AIM To evaluate reproducibility of pulmonary embolism(PE) clot volume quantification using computed tomography pulmonary angiogram(CTPA) in a multicenter setting.METHODS This study was performed using anonymized data ...AIM To evaluate reproducibility of pulmonary embolism(PE) clot volume quantification using computed tomography pulmonary angiogram(CTPA) in a multicenter setting.METHODS This study was performed using anonymized data in conformance with HIPAA and IRB Regulations(March 2015-November 2016). Anonymized CTPA data was acquired from 23 scanners from 18 imaging centers using each site's standard PE protocol. Two independent analysts measured PE volumes using a semi-automated region-growing algorithm on an FDA-approved image analysis platform. Total thrombus volume(TTV) was calculated per patient as the primary endpoint. Secondary endpoints were individual thrombus volume(ITV), Qanadli score and modified Qanadli score per patient. Inter-and intra-observer reproducibility were assessed using intra-class correlation coefficient(ICC) and BlandAltman analysis. RESULTS Analyst 1 found 72 emboli in the 23 patients with a mean number of emboli of 3.13 per patient with a range of 0-11 emboli per patient. The clot volumes ranged from 0.0041-47.34 cm3(mean +/-SD, 5.93 +/-10.15 cm3). On the second read, analyst 1 found the same number and distribution of emboli with a range of volumes for read 2 from 0.0041 – 45.52 cm3(mean +/-SD, 5.42 +/-9.53 cm3). Analyst 2 found 73 emboli in the 23 patients with a mean number of emboli of 3.17 per patient with a range of 0-11 emboli per patient. The clot volumes ranged from 0.00459-46.29 cm3(mean +/-SD, 5.91 +/-10.06 cm3). Inter-and intraobserver variability measurements indicated excellent reproducibility of the semi-automated method for quantifying PE volume burden. ICC for all endpoints was greater than 0.95 for inter-and intra-observer analysis. Bland-Altman analysis indicated no significant biases.CONCLUSION Semi-automated region growing algorithm for quantifying PE is reproducible using data from multiple scanners and is a suitable method for image analysis in multicenter clinical trials.展开更多
Objective： To analyze the value of CTPA in assessing the dissolve of embolus and the function of the right ventricle dynamically. Methods：Twenty-three cases of massive pulmonary embolism were analyzed retrospectivel...Objective： To analyze the value of CTPA in assessing the dissolve of embolus and the function of the right ventricle dynamically. Methods：Twenty-three cases of massive pulmonary embolism were analyzed retrospectively. The pulmonary artery obstruction index and the right ventricular function parameters were collected and analyzed on CTPA before thrombolytic therapy, 24 hours and 14 days after therapy, respectively. Results：The pulmonary artery obstruction index decreased gradually, and there was significant difference before therapy, 24 hours and 2 weeks after therapy. Twenty-four hours after therapy, the maximal short axes diameter and the maximal transverse area of right ventricle（RVd, RV~） decreased significantly, the maximal short axes diameter and the maximal transverse area of left ventricle（LVd, LVs） increased significantly, and the RVd/LVd, RVs/LVS decreased apparently. The pulmonary artery symbolic pressure before and 24 hours after therapy were apparently different. There was no significant difference between azygos vein, the super vena cava, the main pulmonary artery and vein reflux before and after therapy. Conclusion：CTPA can evaluate the pulmonary artery obstruction degree and right ventricular function dynamically.展开更多
To analyze the value of CT pulmonary angiography（CTPA） in assessing right ventdcular dysfunction（RVD） after acute pulmonary embolism. Methods：Thirty-six patients with CTPA-confirmed PE who underwent ultrasonic ca...To analyze the value of CT pulmonary angiography（CTPA） in assessing right ventdcular dysfunction（RVD） after acute pulmonary embolism. Methods：Thirty-six patients with CTPA-confirmed PE who underwent ultrasonic cardiography（UCG） within the ensuing 24 hours were retrospectively reviewed. According to the severity of the disease, the patients were divided into the massive PE group（24 cases） and non-massive PE group（12 cases） respectively. CT scans were analyzed for findings suggestive of RVD. Scans were considered positive for RVD if the right ventricle was dilated（RVd/LVd 〉 1） or if the interventricular septum was straightened or deviated towards the left ventricle. Results were then compared with the results of UCG to estimate the value of CTPA in detecting RVD associated with PE, Results：In all cases, compared with UCG, the diagnostic sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, and negative predictive value of CTPA was 84.61%, 78.26%, 3.892, 0.197, 68.75% and 90% respectively. Kappa value was 0.60, which suggested moderate agreement between CTPA and UCG in the whole level. In the massive PE group, the diagnostic sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, negative predictive value of CTPA was 84.61%, 72.73%, 3.103, 0.212, 78.57% and 80% respectively. Kappa value was 0.58, which suggested moderate agreement between CTPA and UCG in the massive PE group. In the non-massive PE group, the diagnostic specificity of CTPA was 83.33%. By statistics, the value of RVd/LVd had significant difference between the massive PE and the non-massive PE group. Conclusion：CTPA can reliably detect RVD through the evaluation of cardiac morphology. However, this result requires confirmation using a larger prospective cohort study.展开更多
AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conforman...AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.展开更多
文摘AIM To evaluate reproducibility of pulmonary embolism(PE) clot volume quantification using computed tomography pulmonary angiogram(CTPA) in a multicenter setting.METHODS This study was performed using anonymized data in conformance with HIPAA and IRB Regulations(March 2015-November 2016). Anonymized CTPA data was acquired from 23 scanners from 18 imaging centers using each site's standard PE protocol. Two independent analysts measured PE volumes using a semi-automated region-growing algorithm on an FDA-approved image analysis platform. Total thrombus volume(TTV) was calculated per patient as the primary endpoint. Secondary endpoints were individual thrombus volume(ITV), Qanadli score and modified Qanadli score per patient. Inter-and intra-observer reproducibility were assessed using intra-class correlation coefficient(ICC) and BlandAltman analysis. RESULTS Analyst 1 found 72 emboli in the 23 patients with a mean number of emboli of 3.13 per patient with a range of 0-11 emboli per patient. The clot volumes ranged from 0.0041-47.34 cm3(mean +/-SD, 5.93 +/-10.15 cm3). On the second read, analyst 1 found the same number and distribution of emboli with a range of volumes for read 2 from 0.0041 – 45.52 cm3(mean +/-SD, 5.42 +/-9.53 cm3). Analyst 2 found 73 emboli in the 23 patients with a mean number of emboli of 3.17 per patient with a range of 0-11 emboli per patient. The clot volumes ranged from 0.00459-46.29 cm3(mean +/-SD, 5.91 +/-10.06 cm3). Inter-and intraobserver variability measurements indicated excellent reproducibility of the semi-automated method for quantifying PE volume burden. ICC for all endpoints was greater than 0.95 for inter-and intra-observer analysis. Bland-Altman analysis indicated no significant biases.CONCLUSION Semi-automated region growing algorithm for quantifying PE is reproducible using data from multiple scanners and is a suitable method for image analysis in multicenter clinical trials.
基金This work was supported by National"Eleventh-five"Scientific Item(2006BAI01A06)Shen-zhen City Luohu District Foundation (2007029)
文摘Objective： To analyze the value of CTPA in assessing the dissolve of embolus and the function of the right ventricle dynamically. Methods：Twenty-three cases of massive pulmonary embolism were analyzed retrospectively. The pulmonary artery obstruction index and the right ventricular function parameters were collected and analyzed on CTPA before thrombolytic therapy, 24 hours and 14 days after therapy, respectively. Results：The pulmonary artery obstruction index decreased gradually, and there was significant difference before therapy, 24 hours and 2 weeks after therapy. Twenty-four hours after therapy, the maximal short axes diameter and the maximal transverse area of right ventricle（RVd, RV~） decreased significantly, the maximal short axes diameter and the maximal transverse area of left ventricle（LVd, LVs） increased significantly, and the RVd/LVd, RVs/LVS decreased apparently. The pulmonary artery symbolic pressure before and 24 hours after therapy were apparently different. There was no significant difference between azygos vein, the super vena cava, the main pulmonary artery and vein reflux before and after therapy. Conclusion：CTPA can evaluate the pulmonary artery obstruction degree and right ventricular function dynamically.
基金the National"Eleventh-five"Scientific Item(No.2006BAI01A06)Shen-zhen City Luohu District Foundation(No.2007029)
文摘To analyze the value of CT pulmonary angiography（CTPA） in assessing right ventdcular dysfunction（RVD） after acute pulmonary embolism. Methods：Thirty-six patients with CTPA-confirmed PE who underwent ultrasonic cardiography（UCG） within the ensuing 24 hours were retrospectively reviewed. According to the severity of the disease, the patients were divided into the massive PE group（24 cases） and non-massive PE group（12 cases） respectively. CT scans were analyzed for findings suggestive of RVD. Scans were considered positive for RVD if the right ventricle was dilated（RVd/LVd 〉 1） or if the interventricular septum was straightened or deviated towards the left ventricle. Results were then compared with the results of UCG to estimate the value of CTPA in detecting RVD associated with PE, Results：In all cases, compared with UCG, the diagnostic sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, and negative predictive value of CTPA was 84.61%, 78.26%, 3.892, 0.197, 68.75% and 90% respectively. Kappa value was 0.60, which suggested moderate agreement between CTPA and UCG in the whole level. In the massive PE group, the diagnostic sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, negative predictive value of CTPA was 84.61%, 72.73%, 3.103, 0.212, 78.57% and 80% respectively. Kappa value was 0.58, which suggested moderate agreement between CTPA and UCG in the massive PE group. In the non-massive PE group, the diagnostic specificity of CTPA was 83.33%. By statistics, the value of RVd/LVd had significant difference between the massive PE and the non-massive PE group. Conclusion：CTPA can reliably detect RVD through the evaluation of cardiac morphology. However, this result requires confirmation using a larger prospective cohort study.
文摘AIM To examine effects of computed tomography(CT)image acquisition/reconstruction parameters on clot volume quantification in vitro for research method validation purposes.METHODS This study was performed in conformance with HIPAA and IRB Regulations(March 2015-November 2016).A ten blood clot phantom was designed and scanned on a dual-energy CT scanner(SOMATOM Force,Siemens Healthcare Gm BH,Erlangen,Germany)with varying pitch,iterative reconstruction,energy level and slicethickness.A range of clot and tube sizes were used in an attempt to replicate in vivo emboli found within central and segmental branches of the pulmonary arteries in patients with pulmonary emboli.Clot volume was the measured parameter and was analyzed by a single image analyst using a semi-automated region growing algorithm implemented in the FDA-approved Siemens syngo.via image analysis platform.Mixed model analysis was performed on the data.RESULTS On the acquisition side,the continuous factor of energy showed no statistically significant effect on absolute clot volume quantification(P=0.9898).On the other hand,when considering the fixed factor of pitch,there were statistically significant differences in clot volume quantification(P<0.0001).On the reconstruction side,with the continuous factor of reconstruction slice thickness no statistically significant effect on absolute clot volume quantification was demonstrated(P=0.4500).Also on the reconstruction side,with the fixed factor of using iterative reconstructions there was also no statistically significant effect on absolute clot volume quantification(P=0.3011).In addition,there was excellent R^2 correlation between the scale-measured mass of the clots both with respect to the CT measured volumes and with respect to volumes measure by the water displacement method.CONCLUSION Aside from varying pitch,changing CT acquisition parameters and using iterative reconstructions had no significant impact on clot volume quantification with a semi-automated region growing algorithm.
