Angiography Reconstruction Research Articles

Angiographic reconstructions of CT perfusion for occlusion detection in ischemic stroke

BackgroundBoth CT angiography and CT perfusion involve the administration and tracking of a contrast medium bolus for different purposes. In this study, we aim to compare the diagnostic accuracy and subjective image quality of CTP-angiographic reconstructions with conventional CTA for occlusion detection in ischemic stroke patients. MethodsIn this retrospective study, patients with a final diagnosis of ischemic stroke and who underwent both CTA and CTP from September 2020 up to and including September 2021 were included. CTP-AR was reconstructed from the 1 mm CTP series at the time of maximum arterial inflow. Three readers with different levels of experience assessed both CTA and CTP for occlusion detection, expressed certainty, and rated subjective image quality. The reference standard was set at the consensus meeting. Pooled sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Differences in subjective and objective image quality and certainty were assessed using Kendall’s tau correlation and paired samples t-tests. ResultsIn total, 107/210 included patients had an occlusion based on our reference standard. Pooled sensitivity and specificity for occlusion detection were 90 % (95 %CI 85–93 %) and 94 % (95 %CI 90–97 %) for CTA, and 89 % (95 %CI 84–93 %) and 93 % (95 %CI 89–96) for CTP-AR, respectively. The pooled certainty did not significantly differ between CTA and CTP-AR (P=.43). The pooled subjective image quality scores significantly differed between CTA and CTP-AR (τ = 0.3, P < 0.001), where one reader rated subjective image quality higher in CTA and two readers in CTP-AR. ConclusionCTP-AR has comparable diagnostic accuracy to conventional CTA imaging for occlusion detection in ischemic stroke patients. Thus, using CTP-AR instead of CTA plus CTP may conserve contrast medium.

Virtual physiological analysis of non-culprit disease in patients with STEMI and multivessel disease: a substudy of the COMPLETE trial

Abstract Background In the Complete Revascularization with Multivessel PCI for Myocardial Infarction (COMPLETE) trial, patients with ST-segment-elevation myocardial infarction (MI) who underwent staged revascularization of non-culprit coronary stenoses experienced fewer major adverse cardiovascular events than those who underwent a culprit-only approach (1). Inclusion was, however, based on angiographic and not physiological criteria. Purpose To analyse, using computational modelling, the physiological significance of non-culprit lesions included in the COMPLETE trial, to compare these against angiographic measures of severity, and investigate interactions between physiology and the benefits of complete revascularization. Methods Angiograms with appropriate digital imaging and communications in medicine (DICOM) data from the COMPLETE trial (n=1327) underwent software-based 3-dimensional (3D) arterial reconstruction and analysis of 3D-quantitative coronary angiography (QCA) and virtual fractional flow reserve (vFFR) using computational fluid dynamics software. Physiological lesion significance was defined as vFFR ≤0.80 and was compared with operators’ visual angiographic analysis, core-laboratory 2D-QCA and 3D-QCA. Results vFFR was computed successfully in 635 patients (710 lesions). The median vFFR was 0.82 (interquartile range 0.73–0.91). 302 patients (48%) had at least one physiologically significant lesion and 333 (52%) had none. 321 (45%) lesions were physiologically significant and 389 (55%) were not. Physiologically significant lesions were angiographically more severe than non-significant lesions according to the operator’s visual angiographic assessment (mean stenosis 80% vs. 75%, P&amp;lt;0.0001), 2D-QCA (69% vs. 59%, p&amp;lt;0.0001), and 3D-QCA (56% vs. 43, P&amp;lt;0.0001). Percentage lesion stenosis was significantly different when measured visually, with 2D-QCA and with 3D-QCA (80% vs 62% vs 49%, P&amp;lt;0.0001). vFFR was weakly correlated with operators’ visual angiographic severity (Figure 1) and 2D-QCA, but more strongly with 3D-QCA (r=-0.21, -0.21, and -0.60, respectively; all p&amp;lt;0.0001). 3D-QCA predicted vFFR significance more accurately than visual and 2D-QCA (concordance 73% vs 49% vs 59%, respectively). There was no statistically significant interaction between physiological lesion significance and any of the trial coprimary or key secondary clinical outcomes, or on an exploratory outcome of ischaemia-driven revascularization without preceding MI (all interactions P&amp;gt;0.30) (Figure 2). Conclusions In this virtual physiological substudy of the COMPLETE trial, 52% of patients lacked any physiologically-significant lesions, 3D-QCA was a better predictor of physiological significance than either 2D-QCA or operator visual analysis, and the benefits of complete revascularization appeared to be independent of physiological lesion significance. Further research is warranted to compare angiography-guided and physiology-guided complete revascularization strategies.Figure 1.Figure 2.

A Case of A Middle-Aged Woman with Cor Triatriatum Dexter and Sick Sinus Syndrome: Comprehensive Cardiovascular Evaluation

This case study discusses a 51-year-old woman with a complex cardiovascular condition, cor triatriatum dexter, complicated by sick sinus syndrome. The patient presented with a history of bradycardia, dizziness, and amaurosis, and was admitted to the emergency department due to numbness in her right limb. Diagnostic examinations, including computed tomography (CT) and cardiac color-ultrasound screening, revealed cor triatriatum dexter along with an enlarged left atrium and ventricle. Additional findings included the absence of the inferior vena cava and polysplenic syndrome. Based on these results, double-chamber pacemaker surgery was recommended, supported by cardiac and thoracic-abdominal CT angiography and three-dimensional vascular reconstruction. This case underscores the importance of comprehensive examinations in identifying associated cardiovascular abnormalities.

Additional value of CTP maps in occlusion detection on CTP angiographic reconstructions for ischemic stroke

BackgroundCT perfusion angiographic reconstructions (CTP-AR), derived at the peak arterial inflow, have demonstrated similar diagnostic accuracy to CTA for occlusion detection in the anterior circulation. Colour-coded CTP maps may aid in localizing an occlusion. This study aim to assess the additional value of CTP maps for occlusion detection in ischemic stroke patients assessed with CTA or CTP-AR. MethodsIn this single center retrospective study, ischemic stroke patients who underwent both CTA and CTP from September 2020 up to and including September 2021 were included. The 1 mm CTP series at peak arterial inflow corresponds to the CTP-AR. Following the initial assessment of CTA and CTP-AR for occlusion detection, three readers with varying levels of experienced, reassessed the CTA and CTP-AR with access to the color-coded CTP maps. Each CTA and CTP-AR was reviewed by two readers, and certainty of assessment was recorded. The reference standard was determined through a consensus meeting. Differences in certainty were assessed using a t-test for paired samples. ResultsOut of 210 patients, 107 patients had an occlusion based on our reference standard. The addition of CTP maps resulted in the finding of 11 (2.6%) additional occlusions out of 420 CTA readings and 9 (2.1%) out of 420 CTP-AR readings, primarily involving distal occlusions. After addition of CTP maps, 7 (1.6%) initial assessments on CTA and 3 (0.7%) initial assessments on CTP-AR were deemed false positive. The overall certainty of all readers significantly (P < 0.001) increased after addition of CTP maps. ConclusionThe usage of CTP maps improved occlusion detection on both CTA and CTP-AR, especially for distal occlusions, and resulted in the increase of the overall level of certainty among readers with varying levels of experience.

Robust Ultrafast Projection Pipeline for Structural and Angiography Imaging of Fourier-Domain Optical Coherence Tomography.

The current methods to generate projections for structural and angiography imaging of Fourier-Domain optical coherence tomography (FD-OCT) are significantly slow for prediagnosis improvement, prognosis, real-time surgery guidance, treatments, and lesion boundary definition. This study introduced a robust ultrafast projection pipeline (RUPP) and aimed to develop and evaluate the efficacy of RUPP. RUPP processes raw interference signals to generate structural projections without the need for Fourier Transform. Various angiography reconstruction algorithms were utilized for efficient projections. Traditional methods were compared to RUPP using PSNR, SSIM, and processing time as evaluation metrics. The study used 22 datasets (hand skin: 9; labial mucosa: 13) from 8 volunteers, acquired with a swept-source optical coherence tomography system. RUPP significantly outperformed traditional methods in processing time, requiring only 0.040 s for structural projections, which is 27 times faster than traditional summation projections. For angiography projections, the best RUPP variation took 0.15 s, making it 7518 times faster than the windowed eigen decomposition method. However, PSNR decreased by 41-45% and SSIM saw reductions of 25-74%. RUPP demonstrated remarkable speed improvements over traditional methods, indicating its potential for real-time structural and angiography projections in FD-OCT, thereby enhancing clinical prediagnosis, prognosis, surgery guidance, and treatment efficacy.

Exoscopic Clipping of a Ruptured Posterior Communicating Artery Aneurysm Through a Minipterional Approach: 2-Dimensional Operative Video

Posterior communicating artery (PCoA) aneurysms represent approximately 15% to 25% of intracranial aneurysms and carry an estimated risk of rupture of 44%. 1-4 Surgical clipping of PCoA aneurysms bears notable challenges associated with operating in a confined space with limited visualization of deep structures. 1,5 We illustrate the case of a 54-year-old woman who presented with a seven-hour course of intense headaches, vomiting and loss of consciousness. Her neurological examination revealed she had a 4/5 left-sided hemiparesis, a Glasgow coma scale score of 12, and a Hunt and Hess score of 3. A head computed tomography scan without contrast showed subarachnoid hemorrhage in the basal cisterns and Sylvian fissures (Fisher grade 3). Digital subtraction angiography and three-dimensional reconstruction imaging revealed a right bilobed saccular PCoA aneurysm of 4.8 × 5.9 mm projecting anterior-inferiorly. After consideration of her clinical course and aneurysmal features, she underwent a right minipterional craniotomy for exoscopic clipping of the aneurysm neck. The patient tolerated the procedure well, her hemiparesis improved, and she was discharged with a modified Rankin scale score of 1 on postoperative day 3. Exoscopy offered high image quality and expanded 3-dimensional view with digital zoom during the aneurysm repair. 6,7 Although evidence suggests exoscopy is non-inferior to microscopy regarding surgery duration, safety, and outcomes, the capability of providing operator ergonomy during surgery is a worth-noting advantage. 8 IRB and patient consent declaration: This study was exempt from the Institution Review Board because patient consent was granted for the use of clinical information, images, and operative videos. The patient consented to the procedure, and the participants and any identifiable individuals consented to publication of his/her image.

Detectability of intracranial vessel wall atherosclerosis using black-blood spectral CT: a phantom and clinical study

BackgroundComputed tomography (CT) is the usual modality for diagnosing stroke, but conventional CT angiography reconstructions have limitations.MethodsA phantom with tubes of known diameters and wall thickness was scanned for wall detectability, wall thickness, and contrast-to-noise ratio (CNR) on conventional and spectral black-blood (SBB) images. The clinical study included 34 stroke patients. Diagnostic certainty and conspicuity of normal/abnormal intracranial vessels using SBB were compared to conventional. Sensitivity/specificity/accuracy of SBB and conventional were compared for plaque detectability. CNR of the wall/lumen and quantitative comparison of remodeling index, plaque burden, and eccentricity were obtained for SBB imaging and high-resolution magnetic resonance imaging (hrMRI).ResultsThe phantom study showed improved detectability of tube walls using SBB (108/108, 100% versus conventional 81/108, 75%, p < 0.001). CNRs were 75.9 ± 62.6 (mean ± standard deviation) for wall/lumen and 22.0 ± 17.1 for wall/water using SBB and 26.4 ± 15.3 and 101.6 ± 62.5 using conventional. Clinical study demonstrated (i) improved certainty and conspicuity of the vessels using SBB versus conventional (certainty, median score 3 versus 0; conspicuity, median score 3 versus 1 (p < 0.001)), (ii) improved sensitivity/specificity/accuracy of plaque (≥ 1.0 mm) detectability (0.944/0.981/0.962 versus 0.239/0.743/0.495) (p < 0.001), (iii) higher wall/lumen CNR of SBB of (78.3 ± 50.4/79.3 ± 96.7) versus hrMRI (18.9 ± 8.4/24.1 ± 14.1) (p < 0.001), and (iv) excellent reproducibility of remodeling index, plaque burden, and eccentricity using SBB versus hrMRI (intraclass correlation coefficient 0.85–0.94).ConclusionsSBB can enhance the detectability of intracranial plaques with an accuracy similar to that of hrMRI.Relevance statementThis new spectral black-blood technique for the detection and characterization of intracranial vessel atherosclerotic disease could be a time-saving and cost-effective diagnostic step for clinical stroke patients. It may also facilitate prevention strategies for atherosclerosis.Key points• Blooming artifacts can blur vessel wall morphology on conventional CT angiography.• Spectral black-blood (SBB) images are generated from material decomposition from spectral CT.• SBB images reduce blooming artifacts and noise and accurately detect small plaques.Graphical

Anatomic Study of Vascular Supply of the External Ear Using CT Angiography in Congenital Microtia.

The morphology of the arteries of the external ear on the affected side of congenital microtia differs from normal. The present study aimed to use computed tomography angiography (CTA) to describe the anatomic variations of arteries in microtia and provide theoretical guidance for the first stage of autologous auricular reconstruction by the 2-stage method. Ten patients with unilateral microtia from May 2021 to August 2021 were included. Computed tomography angiography and 3-dimensional reconstruction were used to analyze the supply and branches of the main arteries of the auricle. The number of the superficial temporal artery (STA) and posterior auricular artery (PAA) branches to the auricle, vessel diameter, and the presence or absence of the STA and PAA branches were documented. The skin flap and incision were designed combined with the anatomic of auricular arteries. The blood supply of the auricle mainly came from the STA and PAA. The STA's preauricular branch and PAA's posterior auricular branch were absent to varying degrees, and the middle branch was more prominent. The average diameter of the STA on the healthy auricle was 3.07±0.96mm, and the average diameter of the PAA was 1.72±0.50mm. The average diameter of the STA on the microtia auricle was 2.65±0.42mm, and the average diameter of the PAA was 1.53±0.67mm. There was a statistically significant difference in the diameter of STA between the healthy auricle and the microtia auricle (P=0.006). However, there was no significant difference in the diameter of the PAA between the healthy auricle and the microtia auricle (P=0.112). The skin flap and incision were designed and combined with the preoperative CTA images, and no flap necrosis was observed in all patients. The vascular distribution of arteries in microtia patients was clearly and accurately assessed by CTA. In our experience, the data and detailed imaging were useful in designing skin flaps and incisions during the first stage of autologous auricular reconstruction by the 2-stage method.

Pulmonary Arterial Anatomical Patterns: A Classification Scheme Based on Lobectomy and 3D-CTBA.

Preoperative evaluation of pulmonary vascular and tracheal routes and variations is of great importance to the surgeon. Three-dimensional computed tomography bronchography and angiography (3D-CTBA) has evolved in recent years with the optimization of 3D reconstruction techniques and artificial intelligence. We aim to apply CT angiography and Exoview 3D reconstruction technology to assess patients' pulmonary arterial tree and its anatomical variants and to try to summarize a set of anatomical typing of the pulmonary arterial tree that is relatively easy and conducive to promoting teaching based on surgical habits of lobectomy. A total of 358 patients hospitalized in the Department of Thoracic Surgery of the First Affiliated Hospital of Soochow University between July 2020 and August 2021 were included in this study. We carefully analyzed the site of emanation, alignment, and number of branches of the pulmonary artery according to a uniform classification method in conjunction with the two-dimensional CT images and transformed them into 3D reconstruction models. Different types of pulmonary artery were observed in 358 cases. We evaluated the complete pulmonary artery tree and counted the number and frequency of major arteries of the pulmonary based on the surgical habits of anatomical lobectomy. The 3D-CTBA technique enables us to adequately assess the anatomy of the pulmonary arteries. Moreover, we provide a practical classification scheme of pulmonary arterial anatomical patterns based on lobectomy and 3D-CTBA. Our data can be used by clinicians in the teaching of pulmonary artery anatomy and the preoperative preparation for anatomical lobectomy.

Giant Left Atrial Aneurysm In A Three Year Old

Background: The PA to the LA fistula is a rare cause of central cyanosis. Embryologically, incomplete degeneration of septum between the arterial and venous plexus of the pulmonary vascular bed or defective capillary loop leads to formation of thin-walled sacs resulting in formation of pulmonary arteriovenous fistula. The more restrictive the fistula is, the more subtle is the extent of cyanosis and the less evident is the clinical presentation Case Description We describe the case of three years-old patient, who presented with unresolving pneumonia, that necessitated CT imaging. CT imaging revealed a mass in the posterior mediastinum that was communicating with the left atrium. Originally it was thought that this is an aneurysmal dilation of one of the pulmonary veins, that could have resulted from mitral regurge. Echocardiography showed an aneurysmal dilation of the left atrium, with an abnormal retrograde flow across the roof of the left atrium, pulmonary hypertension and mitral regurge were excluded. 3D CT angiographic reconstruction revealed the presence of a fistulous communication between the RPA and left atrium, this explains the low normal oxygen saturations of this patient due to mixing (90-92%) and the high hemoglobin concentration (160) due to chronic subclinical hypoxia. Conclusion and learning points Aneurysmal dilation of left atrium is commonly encountered with severe mitral regurge, rare causes such as PA to LA fistulae should be thought of especially if clinical or subclinical hypoxia or polycythemia is present.

Clinical Impact and Determinants of Fenestration to Target Vessel Misalignment in Fenestrated Endovascular Aortic Repair

This single centre, retrospective study (2014 - 2022) on juxta-, pararenal, or thoraco-abdominal aortic aneurysms treated by fenestrated endovascular aortic repair (FEVAR) was conducted to investigate the clinical impact and determinants of fenestration to target vessel misalignment in FEVAR. Pre-operative supracoeliac, pararenal, and infrarenal aortic angles were measured on three dimensional computed tomography angiography (CTA) reconstructions. Two components of misalignment were measured on the first post-operative CTA: horizontal misalignment (angle between the fenestration and the target vessel ostium on perpendicular CTA cuts) and vertical misalignment (vertical distance between the fenestration and the target vessel at its origin). Endpoints were freedom from target vessel instability (TVI) and alignment change over time. Of 65 patients treated by FEVAR, 60 (202 target arteries) with juxta-, pararenal (80%), or thoraco-abdominal aortic aneurysm (20%) were included. Mean horizontal misalignment was 9 ± 12° (median 5°; IQR 0 - 16) and mean vertical misalignment was 0.7 ± 1 mm (median 0 mm, IQR 0 - 1). Freedom from TVI was 92% (95% CI 88 - 98) at 36 months. Horizontal misalignment > 15° was significantly associated with TVI (HR 5.19; 95% CI 1.54 - 17.48; p=.008); vertical misalignment did not significantly impact TVI (HR 0.99; 95% CI 0.56 - 1.73; p= .97). By multivariable analysis, pararenal aortic angle (OR 1.01 per increased degree of angulation; 95% CI 1.00 - 1.02; p= .044), bridging distance > 5 mm (OR 1.07; 95% CI 1.02 - 1.11; p= .003), and use of higher profile endografts in tortuous iliac access (OR 7.55; 95% CI 4.55 - 1.11; p= .003) were associated with clinically significant misalignment. Bridging distance > 5 mm (OR 2.00; 95% CI 1.02 - 11.29; p= .044), degree of baseline misalignment (OR 1.04; 95% CI 1.01 - 1.08; p= .036), and persistence of any primary endoleak for > 6 months (OR 5.85; 95% CI 1.23 - 29.1; p= .023) were associated with misalignment increase during follow up. Horizontal misalignment > 15° is associated with worsened target vessel outcomes. This may occur as a result of excessive iliac access tortuosity, high pararenal aortic angulation, and bridging distance > 5 mm.

Fast optical coherence tomography angiography image acquisition and reconstruction pipeline for skin application.

Traditional high-quality OCTA images require multi-repeated scans (e.g., 4-8 repeats) in the same position, which may cause the patient to be uncomfortable. We propose a deep-learning-based pipeline that can extract high-quality OCTA images from only two-repeat OCT scans. The performance of the proposed image reconstruction U-Net (IRU-Net) outperforms the state-of-the-art UNet vision transformer and UNet in OCTA image reconstruction from a two-repeat OCT signal. The results demonstrated a mean peak-signal-to-noise ratio increased from 15.7 to 24.2; the mean structural similarity index measure improved from 0.28 to 0.59, while the OCT data acquisition time was reduced from 21 seconds to 3.5 seconds (reduced by 83%).

A hand-held optical coherence tomography angiography scanner based on angiography reconstruction transformer networks.

Optical coherence tomography angiography (OCTA) has successfully demonstrated its viability for clinical applications in dermatology. Due to the high optical scattering property of skin, extracting high-quality OCTA images from skin tissues requires at least six-repeated scans. While the motion artifacts from the patient and the free hand-held probe can lead to a low-quality OCTA image. Our deep-learning-based scan pipeline enables fast and high-quality OCTA imaging with 0.3-s data acquisition. We utilize a fast scanning protocol with a 60 μm/pixel spatial interval rate and introduce angiography-reconstruction-transformer (ART) for 4× super-resolution of low transverse resolution OCTA images. The ART outperforms state-of-the-art networks in OCTA image super-resolution and provides a lighter network size. ART can restore microvessels while reducing the processing time by 85%, and maintaining improvements in structural similarity and peak-signal-to-noise ratio. This study represents that ART can achieve fast and flexible skin OCTA imaging while maintaining image quality.

Analysis of pulmonary artery variation based on 3D reconstruction of CT angiography.

Objective: The aim of this study is to acquire pulmonary CT (Computed tomography) angiographic data for the purpose of creating a three-dimensional reconstruction. Additionally, we aim to analyze the features and deviations of the branches in both pulmonary lobes. This information is intended to serve as a more comprehensive and detailed reference for medical professionals when conducting preoperative evaluations and devising surgical plans. Method: Between August 2019 and December 2021, 420 patients were selected from the thoracic surgery department at the First Hospital of Jilin University, and underwent pulmonary 64 channel contrast enhanced CT examinations (Philips ICT 256). The images were acquired at a 1.5mm slice thickness, and the DCM files that complied with DICOM (Digital Imaging and Communications in Medicine) standards were analysed for 3D (three dimensional) reconstruction using Mimics 22.0 software. The reconstructed pulmonary artery models were assessed by attending chest surgeons and radiologists with over 10years of clinical experience. The two-dimensional image planes, as well as the coronary and sagittal planes, were utilized to evaluate the arteries. The study analyzed the characteristics and variations of the branches and courses of pulmonary arteries in each lobe of the lungs, with the exception of the subsegmental arterial system. Two chest surgeons and two radiologists with professional titles-all of whom had over a decade of clinical experience-jointly evaluated the 3D models of the pulmonary artery and similarly assessed the characteristics and variations of the branches and courses in each lobe of the lungs. Results: Significant variations were observed in the left superior pulmonary artery across the 420 subjects studied. In the left upper lobe, the blood supply of 4 arteries accounted for 50.5% (n = 212), while the blood supply of 2 arteries in the left lower lobe was the most common, accounting for 79.5% (n = 334). The greatest variation in the right pulmonary artery was observed in the branch supply of the right upper lobe mediastinal artery. In the majority of cases (77.9%), there were two arteries present, which was the most common configuration observed accounting for 64% (n = 269). In the right inferior lobe of the lung, there were typically 2-4 arteries, with 2 arteries being the most common configuration (observed in 79% of cases, n = 332). Conclusion: The three-dimensional reconstruction of pulmonary artery CT angiography enables clear observation of the branches and distribution of the pulmonary artery while also highlighting any variations. This technique holds significant clinical value for preoperative assessments regarding lesions and blood vessels.

Motion estimation based on projective information disentanglement for 3D reconstruction of rotational coronary angiography

The 2D projection space-based motion compensation reconstruction (2D-MCR) is a kind of representative method for 3D reconstruction of rotational coronary angiography owing to its high efficiency. However, due to the lack of accurate motion estimation of the overlapping projection pixels, existing 2D-MCR methods may still have a certain level of under-sampling artifacts or lose accuracy for cases with strong cardiac motion. To overcome this, in this study, we proposed a motion estimation approach based on projective information disentanglement (PID-ME) for 3D reconstruction of rotational coronary angiography. The reconstruction method adopts the framework of 2D-MCR, which is referred to as 2D-PID-MCR. The PID-ME consists of two parts: generation of the reference projection sequence based on the fast simplified distance driven projector (FSDDP) algorithm, motion estimation and correction based on the projective average minimal distance measure (PAMD) model. The FSDDP algorithm generates the reference projection sequence faster and accelerates the whole reconstruction greatly. The PAMD model can disentangle the projection information effectively and estimate the motion of both overlapping and non-overlapping projection pixels accurately. The main contribution of this study is the construction of 2D-PID-MCR to overcome the inherent limitations of the existing 2D-MCR method. Simulated and clinical experiments show that the PID-ME, consisting of FSDDP and PAMD, can estimate the motion of the projection sequence data accurately and efficiently. Our 2D-PID-MCR method outperforms the state-of-the-art approaches in terms of accuracy and real-time performance.

Dynamic assessment of the left main-left circumflex bending angle: Implications for ostial left circumflex artery in-stent restenosis after successful two-stent PCI

BackgroundTwo-stent techniques for percutaneous coronary intervention (PCI) on left main (LM) bifurcation (LMB) lesions are associated with an increased risk of in-stent restenosis (ISR) at left circumflex artery (LCx) ostium but the underlying mechanisms are incompletely understood. This study sought to investigate the association between cyclic change of LM-LCx bending angle (BALM-LCx) and the risk of ostial LCx ISR following two-stent techniques. MethodsIn a retrospective cohort of patients undergoing two-stent PCI for LMB lesions, BALM-LCx and distal bifurcation angle (DBA) were computed with 3-dimensional angiographic reconstruction. The analysis was performed both at end-diastole and end-systole, and the angulation change throughout the cardiac cycle was defined as the cardiac motion-induced angulation change (∆CAngle). ResultsA total of 101 patients were included. The mean pre-procedural BALM-LCx was 66.8 ± 16.1° at end-diastole and 54.1 ± 13.3° at end-systole with a range of 13.0 ± 7.7°. Pre-procedural ∆CBALM-LCx > 16.4° was the most relevant predictor of ostial LCx ISR (adjusted OR 11.58, 95% CI 4.04–33.19; p < 0.001). Post-procedural ∆CBALM-LCx > 9.8° and stent-induced diastolic BALM-LCx change > 11.6° were also related with ostial LCx ISR. DBA was positively correlated with BALM-LCx and showed a weaker association of pre-procedural ∆CDBA > 14.5° with ostial LCx ISR (adjusted OR 6.87, 95% CI 2.57–18.37; p < 0.001). ConclusionsThree-dimensional angiographic bending angle is a feasible and reproducible novel method for LMB angulation measurement. A large pre-procedural cyclic change of BALM-LCx was associated with an increased risk of ostial LCx ISR following two-stent techniques.

Multiple Adversarial Learning Based Angiography Reconstruction for Ultra-Low-Dose Contrast Medium CT.

Iodinated contrast medium (ICM) dose reduction is beneficial for decreasing potential health risk to renal-insufficiency patients in CT scanning. Due to the low-intensity vessel in ultra-low-dose-ICM CT angiography, it cannot provide clinical diagnosis of vascular diseases. Angiography reconstruction for ultra-low-dose-ICM CT can enhance vascular intensity for directly vascular diseases diagnosis. However, the angiography reconstruction is challenging since patient individual differences and vascular disease diversity. In this paper, we propose a Multiple Adversarial Learning based Angiography Reconstruction (i.e., MALAR) framework to enhance vascular intensity. Specifically, a bilateral learning mechanism is developed for mapping a relationship between source and target domains rather than the image-to-image mapping. Then, a dual correlation constraint is introduced to characterize both distribution uniformity from across-domain features and sample inconsistency within domain simultaneously. Finally, an adaptive fusion module by combining multi-scale information and long-range interactive dependency is explored to alleviate the interference of high-noise metal. Experiments are performed on CT sequences with different ICM doses. Quantitative results based on multiple metrics demonstrate the effectiveness of our MALAR on angiography reconstruction. Qualitative assessments by radiographers confirm the potential of our MALAR for the clinical diagnosis of vascular diseases.

Better specificity and less ischemia: three-dimensional reconstruction is superior to routine computed tomography angiography in navigation of super-selective clamping robot-assisted laparoscopic partial nephrectomy.

Available technologies could be used to guide surgeons in controlling highly selective tumor-bearing arteries robot-assisted laparoscopic partial nephrectomy (RALPN). Patients undergoing RALPN (from September 2018 to January 2020) for intermediate-high complex renal tumor (R.E.N.A.L. score ≥7) who underwent abdominal computed tomography (CT) scan with angiography and hyper-accuracy 3-dimensional reconstruction (H3DR). All patients underwent high-resolution CT scan with angiography and H3DR with special software, based on which two kinds of highly selective arterial clamp protocols were made for each patient and analyzed independently by two urologists and two radiologists to confirm which renal arterial branch was supplying the tumor. We chose the optimized clamping protocol with the principle of the minimized ischemic regions. During the operation, meticulous microdissection and clip ligation of the specific vascular branch was guided by optimized protocol [H3DR or computed tomography angiography (CTA) reconstruction], according to the in vivo anatomy (identified by intraoperative ultrasound). Of 82 patients, the minimum-ischemic regions planning completed rate (MIRPCR) of preoperative planning with H3DR (90.2%) was higher than that with CTA (34.1%) (P<0.01). H3DR identified 78 high-order arteries (70.3%), whereas CTA identified 33 (29.7%) high-order arteries (P<0.001). H3DR detected a more optimal blocking option in 51 cases that were either missed (n=13) or misclassified by CTA (n=38). A total of 18 cases (56.3%) were converted to H3DR-guided occurred in CTA-guided surgery [5 (10.0%) occurred in group H3DR to CTA, P<0.01]. Moreover, in the CTA-guided group, the separation of renal hilum was avoided in 14 of 19 (73.7%) cases, whereas in the H3DR-guided group, it was avoided in 60 of 63 (95.3%) cases. For patients undergoing RALPN, H3DR-guided surgery compared with standard CTA-guided surgery has higher accuracy and feasibility in controlling arterial branches supplying the tumor and intraoperative surgical navigation. Additionally, it reduces the ischemic lesion area and simplifies vascular isolation steps, thus decreasing procedural difficulty.

Temporal averaging angiographic reconstructions from whole-brain CT perfusion for the detection of vasospasm

PurposeThe aim of this study is to evaluate the image quality and diagnostic performance of angiographic images reconstructed from whole-brain CT perfusion (CTP) using temporal averaging compared to CT angiography (CTA) for the detection of vasospasm. Materials and methods39 CT studies in 28 consecutive patients who underwent brain CTA with CTP for suspected vasospasm between September 2020 and May 2021 were retrospectively evaluated. The image quality of these two vascular imaging techniques was assessed either quantitatively (image noise, vascular enhancement, signal-to-noise (SNR) and contrast-to-noise (CNR) ratios,) and qualitatively (4 criteria assessed on a 5-point scale).Intra and interobserver agreements and a diagnostic confidence score on the diagnosis of vasospasm were measured. Radiation dose parameters (volume CT dose index (CTDIvol) and dose-length product (DLP)) were recorded. ResultsBoth SNR and CNR were significantly higher with temporal averaging compared to CTA, increasing by 104% and 113%, respectively (p<0.001).The qualitative assessment found no significant difference in overall image quality between temporal averaging (4.33 ± 0.48) and brain CTA (4.19 ± 0.52) (p = 0.12).There was a significant improvement in intravascular noise and arterial contrast enhancement with temporal averaging.The evaluation of intra and interobserver agreements showed a robust concordance in the diagnosis of vasospasm between the two techniques. ConclusionsTemporal averaging appeared as a feasible and reliable imaging technique for the detection of vasospasm. The use of temporal averaging, replacing brain CTA, could represent a new strategy of radiation and contrast material doses reduction in these patients.

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.