3D Angiography Research Articles

3D quantitative coronary angiography based vessel FFR: clinical evidence and future perspectives

3D quantitative coronary angiography based vessel FFR: clinical evidence and future perspectives

Evaluación del tracto de salida del ventrículo derecho mediante resonancia magnética con flujo 4D en pacientes sometidos a recambio valvular pulmonar transcatéter

Introduction and objectivesMagnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiogram to balloon sizing of RVOT. MethodsSingle-centre prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiogram. Balloon sizing was considered as the reference. ResultsA total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<0.001) than by diastolic 4D flow MRI (r=0.71, P<0.001), 3D contrast magnetic resonance angiography (r=0.73; P<.001) and 3D SSFP/GRE (r=0.50; P=.04) and not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2mm (95%CI, –3.5 to 3.9 mm), whereas it was wider with other techniques. ConclusionsBeyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

Impact of Dynamic Change of Meandering of Parallel Artery to the Idiopathic Tarsal Tunnel Syndrome.

In idiopathic tarsal tunnel syndrome (TTS), walking seems to make symptoms worse. The findings imply that an ankle movement dynamic component may have an impact on the etiology of idiopathic TTS. We describe how the ankle movement affects the nerve compression caused by the surround tissue, particularly the posterior tibial artery. We enrolled 8 cases (15 sides) that had TTS surgery after tarsal tunnel (TT) MRI preoperatively. Dorsiflexion and plantar flexion were the two separate ankle positions used for the T2* fat suppression 3D and MR Angiography of TT. Based on these findings, we looked at how the two different ankle positions affected the posterior tibial artery's ability to compress the nerve. Additionally, we assessed the posterior tibial artery's distorted angle. We divided the region around the TT into four sections: proximal and distal to the TT and proximal half and distal half to the TT. Major compression cause was posterior tibial artery. Most severe compression point was proximal half in the TT in all cases without one case. In each scenario, the nerve compression worsens by the plantar flexion. The angle of the twisted angle of the posterior tibial artery was significantly worsened by the plantar flexion. In idiopathic TTS, deformation of posterior tibial artery was the primary compression component. Nerve compression was exacerbated by the plantar flexion, and it was attributable with the change of the distorted angle of the posterior tibial artery. This could be a contributing factor of the deteriorating etiology by walking in idiopathic TTS.

Analysis of risk factors associated with cerebral angiography headache

Despite previous studies indicating a moderate/high incidence of angiography headache (AH), there is still limited data about the risk factors associated with its occurrence. The present study aimed to assess the associations among demographic, clinical, and technical characteristics of cerebral digital subtraction angiography (DSA) and the occurrence of AH. Cross-sectional analytical observational study with a sample comprised of individuals with a recommendation for elective DSA. Clinical interviews were conducted to assess the occurrence of AH, using a standardized questionnaire. Among 114 subjects, the mean age was 52.8 (±13.8) years old, 75.4% (86/114) were women, 29.8% (34/114) had a history of migraines, and 10.5% (12/114) had chronic headaches. The overall frequency of AH was 45.6% (52/114). Of those, 88.4% (46/52) underwent 3D angiography, 7.7% (4/52) underwent aortography, and 1.9% (1/52) underwent both procedures. There was a statistically significant association between AH and previous history of migraine (odds ratio [OR]: 4.9; 95% confidence interval [CI] 1.62-14.7; p = 0.005) and 3D angiography (OR 6.62; 95%CI: 2.04-21.5; p = 0.002). 3D angiography is strongly associated with the occurrence of AH, which has never been reported before. The association between a previous history of migraine and AH confirms the results of previous studies.

High-tech radiation methods in the diagnosis of endometrial cancer – multiparametric MRI, ultrasound tomography, 3D angiography, energy dopplerography

The increase in the incidence of endometrial cancer is noted not only in postmenopausal women, but also in a socially active group of women of reproductive age, starting from 25 years. Ultrasound and magnetic resonance imaging (MRI) are the main methods of non-invasive diagnosis of endometrial cancer. Our study included 69 patients with endometrial cancer stages I–IV aged 30 to 79 years. The diagnostic informativeness of the MRI method in detecting tumor invasion into the myometrium for all groups was: sensitivity – 82.30%, specificity – 6.6%, PPV – 93.30%, NPV – 40%. The diagnostic informativeness of the ultrasound method in detecting tumor invasion into the myometrium for all groups was: sensitivity – 91.3%, specificity – 88.4%. The peculiarity of this study was to evaluate the possibilities of radiation methods (ultrasound, MRI) in the staging of endometrial cancer.

4D flow magnetic resonance imaging to assess right ventricular outflow tract in patients undergoing transcatheter pulmonary valve replacement

Introduction and objectivesMagnetic resonance imaging (MRI) including 4D flow is used before percutaneous pulmonary valve implantation (PPVI). As PPVI is limited by the size of the right ventricular outflow tract (RVOT), accurate sizing is needed to plan the intervention. The aim of this study was to compare different MRI modalities and invasive angiography to balloon sizing of RVOT. MethodsSingle-center prospective study of patients who underwent PPVI for isolated pulmonary regurgitation assessed by 4D flow MRI, 3D steady-state free precession/gradient echo (3D SSFP/GRE) and contrast magnetic resonance angiography. Balloon sizing was considered as the reference. ResultsA total of 23 adults were included (mean age, 38.4±12.5 years). Eighteen patients underwent successful primary PPVI. The average of the narrowest RVOT diameter was 25.4±4.3 mm by balloon sizing. Compared to balloon sizing, RVOT diameters were better correlated when estimated by systolic 4D flow MRI (r=0.89, P<.001) than by diastolic 4D flow MRI (r=0.71, P <.001), 3D contrast magnetic resonance angiography (r=0.73; P <.001) and 3D SSFP/GRE (r=0.50; P=.04) and was not significantly correlated when estimated by 2D in diastole and systole. The mean difference between systolic 4D flow MRI and balloon sizing was 0.2 mm (95%CI, –3.5 to 3.9 mm), whereas it was wider with other techniques. ConclusionsBeyond the quantification of pulmonary valve regurgitation, 4D flow allows accurate estimation of RVOT diameters, especially in systole, which is fundamental before planning PPVI.

Abstract Number ‐ 169: Intraprocedural angiographic sign for assessing the stent‐clot interaction during mechanical thrombectomy

Introduction The characteristics of the occlusive clot affect the clot integration with a stent retriever (SR). This relationship, stent‐clot interaction, is considered to be a major factor in the technical success of mechanical thrombectomy. To date, numerous studies analyzing the retrieved clots have shown that both soft erythro‐rich clots and hard fibrin‐rich clots make clot retrieval challenging. Several studies have successfully obtained information on this interaction using three‐dimensional (3D) rotational angiography. However, these 3D imaging technologies have not been utilized in clinical practice due to the time‐consuming nature of image acquisition and processing. Our previous clinical study demonstrated that the angiographic findings about the deployed stent morphology obtained from conventional two‐dimensional (2D) angiography could predict recanalization (1). The greater stent expansion at the occlusion was strongly associated with recanalization after the procedure. This intraprocedural angiographic sign allows us to know the stiffness of the clots in real‐time and to choose the optimal technique. The purpose of this study was to evaluate whether the stent expansion assessed by a 2D angiographical image reflects the actual stent dilation at the occlusion (Figure). We investigated the correlations between 2D images and 3D structures of the deployed SR using an experimental occlusion model. Methods Using occlusion models created with pseudo‐clot with 9 hardness levels (n = 3/clot type), images of the deployed Trevo SR were obtained by cone‐beam computed tomography.As the measurement metric for the 2D images, we used the degree of stent expansion obtained from a plane along the long axis of the device. In clinical practice, however, this 2‐D image is usually obtained from one viewing angle. Therefore, to investigate the difference in measurement by viewing angle, different angle 2D images were created to evaluate the stent expansion. For the 3D structures, we used the stent area obtained from the short‐axis plane of the vascular model, considering this as a surrogate for actual stent expansion. We evaluated the correlation between the 2D images and the 3D structure. Results A total of 27 model image sets were obtained, showing graduated stent expansion (range: 21–79%) depending on the clot type. The median variation in the degree of stent expansion for each model measured at different angles, which means the differences by viewing angles, was 9% (range: 5–20%). The median degree of stent expansion was strongly correlated with the stent area (Pearson’s coefficient: 0.98), indicating that the degree of stent expansion could reflect the 3D structure. Conclusions This study showed that the stent expansion on 2D angiography, even assessed from one direction, could be used as the approximation of the actual stent dilatation at the occlusion. This angiographic sign provides real‐time feedback on the clot characteristics at the occlusion.

Risk of intracranial aneurysm recurrence after microsurgical clipping based on 3D digital subtraction angiography.

Current knowledge of recurrence rates after intracranial aneurysm (IA) surgery relies on 2D digital subtraction angiography (DSA), which fails to detect more than 75% of small aneurysm remnants. Accordingly, the discrimination between recurrence and growth of a remnant remains challenging, and actual assessment of recurrence risk of clipped IAs could be inaccurate. The authors report, for the first time, 3D-DSA-based long-term durability and risk factor data of IA recurrence and remnant growth after microsurgical clipping. Prospectively collected data for 305 patients, with a total of 329 clipped IAs that underwent baseline 3D-DSA, were evaluated. The incidence of recurrent IA was described by Kaplan-Meier curves. Risk factors for IA recurrence were analyzed by multivariable Cox proportional hazards and logistic regression models. The overall observed proportion of IA recurrence after clipping was 2.7% (9 of 329 IAs) at a mean follow-up of 46 months (0.7% per year). While completely obliterated IAs did not recur during follow-up, incompletely clipped aneurysms (76 of 329) demonstrated remnant growth in 11.8% (3.4% per year). Young age and large initial IA size significantly increased the risk of IA recurrence. The findings support those in previous studies that hypothesized that completely clipped IAs have an extremely low risk of recurrence. Conversely, the results highlight the significant risk posed by incompletely clipped IAs. Young patients with initial large IAs and incomplete obliteration have an especially high risk for IA recurrence and therefore should be monitored more closely.

Strong Contrast Stagnation of Unilateral Vertebral Artery on Three-Dimensional Black Blood-Enhanced MRI Predicts Acute Medulla Infarction.

This study aimed to evaluate angiographic and contrast enhancement (CE) patterns on three-dimensional (3D) black blood (BB) contrast-enhanced MRI in patients with acute medulla infarction. From January 2020 to August 2021, we retrospectively analyzed stroke 3D BB contrast-enhanced magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) findings of patients visiting the emergency room for symptom evaluation of acute medulla infarction. In total, 28 patients with acute medulla infarction were enrolled in this study. Four types of 3D BB contrast-enhanced MRI and MRA were classified as follows: 1=unilateral contrast-enhanced vertebral artery (VA)+no visualization of VA on MRA; 2=unilateral enhanced VA+hypoplastic VA; 3=no enhanced VA+unilateral complete occlusion of VA; 4=no enhanced VA+normal VA (including hypoplasia) on MRA. Of the 28 patients with acute medulla infarction, 7 (25.0%) showed delayed positive findings after 24 hours on diffusion-weighted imaging (DWI). Of these patients, 19 (67.9%) showed CE of the unilateral VA on 3D BB contrast-enhanced MRI (type 1 and 2). Of the 19 patients with CE of VA on 3D BB contrast-enhanced MRI, 18 showed no visualization of enhanced VA on MRA (type 1), and 1 showed hypoplastic VA. Of the 7 patients with delayed positive findings on DWI, 5 showed CE of the unilateral VA and no visualization of the enhanced VA on MRA (type 1). Symptom onset to door time or initial MR check time was significantly shorter in the groups with delayed positive findings on DWI (P<0.05). Unilateral CE on 3D BB contrast-enhanced MRI and no visualization of the VA on MRA are related to the recent occlusion of the distal VA. These findings suggest that the recent occlusion of the distal VA is related to acute medulla infarction, including delayed visualization on DWI.

Accuracy of Dose-Saving Artificial-Intelligence-Based 3D Angiography (3DA) for Grading of Intracranial Artery Stenoses: Preliminary Findings

Based on artificial intelligence (AI), 3D angiography (3DA) is a novel postprocessing algorithm for "DSA-like" 3D imaging of cerebral vasculature. Because 3DA requires neither mask runs nor digital subtraction as the current standard 3D-DSA does, it has the potential to cut the patient dose by 50%. The object was to evaluate 3DA's diagnostic value for visualization of intracranial artery stenoses (IAS) compared to 3D-DSA. 3D-DSA datasets of IAS (nIAS = 10) were postprocessed using conventional and prototype software (Siemens Healthineers AG, Erlangen, Germany). Matching reconstructions were assessed by two experienced neuroradiologists in consensus reading, considering image quality (IQ), vessel diameters (VD1/2), vessel-geometry index (VGI = VD1/VD2), and specific qualitative/quantitative parameters of IAS (e.g., location, visual IAS grading [low-/medium-/high-grade] and intra-/poststenotic diameters [dintra-/poststenotic in mm]). Using the NASCET criteria, the percentual degree of luminal restriction was calculated. In total, 20 angiographic 3D volumes (n3DA = 10; n3D-DSA = 10) were successfully reconstructed with equivalent IQ. Assessment of the vessel geometry in 3DA datasets did not differ significantly from 3D-DSA (VD1: r = 0.994, p = 0.0001; VD2:r = 0.994, p = 0.0001; VGI: r = 0.899, p = 0.0001). Qualitative analysis of IAS location (3DA/3D-DSA:nICA/C4 = 1, nICA/C7 = 1, nMCA/M1 = 4, nVA/V4 = 2, nBA = 2) and the visual IAS grading (3DA/3D-DSA:nlow-grade = 3, nmedium-grade = 5, nhigh-grade = 2) revealed identical results for 3DA and 3D-DSA, respectively. Quantitative IAS assessment showed a strong correlation regarding intra-/poststenotic diameters (rdintrastenotic = 0.995, pdintrastenotic = 0.0001; rdpoststenotic = 0.995, pdpoststenotic = 0.0001) and the percentual degree of luminal restriction (rNASCET 3DA = 0.981; pNASCET 3DA = 0.0001). The AI-based 3DA is a resilient algorithm for the visualization of IAS and shows comparable results to 3D-DSA. Hence, 3DA is a promising new method that allows a considerable patient-dose reduction, and its clinical implementation would be highly desirable.

Aneurysm Neck Overestimation has a Relatively Modest Impact on Simulated Hemodynamics.

Overestimation of intracranial aneurysm neck width by 3D angiography is a recognized clinical problem, and has long been a concern for image-based computational fluid dynamics (CFD). Recently, it was demonstrated that neck overestimation in 3D rotational angiography (3DRA) could be corrected via segmentation with upsampled resolution and gradient enhancement (SURGE). Our aim was to leverage this approach to determine whether and how neck overestimation actually impacts CFD-derived hemodynamics. A subset of 17 cases having the largest neck errors from a consecutive clinical sample of 60 was segmented from 3DRA using both standard watershed and SURGE methods. High-fidelity, pulsatile CFD was performed, and a variety of scalar hemodynamic parameters that have been associated with aneurysm growth and/or rupture status were derived. With a few exceptions, flow and wall shear stress (WSS) patterns were qualitatively similar between neck-overestimated and corrected models. Sac-averaged WSS values were significantly lower after neck correction (p = 0.0005) but were highly correlated with their neck-overestimated counterparts (R2 = 0.98). Jet impingement was significantly more concentrated in the neck-corrected vs. -uncorrected models (p = 0.0011), and only moderately correlated (R2 = 0.61). Parameters quantifying velocity or WSS fluctuations were not significantly different after neck correction, but this reflected their poorer correlations (R2 < 0.4). Nevertheless, for all hemodynamic parameters, median absolute differences were < 26%, and no parameter had more than 5/17 cases with absolute differences > 50%. Differences in hemodynamicsdue to neck width overestimationwere found to be at most equal to, and often less than, those reported for other sources of error/uncertainty in intracranial aneurysm CFD, such as solver settings or assumed inflow rates.

Comprehensive evaluation of three-dimensional anatomy of perigastric vessels using enhanced multidetector-row computed tomography

BackgroundTo perform laparoscopic gastrectomy safely, we aimed to comprehensively re-evaluate perigastric vessel anatomies using a three-dimensional angiography reconstructed from enhanced multidetector-row computed tomography data.MethodsPerigastric vessel anatomy was preoperatively analyzed using a multidetector-row computed tomography-based three-dimensional angiography reconstructed in 127 patients undergoing gastric surgery.ResultsOf the 67 left gastric veins that ran along the dorsal side of the arteries, 59 (88.1%) ran along the dorsal side of the common hepatic artery and flowed into the portal vein. In 18 cases, a common trunk of one to three left gastric arteries and the replaced left hepatic artery was observed. The left inferior phrenic artery ramified from the left gastric artery in 5.5% of the cases. The right gastric artery was classified into distal (73.2%), caudal (18.1%), and proximal (8.7%) types. The infra-pyloric artery was also classified into distal (64.6%), caudal (26.0%), and proximal (9.4%) types. The posterior gastric artery branched as a common trunk with the superior polar artery in the proximal (37.9%) and distal (18.4%) regions of the splenic artery. The left gastroepiploic artery ramified from the splenic (18.1%) and inferior terminal arteries (81.9%). No, one, and two gastric branches of the left gastroepiploic artery, which ramified between the roots of the left gastroepiploic artery and its omental branch, were found in 36.5%, 49.2%, and 14.3% of the cases, respectively.ConclusionsPreoperative 3D angiography is useful for the precise evaluation of perigastric vessel anatomies, and may help us to perform laparoscopic gastrectomy and robotic surgery safely.

Abstract 14942: Neurovascular Injury in a Mini-Swine Model of Recanalized Acute Ischemic Stroke

Background, hypothesis: Gyrencephalic large-animal models of acute ischemic stroke (AIS) such as swine gain attention in translating preclinical to clinical stroke research, with brain anatomy similar to humans. Most swine models employ young animals with AIS by permanent occlusion (P-AIS). This does not reflect the, often elderly, stroke patient. Therefore, recanalized AIS (R-AIS) in adult mini-pigs could improve preclinical to clinical translation. Methods: Anesthetized adult (2 yrs) Aachen mini-pigs (n=6) underwent craniotomy to occlude right-side middle cerebral arteries (MCA) with aneurysm clips. Clips were released at 4 hrs to allow recanalization for 2-4 hrs (R-AIS, n=4) or left in place until sacrifice (P-AIS, n=1). 3D angiography confirmed occlusion and recanalization. Infarct size was determined by TTC staining and expressed as % infarct per hemisphere (median, min-max). Qualitative neurovascular histology was performed in HE-stained sections of ischemic and remote (contralateral) tissue. Results: All animals survived until end-of-procedure. In 4 of 5 animals R-AIS successfully induced cortical infarcts (infarct size, 16.2% [9.1%-25.2%]). R-AIS was unsuccessful in 1 animal, with a small striatum infarct (2.7%) without cortical involvement and unclear angiographic occlusion. P-AIS (n=1) resulted in 12.7% infarct. Assessment of ischemic (TTC-neg) tissue revealed characteristic histology of ischemia/reperfusion-derived neurovascular damage, including erythrocyte extravasation, vasostasis, increased perivascular space and intravascular platelet/fibrin aggregates ( Figure 1 ) in all animals. Remote tissue did not show any of these features. Conclusions: Adult Aachen mini-pigs can be used for acute ischemic stroke modelling and display characteristic neurovascular features associated with ischemia and reperfusion. They may serve as a model for translational therapeutic neuro(vascular)-protective research.

Development of multiple intracranial aneurysms: beyond the common risk factors.

The prevalence of multiple intracranial aneurysms (MIAs) has increased over the last decades. Because MIAs have been identified as an independent risk factor for formation, growth, and rupture of intracranial aneurysms (IAs), a more profound understanding of the underlying pathophysiology of MIAs is needed. Therefore, the authors' extensive institutional aneurysm database was analyzed to elucidate differences between patients with a single IA (SIA) and those with MIAs. A total of 2446 patients seen with or for IAs at the University Hospital of Essen, Essen, Germany, from January 2003 to June 2016 were included in this retrospective cohort study and were separated into MIA and SIA subgroups. Patient data were screened for sociodemographic and radiographic parameters, preexisting medical conditions, and results of blood examinations. These parameters were analyzed for their correlations with MIAs and absolute number of IAs. MIAs were identified in 853 (34.9%) patients. In multivariable analysis, MIAs were independently associated with female sex (p = 0.001), arterial hypertension (p = 0.023), tobacco abuse (p = 0.009), AB blood group (p = 0.010), and increased admission values for C-reactive protein (p = 0.006), mean corpuscular volume (p = 0.009), and total serum protein (p = 0.034), but not with diagnostic modality (3D vs 2D digital subtraction angiography, p = 0.912). Absolute number of IAs was independently associated with female sex (p < 0.001), arterial hypertension (p = 0.014), familial predisposition to IA (p = 0.015), tobacco consumption (p = 0.025), increased mean corpuscular volume (p = 0.002), and high platelet count (p = 0.007). In this sizable consecutive series of patients with IAs, the authors confirmed the impact of common IA risk factors on the genesis of MIAs. In addition, specific hemorheological and hemocytological features may also contribute to the development of MIAs.

Self-supervised learning enables 3D digital subtraction angiography reconstruction from ultra-sparse 2D projection views: A multicenter study

Summary3D digital subtraction angiography (DSA) reconstruction from rotational 2D projection X-ray angiography is an important basis for diagnosis and treatment of intracranial aneurysms (IAs). The gold standard requires approximately 133 different projection views for 3D reconstruction. A method to significantly reduce the radiation dosage while ensuring the reconstruction quality is yet to be developed. We propose a self-supervised learning method to realize 3D-DSA reconstruction using ultra-sparse 2D projections. 202 cases (100 from one hospital for training and testing, 102 from two other hospitals for external validation) suspected to be suffering from IAs were conducted to analyze the reconstructed images. Two radiologists scored the reconstructed images from internal and external datasets using eight projections and identified all 82 lesions with high diagnostic confidence. The radiation dosages are approximately 1/16.7 compared with the gold standard method. Our proposed method can help develop a revolutionary 3D-DSA reconstruction method for use in clinic.

Physics-Informed Neural Networks for Brain Hemodynamic Predictions Using Medical Imaging.

Determining brain hemodynamics plays a critical role in the diagnosis and treatment of various cerebrovascular diseases. In this work, we put forth a physics-informed deep learning framework that augments sparse clinical measurements with one-dimensional (1D) reduced-order model (ROM) simulations to generate physically consistent brain hemodynamic parameters with high spatiotemporal resolution. Transcranial Doppler (TCD) ultrasound is one of the most common techniques in the current clinical workflow that enables noninvasive and instantaneous evaluation of blood flow velocity within the cerebral arteries. However, it is spatially limited to only a handful of locations across the cerebrovasculature due to the constrained accessibility through the skull's acoustic windows. Our deep learning framework uses in vivo real-time TCD velocity measurements at several locations in the brain combined with baseline vessel cross-sectional areas acquired from 3D angiography images and provides high-resolution maps of velocity, area, and pressure in the entire brain vasculature. We validate the predictions of our model against in vivo velocity measurements obtained via four-dimensional (4D) flow magnetic resonance imaging (MRI) scans. We then showcase the clinical significance of this technique in diagnosing cerebral vasospasm (CVS) by successfully predicting the changes in vasospastic local vessel diameters based on corresponding sparse velocity measurements. We show this capability by generating synthetic blood flow data after cerebral vasospasm at various levels of stenosis. Here, we demonstrate that the physics-based deep learning approach can estimate and quantify the subject-specific cerebral hemodynamic variables with high accuracy despite lacking knowledge of inlet and outlet boundary conditions, which is a significant limitation for the accuracy of the conventional purely physics-based computational models.

Radiation Dose Reduction of Lens by Adjusting Table Height and Magnification Ratio in 3D Cerebral Angiography

Radiation Dose Reduction of Lens by Adjusting Table Height and Magnification Ratio in 3D Cerebral Angiography

Diagnostic performance of 3D cardiac magnetic resonance perfusion in elderly patients for the detection of coronary artery disease as compared to fractional flow reserve

ObjectivesIn patients of advanced age, the feasibility of myocardial ischemia testing might be limited by age-related comorbidities and falling compliance abilities. Therefore, we aimed to test the accuracy of 3D cardiac magnetic resonance (CMR) stress perfusion in the elderly population as compared to reference standard fractional flow reserve (FFR).MethodsFifty-six patients at age 75 years or older (mean age 79 ± 4 years, 35 male) underwent 3D CMR perfusion imaging and invasive coronary angiography with FFR in 5 centers using the same study protocol. The diagnostic accuracy of CMR was compared to a control group of 360 patients aged below 75 years (mean age 61 ± 9 years, 262 male). The percentage of myocardial ischemic burden (MIB) relative to myocardial scar burden was further analyzed using semi-automated software.ResultsSensitivity, specificity, and positive and negative predictive values of 3D perfusion CMR deemed similar for both age groups in the detection of hemodynamically relevant (FFR < 0.8) stenosis (≥ 75 years: 86%, 83%, 92%, and 75%; < 75 years: 87%, 80%, 82%, and 85%; p > 0.05 all). While MIB was larger in the elderly patients (15% ± 17% vs. 9% ± 13%), the diagnostic accuracy of 3D CMR perfusion was high in both elderly and non-elderly populations to predict pathological FFR (AUC: 0.906 and 0.866).Conclusions3D CMR perfusion has excellent diagnostic accuracy for the detection of hemodynamically relevant coronary stenosis, independent of patient age.Key Points• The increasing prevalence of coronary artery disease in elderly populations is accompanied with a larger ischemic burden of the myocardium as compared to younger individuals.• 3D cardiac magnetic resonance perfusion imaging predicts pathological fractional flow reserve in elderly patients aged ≥ 75 years with high diagnostic accuracy.• Ischemia testing with 3D CMR perfusion imaging has similarly high accuracy in the elderly as in younger patients and it might be particularly useful when other non-invasive techniques are limited by aging-related comorbidities and falling compliance abilities.

Three-Dimensional Angiographic Characteristics versus Functional Stenosis Severity in Fractional and Coronary Flow Reserve Discordance: A DEFINE FLOW Sub Study.

Background: Coronary angiography alone is insufficient to identify lesions associated with myocardial ischemia that may benefit from revascularization. Coronary physiology parameters may improve clinical decision making in addition to coronary angiography, but the association between 2D and 3D qualitative coronary angiography (QCA) and invasive pressure and flow measurements is yet to be elucidated. Methods: We associated invasive fractional flow reserve (FFR), coronary flow reserve (CFR) and coronary flow capacity (CFC) with 2D- and 3D-QCA in 430 intermediate lesions of 366 patients. Results: Overall, 2D-QCA analysis resulted in less severe stenosis severity compared with 3D-QCA analysis. FFR+/CFR− lesions had similar 3D-QCA characteristics as FFR+/CFR+ lesions. In contrast, vessels with FFR−/CFR+ discordance had 3D-QCA characteristics similar to those of vessels with concordant FFR−/CFR−. Contrarily, FFR+/CFR− lesions had CFC similar to that of as FFR-/CFR- lesions. Conclusions: Non-flow-limiting lesions (FFR+/CFR−) have 3D-QCA characteristics similar to those of FFR+/CFR+, but the majority are not associated with inducible myocardial ischemia as determined by invasive CFC. FFR−/CFR+ lesions have 3D-QCA characteristics similar to those of FFR−/CFR− lesions but are more frequently associated with a moderately to severely reduced CFC, illustrating the angiographic–functional mismatch in discordant lesions.

Development and characterization of a chick embryo chorioallantoic membrane (CAM) based platform for evaluation of vasoactive medications.

Among various anti-cancer therapies, tumor vascular disrupting agents (VDAs) play a crucial role, for which their off-targeting effects on normal vessels need also to be investigated. The purpose of this study was to set up an in-ovo platform that combines a laser speckle contrast imaging (LSCI) modality with chick embryo chorioallantoic membrane (CAM) to real-time monitor vascular diameters and perfusion without and with intravascular injection. Two eggshell windows for both observation or measurement and injection were opened. Dynamic blood perfusion images and corresponding statistic graphs were acquired by using a LSCI unit on CAMs from embryo date (ED) 9 to ED15. A dedicated fine needle catheter was made for slow intravascular administration over 30min with simultaneous LSCI acquisition. To verify the connectivity between CAM vessels and the embryonic circulations in the egg, contrast-enhanced 3D micro computed tomography (μCT), 2D angiography and histology were executed. This platform was successfully established to acquire, quantify and demonstrate vascular and hemodynamic information from the CAM. Chick embryos even with air cell opened remained alive from ED9 to ED15. Through collecting LSCI derived CAM vascular diameter and perfusion parameters, ED12 was determined as the best time window for vasoactive drug studies. A reverse correlation between CAM vessel diameter and blood perfusion rate was found (p<0.002). Intravascular infusion and simultaneous LSCI acquisition for 30min in ovo proved feasible. Contrast-enhanced angiography and histomorphology could characterize the connectivity between CAM vasculature and embryonic circulation. This LSCI-CAM platform was proved effective for investigating the in-ovo hemodynamics, which paves the road for further preclinical research on vasoactive medications including VDAs.