Incidence and factors associated with pulmonary embolism among RT-PCR confirmed Covid-19 patients with upfront CT pulmonary angiography in Ethiopia: A nested case-control study

Introduction: Pulmonary embolism is one of the complications of COVID-19, with reported incidence ranging from 3 to 33 % in non-ICU patients to as high as 40% among ICU patients. Since the clinical presentations of COVID-19 and Pulmonary embolism overlap, it is difficult to differentiate between these cases. This study aimed to assess the incidence of pulmonary embolism and associated factors among confirmed Covid-19 Patients in Ethiopia. Methods: A nested case control study was conducted among 131 patients with COVID-19 (40 COVID-19 patients with Pulmonary embolism and 91 COVID-19 patients with no PE) who were on follow up from May, 2021 to May, 2022. Data was summarized using frequencies with percentages. A chi-square test/ Fisher's exact test was run to determine the presence of a significant difference between the exposure variables and the development of PE. To identify factors associated with the development of Pulmonary embolism, a multivariable Binary Logistic Regression model with sensitivity analysis was run. Results: The incidence of PE was 30.5% (95% CI, 22.9% - 37.4%) in the cohort of patients for whom upfront CTPA was performed. The Chi-square/ Fisher's exact test results showed a significantly higher proportion of patients with PE tend to present with shortness of breath, chest pain and anosmia/ageusia than those with no PE. However, in a subsequent regression analysis, only chest pain was found to be significantly associated with the development of PE in COVID-19 patients (AOR= 3.24, 95% CI= 1.10, 9.54, p-value=0.033). Conclusion: The incidence of PE among COVID-19 patients was found to be relatively lower than reports from other countries. Having chest pain was found to be a significant factor that indicates the development of PE, implying that in a setting where performing upfront CTPA is not practical, detailed symptom inquiry could serve as an important clinical criteria.

Comparison of CT Values between Thrombus and Postmortem Clot Based on Cadaveric Pulmonary Angiography / 法医学杂志

OBJECTIVES@#To explore the difference in CT values between pulmonary thromboembolism and postmortem clot in postmortem CT pulmonary angiography (CTPA) to further improve the application value of virtual autopsy.@*METHODS@#Postmortem CTPA data with the definite cause of death from 2016 to 2019 were collected and divided into pulmonary thromboembolism group (n=4), postmortem clot group (n=5), and control group (n=5). CT values of pulmonary trunk and left and right pulmonary artery contents in each group were measured and analyzed statistically.@*RESULTS@#The average CT value in the pulmonary thromboembolism group and postmortem clot group were (168.4±53.8) Hu and (282.7±78.0) Hu, respectively, which were lower than those of the control group (1 193.0±82.9) Hu (P<0.05). The average CT value of the postmortem clot group was higher than that of the pulmonary thromboembolism group (P<0.05).@*CONCLUSIONS@#CT value is reliable and feasible as a relatively objective quantitative index to distinguish pulmonary thromboembolism and postmortem clot in postmortem CTPA. At the same time, it can provide a scientific basis to a certain extent for ruling out pulmonary thromboembolism deaths.

Classification and clinical significance of the branching patterns of the right pulmonary arteries based on the intravital CT data / 解剖学报

[Abstract] Objective To track and make statistics of the right pulmonary arteries’ branches and to study the clinical significance. Methods Technologies of vascular volume rending were used to analyze the 350 CT pulmonary angiography images. And the three-dimensional display was used to classify the pulmonary arteries. Results According to the 350 reconstructed result, the right upper pulmonary arteries were divided into 6 types: anterior trunk+ post ascending artery, anterior trunk, anterior trunk+ anterior ascending artery+ post ascending artery, superior anterior trunk + inferior anterior trunk+ post ascending artery, anterior trunk+ anterior ascending artery and superior anterior trunk+ inferior anterior trunk. The right middle pulmonary arteries were divided into 2 types: one branch and two branches. As for the right lower pulmonary arteries, the apical arteries were divided into 3 types: one branch, two branches and three branches. The basal segmental arteries were divided into 3 types: medial basal segmentalartery+anterior basal segmental artery+lateroposterior basal segmental artery, medioanterior basal segmental artery+lateroposterior basal segmental artery and medial basal segmental artery+anterior and lateral basal segmental artery +posterior basal segmental artery. To be specific, anterior trunk+ post ascending artery type (56. 6%) occupied the most in the right upper pulmonary arteries. The majority type of right middle pulmonary artery was one branch(57. 4%). In the right lower pulmonary arteries, apical artery of the lower lobe (one branch)+medial basal segmental artery+anterior basal segmental artery+lateroposterior basal segmental artery type(32. 5%) was most common. Conclusion The classification of the right pulmonary arteries based on the three dimensional reconstruction of CT pulmonary angiography is of significant to surgical precision therapy of lung tumor.

Application of CT pulmonary angiography in acute pulmonary embolism and right heart function / 中国康复理论与实践

ObjectiveTo explore the application value of CT pulmonary angiography (CTPA) in assessing the severity of acute pulmonary embolism (APE) and right heart function in rehabilitation patients. MethodsFrom January, 2013 to January, 2020, 133 inpatients (94 positive and 39 negative) who underwent CTPA examination in Beijing Bo'ai Hospital were involved. Positive patients were further divided into mild, moderate and severe groups based on the pulmonary artery obstruction index (PAOI). The clinical parameters and right heart function indicators were compared. Spearman correlation analysis was used to analyze the correlation between PAOI, and clinical parameters and right heart function indicators, and Logistic regression analysis was used to predict the risk factors of APE. ResultsThere was significant difference in lower extremity venous thrombosis, D-dimer, oxygen partial pressure, PAOI and left process of interventricular septum among four groups (H ≥ 12.350, P < 0.01). PAOI was moderately positively correlated with D-dimer (r = 0.443, P < 0.001) and left process of interventricular septum (r = 0.520, P < 0.001), and was weakly positively correlated with lower extremity venous thrombosis (r = 0.399, P < 0.001), left pulmonary artery diameter (r = 0.213, P = 0.014) and inferior vena cava regurgitation (r = 0.229, P = 0.008). Lower extremity venous thrombosis (OR = 7.708, P < 0.001) and left process of interventricular septum (OR = 3.641, P = 0.008) were independent risk factors for the onset of APE. The combination of the two indicators was effective for diagnosis of APE, and AUC was 0.795 (95% CI 0.715 to 0.874). ConclusionCTPA may be applied to evaluate the severity of APE and right heart function in rehabilitation patients.

Application value of dual-energy CT perfusion imaging in acute pulmonary embolism examination / 中国辐射卫生

Objective To analyze the pulmonary perfusion defect index (PPDI) of dual-energy computed tomography (CT) and pulmonary artery obstruction index (PAOI) of conventional CT angiography, and to investigate the clinical application value of dual-energy CT perfusion imaging in the examination of patients with acute pulmonary embolism. Methods A retrospective study was conducted on 21 patients diagnosed with acute pulmonary embolism in Weifang People's Hospital from January 1, 2022 to December 31, 2022. PPDI, PAOI, and maximum plasma D-dimer concentration (mg/L) were calculated. According to the 2019 ESC Guidelines, the patients were divided into low-risk group (n = 8) and medium-risk group (n = 12). The Mann-Whitney U test was used for between-group comparisons. The Spearman’s rank correlation coefficient was used to analyze the correlations between PAOI, PPDI, and plasma D-dimer concentration. Results The PPDI, PAOI, and D-dimer values in the low-risk group were 3.33 (2.09, 4.58), 5.00 (3.13, 5.00), and 0.67 (0.52, 0.79), respectively. The PPDI, PAOI, and D-dimer values in the middle-risk group were 8.34 (5.42, 12.50), 12.50 (8.13, 15.00), and 1.18 (0.86, 2.87), respectively. The Z-values of comparison between the two groups were −3.092, −3.650, and −3.318, respectively (all P < 0.05). There were significant differences in PPDI, PAOI, and D-dimer between the low-risk and middle-risk groups (P < 0.05). Positive correlations were observed between PPDI and PAOI, between PPDI and D-dimer, and between PAOI and D-dimer (rs = 0.869, 0.918, 0.909, all P < 0.05). Conclusion Both PPDI and PAOI can be used for the clinical examination of patients with acute pulmonary embolism and evaluation of the severity of the disease. Compared with conventional CT, dual-energy CT perfusion imaging is more efficient in the diagnosis of acute pulmonary embolism, and facilitates accurate clinical treatment.

Multi Slice Spiral CT Pulmonary Angiography in Dynamic Pitch Mode using Volume Helical Shuttle Technology for the Diagnosis of Pulmonary Embolism

Introduction : Multi slice Computed Tomography Pulmonary Angiography (CTPA) in dynamic pitch (Volume Helical Shuttle-VHS) mode is an evolving method to visualize pulmonary arteries including the peripheral pulmonary vasculature. The purpose of this study is to evaluate CT Pulmonary Angiography in dynamic pitch mode (Volume Helical Shuttle) for pulmonary embolism in comparison with standard pitch mode. Methods : We have done a multicentric analytical comparison study with study group involving patients undergone CTPA in dynamic pitch mode-Volume Helical Shuttle (VHS) and comparison group involving patients undergone CTPA in standard pitch mode. Results : Optimal contrast enhancement phase of the pulmonary artery in the study group in Phase I to III were 22.6%, 43.4% and 34%. The best phases were the last two phases in our study. Study Group main pulmonary artery mean signal intensity is 423.83±75.94 HU and comparison groups mean signal intensity is 361.74±98.28HU (P value = 0.039). The percentages of analyzable segmental arteries were 91.6% in study group and 87.3% in comparison group (P value-0.008). The percentages of analyzable sub segmental arteries were 89.5% in study group and 84% in comparison group (P value-0.004). The study group shows less percentage of motion artefacts and higher image quality than the comparison group, however it was not statistically significant (P value >0.05). Conclusions : Multislice CTPA in dynamic pitch mode using Volume Helical Shuttle (VHS) technology increase the ability to obtain the Optimal contrast enhancement in pulmonary arteries, improves the overall image quality, obviate the need for breath holding.

Research progress of CT evaluation of acute pulmonary embolism and right ventricular dysfunction / 中华全科医师杂志

Pulmonary embolism is one of the common cardiothoracic vascular emergencies, and its main fatal complication is right ventricular dysfunction. CT pulmonary angiography is the preferred imaging method for clinical diagnosis of pulmonary embolism.This article reviews the imaging characteristics and mechanism of pulmonary embolism and right heart dysfunction in CT pulmonary angiography, the current clinical application status and limitations of CT pulmonary angiography, and the progress of CT pulmonary angiography technology.

Unilateral absence of pulmonary artery: a radiographically occult cause of life-threatening hemoptysis

Unilateral absence or agenesis of pulmonary artery (UAPA) is a rare congenital abnormality with an estimated prevelance of 1 in 2,00,000 adults. The entity occurs commonly in association with other congenital heart diseases like septal defects or patent ductus arteriosus. The condition usually runs a benign clinical course with patients usually presenting clinically in adulthood with history of recurrent respiratory tract infections. Two such patients presented with recurrent respiratory tract infections, breathlessness and hemoptysis. The chest radiograph of first patient was reported as normal in the referring hospital, while that of second patient showed volume loss in left lung. CT Pulmonary Angiography (CTPA) was then performed which demonstrated the absence of right and left pulmonary arteries respectively in the first and second patients. Pulmonary artery branches were reformed distally by multiple collaterals arising from systemic arteries. The entire spectrum, including embryology, imaging features and management of UAPA are discussed. UAPA remains a potential cause for life-threatening hemoptysis, due to extensive collateralization associated with the condition. It is important for radiologists to be aware of this uncommon entity in order to suspect it on a routine chest radiograph, diagnose it and map associated collaterals on CTPA and also embolize the bleeding collaterals.

Prevalência de tromboembolismo pulmonar diagnosticado por angiotomografia computadorizada em pacientes de um município de médio porte de Minas Gerais / Prevalence of pulmonary thromboembolism diagnosed by computadorized angiotomography in patients in a inner city in state of Minas Gerais

Introdução. O tromboembolismo pulmonar (TEP) é uma doença que apresenta uma clínica inespecífica, o que induz a necessidade de solicitar exames complementares, como a angiotomografia computadorizada (angioTC) de tórax. Com o objetivo de evitar a sua solicitação desnecessária, foram criados sistemas de probabilidade pré-teste, como o escore de Wells, que direcionam a propedêutica. Objetivo. Avaliar a prevalência de tromboembolismo pulmonar (TEP) em dois hospitais de uma cidade de médio porte e verificar o padrão de solicitação da angiotomografia computadorizada de tórax (angioTC). Métodos. Estudo transversal a partir de dados de prontuários de pacientes submetidos à angioTC de tórax no Hospital Regional de Barbacena e no Hospital Ibiapaba no período de janeiro de 2014 até junho de 2018. Resultados. A prevalência de TEP foi de 29,70% (N=259) no período de 54 meses e a mediana de idade, 66 anos (intervalo interquartil: 24). Nos pacientes com o diagnóstico de TEP, o sintoma mais frequente foi dor torácica (38,81%), seguido por hemoptise (33,33%) e tosse (32,99%). Nos prontuários analisados foi observado que a utilização do escore de Wells foi de 2,70%. A probabilidade de TEP, pelo escore de Wells, realizada pelos pesquisadores com base nos dados dos prontuários, em pacientes diagnosticados com TEP pela angioTC foi alta em 45%, moderada em 34,42% e baixa em 9,23%. Conclusão. A prevalência foi de 29,70% no período de 54 meses de diagnóstico de TEP em pacientes que realizaram a angioTC de tórax nos hospitais mencionados. O escore de Wells é um importante instrumento propedêutico. (AU)

Background. Pulmonary embolism (PE) is a disease presented with nonspecific symptoms that requires additional tests such as pulmonary angiography by computadorized tomography. To avoid unnecessary tests, pre-test probability tools were created, such as Wells Score, which guides the propaedeutics. Objective. To evaluate the prevalence of pulmonary embolism (PE) in two hospitals in a medium-sized city and to verify computed tomography pulmonary angiography imaging exam orders. Methods. Cross-sectional study based on data from the hospital records evolving patients underwent computed tomography pulmonary angiography at Hospital Regional de Barbacena and Hospital Ibiapaba through January 2014 and June 2018. Results. The prevalence of PE was 29.70% (259 patients) in the 54-month period and the median age, 66 years (interquartile range, 24). In patients with the diagnosis of PE, the most frequent symptom was chest pain (38.81%) followed by hemoptysis (33.33%), and cough (32.99%). In the analyzed hospital records it was observed that the use of the Wells score was 2.70%. The probability of PE according to the Wells score, performed by the researchers based on data from the medical records, in patients diagnosed with PE by computed tomography pulmonary angiography was high in 45%, moderate in 34.42%, and low in 9.23%. Conclusion. The prevalence of PE was 29.70% (N = 259) in the 54-month period from PE diagnosis in patients who underwent computed tomography pulmonary angiography in the mentioned hospitals. The Wells score is an important diagnostic tool(8)

Comparison of values between Wells score and YEARS algorithm in dignosis of pulmonary embolism / 吉林大学学报(医学版)

Objective:To explore the diagnostic values of Wells score and YEARS algorithm in the patients with pulmonary embolism and to compare the areas under receiver operating characteristic (ROC) curves (AUC) of Wells score and YEARS algorithm, and to find the more suitable score method for pulmonary embolism in clinic.Methods:A total of 139patients who were suspected with pulmonary embolism were collected, among them48patients were clinically as confirmed pulmonary embolism.The disease history, clinical manifestation and results of auxilliary examinations of the patients were collected.All the patients were assessed by Wells score and YEARS algorithm, respectively;the computed tomographic pulmonary angiography (CTPA) was considered as golden standard.The sensitivities, specificities, misdiagnosis rates and omission diagnostic rates, and the accuracies of Wells score and YEARS algorithm of the patients in two groups were analyzed with SPSS 22.0software;the conformities of results of Wells socre, YEARS algorithm, and CTPA were analyzed.Then ROC curves of Wells score and YEARS algorithm in diagnosis of pulmonary embolism were made, and the AUC was calculated and compared.Results:Compared with YEARS algorithm, the specificity and accuracy of Wells score in diagnosis of pulmonary embolism were markedly increased (P＜0.05) , the misdiagnosis rate was decreased (P=0.037) , however the sensitivity and the misdiagnosis rate had no significant differences (P＞0.05) .The Kappa value of Wells score and CTPA was 0.45, the conformity was moderate;the Kappa value of YEARS algorithm and CTPA was 0.22, the conformity was passable;the Kappa value of Wells score and YEARS algorithm was 0.11, the conformity was bad.The AUC of Wells score and YEARS algorithm were 0.753±0.044 (P＜0.01) and 0.585±0.049 (P=0.101) .Conclusion:The Wells score is superior to the YEARS algorithm in the diagnosis of pulmonary embolism.

Computed Tomography Pulmonary Angiography during Pregnancy: Radiation Dose of Commonly Used Protocols and the Effect of Scan Length Optimization

OBJECTIVE: To evaluate the radiation dose for pregnant women and fetuses undergoing commonly used computed tomography of the pulmonary arteries (CTPA) scan protocols and subsequently evaluate the simulated effect of an optimized scan length. MATERIALS AND METHODS: A total of 120 CTPA datasets were acquired using four distinctive scan protocols, with 30 patients per protocol. These datasets were mapped to Cristy phantoms in order to simulate pregnancy and to assess the effect of an effective radiation dose (in mSv) in the first, second, or third trimester of pregnancy, including a simulation of fetal dose in second and third trimesters. The investigated scan protocols involved a 64-slice helical scan at 120 kVp, a high-pitch dual source acquisition at 100 kVp, a dual-energy acquisition at 80/140 kVp, and an automated-kV-selection, high pitch helical scan at a reference kV of 100 kVref. The effective dose for women and fetuses was simulated before and after scan length adaptation. The original images were interpreted before and after scan length adaptations to evaluate potentially missed diagnoses. RESULTS: Large inter-scanner and inter-protocol variations were found; application of the latest technology decreased the dose for non-pregnant women by 69% (7.0–2.2 mSv). Individual scan length optimization proved safe and effective, decreasing the fetal dose by 76–83%. Nineteen (16%) cases of pulmonary embolism were diagnosed and, after scan length optimization, none were missed. CONCLUSION: Careful CTPA scan protocol selection and additional optimization of scan length may result in significant radiation dose reduction for a pregnant patient and her fetus, whilst maintaining diagnostic confidence.

Comparison of values between Wells score and YEARS algorithm in dignosis of pulmonary embolism / 吉林大学学报(医学版)

Objective: To explore the diagnostic values of Wells score and YEARS algorithm in the patients with pulmonary embolism and to compare the areas under receiver operating characteristic (ROC) curves (AUC) of Wells score and YEARS algorithm, and to find the more suitable score method for pulmonary embolism in clinic. Methods: A total of 139 patients who were suspected with pulmonary embolism were collected, among them 48 patients were clinically as confirmed pulmonary embolism. The disease history, clinical manifestation and results of auxilliary examinations of the patients were collected. All the patients were assessed by Wells score and YEARS algorithm, respectively; the computed tomographic pulmonary angiography (CTPA) was considered as golden standard. The sensitivities, specificities, misdiagnosis rates and omission diagnostic rates, and the accuracies of Wells score and YEARS algorithm of the patients in two groups were analyzed with SPSS 22.0 software; the conformities of results of Wells socre, YEARS algorithm, and CTPA were analyzed. Then ROC curves of Wells score and YEARS algorithm in diagnosis of pulmonary embolism were made, and the AUC was calculated and compared. Results: Compared with YEARS algorithm, the specificity and accuracy of Wells score in diagnosis of pulmonary embolism were markedly increased (P<0.05), the misdiagnosis rate was decreased (P= 0.037), however the sensitivity and the misdiagnosis rate had no significant differences ( PX). 05). The Kappa value of Wells score and CTPA was 0. 45, the conformity was moderate; the Kappa value of YEARS algorithm and CTPA was 0.22, the conformity was passable; the Kappa value of Wells score and YEARS algorithm was 0. 11, the conformity was bad. The AUC of Wells score and YEARS algorithm were 0. 753 + 0. 044 ( P<0. 01) and 0. 585 + 0. 049 ( P=0. 101). Conclusion: The Wells score is superior to the YEARS algorithm in the diagnosis of pulmonary embolism.

Predictive value of heart function in acute pulmonary embolism patients based on embolic morphology and quantity / 实用放射学杂志

Objective To explore the value of the morphological quantitative indexes and the number of emboli in predicting heart function in patients with acute pulmonary embolism (APE)based on computer-aided diagnosis (CAD)technique.Methods One-hundred and forty-eight APE patients confirmed by CT pulmonary angiography (CTPA)in our hospital.Total number of emboli (N)and three morphological quantitative indexes,including total volume of emboli (V),total length (L)and total maximum cross-section embolism proportion (P)were obtained by CAD.The maximal short axis and area of left and right ventricular (LVd,RVd,LVS,RVS)were measured by hand on axial image to calculate the ratio of maximal short axis of right and left ventricular (RVd/LVd)and ratio of maximal area of right and left ventricular (RVS/LVS).The correlation of the above indexes was analyzed by the Pearson correlation of SPSS 22.0.Results The ranking of the correlation between CAD indexes and the heart function was in the order of V,L,P and N.The correlation between CAD indexes and the right heart function was greater than that of the left heart.The V had the strongest correlation with RVd (r=0.544,P=0.000),RVS (r=0.515,P=0.000),RVd/LVd (r=0.595,P=0.000)and RVS/LVS (r=0.579,P=0.000),respectively.While other the CAD indexes had lower correlation with the heart function (|r|:0.167-0.476,P<0.05),and there was no correlation between the N and the left heart function.Conclusion In embolic morphology and quantitative indexes,the V is the best quantitative index to reflect the change of right heart function in APE,which can reflect dys-function of right heart and severity of pulmonary embolism dis-ease in the APE embolism patient.

Application of double-low technique and iterative reconstruction in 64-slice MSCT pulmonary angiography / 医疗卫生装备

The development of CT and the clinical application of CT pulmonary angiography (CTPA) in diagnosing pulmonary embolism were introduced,and the methods for decreasing CTPA radiation dose and the importance of iterative reconstruction for low-dose scanning were analyzed.The development and application of contrast agent were described,and the ways to reduce contrast agent dose was expounded.Double-low CTPA combined with iterative reconstruction was pointed out to decrease greatly the radiation dose and contrast agent iodine dose while ensured image quality,and thus the damages to the patient by radiation and contrast agent could be lowered at the most.

Application of low-concentration contrast agent and low-dose technology in 320-slice CT pulmonary angiography / 医疗卫生装备

Objective To explore the feasibility of low-concentration contrast agent and low-dose technology for pulmonary angiography by comparing the image quality and radiation doses to the patient by different tube voltages and concentrations of contrast agents.Methods Totally 60 patients suspected with pulmonary embolism were divided into C, L1 and L2 groups, of which,Group C had the scanning parameters of 120 kV and 350 mgI/ml,Group L1 had the parameters as 100 kV and 350 mgI/ml and Group L2 had the parameters of 100 kV and 270 mgI/ml.The three groups had the tube voltage as 500 mA, the contrast agent dose as 25 ml,physiological saline dose as 40 ml and flow rate as 4.5 ml/s.SPSS 19.0 software was used to compare and analyze the CT values of pulmonary artery segment,superior vena cava and ascending aorta,main pulmonary artery noises,the image quality as well as the radiation doses of volume scanning. Results The three groups had the main pulmonary aortas and their branches display clearly to meet clinical requirements.When compared with Group C,Group L1 had higher CT values of the main pulmonary aorta and its branches,higher image noise while lower radiation dose (P<0.01);Group L2 had equivalent CT values of the main pulmonary aorta and its branches (P>0.05),higher image noise while lower radiation dose (P<0.01).When compared with Group L1,Group L2 had lower CT values of the main pulmonary aorta and its branches (P<0.01),and equivalent image noise and radiation dose (P>0.05).Conclusion Low-concentration contrast agent and low-dose technology gains feasibility and advantages when used in 320-slice CT pulmonary angiography.

A case of large pulmonary embolism in trunk and branches with main manifestation of syncope, vomiting and shock / 中华危重病急救医学

Pulmonary embolism (PE) refers to the endogenous or exogenous emboli blocking pulmonary trunk or branches, causing clinical and pathophysiological syndrome of pulmonary circulation disorder, the incidence rate is high. Sometimes PE patients were lack of specific symptoms and signs, or without any symptoms, which often result in misdiagnosis, un-timely diagnosis, and the delay of treatment. A PE case with syncope, vomiting and shock, which was proved to be pulmonary artery trunk and branch wide embolism later, was presented so as to improve the understanding of the disease.

A New Risk Assessment Model for Suspected Pulmonary Embolism / 中国医科大学学报

Objective To develop a predictive model for pulmonary embolism(PE)based on the related clinical symptoms,signs,and the labo-ratory index,so as to improve the positive rate of CTPA. Methods The model was developed from a database of 119 patients with suspected PE. The risk factors of suspected PE were analyzed by logistic regression analysis ,which included significant differences in the prevalence of PE be-tween non-diseased and non-diseased groups. Receiver operating characteristic(ROC)curves was draw to determine the cut-off value of the clini-cal probability. It was validated in an independent sample of 106 patients with suspected PE. Results According to the univariate analysis ,17 of 51 variables show a significant difference between PE and non-PE patients. The model comprised 4 variables:age,dyspnea,D-dimer and unilater-al leg swelling. The area under the ROC curve is 0.776,and the cut-off value is supposed to be 0.38. In the validation sample,27% patients had PE confirmed by CTPA. The prevalence of PE was 54%when the clinical probability was above 0.38. Conclusion The proposed predictive mod-el in this study can improve the positive rate of CTPA ,simplify the diagnosis process of suspected PE patients.

CTPA image quality analysis of 80 kV and 120 kV in different reconstruction algorithms for obese patients / 实用放射学杂志

Objective To analyze the CT pulmonary angiography(CTPA) image quality and radiation dose of obesity patients with high and low tube voltage iterative reconstruction(IR) and the filtered back projection(FBP) reconstruct algorithm,and to explore the feasibility of low tube voltage IR algorithms in CTPA of obese patients.Methods Obese patients with suspected pulmonary embolism were randomly assigned into 80 kV or 120 kV group, and the images were treated with IR and FBP reconstructions.CT value of the basal segment of the right pulmonary artery, right upper lobe and main pulmonary artery were measured, and the average CT value of the pulmonary artery was further calculated, and the independent sample t test analysis was used.Results Comparing the CT value of the IR and FBP subgroup of two tube voltage groups, the differences were not significant (P>0.05), the differences of noise, signal noise ratio(SNR) and contrast noise ratio (CNR) were statistically significant (P<0.05), respectively.The CT value,noise,SNR and CNR of 80 kV group were significantly higher than those of the 120 kV group, and the differences were statistically significant (P<0.05), while the radiation dose were significantly lower than those of 120 kV group (P=0.000).Conclusion The CTPA image quality of 80 kV IR algorithm is significantly improved compared with the 120 kV FBP algorithm, and the radiation dose is significantly reduced, which could be used for CT pulmonary angiography in obese patients.

A study on the influence of contrast agent protocol on gem spectrum CT pulmonary angiography quality / 重庆医学

Objective To compare the image quality between large dose smart tracking technique and low dose test bolus technique for gem spectral CT pulmonary angiography(CTPA).Methods A total of 106 cases with suspected pulmonary embolism were divided into two groups.Group A(54 cases)was carried out with large dose smart tracking technique.Group B(52 cases)was carried out with low dose test bolus technique.We compared the image quality between the two groups.Results There were significant differences in the CT value of the right pulmonary artery and the content of iodine in the lower lobe of the right pulmonary artery of two groups(P<0.01).There was significant difference of image quality between the two groups(P<0.05).The rate of excellent or good image quality in group A was higher than that in group B,and the difference was statistically significant(P<0.05).Conclusion Large dose smart tracking technique can track the artifacts of pulmonary artery imaging with less artifacts and uniform vascular fixation.The image quality of pulmonary artery imaging is better than that of small dose contrast agent.

Scintigraphic Evidence for Overdiagnosis of Small PE on CT Pulmonary Angiography / 대한핵의학회잡지

A 68-year-old man with recent history of a fall presented with dyspnea on exertion, and underwent computed tomography pulmonary angiography (CTPA) for possible pulmonary embolism (PE). The CTPA was first read by the radiology resident as nondiagnostic for segmental PE. Subsequent planar perfusion (Q) images were normal; meanwhile, the attending radiologist revised the CTPA results as subsegmental PE in the left upper lobe. Further Q-SPECT images were obtained and fused with CTPA for clarification, which showed normal perfusion in the region of PE. The patient was monitored without anticoagulation treatment and remained uneventful for 12 months. This case illustrates that CTPA can lead to overdiagnosis and overtreatment of nonocclusive subsegmental PE.