Drug-coated balloon angioplasty versus drug-eluting stent implantation in ACS patients with different angiographic patterns of in-stent restenosis.

BACKGROUND: Drug-coated balloon (DCB) angioplasty and drug-eluting stents (DES) are two widely used treatments for in-stent restenosis (ISR). Focal and non-focal types of ISR affect the clinical outcomes. The present study aims to compare DES reimplantation versus DCB angioplasty in acute coronary syndrome (ACS) patients with focal ISR and non-focal ISR lesions. METHODS: Patients with ISR lesions underwent percutaneous coronary intervention (PCI) were retrospectively evaluated and divided into DES group and DCB group. The primary endpoint was the incidence of target lesion failure (TLF) at 24 months follow up. Propensity score matching (PSM) was conducted to balance the baseline characteristics. RESULTS: For focal ISR, TLF was comparable in the DES and DCB groups at 24 months of follow-up (Before PSM, hazard ratio [HR]: 0.70; 95% confidence interval [CI]: 0.39-1.27; p = 0.244; After PSM, HR: 0.83; 95% CI: 0.40-1.73; p = 0.625). For non-focal ISR, TLF was significantly decreased in DES compared with DCB group (Before PSM, HR: 0.43; 95% CI: 0.29-0.63; p < 0.001; After PSM, HR: 0.33; 95% CI: 0.19-0.59; p < 0.001), which was mainly attributed to the lower incidence of clinically indicated target lesion revascularization (CD-TLR) (Before PSM, HR: 0.39; 95% CI: 0.26-0.59; p < 0.001; After PSM, HR: 0.28; 95% CI: 0.15-0.54; p < 0.001). CONCLUSIONS: The clinical outcomes for DES and DCB treatment are similar in focal type of ISR lesions. For non-focal ISR, the treatment of DES showed a significant decrease in TLF which was mainly attributed to a lower incidence of CD-TLR.

Arteriovenous Fistula Caused by Ruptured Abdominal Aortoiliac Aneurysm.

Teaching point: A ruptured aorto-iliac aneurysm, complicated by an iliac arteriovenous fistula, is rare but has a possibly fatal outcome and requires prompt diagnosis and appropriate treatment.

Intravoxel incoherent motion and enhanced T2*-weighted angiography for preoperative prediction of microvascular invasion in hepatocellular carcinoma.

Objective: To investigate the value of the combined application of intravoxel incoherent motion (IVIM) and enhanced T2*-weighted angiography (ESWAN) for preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC). Materials and methods: 76 patients with pathologically confirmed HCC were retrospectively enrolled and divided into the MVI-positive group (n=26) and MVI-negative group (n=50). Conventional MRI, IVIM, and ESWAN sequences were performed. Three region of interests (ROIs) were placed on the maximum axial slice of the lesion on D, D*, and f maps derived from IVIM sequence, and R2* map derived from ESWAN sequence, and intratumoral susceptibility signal (ITSS) from the phase map derived from ESWAN sequence was also automatically measured. Receiver operating characteristic (ROC) curves were drawn to evaluate the ability for predicting MVI. Univariate and multivariate logistic regression were used to screen independent risk predictors in clinical and imaging information. The Delong's test was used to compare the differences between the area under curves (AUCs). Results: The D and D* values of MVI-negative group were significantly higher than those of MVI-positive group (P=0.038, and P=0.023), which in MVI-negative group were 0.892×10-3 (0.760×10-3, 1.303×10-3) mm2/s and 0.055 (0.025, 0.100) mm2/s, and in MVI-positive group were 0.591×10-3 (0.372×10-3, 0.824×10-3) mm2/s and 0.028 (0.006, 0.050)mm2/s, respectively. The R2* and ITSS values of MVI-negative group were significantly lower than those of MVI-positive group (P=0.034, and P=0.005), which in MVI-negative group were 29.290 (23.117, 35.228) Hz and 0.146 (0.086, 0.236), and in MVI-positive group were 43.696 (34.914, 58.083) Hz and 0.199 (0.155, 0.245), respectively. After univariate and multivariate analyses, only AFP (odds ratio, 0.183; 95% CI, 0.041-0.823; P = 0.027) was the independent risk factor for predicting the status of MVI. The AUCs of AFP, D, D*, R2*, and ITSS for prediction of MVI were 0.652, 0.739, 0.707, 0.798, and 0.657, respectively. The AUCs of IVIM (D+D*), ESWAN (R2*+ITSS), and combination (D+D*+R2*+ITSS) for predicting MVI were 0.772, 0.800, and, 0.855, respectively. When IVIM combined with ESWAN, the performance was improved with a sensitivity of 73.1% and a specificity of 92.0% (cut-off value: 0.502) and the AUC was significantly higher than AFP (P=0.001), D (P=0.038), D* (P=0.023), R2* (P=0.034), and ITSS (P=0.005). Conclusion: The IVIM and ESWAN parameters showed good efficacy in prediction of MVI in patients with HCC. The combination of IVIM and ESWAN may be useful for noninvasive prediction of MVI before clinical operation.

Pretrained subtraction and segmentation model for coronary angiograms.

This study introduces a novel self-supervised learning method for single-frame subtraction and vessel segmentation in coronary angiography, addressing the scarcity of annotated medical samples in AI applications. We pretrain a U-Net model on a large dataset of unannotated coronary angiograms using an image-to-image translation framework, then fine-tune it on a limited set of manually annotated samples. The pretrained model excels at comprehensive single-frame subtraction, outperforming existing DSA methods. Fine-tuning with just 40 samples yields a Dice coefficient of 0.828 for vessel segmentation. On the public XCAD dataset, our model sets a new state-of-the-art benchmark with a Dice coefficient of 0.755, surpassing both unsupervised and supervised learning approaches. This method achieves robust single-frame subtraction and demonstrates that combining pretraining with minimal fine-tuning enables accurate coronary vessel segmentation with limited manual annotations. We successfully apply this approach to assist physicians in visualizing potential vascular stenosis sites during coronary angiography. Code, dataset, and a live demo will be available available at: https://github.com/newfyu/DeepSA .

Prevention and treatment of coronary catheter kinking.

Coronary catheter kinking is an uncommon but potentially catastrophic complication of cardiac catheterization. Although simple maneuvers can often result in resolution of a kink, tighter knots may not respond to such measures. We provide a systematic, stepwise approach to the prevention and treatment of catheter kinking.

Association of outer retinal and choroidal alterations with neuroimaging and clinical features in posterior cortical atrophy.

BACKGROUND: Posterior cortical atrophy (PCA) is a rare condition characterized by early-onset and progressive visual impairment. Individuals with PCA have relatively early-onset and progressive dementia, posing certain needs for early detection. Hence, this study aimed to investigate the association of alterations in outer retinal and choroidal structure and microvasculature with PCA neuroimaging and clinical features and the possible effects of apolipoprotein E(APOE) ε4 allele on outer retinal and choroidal alterations in participants with PCA, to detect potential ocular biomarkers for PCA screening. METHODS: This cross-sectional study included PCA and age- and sex-matched healthy control participants from June 2022 to December 2023. All participants with PCA completed a comprehensive neurological evaluation. All participants were recorded baseline information and underwent an ophthalmic evaluation. Quantitative analyses were performed using swept-source optical coherence tomography (SS-OCT) and angiography (SS-OCTA). Adaptive optics scanning laser ophthalmoscopy (AO-SLO) was performed in some patients. In participants with PCA, the influence of APOE ε4 on outer retinal and choroidal alterations and the correlation of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA were investigated. RESULTS: A total of 28 participants (53 eyes) with PCA and 56 healthy control participants (112 eyes) were included in the current study. Compared with healthy control participants, participants with PCA had significantly reduced outer retinal thickness (ORT) (p < 0.001), choriocapillaris vessel density (VD) (p = 0.007), choroidal vascular index (CVI) (p = 0.005) and choroidal vascular volume (CVV) (p = 0.003). In participants with PCA, APOE ε4 carriers showed thinner ORT (p = 0.009), and increased choriocapillaris VD (p = 0.004) and CVI (p = 0.004). The PCA neuroimaging features were positively associated with the ORT, CVI and CVV. Furthermore, differential correlations were observed of PCA clinical features with the CRT, CVV and CVI. CONCLUSIONS: Our findings highlighted the association of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA. Noninvasive SS-OCT and SS-OCTA can provide potential biomarkers for the diagnosis and management of PCA, improving awareness of PCA syndrome among ophthalmologists, neurologists, and primary care providers.

Characterization of Retinal Microvascular Abnormalities in Birdshot Chorioretinopathy Using OCT Angiography.

Objective: To characterize changes in the retinal microvasculature in eyes with birdshot chorioretinopathy (BCR) using OCT angiography (OCTA). Design: Retrospective, observational, single center. Subjects: Twenty-eight patients (53 eyes) with BCR and 59 age-matched controls (110 eyes). Methods: En face OCTA images of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) of each eye were assessed for the presence of microvascular abnormalities and used to measure the vessel and foveal avascular zone (FAZ) areas. A longitudinal analysis was performed with a representative cohort of 23 BCR eyes (16 patients) at baseline and at a 2-year time point. Main Outcome Measures: Whole-image vessel density (VD, %), extrafoveal avascular zone (extra-FAZ) VD (%), and FAZ area (%) were calculated and compared between control and BCR eyes. The frequency of microvascular abnormalities in BCR eyes was recorded. Results: In the SCP, increased intercapillary space and capillary loops were common features present on OCTA images. Whole-image and extra-FAZ VD were lower in the BCR group compared with controls (P < 0.0001 [SCP and DCP]). Foveal avascular zone area was enlarged in BCR eyes (P = 0.0008 [DCP]). Worsening best-corrected visual acuity was associated with a decrease in whole-image and extra-FAZ VD in the SCP (P < 0.0001 for both) and the DCP (P < 0.005 for both). Multivariable analysis, with vessel analysis parameters as outcomes, demonstrated that increasing age, increasing disease duration, lower central subfield thickness, and treatment-naive eyes (compared with those on only biologics) were associated with a significant decrease in both DCP whole-image and extra-FAZ VD. Increasing disease duration was associated with a significant decrease in both SCP whole-image and extra-FAZ VD. Longitudinal analysis demonstrated no significant difference in any vessel analysis parameters except for an increase in DCP FAZ area. Conclusions: Our results demonstrate a significant a decrease in VD in BCR eyes and an association on multivariable analysis with disease duration. Quantifying VD in the retinal microvasculature may be a useful biomarker for monitoring disease severity and progression in patients with BCR. Further studies with extended longitudinal follow-up are needed to characterize its utility in monitoring disease progression and treatment response. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Audit and quality assessment of national persian registry of cardiovascular disease(N-PROVE) in terms of comorbidities, angiography, and angioplasty characteristics in Iran.

BACKGROUND: The National Persian Registry of Cardiovascular Disease (N-PROVE) has been established to provide a comprehensive database of cardiovascular diseases in the Iranian community for further investigations and to develop national guidelines for the diagnosis, treatment, and prevention of cardiovascular disease (CVD). As with most clinical registries, a quality control audit is necessary to ensure a comprehensive and accurate registry; the current study aims to assess the validity and quality of the N-PROVE/Angiography/Percutaneous Coronary Intervention (PCI) registry. METHODS: The current cross-sectional quality assessment study serves as an example of data quality assessment in N-PROVE on a sample of patients registered in the N-PROVE/Angiography/PCI registry since 2020. Accordingly, data of 194 patients, including comorbidities, angiography, and angioplasty characteristics, were collected from the N-PROVE/Angiography/PCI registry as the main database and reevaluated by a panel consisting of a cardiologist and two coronary intervention fellowships as a test database. RESULTS: The quality control of the population-based healthcare database, the N-PROVE/PCI, revealed that the average error rate in terms of comorbidities, angiography characteristics, angioplasty characteristics, and in total were 3.8%, 2.3%, 3%, and 3.03%, respectively. CONCLUSION: According to the findings of this study, the N-PROVE/PCI registry had an average error of less than 4% in the assessed dimensions, including comorbidities, angiography, and angioplasty characteristics. Therefore, this registry appears valid and may be used for contemporary epidemiological studies.

[Diagnostic capabilities of spinal MR-angiography and spinal MR-tractography in Foix-Alajouanine syndrome]. / Diagnosticheskie vozmozhnosti spinal'noi MR-angiografii i spinal'noi MR-traktografii pri sindrome Fua­Alazhuanina.

The Foix-Alajouanine syndrome was originally reported by these authors in 1926, as rapidly progressive vasculitis on the background of a viral infection. The pathology was represented by the huge, more than 10 times, dilation either of the lumen, or the walls of the spinal vessels, either of the arteries, or the veins. There were no signs of thrombosis, no malformations. Massive necrosis was observed in the spinal cord. Though plenty of observations of the syndrome were reported over the past 100 years, most of them deal with arteriovenous malformations and/or thrombosis, which had not been revealed originally. We present the case of spinal viral vasculitis detected by means of spinal MR-angiography. The undoubted viral etiology of vasculitis allows us to attribute this observation to Foix-Alajouanine syndrome.

Carbon dioxide angiography during angioembolization for trauma patients increases the detection of active bleeding and leads to reliable hemostasis: a retrospective, observational study.

BACKGROUND: Angiography with carbon dioxide (CO2) has long been used as an alternative when iodine contrast media (ICM) cannot be used due to allergy to iodine or renal dysfunction. Conversely, CO2 angiography is also known as a provocation method for active bleeding. In this study, we examined the efficacy of CO2 angiography in angioembolization (AE) for trauma patients. METHODS: This was a single-center, retrospective, observational study of trauma patients who underwent AE at our facility between January 2012 and April 2023. RESULTS: Within this period, 335 AEs were performed. CO2 angiography was performed in 102 patients (30.4%), and in 113 procedures. CO2angiography was used to provoke active bleeding which went undetected using ICM in 83 procedures, and to confirm hemostasis after embolization in 30 procedures. Of the 80 procedures wherein, active bleeding was not detected on ICM, 35 procedures (43.8%) were detected using CO2. The spleen had the highest detection rate of active bleeding by CO2 angiography among the organs. There were 4/102 (1.9%) patients with CO2 contrast who underwent some form of reintervention. Two patients were re-embolized with n-butyl-2-cyanoacrylate because of recanalization after embolization with gelatin sponge. The other two patients had pseudoaneurysm formation which required reintervention, and CO2 angiography was not used. Vomiting was the most common complication of CO2 angiography in 10 patients (9.8%), whereas all were transient and did not require treatment. CONCLUSIONS: CO2 angiography of trauma patients may have a better detection rate of active bleeding compared with ICM, leading to reliable hemostasis.

Retinal microvascular changes in patients with pancreatitis and their clinical significance.

Acute pancreatitis, a common exocrine inflammatory disease affecting the pancreas, is characterized by intense abdominal pain and multiple organ dysfunction. However, the alterations in retinal blood vessels among individuals with acute pancreatitis remain poorly understood. This study employed optical coherence tomography angiography (OCTA) to examine the superficial and deep retinal blood vessels in patients with pancreatitis. Sixteen patients diagnosed with pancreatitis (32 eyes) and 16 healthy controls (32 eyes) were recruited from the First Affiliated Hospital of Nanchang University for participation in the study. Various ophthalmic parameters, such as visual acuity, intraocular pressure, and OCTA image for retina consisting of the superficial retinal layer (SRL) and the deep retinal layer (DRL), were recorded for each eye. The study observed the superficial and deep retinal microvascular ring (MIR), macrovascular ring (MAR), and total microvessels (TMI) were observed. Changes in retinal vascular density in the macula through annular partitioning (C1-C6), hemispheric quadrant partitioning (SR, SL, IL, and IR), and early diabetic retinopathy treatment studies (ETDRS) partitioning methods (R, S, L, and I). Correlation analysis was employed to investigate the relationship between retinal capillary density and clinical indicators. Our study revealed that in the superficial retinal layer, the vascular density of TMI, MIR, MAR, SR, IR, S, C2, C3 regions were significantly decreased in patients group compared with the normal group. For the deep retinal layer, the vascular density of MIR, SR, S, C1, C2 regions also reduced in patient group. The ROC analysis demonstrated that OCTA possesses significant diagnostic performance for pancreatitis. In conclusion, patients with pancreatitis may have retinal microvascular dysfunction, and OCTA can be a valuable tool for detecting alterations in ocular microcirculation in pancreatitis patients in clinical practice.

Saphenous Vein Graft Pseudoaneurysm Treated With Covered Stenting.

Saphenous vein graft (SVG) pseudoaneurysms are an infrequent, but life-threatening complication of coronary artery bypass grafting (CABG) surgery if left untreated. Here, we discuss the case of a 77-year-old patient, with a prior history of CABG and transcatheter aortic valve implantation (TAVI), who was incidentally found on computed tomography angiography (CTA) to have a pseudoaneurysm of his SVG with an initial chief complaint of dizziness. Despite increasing reports of SVG pseudoaneurysm, there is no consensus on definitive treatment. Due to the high mortality risk of this patient with surgical intervention, a minimally invasive percutaneous coronary intervention was performed. The patient was effectively treated with two overlapping Viabahn-covered stents, which completely excluded the pseudoaneurysm. Follow-up imaging at two months showed two well-positioned overlapping self-expanding stents with total occlusion of the pseudoaneurysm.

Lower Back Pain Beyond Routine Causes: Sacral Spinal Epidural Arteriovenous Fistula (SEDAVF).

Lower back pain (LBP) is a frequent complaint, even among young people. The most common cause is attributed to slipped discs or vertebral fractures. Less common etiologies should also be considered when presenting with typical symptoms of severe backache. Here, we are presenting one such uncommon case. A 32-year-old man with a history of meningocele repair in neonates presented with severe backache, urinary retention, and constipation in an emergency. Initially, the patient was treated elsewhere, but symptoms persisted. A contrast-enhanced MRI done in the emergency revealed a rare sacral spinal epidural arteriovenous fistula (SEDAVF) with cord congestion. The patient was taken up for digital subtraction angiography, which confirmed the diagnosis, and was treated successfully with endovascular embolization. This case highlights the complex presentation of SEDAVF and the importance of prompt diagnosis and intervention.

Efficacy and safety of a new torque-controlled angiographic catheter in cerebral angiography: A multicenter, randomized, open-label trial.

Objective: We aimed to examine the effectiveness and safety of a novel torque-controlled catheter for cerebral angiography. Methods: A total of 417 patients who underwent routine transfemoral cerebral angiography were enrolled in a randomized controlled study to compare the new torque-controlled and control group catheters. Device success was assessed on parameters such as the assessment of the common carotid artery, device rotation force, and success rate with the crossover group after the failed procedure. Four neurointerventionalists investigated the degree of satisfaction of using the new device. Superiority and non-inferiority tests of satisfaction scores were estimated for the new torque-controlled and the control group catheters. Results: The new torque-controlled catheter showed improved performance in terms of technical device success (92.79 vs. 98.09 %, P = 0.010), crossover after technical device failure (0 vs. 86.67 %, P = 0.004), and common carotid artery access (92.79 vs. 98.56 %, P = 0.004). The flexibility and rotational force of the new torque-controlled catheter were higher than those of the control group catheters (75.48 vs. 100 %, P < 0.001). No marked adverse cerebrovascular accidents or vessel damage occurred in either group during the procedure. The differences between the two groups in terms of the device rotational force and operator satisfaction were 1.836 (1.765-1.907) and 2.092 (2.000-2.183), respectively. The new torque-controlled catheter showed superior device rotational force satisfaction, operator satisfaction, and manufacturer satisfaction, with statistical significance. Conclusion: The new torque-controlled catheter was effective, safe, and convenient compared to the control group catheters for diagnostic cerebrovascular angiography.

Interobserver Variability of Coronary Stenosis Characterized by Coronary Angiography: A Single-Center (Toronto General Hospital) Retrospective Chart Review by Staff Cardiologists.

Introduction: The reliability of interpretation of coronary angiography as a diagnostic tool was investigated. Furthermore, the impact of interobserver variability of coronary lesions on clinical decision-making was assessed. One of our motivations to do this research was the research gaps and our aim to have up-to-date information regarding interobserver variability among different cardiologists. Methods: Our objective was to quantify interobserver variability among cardiologists who have seen angiograms independently. Disagreement among cardiologists in the visual assessment of invasive coronary angiography of coronary artery stenosis is not uncommon in previous studies. Three cardiologists with extensive experience in coronary angiography, including the primary cardiologist of each patient, read the angiograms of 200 patients from Toronto General Hospital independently. Results: Our research showed the mean agreement among all participating observers was 77.4%; therefore, the interobserver variability of coronary angiography interpretation was 22.6%. Discussion: Coronary angiography is still the gold-standard technique for guidance regarding coronary lesions. Sometimes, coronary angiography results in underestimation or overestimation of a lesion's functional severity. Interobserver variability should also be considered when interpreting the severity of coronary stenoses via invasive coronary angiography. This research shows that interobserver variability regarding coronary angiograms is still present (22.6%).

Plain language summary: The gold-standard method for diagnosing coronary stenosis, invasive coronary angiography has some challenges too. One of these challenges has been the difference among various cardiologists regarding determination of severity of each coronary stenosis. In this study, we focused on differences in interobserver variability in coronary angiography interpretation. Three cardiologists who were experienced in coronary angiography read each patient's coronary angiogram separately. Overall, 200 patients with a history of angiography at Toronto General Hospital were selected randomly. The research showed that overall agreement among all participating cardiologists with regard to the reading of coronary angiograms was 77.4%. In other words, interobserver variability of 22.6% was seen among the readers.

Multifocal Mycotic Aneurysms and Pseudoaneurysms.

Mycotic aneurysms and pseudoaneurysms, though rare, present significant diagnostic and therapeutic challenges. The case follows a 74-year-old male with a history of bladder cancer who developed multifocal mycotic aneurysms and pseudoaneurysms following sepsis. Initially misdiagnosed as a Pancoast tumor, imaging revealed an extensive disease involving the right subclavian artery, proximal descending thoracic aorta, infrarenal abdominal aorta, and right common iliac artery. This case highlights the importance of considering mycotic aneurysms in the differential diagnosis of patients with a history of infection and highlights the role of Computed Tomography Angiography in early diagnosis.

Combined risk estimates of diabetes and coronary angiography-derived index of microcirculatory resistance in patients with non-ST elevation myocardial infarction.

BACKGROUND: Diabetes mellitus (DM) and coronary microvascular dysfunction (CMD) increase the risk of adverse cardiac events in patients with non-ST-segment elevation myocardial infarction (NSTEMI). This study aimed to evaluate the combined risk estimates of DM and CMD, assessed by the angiography-derived index of microcirculatory resistance (angio-IMR), in patients with NSTEMI. METHODS: A total of 2212 patients with NSTEMI who underwent successful percutaneous coronary intervention (PCI) were retrospectively enrolled from three centers. The primary outcome was a composite of cardiac death or readmission for heart failure at a 2-year follow-up. RESULTS: Post-PCI angio-IMR did not significantly differ between the DM group and the non-DM group (20.13 [17.91-22.70] vs. 20.19 [18.14-22.77], P = 0.530). DM patients exhibited a notably higher risk of cardiac death or readmission for heart failure at 2 years compared to non-DM patients (9.5% vs. 5.4%, P < 0.001). NSTEMI patients with both DM and CMD experienced the highest cumulative incidence of cardiac death or readmission for heart failure at 2 years (24.0%, P < 0.001). The combination of DM and CMD in NSTEMI patients were identified as the most powerful independent predictor for cardiac death or readmission for heart failure at 2 years (adjusted HR: 7.894, [95% CI, 4.251-14.659], p < 0.001). CONCLUSIONS: In patients with NSTEMI, the combination of DM and CMD is an independent predictor of cardiac death or readmission for heart failure. Angio-IMR could be used as an additional evaluation tool for the management of NSTEMI patients with DM. TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov ; Unique identifier: NCT05696379.

Customized Soft Tissue Free Flaps in Head and Neck Reconstruction.

The integration of imaging technologies such as computed tomography angiography and color Doppler ultrasonography are transforming soft tissue free flap reconstruction. The search for thinner and more refined flaps has expanded indications for flaps harvested from donor sites that were not commonly used in head and neck reconstruction. This article explores how these tools and techniques facilitate precise flap selection, thickness, and design customization based on detailed patient preoperative perforator anatomy and vascular configuration mapping. Optimizing outcomes with tailored flap designs improves surgical accuracy and patient-specific results in soft tissue reconstruction.

Improved visualization of intracranial distal arteries with multiple 2D slice dynamic ASL-MRA and super-resolution convolutional neural network.

PURPOSE: To develop a novel framework to improve the visualization of distal arteries in arterial spin labeling (ASL) dynamic MRA. METHODS: The attenuation of ASL blood signal due to the repetitive application of excitation RF pulses was minimized by splitting the acquisition volume into multiple thin 2D (M2D) slices, thereby reducing the exposure of the arterial blood magnetization to RF pulses while it flows within the brain. To improve the degraded vessel visualization in the slice direction due to the limited minimum achievable 2D slice thickness, a super-resolution (SR) convolutional neural network (CNN) was trained by using 3D time-of-flight (TOF)-MRA images from a large public dataset. And then, we applied domain transfer from 3D TOF-MRA to M2D ASL-MRA, while avoiding acquiring a large number of ASL-MRA data required for CNN training. RESULTS: Compared to the conventional 3D ASL-MRA, far more distal arteries were visualized with higher signal intensity by using M2D ASL-MRA. In general, however, the vessel visualization with a conventional interpolation was prone to be blurry and unclear due to the limited spatial resolution in the slice direction, particularly in small vessels. Application of CNN-based SR transferred from 3D TOF-MRA to M2D ASL-MRA successfully addressed such a limitation and achieved clearer visualization of small vessels than conventional interpolation. CONCLUSION: This study demonstrated that the proposed framework provides improved visualization of distal arteries in later dynamic phases, which will particularly benefit the application of this approach in patients with cerebrovascular disease who have slow blood flow.

Optical Coherence Tomography-Guided Stenting for Common Carotid Free-Floating Thrombus.

CLINICAL IMPACT: Digital subtraction angiography (DSA) has traditionally been considered an effective method for visualizing carotid free-floating thrombus (CFFT), but it falls short in providing detailed structures of the lumen and the composition of thrombi, making it challenging to determine the etiology. Intravascular optical coherence tomography (OCT) is a valuable adjunct to DSA that can precisely evaluate the characteristics of the intrinsic vessel wall and accurately distinguish between red and white thrombus, providing clues to the etiology of CFFTs. Moreover, OCT not only precisely determined the scope of a floating thrombus but also provided guidance for decision-making in endovascular treatment.