plaques and the degree of stenosis and reconstruction of the lumen were studied and analyzed by gem energy spectrum CT;2.Quantitative analysis of the length and area of different types of coronary plaques,analysis of the law;3.The calcification scores of main branches of coronary artery in different age groups were analyzed.To evaluate the value of gem energy spectrum CT in the treatment of coronary atherosclerotic plaque in patients with unstable angina pectoris,and to provide theoretical basis for clinical risk stratification and intervention.Methods:1.A total of 70 cases of unstable angina pectoris were collected from the Fourth Affiliated Hospital of Inner Mongolia Medical University from August 2017 to December 2019,including 42 males?60%?and 28 females?40%?.According to the CT value,the coronary plaque was divided into vulnerable plaque?CT value<40 Hu?,mixed plaque?density mixed plaque?,fibrous plaque?CT value between 40hu and 130hu?,calcified plaque?CT value>130hu?.The plaque types and distribution of each of the 8 segments?RCA₁?RCA₂?LM?LAD₁?LAD₂?D₁?LCX₁?OM?of the coronary artery were analyzed.The vascular lumen reconstruction of plaque can be divided into positive reconstruction and negative reconstruction.The degree of stenosis was divided into mild stenosis?including normal?,mild stenosis,moderate stenosis and severe stenosis.The reconstruction of coronary lumen and the degree of stenosis caused by these four kinds of plaque were analyzed and compared.Seventy patients were divided into two groups:60 years old group and over 60 years old group.The calcification degree of the two groups and four branches of coronary artery?LM,lad,LCX,RCA?was evaluated by calcification score.Results:1.Four branches of the coronary artery:left main trunk?LM?,left anterior descending branch?LAD?,left circumflex branch?LCX?and right coronary artery?RCA?.In 70 patients with UAP,the ratio of two branches of the coronary artery was 44.29%?31 cases?,the ratio of multiple branches was 30.00%?21 cases?,and the ratio of single branch was 25.71%?18 cases?.2.A total of 191 atherosclerotic plaques were detected in 70 UAP patients.The most vulnerable plaques were 43.98%?84?,mixed plaques 27.23%?52?,calcified plaques 20.42%?39?,and fibrous plaques 8.37%?16?.3.The distribution of various atherosclerotic plaques in the selected coronary arteries in 70UAP patients was statistically significant?X²=36.049,P<0.05?.Among them,the segment with the most plaque distribution was LAD₁?27.23%?,followed by RCA₁?17.80%?,LCX₁?16.75%?,and the segment with the least plaque distribution was LM and D₁?also 4.71%?.In addition,the distribution of vulnerable plaques,mixed plaques,and fibrous plaques in the selected eight coronary arteries also had significant differences,and they were statistically significant?P<0.05?.Vulnerable plaques are mainly distributed in LAD₁?46.43%of total vulnerable plaques?and RCA₁?15.48%of total vulnerable plaques?,and mixed plaques are mainly distributed in RCA₁?23.08%of total mixed plaques?.And LCX₁?accounting for21.15%of the total mixed plaques?,the fibrous plaques were mainly distributed in the OM?37.50%of the fibrous plaques?.4.Comparison of the length and area of various plaques in 70 UAP patients:the length of vulnerable plaques is higher than mixed plaques and calcified plaques,the length of fiber plaques is higher than other plaques;the area of fiber plaques is larger than vulnerable plaques,mixed plaques and calcified plaques.5.Among the 70 UAP patients with different degrees of coronary stenosis,mild stenosis was the most?31.94%?,mild stenosis?including normal?was the second?30.37%?,and moderate and severe stenosis were less?respectively?.20.42%,accounting for 17.27%).Vulnerable plaques and mixed plaques caused statistically significant differences in the degree of stenosis of the lumen?P<0.05?.Vulnerable plaques mainly caused slight stenosis?including normal?of blood vessels?41.67%?and mild stenosis?36.90%?.Mixed plaque mainly caused severe stenosis?36.54%?and moderate stenosis?26.92%?.6.There was a significant difference in the rate of remodeling of coronary lumen caused by various plaques in 70 UAP patients?X²=17.476,P<0.05?.The positive remodeling rate of vulnerable plaque and mixed plaque was 65.47%and 53.85%respectively.Calcified plaque and fibroplaques are easy to cause negative remodeling of lumen,and the positive remodeling rate is 26.64%and 43.75%respectively.7.In 70 UAP patients,the difference of calcification score between the two age groups was statistically significant?P<0.05?,and the calcification score and calcification degree of?60years old group were higher than those of<60 years old group.The incidence and degree of calcification in the four major branches of the coronary artery?LM,LAD,LCX,RCA?were different.LAD had the highest incidence of calcification,followed by RCA.RCA is the most calcified,followed by LAD.Conclusions:1.Gem energy spectrum CT can classify UAP coronary atherosclerotic plaques by measuring CT value,and then analyze and evaluate the constitution,distribution and shape of UAP coronary atherosclerotic plaques more accurately,so as to further distinguish the stability of various plaques,and analyze the relationship and clinical significance between various plaques and different stenosis degree and reconstruction of lumen,so as to guide UAP Bed risk stratification,clinical intervention and treatment can reduce the incidence of acute cardiovascular events.2.Gem energy spectrum CT coronary imaging can clearly show the major branches of UAP coronary artery,and can better show the pathological changes,especially the dynamic zoom and new iterative algorithm reconstruction data technology are applied in energy spectrum CT,which greatly inhibit the hardening effect of calcified plaque,reduce the artifacts of high-density sclerotic beam,and improve the diagnosis of calcified plaque and the degree of stenosis of the lumen and analytical ability.