Objective: To evaluate what specific combination of clinical criteria and d-dimer values may yield at least a 10% positive pulmonary embolism (PE) rate in patients undergoing pulmonary CT angiography (CTA). Materials ...Objective: To evaluate what specific combination of clinical criteria and d-dimer values may yield at least a 10% positive pulmonary embolism (PE) rate in patients undergoing pulmonary CT angiography (CTA). Materials and Methods: Retrospective review of all patients presenting to the Emergency Department with possible PE who underwent pulmonary CTA and had a d-dimer drawn. Wells scores were retrospectively assigned based on data gathered through medical records. Results: During a 29-month period, 1110 patients underwent pulmonary CTA. Of these, 773 also had a d-dimer drawn. These subjects were stratified based on serum d-dimer levels into negative (≤4 μg/ml), nonpositive (0.41 - 1.0 μg/ml), or positive (>1.0 μg/ml) d-dimer categories. The prevalence of positive CTA studies was >10% only in the positive d-dimer group. Subjects were also stratified based on their Wells score into three clinical categories: low (score 2), intermediate (score = 2 - 6), and high risk of pulmonary embolism (score > 6). The prevalence of positive CTA was > 10% only in the group of subjects with high clinical risk. When stratified according to both Wells criteria and d-dimer, only those patients with intermediate or high clinical risk combined with a positive d-dimer (>1.0 μg/ml) had a prevalence of positive pulmonary CTA > 10%. By limiting the use of CTA studies to those patients with positive d-dimer values or high clinical risk, 438 (55.4%) patients could have avoided CTA imaging. Conclusion: Utilizing CTA only in patients suspected of PE with a combination of high clinical risk based on a Wells criteria threshold score > 6 and a serum d-dimer cutoff of 1 μg/ml would increase the prevalence of positive pulmonary CTA studies above 10% and avoid a large number of CTA imaging studies.展开更多
Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-...Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-energy CT.Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energyscanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group,80 kV group, and 140 kV group) were reconstructed after scanning;31 patients underwent single-energyscanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and rightpulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonaryarteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the fivegroups were calculated. The subjective image quality of the five groups was assessed. The radiation dosesof the dual- and single-energy groups were recorded and calculated.Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than thosein the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05;SNRof pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR andSNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergygroup was lower than that of the single-energy group (t = –4.52, P < 0.05). The subjective scores ofimages in the NLB group were the highest (4.28 ± 0.74).Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reducethe radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.展开更多
In the present study, we evaluated computed tomography pulmonary angiography （CTPA） in guiding therapeutic decisions and monitoring patients undergoing percutaneous catheter fragmentation in acute massive pulmonary ...In the present study, we evaluated computed tomography pulmonary angiography （CTPA） in guiding therapeutic decisions and monitoring patients undergoing percutaneous catheter fragmentation in acute massive pulmonary embolism. From Jan 2003 to Dec 2009, 35 patients were diagnosed with acute massive pulmonary embolism by CTPA （TO） and treated with percutaneous catheter fragmentation. The severity was assessed by CT obstruction index （Qanadli index） and compared with Miller index. CTPA, oxygen saturation （SaO2） and pulmonary artery pressure were performed as follow-up index. The mean percentage of Qanadli index was （55 ± 13）% （range, 40%- 75%）, and Miller index was （62 ± 15）% （range, 45%-85%）. Correlations between them were statistically significant （r = 0.867, P 〈 0.0001）. The Qanadli index showed significant reduction [TO： （55±13）%; TI： （12±10）%; P 〈 0.001] in 33 patients. Significant correlation was observed between the Qanadli index, SaO2 （r = 0.934）, and pulmonary artery pressure （r = 0.813）. The Qanadli index provides an accurate method for distinguishing massive pulmonary embolism from sub-massive pulmonary embolism. It can be used to determine therapeutic options and monitor clinical outcomes.展开更多
This study was undertaken to identify the prevalence of pulmonary embolism （PE） in the emergency department （ED） of an urban teaching hospital and also to test a Bayesian model in estimating the number of CT pulmo...This study was undertaken to identify the prevalence of pulmonary embolism （PE） in the emergency department （ED） of an urban teaching hospital and also to test a Bayesian model in estimating the number of CT pulmonary angiography （CTA） expected to be performed in an emergency department. The data for this study was obtained through a retrospective review of electronic medical records for all ED patients suspected of PE who underwent chest CTA or ventilation perfusion scanning （V/Q） between 2009 and 2010. The data is presented as means and standard deviation for continuous variables and percentages with 95% confidence intervals （95%CI） for proportions. The prevalence of PE was used as pre-test probability in the Bayesian model. Post-test probability was obtained using a Fagan nomogram and likelihood ratios for CTA. A total of 778 patients （560 females） with mean age of 50 years （range 18-98 years） were enrolled （98.3% underwent chest CTA and 1.7% underwent V/Q scan）. A total of 69 patients had PE, rendering an overall prevalence of 8.9% （95%CI, 7.1% to 11.1%） for PE. We calculated that 132 CTA＇s per year could be avoided in our institution, without compromising safe exclusions of PE （keeping post-test probability of PE below 2%）. Despite differences in our patient populations and/or study designs, the prevalence of PE in our institution is about average compared to other institutions. Our proposed model for calculating redundant chest CTA is simple and can be used by institutions to identify overuse of CTA.展开更多
We report a case of left pulmonary artery sling associated with patent ductus arteriosus and atrial septal defect in a 21-month-old child. 256-slice MDCT provides valuable information, such as abnormal origin of the l...We report a case of left pulmonary artery sling associated with patent ductus arteriosus and atrial septal defect in a 21-month-old child. 256-slice MDCT provides valuable information, such as abnormal origin of the left pulmonary artery, the relationship between pulmonary artery and airway, the diameter of the patent ductus artery and atrial septal defect. The information is helpful in diagnosis, pre-operative evaluation and post-operative follow-up of LPS.展开更多
文摘Objective: To evaluate what specific combination of clinical criteria and d-dimer values may yield at least a 10% positive pulmonary embolism (PE) rate in patients undergoing pulmonary CT angiography (CTA). Materials and Methods: Retrospective review of all patients presenting to the Emergency Department with possible PE who underwent pulmonary CTA and had a d-dimer drawn. Wells scores were retrospectively assigned based on data gathered through medical records. Results: During a 29-month period, 1110 patients underwent pulmonary CTA. Of these, 773 also had a d-dimer drawn. These subjects were stratified based on serum d-dimer levels into negative (≤4 μg/ml), nonpositive (0.41 - 1.0 μg/ml), or positive (>1.0 μg/ml) d-dimer categories. The prevalence of positive CTA studies was >10% only in the positive d-dimer group. Subjects were also stratified based on their Wells score into three clinical categories: low (score 2), intermediate (score = 2 - 6), and high risk of pulmonary embolism (score > 6). The prevalence of positive CTA was > 10% only in the group of subjects with high clinical risk. When stratified according to both Wells criteria and d-dimer, only those patients with intermediate or high clinical risk combined with a positive d-dimer (>1.0 μg/ml) had a prevalence of positive pulmonary CTA > 10%. By limiting the use of CTA studies to those patients with positive d-dimer values or high clinical risk, 438 (55.4%) patients could have avoided CTA imaging. Conclusion: Utilizing CTA only in patients suspected of PE with a combination of high clinical risk based on a Wells criteria threshold score > 6 and a serum d-dimer cutoff of 1 μg/ml would increase the prevalence of positive pulmonary CTA studies above 10% and avoid a large number of CTA imaging studies.
基金Supported by a grant from the Science and Technology Plan of Sichuan Province(No.2021YFS0225)the Science and Technology Plan of Chengdu(No.2021-YF05-01507-SN).
文摘Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-energy CT.Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energyscanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group,80 kV group, and 140 kV group) were reconstructed after scanning;31 patients underwent single-energyscanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and rightpulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonaryarteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the fivegroups were calculated. The subjective image quality of the five groups was assessed. The radiation dosesof the dual- and single-energy groups were recorded and calculated.Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than thosein the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05;SNRof pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR andSNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergygroup was lower than that of the single-energy group (t = –4.52, P < 0.05). The subjective scores ofimages in the NLB group were the highest (4.28 ± 0.74).Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reducethe radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.
文摘In the present study, we evaluated computed tomography pulmonary angiography （CTPA） in guiding therapeutic decisions and monitoring patients undergoing percutaneous catheter fragmentation in acute massive pulmonary embolism. From Jan 2003 to Dec 2009, 35 patients were diagnosed with acute massive pulmonary embolism by CTPA （TO） and treated with percutaneous catheter fragmentation. The severity was assessed by CT obstruction index （Qanadli index） and compared with Miller index. CTPA, oxygen saturation （SaO2） and pulmonary artery pressure were performed as follow-up index. The mean percentage of Qanadli index was （55 ± 13）% （range, 40%- 75%）, and Miller index was （62 ± 15）% （range, 45%-85%）. Correlations between them were statistically significant （r = 0.867, P 〈 0.0001）. The Qanadli index showed significant reduction [TO： （55±13）%; TI： （12±10）%; P 〈 0.001] in 33 patients. Significant correlation was observed between the Qanadli index, SaO2 （r = 0.934）, and pulmonary artery pressure （r = 0.813）. The Qanadli index provides an accurate method for distinguishing massive pulmonary embolism from sub-massive pulmonary embolism. It can be used to determine therapeutic options and monitor clinical outcomes.
文摘This study was undertaken to identify the prevalence of pulmonary embolism （PE） in the emergency department （ED） of an urban teaching hospital and also to test a Bayesian model in estimating the number of CT pulmonary angiography （CTA） expected to be performed in an emergency department. The data for this study was obtained through a retrospective review of electronic medical records for all ED patients suspected of PE who underwent chest CTA or ventilation perfusion scanning （V/Q） between 2009 and 2010. The data is presented as means and standard deviation for continuous variables and percentages with 95% confidence intervals （95%CI） for proportions. The prevalence of PE was used as pre-test probability in the Bayesian model. Post-test probability was obtained using a Fagan nomogram and likelihood ratios for CTA. A total of 778 patients （560 females） with mean age of 50 years （range 18-98 years） were enrolled （98.3% underwent chest CTA and 1.7% underwent V/Q scan）. A total of 69 patients had PE, rendering an overall prevalence of 8.9% （95%CI, 7.1% to 11.1%） for PE. We calculated that 132 CTA＇s per year could be avoided in our institution, without compromising safe exclusions of PE （keeping post-test probability of PE below 2%）. Despite differences in our patient populations and/or study designs, the prevalence of PE in our institution is about average compared to other institutions. Our proposed model for calculating redundant chest CTA is simple and can be used by institutions to identify overuse of CTA.
文摘We report a case of left pulmonary artery sling associated with patent ductus arteriosus and atrial septal defect in a 21-month-old child. 256-slice MDCT provides valuable information, such as abnormal origin of the left pulmonary artery, the relationship between pulmonary artery and airway, the diameter of the patent ductus artery and atrial septal defect. The information is helpful in diagnosis, pre-operative evaluation and post-operative follow-up of LPS.
