Digital subtraction angiography (DSA) is considered the reference method for the assessment of carotid artery stenosis; however, the procedure is invasive and accompanied by ionizing radiation. Velocity estimation with duplex ultrasound (DUS) is widely used for carotid artery stenosis assessment since no radiation or intravenous contrast is required; however, the method is angle-dependent. Vector concentration (VC) is a parameter for flow complexity assessment derived from the angle independent ultrasound method vector flow imaging (VFI), and VC has shown to correlate strongly with stenosis degree. The aim of this study was to compare VC estimates and DUS estimated peak-systolic (PSV) and end-diastolic velocities (EDV) for carotid artery stenosis patients, with the stenosis degree obtained with DSA. Eleven patients with symptomatic carotid artery stenosis were examined with DUS, VFI, and DSA before and after stent treatment. Compared to DSA, VC showed a strong correlation (r = −0.79, p < 0.001), while PSV (r = 0.68, p = 0.002) and EDV (r = 0.51, p = 0.048) obtained with DUS showed a moderate correlation. VFI using VC calculations may be a useful ultrasound method for carotid artery stenosis and stent patency assessment.

Volume flow estimation in the common carotid artery (CCA) can assess the absolute hemodynamic effect of a carotid stenosis. The aim of this study was to compare a commercial vector flow imaging (VFI) setup against the reference method magnetic resonance phase contrast angiography (MRA) for volume flow estimation in the CCA. Ten healthy volunteers were scanned with VFI and MRA over the CCA. VFI had an improved precision of 19.2% compared to MRA of 31.9% (p = 0.061). VFI estimated significantly lower volume flow than MRA (mean difference: 63.2 mL/min, p = 0.017), whilst the correlation between VFI and MRA was strong (R² = 0.81, p < 0.0001). A Bland–Altman plot indicated a systematic bias. After bias correction, the percentage error was reduced from 41.0% to 25.2%. This study indicated that a VFI setup for volume flow estimation is precise and strongly correlated to MRA volume flow estimation, and after correcting for the systematic bias, VFI and MRA become interchangeable.

In order to support or refute the clinical suspicion of cranial giant cell arteritis (GCA), a supplemental imaging modality is often required. High-resolution black blood Magnetic Resonance Imaging (BB MRI) techniques with contrast enhancement can visualize artery wall inflammation in GCA. We compared findings on BB MRI without contrast enhancement with findings on 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/low-dose computed tomography (2-[¹⁸F]FDG PET/CT) in ten patients suspected of having GCA and in five control subjects who had a 2-[¹⁸F]FDG PET/CT performed as a routine control for malignant melanoma. BB MRI was consistent with 2-[¹⁸F]FDG PET/CT in 10 out of 10 cases in the group with suspected GCA. In four out of five cases in the control group, the BB MRI was consistent with 2-[¹⁸F]FDG PET/CT. In this small population, BB MRI without contrast enhancement shows promising performance in the diagnosis of GCA, and might be an applicable imaging modality in patients.

Background/Objectives: Antiplatelet therapy after emergent carotid stenting (eCAS) represents a challenge in balancing the risk of intracerebral hemorrhages (ICHs) and in-stent thrombosis (IST). Post-procedural platelet function monitoring may guide antiplatelet therapy and could potentially improve outcomes due to fewer post-procedural complications. Methods: Consecutive eCAS patients (2019–2021) were included in a single-center retrospective observational study. Patients treated with eCAS received peri-procedural eptifibatide followed by dual antiplatelet treatment with aspirin and clopidogrel. The effect of platelet ADP inhibition by clopidogrel was monitored using the Multiplate^® Analyzer (Roche). Clopidogrel non-responders were changed to ticagrelor treatment. The primary outcome was defined as a favorable outcome at 90 days using the modified Rankin Scale (mRS) of 0–2 versus 3–6. Safety outcomes included ICH, IST, and mortality. Data were analyzed and compared in clopidogrel- and ticagrelor-treated patients using Fischer’s exact test and multivariate logistic regression. Results: A total of 105 patients had eCAS, and 28 patients (27%) were clopidogrel non-responders and were changed to treatment with ticagrelor. The favorable outcome was more frequent in ticagrelor-treated patients, 23 (82%), than in clopidogrel-treated patients, 44 (57%), p = 0.036. Numerically, ICH, IST, and mortality were more frequent in clopidogrel-treated patients, but none of the differences were statistically significant. In multivariate analyses, ticagrelor treatment was significantly associated with the favorable outcome, OR = 3.89 (95% CI: 1.09–13.86), p = 0.036. Conclusions: One in four eCAS patients were clopidogrel non-responders. This study suggests that personalized antiplatelet treatment therapy was safe, and that changing treatment to ticagrelor in clopidogrel non-responders was associated with better outcomes in eCAS patients.

Background: High inter-rater variability in DWI-FLAIR mismatch assessments for acute ischemic stroke (AIS) has spurred interest in assisting automated imaging measures. In this study, we explored whether DWI-FLAIR mismatch assessment and automated quantification of FLAIR hyperintensity, DWI-FLAIR volume ratio, and DWI volume could predict changes in NIHSS score following intravenous thrombolysis (IVT) in patients with AIS of unknown time since onset (TSO). We also exploratively compared radiological DWI-FLAIR mismatch assessments and imaging measures between patients who received IVT and those who did not. Methods: We conducted a retrospective, exploratory, single-center study analyzing brain MRIs from a consecutive cohort of patients with suspected AIS and unknown TSO admitted over two years. Patients with DWI hyperintensity lesions related to ischemia, identified automatically and subsequently verified radiologically, were included. We examined the correlation between automated imaging measures, retrospective DWI-FLAIR mismatch assessments, and changes in NIHSS score from baseline to 24 h post-treatment. Results: Of 333 patients included, 109 received IVT (mean age 68.9 ± 15.2 years) and 224 did not (mean age 70.8 ± 13.8 years). The median baseline NIHSS score was 5 in both groups, improving to 2 after IVT. The DWI volume significantly correlated with changes in NIHSS score (p = 0.002); FLAIR intensity demonstrated borderline significance (p = 0.056); and DWI-FLAIR volume ratio showed no statistically significant association in this cohort (p = 0.511). We did not find statistical evidence that the retrospective binary mismatch assessment was correlated with differences in outcome (p > 0.145). Conclusions: This study supports moving beyond binary DWI-FLAIR mismatch, suggesting that continuous, automated imaging parameters could potentially assist the radiologist in AIS management. As evidence remains preliminary, large-scale research is needed to establish clinical utility.