Coronary CT angiography instead of invasive angiography before TAVI: Feasibility and outcomes.

AIMS: Concomitant coronary artery disease (CAD) is frequent in transcatheter aortic valve implantation (TAVI) candidates. Despite societal recommendations of performing invasive coronary angiography (ICA) for coronary assessment in the pre-TAVI diagnostic workup, the prognostic value of ICA and beneficial effect of revascularization in these patients remains unclear. We aimed to determine feasibility and outcomes following a strategy of cardiac CT + coronary CT angiography (cCTA) rather than cardiac CT + ICA before TAVI. METHODS AND RESULTS: We performed a single-center, observational cohort study including all patients, without previous coronary intervention, referred to TAVI between April 2020 and November 2021. CAD was assessed by cCTA, and only patients with proximal stenosis >70 %, or left main stenosis >50 %, or cCTA was non-evaluable regarding proximal segments were subsequently referred to ICA. 240 patients were included in the study. No adverse effects to pre-cCTA-scan nitroglycerin administration were observed. On cCTA, 92 % of the patients had atheroscerosis. 191 (80 %) patients had cCTA only performed, while 49 (20 %) patients underwent subsequent ICA. During a median (range) follow-up of 15 (Abdel-Wahab et al., 2012; Rapp et al., 2001; Sabbah et al., 2021; Gautier et al., 2011; Sankaramangalam et al., 2017; Otto et al., 2021; Tarantini et al., 2023; Vahanian et al., 2021; Faroux et al., 2019; Ferraro et al., 2020; Patterson et al., 2021; Blanke et al., 2019; Bleakley and Monaghan, 2018; Knuuti et al., 2020; Moss et al., 2017; van den Boogert et al., 2018; Collet et al., 2018; Linde et al., 2020; Schmidt et al., 2018; Hansson et al., 2013 [6-25]) months, no difference in procedural complication rates, mortality rates, or number of unplanned ICA was observed between patients evaluated with only cCTA vs cCTA+ICA. CONCLUSIONS: Upfront cCTA instead of ICA for assessment of obstructive CAD in the diagnostic workup of patients with severe aortic stenosis referred to TAVI is feasible, safe, and with similar procedural and clinical outcomes. Randomized studies are warranted to further validate the safety of using CTA rather than ICA for coronary assessment in TAVI candidates.

Cost-effectiveness of ultrahigh-resolution photon-counting detector coronary CT angiography for the evaluation of stable chest pain.

BACKGROUND: The increased specificity of ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT over energy-integrating detector (EID)-CT for coronary CT angiography (CCTA) could defer unwarranted downstream tests. The objective of the study was to simulate the cost-effectiveness of UHR CCTA in stable chest pain patients with coronary calcifications. METHODS: A decision and simulation model was developed using Monte Carlo simulations with 1000 bootstrap resamples to estimate the costs associated with PCD-CT in lieu of EID-CT for CCTA and the referral for subsequent testing. The model was constructed using the diagnostic accuracy metrics of 55 coronary lesions in patients who underwent CCTA on both CT systems and subsequent invasive coronary angiography (ICA). Sensitivity and specificity were defined for each Coronary Artery Disease Reporting and Data System category. The aggregate healthcare expenditures were derived from the hospital billing system. RESULTS: Assuming a projected cohort of 15,000 patients over the lifetime of the PCD-CT, its implementation resulted in a 18.9 â€‹% reduction in the number of functional follow-up tests (6330.3 â€‹± â€‹59.5 vs. 5135.7 â€‹± â€‹60.6, p â€‹< â€‹0.001), a 6.0 â€‹% reduction in performed ICAs (1447.7 â€‹± â€‹36.2 vs. 1360.2 â€‹± â€‹34.7, p â€‹< â€‹0.001), and a 9.4 â€‹% decrease in major procedure-related complications. Over a 10-year expected life expectancy, PCD-CT led to an average cost saving of $794.50 â€‹± â€‹18.50 per patient and an overall cost difference of $11,917,500 â€‹± â€‹4,350,169. CONCLUSIONS: PCD-CT has the potential to reduce the financial burden on healthcare systems and procedure-related complications for stable chest pain patients with coronary calcification when compared to EID-CT.

Can the second phase of contrast-enhanced MRA of the neck provide additional information in the acute stroke setting?

BACKGROUND: Double-concentration magnetic resonance imaging (MRI) contrast agents are frequently used in contrast-enhanced MR angiography (CE-MRA) of the head and neck. To avoid mistiming the peak concentration of intraluminal contrast (due to shorter duration of peak), a second acquisition is sometimes performed. PURPOSE: To evaluate additional information from the second acquisition of CE-MRA and compare the collateral scoring to the hypoperfusion index obtained on MR perfusion, and to investigate presence of pseudo-occlusion using the second phase of CE-MRA. MATERIAL AND METHODS: A retrospective study was conducted. CE-MRA of the brain/neck, dynamic susceptibility contrast (DSC) MR perfusion scan (in majority) and subsequent digital subtraction angiography (DSA) were evaluated in patients with previous acute internal carotid artery (ICA)/middle cerebral artery (MCA) occlusion. Evaluation of CE-MRA/MR perfusion and DSA was performed by three experienced neuroradiologists and one neurointerventionist, respectively. RESULTS: The site of ICA occlusion was seen to be distal to the site noted on early arterial phase (pseudo-occlusion of ICA) in 28.5% of patients. A significant negative correlation was seen between a higher HIR and collateral score. CONCLUSION: Evaluation of second phase CE-MRA can provide valuable information that may be otherwise lost if only the early arterial phase is evaluated.

Integrating myocardial CT perfusion with coronary CT angiography improves risk stratification in patients with dialysis-dependent end-stage renal disease.

PURPOSE: Risk stratification for incidence of major adverse cardiovascular events (MACE) in patients with dialysis-dependent end-stage renal disease (dd-ESRD) is challenging. Moreover, the usefulness of coronary CT angiography (CCTA) is often limited because of high calcification. This study aimed to investigate the prognostic value of comprehensive cardiac CT in patients with dd-ESRD for predicting MACE. MATERIALS AND METHODS: This retrospective analysis included 92 patients with dd-ESRD who underwent comprehensive cardiac CT. Obstructive coronary artery disease (CAD) was defined by CCTA with > 50% stenosis. Global myocardial blood flow (MBF) and summed stress score (SSS) were obtained through dynamic CTP. Cox regression analysis was used to assess correlation with MACE. Kaplan-Meier curves were used to estimate cumulative event rates, and the global Chi-square test was used to assess the incremental value of dynamic CTP over CCTA. RESULTS: During a median follow-up of 2.3 years, 43 patients experienced MACE. Univariate analysis revealed that presence of obstructive CAD, higher SSS, and lower global MBF were significantly associated with increased risk of MACE. In multivariable analysis, lower global MBF and presence of obstructive CAD were independently associated with MACE (p = 0.02, and p = 0.04, respectively). CCTA and dynamic CTP combination had incremental value over CCTA alone for predicting MACE, respectively (global Chi-square score, 19.3 and 11.7, respectively). CONCLUSION: Presence of obstructive CAD on CCTA and lower global MBF on dynamic CTP are independently associated with increased risk of MACE in patients with dd-ESRD. The addition of dynamic CTP to CCTA may improve risk stratification in this population.

Prognostic value of left ventricular mass measured on coronary computed tomography angiography.

BACKGROUND: Left ventricular (LV) mass is a well-established prognostic indicator for cardiovascular risk. Measurement of LV mass on coronary computed tomography angiography (CCTA) is considered optional. We aimed to assess for associations between LV mass measured on CCTA with all-cause mortality (ACM) risk and to determine age- and sex-specific distributions. METHODS: We evaluated patients without known coronary artery disease (CAD) who underwent CCTA at a single center. We assessed age- and sex-specific distributions (10th, 25th, 50th, 75th, and 90th percentiles) of LV mass index. ACM, the primary endpoint, was recorded over a median period of 5.1 [interquartile range: 1.4-8.4] years. The association between LV mass and mortality risk was assessed using multivariable Cox models adjusted for age, sex, medical history, coronary artery calcium (CAC) score and CCTA stenosis. RESULTS: 4187 patients (mean age: 61.9 â€‹± â€‹11.7, 63 â€‹% male) were included. Male sex, African American ethnicity, Hypertension, CAC>400, and smoking were independent predictors of increased LV mass index. During the median 5.1 years of study follow, 265 (6.3 â€‹%) deaths occurred. Increased LV mass index percentiles were associated with increased risk of ACM. The addition of LV mass index percentiles improved discrimination and reclassification for mortality prediction over a model with age, sex, conventional risk factors, CAC score and CCTA stenosis severity (X2 improvement: 22.68, NRI: 28 â€‹%, both p â€‹< â€‹0.001). CONCLUSION: In a large sample of patients without known CAD who underwent CCTA, increased LV mass index provided independent and incremental prognostic value for all-cause mortality. Assessment of LV mass by CCTA, considering age and gender distribution, can be utilized clinically to identify patients with high myocardial mass.

Computed Tomography-Derived Fractional Flow Reserve: Developing A Gold Standard for Coronary Artery Disease Diagnostics.

In recent years, a new technique called computed tomography-derived fractional flow reserve (CT-FFR) has been developed. CT-FFR overcomes many limitations in the current gold-standard fractional flow reserve (FFR) techniques while maintaining a better concordance with FFR. This technique integrates static coronary CT angiography data with hydrodynamic models, employing algorithms rather than guidewire interventions to compute the FFR. In addition to diagnosing coronary heart disease, CT-FFR has been applied in the preoperative risk assessment of major adverse cardiovascular events (MACEs) in organ transplantation and transcatheter aortic valve replacement (TAVR). Continuous advancements in CT-FFR techniques and algorithms are expanding their applicability to other methodologies. Subsequently, with robust clinical trial validation, CT-FFR can potentially supersede FFR as the primary "gatekeeper" for interventions.

Diagnostic performance of high and ultra-high-resolution photon counting CT for detection of coronary artery disease in patients evaluated for transcatheter aortic valve implantation.

We assessed the diagnostic performance of both ultra-high-resolution (UHR) and high-resolution (HR) modes of photon-counting detector (PCD)-CT within the confines of standard pre-TAVI CT scans, as well as the performance of UHR mode adjusted specifically for coronary imaging, using quantitative coronary angiography (QCA) as the reference. We included 60 patients undergoing pre-TAVI planning CT scans. Patients were divided into 3 groups: 20 scanned in HR mode, 20 in UHR mode, and 20 in adjusted UHR mode, on a dual-source PCD-CT. The adjusted UHR mode employed a lower tube voltage (90 kV vs. 120 kV) and a higher image quality level (65 vs. 34) to enhance coronary artery visualization. Patients underwent invasive coronary angiography as part of clinical routine. CCTA and QCA were reviewed to assess CAD presence defined as stenosis ≥ 50% in proximal and middle coronary segments. We included 60 patients (mean age 79 ± 7 years; 39(65%) men). Mean heart rate during scanning was 72 ± 13 bpm. Median coronary calcium score was 973 [379-2007]. QCA identified significant CAD in 24 patients (40%): 9 patients scanned with HR mode, 10 patients with the UHR mode, and 5 patients with the UHR adjusted mode. Per-patient area under the curves were 0.57 for HR, 0.80 for UHR, and 0.80 for adjusted UHR, with no significant differences between the scan modes, and per-vessel the area under the curves were 0.73 for HR, 0.69 for UHR, and 0.87 for adjusted UHR, with significant differences between UHR and adjusted UHR (p = 0.04). UHR and adjusted UHR modes of dual source PCD-CT show potential for improved sensitivity and negative predictive value for detecting CAD in patients undergoing pre-TAVI scans, however, no statistically significant difference from HR mode was observed.

Coronary Computed Tomography Angiography (CTA) Findings in COVID-19.

(1) Background: The novel SARS-CoV-2 virus infects the endothelium. Vasculitis may lead to specific coronary artery wall lesions. Coronary computed tomography angiography (CTA) imaging findings have not been systematically reported. The aim of this study was to describe a case series using CTA. (2) Methods: Patients with recent RT-PCR confirmed SARS-CoV-2 infection referred for coronary CTA for clinical indications (e.g., chest pain, troponin+, and ECG abnormalities) were included. Coronary CTA findings, such as atypical coronary lesions suggestive of vasculitis, perivascular inflammation measured by using pericoronary fat attenuation (PCAT) index, coronary artery disease, and extracoronary findings were collected. (3) Results: Results for 12 patients (54.8 ± 22 years; four females) with SARS-CoV-2 infection within 60 days (four acute care and eight stable patients) are reported. Time to positive RT-PCR was a mean of 15.1 days (range, 0-51). In four acute patients with signs of myocardial injury, plaque rupture (n = 1), hyperenhancing myocardium/MINOCA (n = 1), MINOCA (n = 1), and pericarditis with acute heart failure (LVEF 20%) (n = 1) were found. All (100%) had pericardial effusion and signs of perivascular inflammation. Among eight stable patients, pericardial effusion or perivascular inflammation were found in only two (25%). Coronary artery disease was ruled out in five (62.5%) (4) Conclusions: Coronary CTA is a useful imaging modality in the diagnostic work up of patients with COVID-19 infection, and is able to describe coronary and other cardiac abnormalities.

Super Learner Algorithm for Carotid Artery Disease Diagnosis: A Machine Learning Approach Leveraging Craniocervical CT Angiography.

This study introduces a machine learning (ML) approach to diagnosing carotid artery diseases, including stenosis, aneurysm, and dissection, by leveraging craniocervical computed tomography angiography (CTA) data. A meticulously curated, balanced dataset of 122 patient cases was used, ensuring reproducibility and data quality, and this is publicly accessible at (insert dataset location). The proposed method integrates a super learner model which combines adaptive boosting, gradient boosting, and random forests algorithms, achieving an accuracy of 90%. To enhance model robustness and generalization, techniques such as k-fold cross-validation, bootstrapping, data augmentation, and the synthetic minority oversampling technique (SMOTE) were applied, expanding the dataset to 1000 instances and significantly improving performance for minority classes like aneurysm and dissection. The results highlight the pivotal role of blood vessel structural analysis in diagnosing carotid artery diseases and demonstrate the superior performance of the super learner model in comparison with state-of-the-art (SOTA) methods in terms of both accuracy and robustness. This manuscript outlines the methodology, compares the results with state-of-the-art approaches, and provides insights for future research directions in applying machine learning to medical diagnostics.

Coronary CT angiography-based FFR with ultrahigh-resolution photon-counting detector CT: Intra-individual comparison to energy-integrating detector CT.

PURPOSE: To evaluate the feasibility of CT angiography-derived fractional flow reserve (CT-FFR) calculations on ultrahigh-resolution (UHR) photon-counting detector (PCD)-CT series and to intra-individually compare the results with energy-integrating (EID)-CT measurements. METHOD: Prospective patients with calcified plaques detected on EID-CT between April 1st, 2023 and January 31st, 2024 were recruited for a UHR CCTA on PCD-CT within 30 days. PCD-CT was performed using the same or a lower CT dose index and an equivalent volume of contrast media. An on-site machine learning algorithm was used to obtain CT-FFR values on a per-vessel and per-patient basis. For all analyses, CT-FFR values ≤ 0.80 were deemed to be hemodynamically significant. RESULTS: A total of 34 patients (age: 67.3 ± 6.6 years, 7 women [20.6 %]) were included. Excellent inter-scanner agreement was noted for CT-FFR values in the per-vessel (ICC: 0.93 [0.90-0.95]) and per-patient (ICC: 0.94 [0.88-0.97]) analysis. PCD-CT-derived CT-FFR values proved to be higher compared to EID-CT values on both vessel (0.58 ± 0.23 vs. 0.55 ± 0.23, p < 0.001) and patient levels (0.73 ± 0.23 vs. 0.70 ± 0.22, p < 0.001). Two patients (5.9 %) with hemodynamically significant lesions on EID-CT were reclassified as non-significant on PCD-CT. All remaining participants were classified into the same category with both scanner systems. CONCLUSIONS: While UHR CT-FFR values demonstrate excellent agreement with EID-CT measurements, PCD-CT produces higher CT-FFR values that could contribute to a reclassification of hemodynamic significance.

Ultra-High-Resolution Photon-Counting Detector CT Benefits Visualization of Abdominal Arteries: A Comparison to Standard-Reconstruction.

This study aimed to investigate the potential benefit of ultra-high-resolution (UHR) photon-counting detector CT (PCD-CT) angiography in visualization of abdominal arteries in comparison to standard-reconstruction (SR) images of virtual monoenergetic images (VMI) at low kiloelectron volt (keV). We prospectively included 47 and 47 participants to undergo contrast-enhanced abdominal CT scans within UHR mode on a PCD-CT system using full-dose (FD) and low-dose (LD) protocols, respectively. The data were reconstructed into six series of images: FD_UHR_Br48, FD_UHR_Bv56, FD_UHR_Bv60, FD_SR_Bv40, LD_UHR_Bv48, and LD_SR_Bv40. The UHR reconstructions were performed with three kernels (Bv48, Bv56, and Bv60) within 0.2 mm. The SR were virtual monoenergetic imaging reconstruction with Bv40 kernel at 40-keV within 1 mm. Each series of axial images were reconstructed into coronal and volume-rendered images. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of seven arteries were measured. Three radiologists assessed the image quality, and visibility of nine arteries on all the images. SNR and CNR values of SR images were significantly higher than those of UHR images (P < 0.001). The SR images have higher ratings in image noise (P < 0.001), but the FD_UHR_Bv56 and FD_UHR_Bv60 images has higher rating in vessel sharpness (P < 0.001). The overall quality was not significantly different among FD_VMI_40keV, LD_VMI_40keV, FD_UHR_Bv48, and LD_UHR_Bv48 images (P > 0.05) but higher than those of FD_UHR_Bv56 and FD_UHR_Bv60 images (P < 0.001). There is no significant difference of nine abdominal arteries among six series of images of axial, coronal and volume-rendered images (P > 0.05). To conclude, 1-mm SR image of VMI at 40-keV is superior to 0.2-mm UHR regardless of which kernel is used to visualize abdominal arteries, while 0.2-mm UHR image using a relatively smooth kernel may allow similar image quality and artery visibility when thinner slice image is warranted.

Regional Reliability of Combining CT Angiography-source Image and Non-contrast CT in Acute Ischemic Stroke.

Purpose: CT angiography-source image (CTA-SI) can be used as an effective alternative to diffusion-weighted imaging (DWI) for identifying acute ischemic stroke (AIS). This study investigates the reliability of combining CTA-SI with non-contrast CT (NCCT) for AIS diagnosis, with a focus on how different brain areas affect diagnostic accuracy. Methods: Patients with various subtypes of AIS who underwent NCCT, CTA, and DWI from January to December 2022 were included. Two experienced neuroradiologists analyzed ischemic core across NCCT, CTA-SI, and NCCT+CTA-SI models, evaluating interobserver reliability and lesion detection rate. Results: A total of 304 patients (63% male, age 67.2 ± 11.9 years) with AIS were included. The distribution of stroke subtypes was as follows: 23% large vessel trunk infarction, 46% deep perforator vessel infarction, 9% superficial perforator vessel infarction, 5% watershed infarction, and 17% infratentorial infarction. The interobserver reliability was substantial in the three image models, especially the NCCT+CTA-SI model (all p<0.05). The NCCT+CTA-SI model demonstrated higher lesion detection rate than the NCCT (59.20% vs 48.7%, p<0.05) and CTA-SI model (59.2% vs 45.4%, p<0.05), particularly when detecting large vessel trunk infarction (82.90% vs 58.60%, p<0.05) and deep perforator vessel infarctions (64.80% vs 44.40%, p<0.05). Conclusions: The NCCT+CTA-SI model may be a valuable tool for evaluating AIS when DWI is not feasible. Smaller hospitals might consider adopting this combination for improved stroke diagnosis, highlighting the need for careful evaluation of deep perforator vessel infarction when large vessel trunk infarction is not evident.

Clinical risk prediction, coronary computed tomography angiography, and cardiovascular events in new-onset chest pain: the PROMISE and SCOT-HEART trials.

BACKGROUND AND AIMS: Whether index testing using coronary computed tomography angiography (CTA) improves outcomes in stable chest pain is debated. The risk factor weighted clinical likelihood (RF-CL) model provides likelihood estimation of obstructive coronary artery disease. This study investigated the prognostic effect of coronary CTA vs. usual care by RF-CL estimates. METHODS: Large-scale studies randomized patients (N = 13 748) with stable chest pain to coronary CTA as part of the initial work-up in addition to or instead of usual care including functional testing. Patients were stratified according to RF-CL estimates [RF-CL: very-low (≤5%), low (>5%-15%), and moderate/high (>15%)]. The primary endpoint was myocardial infarction or death at 3 years. RESULTS: The primary endpoint occurred in 313 (2.3%) patients. Event rates were similar in patients allocated to coronary CTA vs. usual care [risk difference (RD) 0.3%, hazard ratio (HR) 0.84 (95% CI 0.67-1.05)]. Overall, 33%, 44%, and 23% patients had very-low, low, and moderate/high RF-CL. Risk was similar in patients with very low and moderate/high RF-CL allocated to coronary CTA vs. usual care [very low: RD 0.3%, HR 1.27 (0.74-2.16); moderate/high: RD 0.5%, HR 0.88 (0.63-1.23)]. Conversely, patients with low RF-CL undergoing coronary CTA had lower event rates [RD 0.7%, HR 0.67 (95% CI 0.47-0.97)]. The number needed to test using coronary CTA to prevent one event within 3 years was 143. CONCLUSIONS: Despite an overall good prognosis, low RF-CL patients have reduced risk of myocardial infarction or death when allocated to coronary CTA vs. usual care. Risk is similar in patients with very-low and moderate/high likelihood.

Dual-energy CT angiography in detecting underlying causes of intracerebral hemorrhage: an observational cohort study.

BACKGROUND: CT angiography (CTA) is often used to detect underlying causes of acute intracerebral hemorrhage (ICH). Dual-energy CT (DECT) is able to distinguish materials with similar attenuation but different compositions, such as hemorrhage and contrast. We aimed to evaluate the diagnostic yield of DECT angiography (DECTA), compared to conventional CTA in detecting underlying ICH causes. METHODS: All non-traumatic ICH patients who underwent DECTA (both arterial as well as delayed venous phase) at our center between January 2014 and February 2020 were analyzed. Conventional CTA acquisitions were reconstructed ('merged') from DECTA data. Structural ICH causes were assessed on both reconstructed conventional CTA and DECTA. The final diagnosis was based on all available diagnostic and clinical findings during one-year follow up. RESULTS: Of 206 included ICH patients, 30 (14.6%) had an underlying cause as final diagnosis. Conventional CTA showed a cause in 24 patients (11.7%), DECTA in 32 (15.5%). Both false positive and false negative findings occurred more frequently on conventional CTA. DECTA detected neoplastic ICH in all seven patients with a definite neoplastic ICH diagnosis, whereas conventional CTA only detected four of these cases. Both developmental venous anomalies (DVA) and cerebral venous sinus thrombosis (CVST) were more frequently seen on DECTA. Arteriovenous malformations and aneurysms were detected equally on both imaging modalities. CONCLUSIONS: Performing DECTA at clinical presentation of ICH may be of additional diagnostic value in the early detection of underlying causes, especially neoplasms, CVST and DVAs.

Non-invasive physiological assessment of coronary artery obstruction on coronary computed tomography angiography.

Computed tomography-derived fractional flow reserve (CT-FFR) enhances the specificity of coronary computed tomography angiography (CCTA) to that of the most specific non-invasive imaging techniques, while maintaining high sensitivity in stable coronary artery disease (CAD). As gatekeeper for invasive coronary angiography (ICA), use of CT-FFR results in a significant reduction of negative ICA procedures and associated costs and complications, without increasing cardiovascular events. It is expected that CT-FFR algorithms will continue to improve, regarding accuracy and generalisability, and that introduction of new features will allow further treatment guidance and reduced invasive diagnostic testing. Advancements in CCTA quality and artificial intelligence (AI) are starting to unfold the incremental diagnostic and prognostic capabilities of CCTA's attenuation-based images in CAD, with future perspectives promising additional CCTA parameters which will enable non-invasive assessment of myocardial ischaemia as well as CAD activity and future cardiovascular risk. This review discusses practical application, interpretation and impact of CT-FFR on patient care, and how this ties into the CCTA 'one stop shop' for coronary assessment and patient prognosis. In this light, selective adoption of the most promising, objective and reproducible techniques and algorithms will yield maximal diagnostic value of CCTA without overcomplicating patient management and guideline recommendations.

Incidence of Congenital Posterior Arch Defects of the Atlas in Chinese Population.

OBJECTIVE: To study the incidence of congenital posterior arch defects of the atlas and in combination with other congenital variations in the Chinese population. METHODS: 1405 images of cervical three-dimensional computed tomography (3D CT) and 1284 images of head and cervical three-dimensional computed tomography angiography (3D CTA) were retrospectively reviewed, including images of 1539 males and 1150 females. These images of cervical 3D CT and head and cervical 3D CTA were obtained in the Department of Radiology of two hospitals, Second and Third People's Hospital of Jingzhou, China, from January 2020 to October 2023. And congenital posterior arch defects of the atlas were classified according to the criteria of Currarino et al. Congenital posterior arch defects of the atlas combined with other congenital variations including occipitalization of the atlas, the ponticulus posticus variation of the vertebral artery groove of the atlas, cervical fusion, and the transversal foramen of the atlas variant were also observed. RESULTS: A total of 2689 subjects were included in this study. The overall prevalence of congenital posterior arch defects of the atlas was 0.74% (20/2689). There was no statistically significant difference in incidence between males (0.78%,12/1539) and females (0.70%,8/1150) (P >0.05). Among all posterior defects, type A and B defects were found in 0.6% (16/2689) and 0.15% (4/2689) cases, respectively. There were no type C, D, and E defects and no anterior arch defects. But in 20 cases of congenital posterior arch defects of atlas, 40%(8/20) combined with other congenital variations including occipitalization of atlas in 4 type A cases, bilateral complete ponticus posticus variation of atlas vertebral groove in one type A case, C2-3 fusion in one type A case, coexistence of unilateral complete ponticulus posticus variation of the vertebral artery groove of the atlas and unilateral unclosed transverse foramen in one type B case, and coexistence of unilateral unclosed transverse foramen in one type A case. CONCLUSION: The incidence of congenital posterior arch defects of the atlas was low in Chinese population. There was no difference between males and females. Type A and B were the two major defects in Chinese population, and the prevalence of type A and B combined with other congenital cervical variations were higher than those of type C, D, and E.

Imaging Challenges and Developments in Large-vessel Vasculitis.

Vascular imaging is an integral part of large-vessel vasculitis (LVV) evaluation and management. Several imaging modalities are currently employed in clinical practice including vascular ultrasound, computed tomography angiography, MRI and magnetic resonance angiography, and 18F-fluorodeoxyglucose PET. Well-established roles for imaging in LVV include disease diagnosis and assessment of luminal lesions reflecting vascular damage. The ability of imaging to determine treatment response, monitor disease activity, and predict future arterial damage is an area of active research.

Kugel's Artery in Coronary Computed Tomography Angiography in a Patient with Left Main Subtotal Stenosis.

The artery of Kugel is defined as a rare anatomical variant of the coronary arteries. It consists of an anastomotic connection between the branches of the right coronary artery (RCA) and the left circumflex artery (LCx). In patients with coronary artery occlusion, the presence of this connection bypassing the area of the occluded vessel may be a factor that prevents significant necrosis of a specific area of the myocardium. Most cases are detected by invasive coronary angiography. We present images from coronary computed tomography angiography (CCTA), which documented the existence of Kugel's artery in a 67-year-old patient with subtotal stenosis of the left main artery. The presented images clearly indicate that CCTA can visualize the existing rescue collateral circulation in patients with significant coronary artery disease.

Anatomical analysis of the abdominal aorta in a South African sample: influence of age and sex.

PURPOSE: The anatomy of the abdominal aorta (AA) varies with age and sex; however, limited studies exist from South Africa. Given the increased incidence of endovascular treatment of the AA, reference values are relevant for interventionalists for improving the safety of endovascular procedures. Therefore, the study aimed to determine the lengths, diameters and tortuosity of the AA and their association with age and sex in a South African sample. METHODS: After ethical approval, 97 computed tomography angiography (CTA) scans from an adult sample (54 male and 43 female), mean age 48.5 ± 17.2 years were analysed. The aortic length was measured from the origin of the coeliac trunk to the bifurcation point of the AA. The lumen diameters of the aorta were measured at three landmarks. Tortuosity of the AA was quantified with the tortuosity index and its prevalence was determined. RESULTS: The AA was longer in males and showed a significant weak positive correlation with age. The mean diameters of the AA were larger in males and had a significant strong positive correlation with age in both sexes (p < .001). There was a strong positive correlation between age and tortuosity in both sexes (p < .001). The prevalence of a tortuous c-shaped-curve phenotype was 8.2%, with a 7:1 male-to-female ratio. CONCLUSION: The dimensions and tortuosity differed between sexes and varied significantly with age. These findings may contribute towards reference values in the South African setting, inform patient selection and complement decision-making of endovascular treatment strategies.