Feasibility of Subtraction Coronary Computed Tomographic Angiography and Influencing Factor Analysis: a Retrospective Study

Objective To investigate the feasibility of subtraction coronary computed tomographic(CT)angiography(SubCCTA)to decline calcium artifacts and improve diagnostic accuracy in the presence of coronary calcification and analyze the factors that influence SubCCTA.Methods A total of 294 patients suspected of having coronary artery diseases underwent coronary computed tomographic angiography(CCTA)and SubCCTA.Coronary stenoses were blindly evaluated by two experienced radiologists,which were compared with invasive coronary angiography(ICA).Multiple statistical indexes were adopted to analyze the value of SubCCTA for the diagnosis of calcium stenoses.Results The diagnosable rate of SubCCTA was 67.2%(n=197),and the non-diagnosable rate was 32.8%(n=97).Using SubCCTA,the false positive rate decreased from 56.5%to 17.4%,and the corresponding diagnostic accuracy was increased from 83.6%to 92.9%.Univariate logistic regression analysis showed that height(OR=1.029,95%CI=1.001–1.058),weight(OR=1.025,95%CI=1.004–1.046),left ventricular size(OR=1.018,95%CI=1.007–1.030),cardiothoracic ratio(OR=39.917,95%CI=1.244–1281.098),the average heart rate(OR=0.866,95%CI=0.836–0.896)and heart rate range(OR=0.882,95%CI=0.853–0.912)might be the factors influencing SubCCTA.Conclusion This study suggested that SubCCTA could help improve diagnostic accuracy in the presence of calcium plaques.Moreover,several factors were discovered for the first time to possibly influence SubCCTA,which will be helpful in improving the subtracted image quality.

The value of three-dimensional computed tomographic angiography in the early diagnosis and treatment of spontaneous subarachnoid hemorrhage (616 cases report)

Objective To evaluate the clinical value of three dimensional computerized tomography angiography in the diagnosis and treatment of spontaneous subarachnoid hemorrhage. Methods 616 cases were diagnosed as suspected intracranial aneurysms in 3D CTA system. Computed tomographic scans and CTA studies were

Noninvasive three-dimensional computed tomographic angiography in preoperative detection of intracranial arteriovenous malformations

Obejctive To assess the value of noninvasive three dimensional computed tomographic angiography (3D CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs) Methods A prospective evaluation at a single institute over a 2 year period included 23 patients suspected of intracranial AVMs All patients underwent 3D CTA and digital subtraction angiography (DSA) Results from both procedures were compared Results 3D CTA imaging provided excellent visualization of intracranial AVMs The false positive error and false negative error were zero in our sample The details of arterial supply (numerical measure, orientation, caliber and routing) and vascular nidus (size, morphosis and location) provided by 3D CTA images were the same as DSA and the details of venous drainage were an approximate match Additionally, 3D CTA can depict tridimensional anatomical information for AVMs and their relationship to adjacent structures, a function not possible with DSA This assisted the surgeons in making better surgical planning and reduced trauma As a non invasive course, there were no related complications in the course of 3D CTA processing Conclusions DSA is still regarded as the gold standard for intracranial AVMs detection The modality of 3D CTA is accurate, noninvasive, nearly risk free and low price; we could routinely use it instead of or as a supplement to DSA, in the preoperative detection of suspected intracranial AVMs and postoperative radiological follow up 3D CTA adds tridimensional aspect and assists the surgeon in a the more accurate therapeutic scheme Preliminary data suggest that 3D CTA is playing a favorable role in the assessment of patients with intracranial AVMs

Impact of Clinical Guideline Recommendations on the Application of Coronary Computed Tomographic Angiography in Patients with Suspected Stable Coronary Artery Disease

Background： Coronary computed tomographic angiography （CCTA） has been widely used in patients who are at intemaediate risk for having stable coronary artery disease （SCAD）, and 2013 European Society of Cardiology Guidelines on the Management of SCAD （2013G） recommended the appropriate application of CCTA. However, 2013G has not been subjected to systematic analyses for subsequent impact on clinical practice. Methods： A total of 5320 patients suspected with SCAD were enrolled and scheduled for CCTA from March 2013 to September 2014. For each patient, pretest probability of SCAD was calculated according to updated Diamond-Forrester model （UDFM）. Appropriate CCTA or appropriate stress test was determined as described in the 2013G. A generalized estimating equation model was used to determine the trends in the half-monthly rate of appropriate CCTA. Results： Overall, only 61.37% of patients received appropriate CCTA, and there was insignificant change over time （P = 0.8701）. The application of CCTA in patients who should have had a stress test accounted for most of the inappropriate CCTA before （22.29%） or after （19.98%） the publication of the 2013G. In all patients or any subgroup, no significant change in the adjusted half-monthly rate of appropriate CCTA was found after the publication of the 2013G （odds ratio, 1.002; 95% confidence interval, 0.982-1.021; P = 0.8678）. Conclusions： These findings suggest that the 2013G have not, to date, been fully incorporated into clinical practice, and the clinical utilization of CCTA remains unreasonable to some extent.

Coronary Computed Tomographic Angiography for Suspected Stable Coronary Artery Disease： Gap Between the 2013 European Society of Cardiology Guideline Recommendations and Clinical Practice

Coronary computed tomographic angiography （CCTA） as a noninvasive diagnostic technique for the evaluation of coronary anatomy is widely used clinically. Its advantages include high sensitivity and specificity for the diagnosis of present of coronary artery lesions and lesion characteristics,

Understanding the predictive value and methods of risk assessment based on coronary computed tomographic angiography in populations with coronary artery disease:a review

Risk assessment in coronary artery disease plays an essential role in the early identification of high-risk patients.However,conventional invasive imaging procedures all require long intraprocedural times and high costs.The rapid development of coronary computed tomographic angiography(CCTA)and related image processing technology has facilitated the formulation of noninvasive approaches to perform comprehensive evaluations.Evidence has shown that CCTA has outstanding performance in identifying the degree of stenosis,plaque features,and functional reserve.Moreover,advancements in radiomics and machine learning allowmore comprehensive interpretations of CCTA images.This paper reviews conventional as well as novel diagnostic and risk assessment tools based on CCTA.

Numerical Simulation of Flow Behavior in Basilar Bifurcation Aneurysms Based on 4-Dimensional Computed Tomography Angiography

Initiation, growth, and rupture of cerebral aneurysms are caused by hemodynamic factors. It is extensively accepted that the cerebral aneurysm wall is assumed to be rigid using computational fluid dynamics (CFD). Furthermore, fluid-structure interactions have been recently applied for simulation of an elastic cerebral aneurysm model. Herein, we examined cerebral aneurysm hemodynamics in a realistic moving boundary deformation model based on 4-dimensional computed tomographic angiography (4D-CTA) obtained by high time-resolution using numerical simulation. The aneurysm of the realistic moving deformation model based on 4D-CTA at each phase was constructed. The effect of small wall deformation on hemodynamic characteristics might be interested. So, four hemodynamic factors (wall shear stress, wall shear stress divergence, oscillatory shear index and residual residence time) were determined from the numerical simulation, and their behaviors were assessed in the basilar bifurcation aneurysm.

Intentionally unilateral prostatic artery embolization:Patient selection,technique and potential benefits

BACKGROUND Prostatic artery embolization(PAE)is a promising but also technically demanding interventional radiologic treatment for symptomatic benign prostatic hyperplasia.Many technical challenges in PAE are associated with the complex anatomy of prostatic arteries(PAs)and with the systematic attempts to catheterize the PAs of both pelvic sides.Long procedure times and high radiation doses are often the result of these attempts and are considered significant disadvantages of PAE.The authors hypothesized that,in selected patients,these disadvantages could be mitigated by intentionally embolizing PAs of only one pelvic side.AIM To describe the authors’approach for intentionally unilateral PAE(IU-PAE)and its potential benefits.METHODS This was a single-center retrospective study of patients treated with IU-PAE during a period of 2 years.IU-PAE was applied in patients with opacification of more than half of the contralateral prostatic lobe after angiography of the ipsilateral PA(subgroup A),or with markedly asymmetric prostatic enlargement,with the dominant prostatic lobe occupying at least two thirds of the entire gland(subgroup B).All patients treated with IU-PAE also fulfilled at least one of the following criteria:Severe tortuosity or severe atheromatosis of the pelvic arteries,non-visualization,or visualization of a tiny(<1 mm)contralateral PA on preprocedural computed tomographic angiography.Intraprocedural contrast-enhanced ultrasonography(iCEUS)was applied to monitor prostatic infarction.IU-PAE patients were compared to a control group treated with bilateral PAE.RESULTS IU-PAE was performed in a total 13 patients(subgroup A,n=7;subgroup B,n=6).Dose-area product,fluoroscopy time and operation time in the IU-PAE group(9767.8μGy∙m^(2),30.3 minutes,64.0 minutes,respectively)were significantly shorter(45.4%,35.9%,45.8%respectively,P<0.01)compared to the control group.Clinical and imaging outcomes did not differ significantly between the IU-PAE group and the control group.In the 2 clinical failures of IU-PAE(both in subgroup A),the extent of prostatic infarction(demonstrated by iCEUS)was significantly smaller compared to the rest of the IU-PAE group.CONCLUSION In selected patients,IU-PAE is associated with comparable outcomes,but with lower radiation exposure and a shorter procedure compared to bilateral PAE.iCEUS could facilitate patient selection for IU-PAE.

Unfavorable Outcome of Percutaneous Coronary Intervention for Coronary Heart Disease with Rare Severe Pericoronary Fat Stranding

Background: Pericoronary fat stranding (PCFS) is a novel noninvasive imaging sign of coronary inflammation, and has important implications for cardiovascular risk stratification, and the outcome of percutaneous coronary intervention (PCI) for coronary heart disease patients with pericoronary fat stranding remains unknown. Aim: We report two rare cases of PCI-treated coronary heart disease patients with severe PCFS. Case Presentation: This is the first report of two rare cases of PCI for patients with coronary heart disease surrounded by severe PCFS. We demonstrated that the outcome in these cases is poor, and in-stent restenosis or occlusion occurs rapidly within 2- 6 months following PCI. However, Case 2 underwent coronary artery bypass grafting after the rapid occurrence of in-stent occlusion, and the bypass graft remained intact over the 5 years following coronary artery bypass grafting. Conclusion: Coronary artery bypass grafting rather than PCI may be appropriate for coronary heart disease patients with severe PCFS.

CT angiography of pulmonary embolism using a 64 slice multi-detector scanner

Background Multi-detector computed tomography （MDCT） has already been the first line investigation method for diagnosis of pulmonary embolism （PE）. Reducing the amount of contrast medium used during CT scanning could decrease the incidental rate of adverse reactions. Our study amied to evaluate the image quality of pulmonary arteries using 64 slice multi-detector CT with small volumes of contrast media injection. Methods Forty nonconsecutive patients without PE or other lung diseases were randomly assigned to two groups. Group A underwent CT scanning with 16×1 .25 mm collimation and a 70 ml contrast injection, while group B had CT with 64×0.625 mm collimation and 20 ml of contrast injection. Two readers independently depicted the segmental and subsegmental pulmonary arteries. Reasons we could not analyze the pulmonary artery or that led to misdiagnosis of pulmonary embolism were evaluated, including the degree of contrast enhancement of the main pulmonary artery, and factors that caused misdiagnosis of PE （flow-related artifacts, partial volume artifact, beam-hardening artifacts and enhancement of pulmonary vein）. The independent samples t-test, Mann-Whitney U test and Pearson chi-square test were applied. Results There were no significant differences in image quality of segmental and subsegmental arteries between the two groups. No significant difference was found for factors that made pulmonary arteries non-analyzable or in the misdiagnosis of PE, except the degree of contrast enhancement. Conclusion 64×0.625 mm collimation with 20 ml contrast injection could depict the pulmonary arteries well.

Virtual reality system for diagnosis and therapeutic planning of cerebral aneurysms

Background The virtual reality （VR） system can provide the neurosurgeon to intuitively interact with and manipulate the three dimensional （3-D） image similarly to manipulate a real object.it was seldom reported that the system was used in diagnosis and treatment of cerebral aneurysms.This study aimed to investigate the application of VR system in diagnosis and therapeutic planning of cerebral aneurysms.Methods A total of 24 cases of cerebral aneurysms were enrolled in this study from 2006 to 2008, which diagnosed by 3-D digital subtraction angiography （3D-DSA） or VR-based computed tomography angiographies （CTA）.The VR system and 3D-DSA system were used to observe and measure aneurysms and the adjacent vessels.The data of observation and measurements were compared between VR image and 3D-DSA image.All the patients underwent surgical plan and simulated neurosurgical procedures in the VR system.Results There were 28 aneurysms detected in VR system and 3D-DSA system.The VR system generated clear and vivid 3-D virtual images which clearly displayed the location and size of the aneurysms and their precise anatomical spatial relations to the parent arteries and skull.The location, size and shape of the aneurysms and their anatomical relationship with the adjacent vessels were similar between 3-D virtual image and 3D-DSA, but the spatial relationship between aneurysms and skull only been displayed by VR system.This VR system also could simulate simple surgical procedures and surgical environments.Conclusions The VR system can provide a highly effective way to provide precise imaging details as same as 3D-DSA system and assist the diagnosis of cerebral aneurysms with virtual 3-D data based on CTA.It significantly enhances the chosen therapeutic strategy of cerebral aneurysms.