Computed Tomography Angiography Data Research Articles

Automatic segmentation of coronary tree in CT angiography images

SummaryIn this study, we proposed an automatic approach to segment the three‐dimensional coronary tree from computed tomography angiography (CTA) image data. Compared to the previous studies, our approach can efficiently locate the coronary root through extracting aorta by using circular Hough transform. Then, we extracted the two‐dimensional coronary borders in multiple projection directions by dynamic programming and used the border information to reconstruct the coronary surface by the spline fitting. The performance of our approach has been validated on the CTA dataset from 50 subjects, with the comparison to the manual segmentation by an experienced medical physician on the corresponding CTA data and X‐ray angiography data. Our experiments have shown that the average bias between our approach and the manual segmentation are 2.44 mm2 with confidence interval [‐2.20 mm2, 6.68 mm2] for cross‐sectional lumen area, 0.84 mm with confidence interval [‐2.76 mm, 4.44 mm] for maximum lumen diameter, and 0.32 mm with confidence interval [‐1.14 mm, 1.78 mm] for minimum lumen diameter. The results can demonstrate the potential effectiveness of our approach in CTA image processing.

The Significance of Equivocal Exercise Treadmill ECG for Intermediate Risk Chest Pain Assessment – Insight From Coronary CT Angiography Data

Exercise treadmill test (ETT) is commonly the first-line investigation in troponin-negative chest pain patients. Inconclusive results are common and often lead to repeated functional testings. Coronary computed tomographic angiography (CCTA) has excellent negative predictive value for coronary artery disease detection and may play an important role in their diagnostic workup. We aim to analyse ETT and CCTA findings to understand their modern roles in intermediate risk chest pain population with inconclusive ETT. Patients who underwent both ETT and CCTA at our institution between August 2011 and February 2013 were retrospectively investigated. The ETTs were blindly reviewed, with equivocal ETTs defined as any indeterminate results not strictly adhering to ACC/AHA guidelines for positive ETT. Baseline demographics, clinical characteristics and investigation results were collated. Follow-up outcome data for subsequent investigations, representations, major cardiac adverse events (MACE) and unexpected revascularisations were also analysed. 346 consecutive patients were identified (age 57±10years, 53% females, body mass index (BMI) 28±4, Dukes Clinical Score 48±30%, mean follow-up 2.1±0.4years). The ETT was positive in 31%, equivocal in 54% and negative in 15%. Obstructive coronary artery disease (CAD) prevalence was 25% (29% males, 13% females). Those with negative ETTs had obstructive CAD in 8%, with no adverse outcomes during follow-up. Obstructive CAD was seen in 20% with "equivocal" ETTs and 29% with "positive" ETTs. In females, obstructive CAD prevalence was low, and similar in those with equivocal or positive ETT (16% and 11% respectively). In males, obstructive CAD was almost 50% in those with positive ETT (p=0.005). Obstructive CAD was found in one in five "equivocal" ETTs, hence, not all should be considered negative. Obstructive CAD was only found in one in three "positive" ETTs, hence not all should proceed to invasive angiography. CCTA may be an important gatekeeper test in those with low-intermediate pre-test probability of obstructive CAD.

Prognostic Value of Stress Dynamic Myocardial Perfusion CT in a Multicenter Population With Known or Suspected Coronary Artery Disease.

The purpose of this study was to determine the prognostic value of myocardial perfusion CT for major adverse cardiac events (MACE). Data from six centers in Asia, Europe, and North America on 144 patients with known or suspected coronary artery disease who had undergone coronary CT angiography (CCTA) and dynamic myocardial perfusion CT with a dual-source CT system were analyzed. CCTA studies were acquired at rest. Dynamic myocardial perfusion CT was performed under vasodilator stress. CCTA data were evaluated for the presence of coronary artery stenosis (≥ 50% luminal narrowing) on a per-vessel basis. Myocardial perfusion CT data were qualitatively evaluated for perfusion defects in each vessel territory. Patient follow-up was performed 6, 12, and 18 months after imaging. The prognostic value of CT findings was assessed with Kaplan-Meier statistics and the multivariate Cox proportional hazards regression model. According to the CCTA findings, 62 of 144 patients (43.1%) had at least one 50% or greater stenosis. According to the myocardial perfusion CT findings, 51 patients (35.4%) had one or more perfusion defects. Patients with at least one perfusion defect at myocardial perfusion CT were at increased risk of MACE (hazard ratio, 2.50; 95% CI, 1.34-4.65; p = 0.0040). This association remained significant after adjustment for age, sex, and clinical risk factors (hazard ratio, 2.41; 95% CI, 1.28-4.51; p = 0.0064) and after further adjustment for CCTA findings (hazard ratio, 2.03; 95% CI, 1.04-3.97; p = 0.0390). The number of territories with perfusion defects was strongly predictive of MACE with adjusted hazard ratios of 1.41, 3.44, and 4.76 for one, two, and three affected territories. In assessment for future MACE, myocardial perfusion CT has incremental predictive value over clinical risk factors and detection of coronary artery stenosis with CCTA.

The optimal monochromatic spectral computed tomographic imaging plus adaptive statistical iterative reconstruction algorithm can improve the superior mesenteric vessel image quality

ObjectiveTo investigate the effect of the optimal monochromatic spectral computed tomography (CT) plus adaptive statistical iterative reconstruction on the improvement of the image quality of the superior mesenteric artery and vein. Materials and methodsThe gemstone spectral CT angiographic data of 25 patients were reconstructed in the following three groups: 70KeV, the optimal monochromatic imaging, and the optimal monochromatic plus 40%iterative reconstruction mode. The CT value, image noises (IN), background CT value and noises, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR) and image scores of the vessels and surrounding tissues were analyzed. ResultsIn the 70KeV, the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group, the mean scores of image quality were 3.86, 4.24 and 4.25 for the superior mesenteric artery and 3.46, 3.78 and 3.81 for the superior mesenteric vein, respectively. The image quality scores for the optimal monochromatic and the optimal monochromatic plus 40% iterative reconstruction groups were significantly greater than for the 70KeV group (P<0.05). The vascular CT value, image noise, background noise, CNR and SNR were significantly (P<0.001) greater in the optimal monochromatic and the optimal monochromatic images plus 40% iterative reconstruction group than in the 70KeV group. The optimal monochromatic plus 40% iterative reconstruction group had significantly (P<0.05) lower image and background noise but higher CNR and SNR than the other two groups. ConclusionThe optimal monochromatic imaging combined with 40% iterative reconstruction using low-contrast agent dosage and low injection rate can significantly improve the image quality of the superior mesenteric artery and vein.

3D Printing of Preoperative Simulation Models of a Splenic Artery Aneurysm: Precision and Accuracy

Three-dimensional (3D) printing is attracting increasing attention in the medical field. This study aimed to apply 3D printing to the production of hollow splenic artery aneurysm models for use in the simulation of endovascular treatment, and to evaluate the precision and accuracy of the simulation model. From 3D computed tomography (CT) angiography data of a splenic artery aneurysm, 10 hollow models reproducing the vascular lumen were created using a fused deposition modeling-type desktop 3D printer. After filling with water, each model was scanned using T2-weighted magnetic resonance imaging for the evaluation of the lumen. All images were coregistered, binarized, and then combined to create an overlap map. The cross-sectional area of the splenic artery aneurysm and its standard deviation (SD) were calculated perpendicular to the x- and y-axes. Most voxels overlapped among the models. The cross-sectional areas were similar among the models, with SDs <0.05 cm2. The mean cross-sectional areas of the splenic artery aneurysm were slightly smaller than those calculated from the original mask images. The maximum mean cross-sectional areas calculated perpendicular to the x- and y-axes were 3.90 cm2 (SD, 0.02) and 4.33 cm2 (SD, 0.02), whereas those calculated from the original mask images were 4.14 cm2 and 4.66 cm2, respectively. The mean cross-sectional areas of the afferent artery were, however, almost the same as those calculated from the original mask images. The results suggest that 3D simulation modeling of a visceral artery aneurysm using a fused deposition modeling-type desktop 3D printer and computed tomography angiography data is highly precise and accurate.

Automatic segmentation of coronary arteries from computed tomography angiography data cloud using optimal thresholding

Manual analysis of the bulk data generated by computed tomography angiography (CTA) is time consuming, and interpretation of such data requires previous knowledge and expertise of the radiologist. Therefore, an automatic method that can isolate the coronary arteries from a given CTA dataset is required. We present an automatic yet effective segmentation method to delineate the coronary arteries from a three-dimensional CTA data cloud. Instead of a region growing process, which is usually time consuming and prone to leakages, the method is based on the optimal thresholding, which is applied globally on the Hessian-based vesselness measure in a localized way (slice by slice) to track the coronaries carefully to their distal ends. Moreover, to make the process automatic, we detect the aorta using the Hough transform technique. The proposed segmentation method is independent of the starting point to initiate its process and is fast in the sense that coronary arteries are obtained without any preprocessing or postprocessing steps. We used 12 real clinical datasets to show the efficiency and accuracy of the presented method. Experimental results reveal that the proposed method achieves 95% average accuracy.

Mimicking arterial thrombosis in a 3D-printed microfluidic in vitro vascular model based on computed tomography angiography data.

Arterial thrombosis is the main instigating factor of heart attacks and strokes, which result in over 14 million deaths worldwide every year. The mechanism of thrombosis involves factors from the blood and the vessel wall, and it also relies strongly on 3D vessel geometry and local blood flow patterns. Microfluidic chip-based vascular models allow controlled in vitro studies of the interaction between vessel wall and blood in thrombosis, but until now, they could not fully recapitulate the 3D geometry and blood flow patterns of real-life healthy or diseased arteries. Here we present a method for fabricating microfluidic chips containing miniaturized vascular structures that closely mimic architectures found in both healthy and stenotic blood vessels. By applying stereolithography (SLA) 3D printing of computed tomography angiography (CTA) data, 3D vessel constructs were produced with diameters of 400 μm, and resolution as low as 25 μm. The 3D-printed templates in turn were used as moulds for polydimethylsiloxane (PDMS)-based soft lithography to create microfluidic chips containing miniaturized replicates of in vivo vessel geometries. By applying computational fluid dynamics (CFD) modeling a correlation in terms of flow fields and local wall shear rate was found between the original and miniaturized artery. The walls of the microfluidic chips were coated with human umbilical vein endothelial cells (HUVECs) which formed a confluent monolayer as confirmed by confocal fluorescence microscopy. The endothelialised microfluidic devices, with healthy and stenotic geometries, were perfused with human whole blood with fluorescently labeled platelets at physiologically relevant shear rates. After 15 minutes of perfusion the healthy geometries showed no sign of thrombosis, while the stenotic geometries did induce thrombosis at and downstream of the stenotic area. Overall, the novel methodology reported here, overcomes important design limitations found in typical 2D wafer-based soft lithography microfabrication techniques and shows great potential for controlled studies of the role of 3D vessel geometries and blood flow patterns in arterial thrombosis.

The use of high-flow extracranial-intracranial artery bypass in pathology of the cerebral and brachiocephalic arteries: technical features and surgical outcomes

Poor outcomes of surgical treatment for complex cerebral aneurysms due to the development of cerebral ischemia were the cause to use cerebral revascularization surgery for this pathology. the study objective was to master a high-flow extracranial-intracranial (EC-IC) artery bypass technique and evaluate its application in surgical treatment of complex and giant cerebral aneurysms as well as complex lesions of the brachiocephalic arteries. Fifty two patients underwent high-flow IC-EC bypass surgery; of these, 34 patients had complex cerebral aneurysms, and 18 patients had complex stenotic occlusive lesions of the brachiocephalic arteries. After bypass placement, the patients with aneurysms underwent different variants of aneurysm exclusion (trapping or proximal clipping/ligation of the parent artery). All patients underwent follow-up studies of the bypass function and clinical condition in the early postoperative period and 6 and 12 months after surgery. High-flow IC-EC bypass surgery is routinely used in clinical practice of the Novosibirsk Federal Center of Neurosurgery. Fifty one out of the 52 patients were followed-up in a range of 4 to 56 months. According to the direct or CT angiography data, bypasses functioned in 51 (98.1%) patients in the early and long-term postoperative periods. The clinical efficacy (no ischemic changes and improved cerebral perfusion) of high-flow IC-EC bypasses was demonstrated in 31 (91.2%) of 34 patients with aneurysms and in 17 (94.4%) of 18 patients with complex lesions of the brachiocephalic arteries. The total number of surgical complications was 8 (15.4%) cases: 7 complications occurred in patients with aneurysms, and 1 complication developed in a patient with bilateral ICA occlusion. Of these, ischemic complications developed in 4 (7.7%) cases, hemorrhagic complications occurred in 2 (3.8%) cases, and cranial nerve complications were found in 2 (3.8%) cases. One (1.9%) female patient with a giant aneurysm died from hemispheric stroke due to insufficient blood flow through the bypass. Implementation of a large number of surgeries enabled improvement of the technique and clarification of the prerequisites for preoperative examination, intraoperative control, and postoperative management of patients. A low mortalits rate suggests this technique for use in clinical practice. The surgery is indicated for the treatment of giant aneurysms of the petrous, cavernous, and clinoid segments of the ICA. In the case of giant supraclinoid aneurysms, the surgery may be combined with removal of thrombotic masses from the aneurysm sac for rapid decompression of the cranial nerves. Application of this surgery for treatment of giant aneurysms of the trunk and bifurcation of the basilar artery is promising but requires further investigation. The surgery is also recommended for improving cerebral perfusion in the setting of complex stenotic occlusive lesions of the BCA: prolonged BCA stenoses, tandem ICA stenoses located in both the extracranial and intracranial segments, nonspecific vasculitis and arteriitis, subcranial aneurysms, kinking etc.

IMAGING ALGORITHMS FOR OCCLUSIVE CAROTID DISEASE IN TREATMENT STRATEGY

Objective – to optimize imaging algorithms of preoperative evaluation and postoperative changes and complications in patients with occlusive carotid disease. Material and methods. Results of pre- and postoperative imaging of patients with occlusive carotid disease during 2012–2016 years were analyzed. Four groups were defined: assessment of CT-angiography (CTA) for preoperative planning (256 patients); the role of CTA for postoperative changes (51 patients); CT-perfusion (CTP) abilities in cerebral circulation assessment before and after surgery (103 and 76 patients); CT and MRI in diagnosis of postoperative neurologic complications (595 patients). Results. CTA employment in preoperative examination increased accuracy of occlusive process evaluation and changed management strategy in 6 patients. With CTA data we were able to define three variants of postoperative carotid changes: “expected” condition; changes that require further dynamic control studies; complications. The most reasonable was CTP employment for patients with combination of stenosis of one carotid artery and occlusion of contralateral artery. For diagnosis of neurologic complication first line examination was MRI, than for further assessment – CTA and CTP. Conclusion. Complex imaging algorithm for occlusive carotid disease assessment, defining of postoperative vascular status and possible neurologic complications provide necessary information for management strategy examination.

Clinical testing of Belarusian aortic stent graft system

Aim. The study looks at the results of clinical testing of the first Belarusian aortic stent graft system developed and manufactured by a team of specialists from RSPC "Cardiology", Minsk, Belarus, and Belarusian Technical University.Methods. The original system of aortic stent graft includes a delivery system and an aortic stent graft itself. It is used in surgical treatment of complicated and common aneurysms of the thoracic aorta, as well as in cases of concomitant thoracic aneurysms and heart pathology to be treated under cardiopulmonary bypass. Clinical testing of the stent graft was carried out according to the requirements of Ministry of Health of the Republic of Belarus on the basis of three different cardiac hospitals of the country. Results. All the three hospitals treated one patient each. The first patient underwent implantation of the stent graft into the descending thoracic aorta, with the thoracic aorta aneurysm isolated and the aortic valve replaced with bioprosthesis. The second patient underwent ascending aorta and aortic valve replacement with a conduit and implantation of aortic stent graft into the descending thoracic aorta. In the third patient the domestic aortic stent graft was implanted into the descending thoracic aorta with isolation of the thoracic aneurysm; aortic valve and ascending aorta were replaced with ‘MedEng' conduit and the aortic arch was also replaced, with the brachiocephalic arteries re-implanted in place. All the patients were followed-up for both early and long-term outcomes for more than 1 year and were examined by using CT angiography in the early postoperative period and after 1 year. Uncomplicated postoperative course was observed in all the patients. There were no complications in the long-term follow-up as well. CT angiography data confirmed good positioning of the stent graft and good isolation of the aneurysm lumen. Preoperative and postoperative СТ data of one patient are presented in the article.Conclusion. The Belarusian system of aortic stent graft successfully passed clinical testing and may be certified and used in clinical practice at a later time on the territory of Belarus.Received 21 June 2016. Accepted 11 November 2016.Funding: The research was financed by Ministry of Health Care of Republic of Belarus.Conflict of interest: The authors declare no conflict of interest.Author contributionsConceptualization and study design: Shket A.P.Material acquisition and analysis: Shket A.P., Nizhnikova O.G. Statistical data processing: Glybovskaya T.V.Article writing: Shket A.P., Krutov V.G.Review &amp; editing: Ostrovskii Y.P.

Improving Image Quality of Coronary Computed Tomography Angiography Using Patient Weight and Height-Dependent Scan Trigger Threshold

We aim to improve the image quality of coronary computed tomography angiography (CCTA) by using personalized weight and height-dependent scan trigger threshold. This study was divided into two parts. First, we performed and analyzed the 100 scheduled CCTA data, which were acquired by using body mass index-dependent Smart Prep sequence (trigger threshold ranged from 80 Hu to 250 Hu based on body mass index). By identifying the cases of high quality image, a linear regression equation was established to determine the correlation among the Smart Prep threshold, height, and body weight. Furthermore, a quick search table was generated for weight and height-dependent Smart Prep threshold in CCTA scan. Second, to evaluate the effectiveness of the new individual threshold method, an additional 100 consecutive patients were divided into two groups: individualized group (n = 50) with weight and height-dependent threshold and control group (n = 50) with the conventional constant threshold of 150 HU. Image quality was compared between the two groups by measuring the enhancement in coronary artery, aorta, left and right ventricle, and inferior vena cava. By visual inspection, image quality scores were performed to compare between the two groups. Regression equation between Smart Prep threshold (K, Hu), height (H, cm), and body weight (BW, kg) was K = 0.811 × H + 1.917 × BW - 99.341. When compared to the control group, the individualized group presented an average overall increase of 12.30% in enhancement in left main coronary artery, 12.94% in proximal right coronary artery, and 10.6% in aorta. Correspondingly, the contrast-to-noise ratios increased by 26.03%, 27.08%, and 23.17%, respectively, and by 633.1% in contrast between aorta and left ventricle. Meanwhile, the individualized group showed an average overall decrease of 22.7% in enhancement of right ventricle and 32.7% in inferior vena cava. There was no significant difference of the image noise between the two groups (P > .05). By visual inspection, the image quality score of the individualized group was higher than that of the control group. Using personalized weight and height-dependent Smart Prep threshold to adjust scan trigger time can significantly improve the image quality of CCTA.

Preliminary study of endovascular aneurysm repair using fenestration on table for abdominal aortic aneurysm with short proximal neck

Objective: To investigate the clinical value of endovascular aneurysm repair(EVAR) using fenestration on table for abdominal aortic aneurysm(AAA) with short proximal neck. Methods: A retrospective analysis of four cases with short proximal neck AAA from Aug. 2015 to May. 2016 of Tianjin Medical University General Hospital treated by EVAR using fenestration on table. Fenestrated stent-grafts were designed according to the preoperative computer tomography angiography(CTA) data. All cases underwent EVAR with the fenestrated stent-grafts on table to revascularize visceral branches. Results: FEVAR was performed in all of the 4 cases successfully. Device deploying success rate was 100%. No type Ⅰ endoleak was found in all of the 4 cases. Transient renal dysfunction occurred in two cases during 7 post-operative days and improved with the medical treatment. Mean follow-up period was 4.7 months(range, 1-9 months). CTA (3 cases) and ultrasonic imaging(1 case) were performed postoperatively. No endoleak was found around fenestrated stent graft and patency of visceral stent grafts were maintained in all of the 4 cases. Conclusion: EVAR using fenestration on table for short proximal neck AAA is safe and feasible, which expand the indication of EVAR for AAA, and the long-term safety and outcomes of this technique need to be assessed in the future.

Abstract 11638: Angiographic Efficacy of the Atriclip Left Atrial Appendage (LAA) Exclusion Device Placed by Minimally Invasive Thoracoscopic Approach

Introduction: Closure of the LAA with an endocardial device is associated with a low risk for AF related embolic stroke. The Atriclip exclusion device (Atricure, Inc., West Chester, OH, USA) allows epicardial closure of the LAA, avoiding the need for oral anticoagulation (OAC) post procedure. We sought to assess long-term LAA closure efficacy of the Atriclip applied via totally thoracoscopic (TT) approach. Hypothesis: LAA closure efficacy will be high. Methods: We performed a prospective CT angiography (CTA) study of all TT placed Atriclips at Vanderbilt Medical Center implanted June 13, 2011 to October 6, 2015. All subjects provided informed consent under Vanderbilt IRB approved protocol. Intra-op TEE was performed in all cases to confirm procedural success. At a minimum of 90 days postimplant, 3-D volumetric two phase CTA was performed to assess the presence of contrast leak, exposed trabeculations, residual stump and clip position. All CTA interpretation and data was obtained by chest radiologists. Results: As of June 1, 2016, 63 patients completed CTA. The mean age was 64.8 ± 8.87 years and 77.8% were male. The majority of patients had persistent AF (82.5%). Mean CHADS2VASC score was 2.43 ± 1.44 and HASBLED was score 2.21 ± 1.23. Adequate LAA closure was defined as complete exclusion of the trabeculated LAA, which was confirmed in 59 subjects (93.6%). Cases without complete closure (n=4) include: 2 malpositioned clip not addressing a secondary LAA lobe, and 2 clips placed too distal leaving a stump with exposed trabeculae. Of the patients with complete closure, 30 (50.8%) had a smooth proximal stump. There were no major complications associated with TT placed Atriclips. Prospective follow-up over 143 observed patient-years reveals 1 stroke in a patient with documented complete LAA closure and no thrombus (hypertensive CVA). Conclusions: Angiographic LAA closure efficacy with a TT placed Atriclip is high (93.6%). The clinical significance of a remnant stump is unknown.

Building 3D anatomical model of coiling of the internal carotid artery derived from CT angiographic data.

The purpose of this study is to recreate live patient arterial anomalies using new recent application of three-dimensional (3D) printed anatomical models. Another purpose of building such models is to evaluate the effectiveness of angiographic data. With the help of the DICOM files from computed tomographic angiography (CT-A), we were able to build a printed model of variant course of the internal carotid artery (ICA). Images of coiling of the ICA taken by CT-A, were then converted into 3D images using Google SketchUp free software, and the images were saved in stereolithography format. Imaging helped us conduct the examination in details with reference to geometrical features of ICA, degree of curve, its extension, location and presence of loop. Challenging vascular anatomy was exposed with models of adverse curve of carotid anatomy, including highly angulated necks, conical necks, short necks, tortuous carotid arteries, and narrowed carotid lumens. It assisted us to comprehend spatial anatomy configuration of life-like models. 3D model can be very effective in cases when anatomical difficulties are detected through the CT-A, and therefore, a tactile approach is demanded preoperatively. 3D life-like models serve as an essential office-based tool in vascular surgery as they assist surgeons in preoperative planning, develop intraoperative guidance, teach both the patients and the surgical trainees, and simulate to show patient-specific procedures in medical field.

Geometrical characteristics of aortic root and left ventricular dysfunction in aortic stenosis: quantification of 256-slice coronary CT angiography.

The purpose of this study is to analyze the geometrical characteristics of aortic root and left ventricular (LV) function in aortic stenosis (AS) using 256-slice coronary-computed tomography angiography (CCTA). Retrospective ECG-gated 256-slice CCTA data from 32 patients with tricuspid AS scheduled for aortic valve replacement, and 11 controls were analyzed. Aortic root geometry was measured using multiplanar reconstruction CT images. CCTA data set was transformed into 100 phases/cycle using motion coherence image processing. Systolic shortening (SS, mm/ms) and diastolic relaxation (DR, mm/ms2) in the circumferential and longitudinal directions on time curves of myocardial length were calculated, and were used as estimates of geometric LV function. Comparison of parameters was analyzed by Mann-Whitney U test. Receiver-operating-characteristic (ROC) analysis was performed to determine the optimal cutoff of parameters for differentiating AS patients. Height of the right coronary cusp was significantly lower for AS patients than controls (11.4±2.4 vs. 13.9±2.0mm/m2, p<0.005). Vertical-longitudinal SS was significantly lower for AS patients than for controls (1.7±0.8 vs. 2.7±0.7mm/ms/m2, p<0.001). ROC analysis revealed optimal height of the right coronary cusp of 12.4mm/m2 and vertical-longitudinal SS of 2.4mm/ms/m2 for differentiating AS patients from controls, with C statistics of 0.82 and 0.85. In AS patients, ROC analysis revealed optimal vertical-longitudinal DR of 0.05mm/ms2/m2 for predicting patients with stroke volume index <35ml with C statistics of 0.93. Quantification of CCTA demonstrates that AS is characterized by small coronary cusps as aortic root remodeling and vertical-longitudinal LV dysfunction related to restrictive physiology.

Clinical and prognostic correlates of pulmonary congestion in coronary computed tomography angiography data sets

BackgroundSigns of pulmonary congestion obtained from cardiac computed tomography angiographic (coronary CTA) images have not previously been related to clinical congestion or outcome and the clinical value is, therefore, unknown. Our objective was to test the hypothesis that signs of pulmonary congestion predict clinical heart failure and adverse outcome in patients with myocardial infarction. MethodsCoronary CTA was performed before invasive treatment in 400 prospectively included patients with non ST segment elevation myocardial infarction in an observational study. Using a previously described chest computed tomography evaluation algorithm, patients were classified as having “no congestion”, “mild to moderate congestion” or “severe congestion”. ResultsUsing multivariate analyses, presence of pulmonary congestion on coronary CTA images was associated with age, female gender, left ventricular ejection fraction (LVEF) and left atrial size. The diagnostic accuracy for predicting clinical heart failure, defined as Killip class >1, was: sensitivity: 83%, specificity: 69%, positive predictive value: 25%, and negative predictive value: 97%. The median follow-up time was 50 months and the study end-point of death or hospitalization due to heart failure was reached in 68 (16%) patients. In a Cox proportional hazards model with adjustments for known risk factors and Killip class, the presence of “mild to moderate congestion” and “severe congestion” was independently associated with adverse outcome (Hazard ratio: 2.6 (95% CI:1.3–5.0) and 3.2 (1.3–7.5)). ConclusionSigns of pulmonary congestion on coronary CTA images are closely correlated to cardiac dysfunction, predict clinical heart failure, and provide prognostic value independent of LVEF and Killip class.

The computed tomography angiography study of the spatial relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery

Background ContextTo our knowledge, there is no study that has systematically analyzed the relationship between C1 transpedicular screw trajectory and V3 segment of vertebral artery (VA V3 segment). PurposeTo study the relationship between C1 transpedicular screw trajectory and VA V3 segment. Study DesignA morphologic computed tomography angiography (CTA) analysis of the spatial relationship between C1 transpedicular screw trajectory and VA V3 segment. MethodsMeasurements were made on a workstation by using CTA data of 62 patients. Firstly, parameters related to the relationship between C1 vertebral artery groove (VAG) and vertebral artery (VA) were measured: (A) the shortest distance between the posterosuperior aspect of C1 posterior arch and VA; (B) distance between the outer aspect of VAG and VA; (C) distance between midpoint of VAG and VA; and (D) distance between the inner aspect of the VAG and VA. Then, the central axis of trajectory perpendicular to the coronal plane (axis P) and the central axis of trajectory with a medial inclination (axis M) were designed for the basis of measurements. Parameters related to the relationship between axis P/M and VA V3 segment were measured respectively: (E, E′), distance between insertion point and anterior aspect of VA along axis P/M; (F, F′), the shortest distance between axis P/M and the outer cortex of C1 transverse foramen; and (G, G′), the narrowest width of C1 internal medullary canal along axis P/M. ResultA, B, C, and D were 1.7±1.0 mm, 1.6±0.9 mm, 1.5±0.7 mm, 2.3±1.1 mm, respectively. E, E′ were 5.5±1.7 mm and 4.1±2.3 mm. F, F′ were 1.9±0.7 mm and 2.9±0.7 mm. G, G′ were 3.7±1.4 mm and 4.8±1.2 mm. There was a little interspace between atlas VAG and VA, which was mainly filled with venous plexus. ConclusionsThere is a close relationship between C1 transpedicular screw trajectory and VA V3 segment. Trajectory with medial inclination technique is suggested especially for female patients.

The prevalence of coronary artery anomalies in Qassim Province detected by cardiac computed tomography angiography

BackgroundCoronary artery anomalies (CAAs) affect about 1% of the general population based on invasive coronary angiography (ICA) data, computed tomography angiography (CTA) enables better visualization of the origin, course, relation to the adjacent structures, and termination of CAAs compared to ICA. ObjectiveThe aim of our work is to estimate the frequency of CAAs in Qassim province among patients underwent cardiac CTA at Prince Sultan Cardiac Center. MethodsRetrospective analysis of the CTA data of 2235 patients between 2009 and 2015. ResultsThe prevalence of CAAs in our study was 1.029%. Among the 2235 patients, 241 (10.78%) had CAAs or coronary variants, 198 (8.85%) had myocardial bridging, 34 (1.52%) had a variable location of the Coronary Ostia, Twenty two (0.98%) had a separate origin of left anterior descending (LAD) and left circumflex coronary (LCX) arteries, ten (0.447%) had a separate origin of the RCA and the Conus artery. Seventeen (0.76%) had an anomalous origin of the coronaries. Six (0.268%) had a coronary artery fistula, which is connected mainly to the right heart chambers, one of these fistulas was complicated by acute myocardial infarction. ConclusionsThe incidence of CAAs in our patient population was similar to the former studies, CTA is an excellent tool for diagnosis and guiding the management of the CAAs.

Grading of proximal internal carotid artery (ICA) stenosis by Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA): correlation and interrater reliability in real-life practice.

Doppler/duplex ultrasound (DUS) and computed tomographic angiography (CTA) are frequently applied methods to assess the degree of proximal internal carotid artery (ICA) stenoses in patients with acute ischemic stroke. This study evaluated the agreement and interrater reliability (IR) of both methods using a revised DUS grading system as well as different criteria (ECST/NASCET) under real-life conditions. CTA and DUS data of 281 proximal ICA stenoses [143 patients; 65.7% male; age (mean (years)±SD, range) 72.2±11.1, 40-99] were retrospectively analyzed. For both methods, two independent raters estimated the degree of stenosis according to NASCET and ECST criteria. DUS raters applied revised German DUS criteria. For agreement and IR assessment, the linear weighted Kappa statistic was used. Correlation between DUS and CTA was substantial irrespective of the applied classification [weighted Kappa: 0.77 (NASCET)/0.79 (ECST)]. IR for DUS was almost perfect (weighted Kappa: 0.94) and better than for CTA [weighted Kappa: 0.78 (NASCET)/0.78 (ECST)]. In a real-life setting, CTA and DUS assessments of the degree of proximal ICA stenoses agreed substantially irrespective of the criteria applied (ECST/NASCET). For DUS, IR was better than for CTA.

Software-based on-site estimation of fractional flow reserve using standard coronary CT angiography data.

The significance of a coronary stenosis can be determined by measuring the fractional flow reserve (FFR) during invasive coronary angiography. Recently, methods have been developed which claim to be able to estimate FFR using image data from standard coronary computed tomography angiography (CCTA) exams. To evaluate the accuracy of non-invasively computed fractional flow reserve (cFFR) from CCTA. A total of 23 vessels in 21 patients who had undergone both CCTA and invasive angiography with FFR measurement were evaluated using a cFFR software prototype. The cFFR results were compared to the invasively obtained FFR values. Correlation was calculated using Spearman's rank correlation, and agreement using intraclass correlation coefficient (ICC). Sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for significant stenosis (defined as both FFR ≤0.80 and FFR ≤0.75) were calculated. The mean cFFR value for the whole group was 0.81 and the corresponding mean invFFR value was 0.84. The cFFR sensitivity for significant stenosis (FFR ≤0.80/0.75) on a per-lesion basis was 0.83/0.80, specificity was 0.76/0.89, and accuracy 0.78/0.87. The positive predictive value was 0.56/0.67 and the negative predictive value was 0.93/0.94. The Spearman rank correlation coefficient was ρ = 0.77 (P < 0.001) and ICC = 0.73 (P < 0.001). This particular CCTA-based cFFR software prototype allows for a rapid, non-invasive on-site evaluation of cFFR. The results are encouraging and cFFR may in the future be of help in the triage to invasive coronary angiography.