Pretreatment Effects of Cutting Balloon on Coronary Artery Calcification Based on Finite Element Analysis / 医用生物力学

Objective To investigates the applicability of cutting balloon in the pretreatment of superficial coronary artery calcified lesions, so as to decrease the occurrence of serious consequences in the treatment of calcified lesions. Methods The effect of cutting balloon on calcified plaques with different curvatures, thickness, and length was analyzed using the finite element method, with normal balloon as a control. The thickness of calcified plaque was set to 0.3 mm and 0.4 mm, and the length was set to 2 mm and 4 mm. The calcification degree was set to 120°, 180°, 270°and 360° according to the intravenous ultrasound (IVUS) calcification severity grading, with a total of 16 types of calcified plaques. The brittle fracture module was used to simulate calcification fracture of calcified plaques, and virtual stent implantation was carried out based on pretreatment simulation. The effect of pretreatment was evaluated by calcification fracture condition and stent roundness. Results For superficial calcification lesions, in lesions less than 120°, the balloon could not remove the calcification plaque obstruction, and the stent roundness rate was 82.75%. In 180° calcified lesions with thickness of less than 0.3 mm, the calcification was broken by cutting balloon under 1 215.9 kPa expansion pressure, and the post-stent roundness rate was 74.42%; normal balloon could not cause calcification fracture under safe expansion pressure (1 418.55 kPa). In 270°calcified lesions with thickness less than 0.3 mm, the normal balloon produced 3 fractures under 1 013.25 kPa expansion pressure. The cutting balloon produced 2 fractures under 1 013.25 kPa expansion pressure, and the balloon could not fracture the circular calcified lesions with thickness of 0.3 mm. Conclusions Cutting balloon is recommended for 180°calcified lesions with thickness less than 0.3 mm, the normal balloon is recommended for 270°calcified lesions, and balloon pretreatment is not recommended for annular lesions with thickness greater than 0.3 mm.

CTA observation on relationship of right collateral ischemic colitis and calcified plaque of superior mesenteric artery / 中国医学影像技术

Objective: To explore the relationship of right collateral ischemic colitis (IC) and calcified plaque of superior mesenteric artery (SMA). Methods Totally 605 patients who underwent CTA of SMA were enrolled and analyzed retrospectively, including 81 patients in IC group and 524 patients in the non-IC group. The detection rate of SMA calcified plaque was compared between the 2 groups. The number, morphology and location of SMA calcified plaque, as well as the degree of stenosis of the opening and the narrowest part of SMA in IC group and the non-IC group were analyzed and compared, and the ROC curve was used to evaluate the efficacy of SMA stenosis degree in diagnosis of IC. Results The incidence of SMA calcified plaques in IC group (13/81, 16.05%) was higher than that in non-IC group (33/524, 6.30%; P=0.002). The number of SMA calcified plaques in IC group was more than that in the non-IC group (P=0.043). Significant difference in the location of calcified plaque was found between the 2 groups (P<0.001). SMA calcified plaques mostly located in the distal segment in IC group, while in the proximal or middle segment in non-IC group. There was no significant difference of plaque morphology between the 2 groups (P=0.421). Statistically significant difference of the narrowest stenosis degree was detected between the 2 groups (P<0.001). The AUC of the narrowest stenosis degree in diagnosis of IC was 0.838 (P<0.001), the sensitivity was 76.92% (10/13), and the specificity was 87.88% (29/33). Conclusion When there are more calcified plaques located in the distal segment of SMA and stenosis degree of the narrowest segment of SMA ≥25%, IC should be considered.

Coronary calcified plaque imaging using dual-energy CT: a phantom study / 中华放射学杂志

Objective To analyze the impact of dual energy monochromatic reconstructions (50-160 keV) on coronary calcified plaque stenosis quantification in a cardiac phantom with the real stenosis as standard of reference.Methods Signal-to-noise(SNR)and contrast-to-noise ratios(CNR)were calculated. In conventional 120 kV coronary CT angiography (CCTA) images as well as 12 monochromatic series(50-160 keV),luminal narrowing of calcified plaque was measured and compared to the real stenosis. Bland-Altman plots were performed to analyze the correlation of reference standard with conventional 120 kV and 12 monochromatic series (50-160 keV). The sensitivity, specificity, and accuracy of CCTA for detection of≥50% stenosis were calculated and receiver operating characteristic(ROC)curve was analyzed with the real stenosis as reference standard.Results The SNR and CNR were decreased with the increase of keV from 70 keV.The SNR and CNR of monochromatic imaging were lower compared with conventional 120 kV images(SNR:76.4±16.1;CNR:274.7±54.1)(P<0.05).The Bland-Altman plots presented a smaller measurement bias towards 90-160 keV than conventional 120 kV, and smallest measurement bias was revealed in 100-130 keV imaging(100-130 keV:bias 17.2% vs 120 kV:21.4%).Using the stenosis≥50% as cut-off value, the specificity were higher in the monochromatic series (70-160 keV) than conventional 120 kV CCTA.The specificity(75.0%)were the highest in the 120 keV and 130 keV images.The area under the ROC curve(AUC)of 90-130 keV(0.991-0.995)was higher than that in conventional 120 kV imaging (0.990). Conclusions The use of monochromatic imaging improves the overall accuracy of stenosis evaluation in coronary calcified plaques. Reconstructions at 100-130 keV for calcified lesions yielded the optimal results.

Investigation of clinical application for severe segmental calcification by subtraction technique of coronary artery CT angiography / 复旦学报（医学版）

Objective To investigate the feasibility of subtraction coronary computed tomography angiography (Sub-CCTA) for the diagnosis of coronary heart disease in the segment with severe calcification.Methods A retrospective analysis was performed on 27 patients who underwent clinically indicated digital subtraction angiography (DSA) and CCTA using a 320-detector row CT.Compared with the results of DSA,sensitivity,specificity,positive predictive value,negative predictive value and accuracy of Con-CCTA and Sub-CCTA were calculated.The clinical diagnostic accuracy of the two imaging methods was evaluated using the receiver operating characteristic (ROC) curve.The stenosis of coronary segments was divided into four grades (Ⅰ,Ⅱ,Ⅲ,Ⅳ).Kappa coefficient was used to measure agreement between two imaging methods.Image quality of 4-scale grade scoring method was used and t test was conducted.Results A total of 52 segments with severe calcification were evaluated.The scores of image quality in Con-CCTA and Sub-CCTA were 2.8 ± 0.5 and 3.4 ± 0.7,respectively.There was significant difference between them (t =5.9,P ＜ 0.05).Compared with the result of DSA as the golden standard,the Kappa coefficients were 0.55 and 0.81 respectively in Con-CCTA and Sub-CCTA for the quantitative evaluation of the severe calcified segments.The sensitivity,specificity,positive predictive value and negative predictive value and accuracy of Con-CCTA were 81.0％,63.1％,63.1％,81.1％ and 70.8 ％;and for Sub-CCTA they were 90.5 ％,85.2％,82.1 ％,92.0％ and 87.5 ％ respectively.Compared with Con-CCTA,the area under the ROC curve of Con-CCTA and Sub-CCTA were 0.84 (95％CI:0.70-0.93) and 0.96 (95％ CI:0.86-1.00),respectively,and the difference was statistically significant (P =0.03).Conclusions Sub-CCTA can improve the diagnostic accuracy of coronary artery stenosis in severe calcified segment.Application of subtraction technique in CCTA can reduce or even eliminate the artifacts caused by severe calcified plaque,and has a good clinical application prospect.

The treatment of calcified type B aortic intramural hematoma / 介入放射学杂志

Objective To investigate the suitable therapeutic schedule for Stanford B aortic intramural hematoma associated with calcification. Methods During the period from March 2009 to March 2012, a total of 15 patients of Stanford B aortic intramural hematoma with calcified plaque were admitted to authors’ hospital. The diagnosis was proved in all patients by CT angiography of the entire aorta with a 64-row CT scanner. Of the 15 patients, death occurred in one, thoracic endovascular aortic repair (TEVAR) treatment was adopted in 7 and conservative therapy was carried out in 7. All the patients were followed up for one year. CT angiography was employed at 3, 6 and 12 months after the treatment to evaluate the therapeutic results. Results One patient died of acute myocardial infarction after admission to hospital when the long-tem use of antiplatelet drugs was stopped. Seven patients received TEVAR treatment and the remaining 7 patients were treated with strict conservative therapy, and all these patients were asymptomatic at the time of discharge. During the follow- up period, CT angiography performed at 3, 6 and 12 months after the treatment showed that the intramural hematoma lesions gradually shrank or were absorbed in 13 patients, and the patients were asymptomatic. The remaining one patient was lost in touch. Conclusion The key to treat Stanford B aortic intramural hematoma with calcification is to prevent deterioration of the lesion. While strict conservative treatment is kept on, TEVAR should be promptly carried out for patients who need to take antiplatelet drugs over a long period of time, for patients whose clinical symptoms are not improved, for patients in whom the relived symptoms recur, and for patients whose CT angiography shows that the penetrating aortic ulcer becomes worse.

The effect of conservative treatment for Stanford B aortic intramural hematoma without calcified plaque / 中华胸心血管外科杂志

Objective To explore the effect of conservative treatment for Stanford B aortic intramural hematoma without calcified plaque and the midterm follow-ups.Methods Clinical data of 20 patients with Stanford B aortic intramural hematoma without calcified plaque which were confirmed by CTA of the whole aorta were retrospectively analyzed.There were 12 males and 8 females,with the age of 35～ 52 years.All of them received pharmacotherapy and psychotherapy.Results All the 20 cases were asymptomatic after conservative medical treatment when they discharged,and were followed up whit imaging tests.They all lived without symptoms during the follow-up period.The pleural fluid on the left side was disappeared in 11 cases after 3 months and the aortic intramural hematoma was absorbed in 13 cases after 6 months.After 1 year there were total 18 cases without aortic intramural hematoma,while The thickness and scope of the hematoma were reduced significantly in the other 2 cases.Conclusion It' s ease to find whether the patient with Stanford B aortic intramural hematoma got calcified plaque or not; the conservative treatment for Stanford B aortic intramural hematoma without calcified plaque has satisfactory clinical effect in midterm follow-ups.

Volumen de placas coronarias calcificadas por tomografía computarizada y presencia de estenosis significativa por angiografía coronaria / Volume of coronary calcified plaques by computed tomography and presence of significant stenosis by coronary angiography

Introducción: La presencia de calcio en las arterias coronarias es prácticamente patognomónica de aterosclerosis. En 1990, Agatston diseñó un método para cuantificar el puntaje de calcio coronario a través de la tomografía computarizada. Nuestro objetivo fue determinar la asociación entre el volumen de las placas calcificadas en las arterias coronarias determinado por tomografía de 64 cortes y la presencia de estenosis coronaria significativa diagnosticada por coronariografía invasiva. Método: Se estudiaron consecutivamente 150 pacientes, 66.6% varones, programados para coronariografía invasiva. Previo a este procedimiento, se les cuantificó el puntaje de calcio por arteria y por paciente a través de la tomografía. Se incluyeron 128 placas calcificadas, a las que se les determinó el volumen a través del método de Callister introducido en el año 1998. Las placas se consideraron pequeñas si el volumen era ≤ 10 mm³ y grandes si >10 mm³. Resultados: Se asociaron a estenosis coronaria significativa 79% de las placas con volumen mayor a 10 mm³, contra 17% con volumen pequeño (p < 0.0001). Más de 75% de las placas con volumen mayores de 10 mm³ en las arterias circunfleja, descendente anterior y coronaria derecha, se asociaron a estenosis coronaria significativa en el segmento de la placa (p < 0.0001). Correlación de Spearman 0.8. La sensibilidad y especificidad diagnóstica de estenosis coronaria significativa fueron 98.7% y 71.7 % respectivamente para un valor de corte 6.5 mm³ con un área bajo la curva de 0.88 ± 0.32 (IC 95%, 0.815 a 0.940). Conclusiones: Se observó asociación entre el volumen de las placas calcificadas circunscritas en las arterias coronarias diagnosticada por tomografía computada y la presencia de estenosis coronaria significativa diagnosticada por coronariografía invasiva.

Background: Coronary artery calcium is almost patognomonic of atherosclerosis. In 1990, Agatston designed a method to measure the coronary calcium score by computed tomography. Our aim was to establish the association between coronary calcified plaque volumes calculated by 64 slice computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography. Method: 150 consecutive patients, 66.6% male, scheduled for invasive coronary angiography were studied. Coronary calcium score was measured per patient and per artery by computed tomography previous to invasive coronary angiography. 128 calcified plaques were enrrolled and volume was determined by Callister method introduced in 1998. According to the volume, the plaques were classified in two groups: small if volume ≤ 10 mm³ and big if > 10 mm³. Results: In 79% of plaques with a volume > 10 mm³, significant coronary stenosis was detected by invasive coronary angiography versus 17% with small volume (p < 0.0001). More than 75% of plaques with volume > 10 mm³ in circumflex artery, anterior descending artery and right coronary artery were associated with significant coronary stenosis (p < 0.0001). Spearman correlation was 0.8. The sensitivity and specificity of significant coronary stenosis were 98.7% and 71.7% respectively for a cut off value of 6,5 mm³, area under the curve of 0,88 ± 0,32 (CI 95%, 0.815 to 0.940). Conclusions: Association between coronary calcified plaque volume diagnosed by computed tomography and the presence of significant coronary stenosis diagnosed by invasive coronary angiography was observed.