Safety and Feasibility of the BYCROSS® Atherectomy Device for the Treatment of Femoropopliteal Arterial Obstructions: Single-Center Short-Term Outcomes.

Background: Endovascular techniques have gained preference over peripheral arterial bypass surgery due to their minimally invasive nature; however, endovascular treatments often show limited efficacy in arterial segments with a high atherosclerotic load. The use of atherectomy devices enables the removal of calcified plaque material and may promote arterial wall remodeling. This study assessed the technical success, safety, and feasibility of the BYCROSS® atherectomy device in femoropopliteal lesions. Methods: This single-center, retrospective cohort study analyzed elective patients undergoing BYCROSS® atherectomy for chronic peripheral arterial disease from March 2022 to May 2023. Patient data, procedural details, and outcomes were retrospectively collected from electronic patient records. The primary performance endpoints of this study were technical success, complications, and patency rates. Primary safety endpoints included 30-day and short-term major adverse limb events (MALEs), major adverse cardiovascular events (MACEs), and mortality rate. Results: The study included 19 patients (median age, 71 years; 63% male) with Fontaine class IIb (26%), III (21%), or IV (53%). The BYCROSS® atherectomy device was used to treat 22 limbs in the femoropopliteal tract, of which 11 lesions (50%) were occlusions and 11 were stenoses, with a median length of 24 cm (interquartile range: 17-38). Technical success was achieved in all cases: 4.5% required atherectomy only, 50% required additional balloon angioplasties, 41% required balloon angioplasties and stenting, and 4.5% required segments only stenting. Additional treatment of below-the-knee arteries was performed in 12 patients. Procedurally related complications (not limited to the use of the BYCROSS® device) occurred in 23% of limbs, including distal embolization and laceration. At 30 days, mortality was 5%, the MACE rate was 11%, and the MALE rate was 0%. The observed mortality rate was not directly related to the procedure. Patency (<50% restenosis at duplex ultrasound) was 83% at 30 days. Conclusions: The use of the BYCROSS® atherectomy device for the treatment of femoropopliteal lesions appears to be safe and feasible, with high technical success and low MALE and MACE rates in a challenging population with long-segment femoropopliteal lesions. Long-term follow-up in larger patient series is needed to confirm these findings and to determine the durability of this technique.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation.

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available. OBJECTIVES: In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging. MATERIAL AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60). RESULTS: Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques. CONCLUSION: Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.

Carotid calcium burden derived from computed tomography angiography as a predictor of all-cause mortality after carotid endarterectomy.

OBJECTIVE: Carotid endarterectomy (CEA) aims to reduce the risk of stroke in patients with atherosclerotic carotid disease. Preoperative risk assessments that predict complications are needed to optimize the care in this patient group. The current approach, namely relying solely on symptomatology and degree of stenosis, is outdated and calls for innovation. The Agatston calcium score was applied in several vascular specialties to assess cardiovascular risk profile but has been little studied in carotid surgery. It is hypothesized that a higher calcium burden at initial presentation equates to a worse prognosis attributable to an increased cerebrovascular and cardiovascular risk profile. The aim was to investigate the association between preoperative ipsilateral calcium score and postoperative all-cause mortality in patients undergoing CEA. METHODS: This single-center retrospective cohort study included 89 patients who underwent CEA at a tertiary referral center between 2010 and 2018. Preoperative calcium scores were measured on contrast-enhanced computed tomography images with patient-specific Hounsfield thresholds at the level of the carotid bifurcation. The association between these calcium scores and all-cause mortality was analyzed using multivariable adjusted Cox proportional hazard analysis. RESULTS: Cox proportional hazard analysis demonstrated a significant association between preoperative ipsilateral carotid calcium score and all-cause mortality (hazard ratio, 1.10; 95% confidence interval, 1.03-1.16; P = .003). After adjusting for age, preoperative estimated glomerular filtration rate, and diabetes mellitus, a significant association remained (hazard ratio, 1.07; 95% confidence interval, 1.00-1.15; P = .05). CONCLUSIONS: A higher calcium burden was predictive of worse outcome, which might be explained by an overall poorer health status. These results highlight the potential of calcium measurements in combination with other traditional risk factors, for preoperative risk assessment and thus for improved patient education and care.

Effectiveness and safety of catheter-directed thrombolysis in conjunction with percutaneous mechanical thrombectomy for acute iliofemoral deep vein thrombosis: A meta-analysis.

BACKGROUND: Patients with severe acute low iliofemoral deep vein thrombosis (DVT), such as phlegmasia cerulea dolens, benefit from catheter-directed thrombolysis (CDT). This meta-analysis investigated the effectiveness and safety of adjuvant percutaneous mechanical thrombectomy (PMT) during CDT compared with CDT alone in the treatment of acute iliofemoral DVT. METHODS: A meta-analysis was performed in accordance with the PRISMA guidelines. Medline, Embase, the Cochrane Library, China National Knowledge Internet, and Wanfang data were searched for studies on the management of acute iliofemoral DVT by means of CDT or CDT with adjuvant PMT. Randomized, controlled trials and nonrandomized studies were included. The primary outcomes were venous patency rate, major bleeding complications, and post-thrombotic syndrome occurrence within 2 years of the procedure. The secondary outcomes were thrombolytic time and volume, as well as the rates of thigh detumescence and iliac vein stenting. RESULTS: The meta-analysis included 20 eligible studies with a total of 1686 patients. The rates of venous patency (mean difference, 10.11; 95% confidence interval [CI], 5.59-14.62) and thigh detumescence (mean difference, 3.64; 95% CI, 1.10-6.18) of the adjuvant PMT group were higher than those of the CDT alone group. Compared with CDT alone, the adjuvant PMT group experienced fewer incidences of major bleeding complications (odds ratio, 0.45; 95% CI, 0.26-0.77) and occurrences of post-thrombotic syndrome within 2 years of the procedure (odds ratio, 0.55; 95% CI, 0.33-0.92). Furthermore, the duration of thrombolytic therapy was shorter, and the total dose of administered thrombolytics was lower with adjuvant PMT. CONCLUSIONS: Adjuvant PMT during CDT is associated with improved clinical outcomes and a lower incidence of major bleeding complications. The studies investigated were, however, single-center cohort studies, and future randomized controlled trials are needed to substantiate these findings.

Comparison of Recent Practice Guidelines for the Management of Patients With Asymptomatic Carotid Stenosis.

Despite the publication of several national/international guidelines, the optimal management of patients with asymptomatic carotid stenosis (AsxCS) remains controversial. This article compares 3 recently released guidelines (the 2020 German-Austrian, the 2021 European Stroke Organization [ESO], and the 2021 Society for Vascular Surgery [SVS] guidelines) vs the 2017 European Society for Vascular Surgery (ESVS) guidelines regarding the optimal management of AsxCS patients.The 2017 ESVS guidelines defined specific imaging/clinical parameters that may identify patient subgroups at high future stroke risk and recommended that carotid endarterectomy (CEA) should or carotid artery stenting (CAS) may be considered for these individuals. The 2020 German-Austrian guidelines provided similar recommendations with the 2017 ESVS Guidelines. The 2021 ESO Guidelines also recommended CEA for AsxCS patients at high risk for stroke on best medical treatment (BMT), but recommended against routine use of CAS in these patients. Finally, the SVS guidelines provided a strong recommendation for CEA+BMT vs BMT alone for low-surgical risk patients with >70% AsxCS. Thus, the ESVS, German-Austrian, and ESO guidelines concurred that all AsxCS patients should receive risk factor modification and BMT, but CEA should or CAS may also be considered for certain AsxCS patient subgroups at high risk for future ipsilateral ischemic stroke.

Post-treatment three-dimensional voxel-based dosimetry after Yttrium-90 resin microsphere radioembolization in HCC.

BACKGROUND: Post-therapy [90Y] PET/CT-based dosimetry is currently recommended to validate treatment planning as [99mTc] MAA SPECT/CT is often a poor predictor of subsequent actual [90Y] absorbed dose. Treatment planning software became available allowing 3D voxel dosimetry offering tumour-absorbed dose distributions and dose-volume histograms (DVH). We aim to assess dose-response effects in post-therapy [90Y] PET/CT dosimetry in SIRT-treated HCC patients for predicting overall and progression-free survival (OS and PFS) and four-month follow-up tumour response (mRECIST). Tumour-absorbed dose and mean percentage of the tumour volume (V) receiving ≥ 100, 150, 200, or 250 Gy and mean minimum absorbed dose (D) delivered to 30%, 50%, 70%, and 90% of tumour volume were calculated from DVH's. Depending on the mean tumour -absorbed dose, treated lesions were assigned to a < 120 Gy or ≥ 120 Gy group. RESULTS: Thirty patients received 36 SIRT treatments, totalling 43 lesions. Median tumour-absorbed dose was significantly different between the ≥ 120 Gy (n = 28, 207 Gy, IQR 154-311 Gy) and < 120 Gy group (n = 15, 62 Gy, IQR 49-97 Gy, p <0 .01). Disease control (DC) was found more frequently in the ≥ 120 Gy group (79%) compared to < 120 Gy (53%). Mean tumour-absorbed dose optimal cut-off predicting DC was 131 Gy. Tumour control probability was 54% (95% CI 52-54%) for a mean tumour-absorbed dose of 120 Gy and 90% (95% CI 87-92%) for 284 Gy. Only D30 was significantly different between DC and progressive disease (p = 0.04). For the ≥ 120 Gy group, median OS and PFS were longer (median OS 33 months, [range 8-33 months] and median PFS 23 months [range 4-33 months]) than the < 120 Gy group (median OS 17 months, [range 5-33 months] and median PFS 13 months [range 1-33 months]) (p < 0.01 and p = 0.03, respectively). CONCLUSIONS: Higher 3D voxel-based tumour-absorbed dose in patients with HCC is associated with four-month DC and longer OS and PFS. DVHs in [90Y] SIRT could play a role in evaluative dosimetry.

Diagnostic performance of an algorithm for automated large vessel occlusion detection on CT angiography.

BACKGROUND: Machine learning algorithms hold the potential to contribute to fast and accurate detection of large vessel occlusion (LVO) in patients with suspected acute ischemic stroke. We assessed the diagnostic performance of an automated LVO detection algorithm on CT angiography (CTA). METHODS: Data from the MR CLEAN Registry and PRESTO were used including patients with and without LVO. CTA data were analyzed by the algorithm for detection and localization of LVO (intracranial internal carotid artery (ICA)/ICA terminus (ICA-T), M1, or M2). Assessments done by expert neuroradiologists were used as reference. Diagnostic performance was assessed for detection of LVO and per occlusion location by means of sensitivity, specificity, and area under the curve (AUC). RESULTS: We analyzed CTAs of 1110 patients from the MR CLEAN Registry (median age (IQR) 71 years (60-80); 584 men; 1110 with LVO) and of 646 patients from PRESTO (median age (IQR) 73 years (62-82); 358 men; 141 with and 505 without LVO). For detection of LVO, the algorithm yielded a sensitivity of 89% in the MR CLEAN Registry and a sensitivity of 72%, specificity of 78%, and AUC of 0.75 in PRESTO. Sensitivity per occlusion location was 88% for ICA/ICA-T, 94% for M1, and 72% for M2 occlusion in the MR CLEAN Registry, and 80% for ICA/ICA-T, 95% for M1, and 49% for M2 occlusion in PRESTO. CONCLUSION: The algorithm provided a high detection rate for proximal LVO, but performance varied significantly by occlusion location. Detection of M2 occlusion needs further improvement.

Brachial and Axillary Artery Vascular Access for Endovascular Interventions.

BACKGROUND: Endovascular access is usually achieved through the common femoral artery due to its large size and accessibility. Access through the upper extremity can however be necessary due to anatomic reasons, obesity, or peripheral arterial disease. The 2 main methods of access are surgical cutdown and percutaneous puncture. In this single-centre retrospective cohort study we compared complication risks for both surgical cutdown and percutaneous puncture of an upper arm approach. MATERIALS AND METHODS: Data was obtained from patients receiving endovascular access through the brachial or axillary artery between 2005 and 2018. A total of 109 patients were included. Patient demographics including age, sex, medical history, smoking status, and actual medication were registered, as well as postoperative complications including hematoma, thrombosis, dissection, infection, pseudoaneurysm, nerve injury, reoperation, and readmission. RESULTS: Access was achieved through surgical cutdown in 53% (n = 58) and through percutaneous puncture in 47% (n = 51) of patients. Fifty-eight percent (n = 63) received access via the brachial artery (BA) and 42% (n = 46) via the axillary artery. Complication rate was 25.0% (3 of 12) for surgical cutdown via the BA, 29.4% (15 of 51) for percutaneous puncture via the BA, and 10.9% (5 of 46) for surgical cutdown via the axillary artery. Major complication rate was 8.3% (1 of 12) for surgical cutdown via the BA, 13.7% (7 of 51) for percutaneous puncture via the BA, and 4.3% (2 of 46) for surgical cutdown via the axillary artery. There was no association between baseline patient characteristics and complication rate. CONCLUSIONS: In this nonrandomized retrospective study, surgical cutdown via the axillary artery was the safest option with fewest complications, but selection of patients may have blurred the results. Surgical cutdown and percutaneous puncture seem equally safe in terms of complication rate in the BA.

Arterial thrombotic complications in COVID-19 patients.

The coronavirus disease 2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been described to predispose to thrombotic disease in both the venous and arterial circulations. We report four cases of an acute arterial occlusion in COVID-19 patients and literature review on the occurrence of arterial thrombosis in patients with COVID-19. Our findings demonstrate that physicians should be vigilant for signs of thrombotic complications in both hospitalized and new COVID-19 patients.

Effect of muscle depletion on survival in peripheral arterial occlusive disease: Quality over quantity.

OBJECTIVE: Patients with peripheral arterial occlusive disease (PAOD) have a poor prognosis and a high prevalence of comorbidity. This study investigated whether sarcopenia and/or myosteatosis negatively affect long-term survival in patients with PAOD. METHODS: This was a single-center, retrospective cohort study of 686 consecutive patients diagnosed and treated for PAOD and who underwent computed tomography scanning. Cross-sectional muscle measurements were obtained at the level of the third lumbar vertebra. Optimal stratification was used to define sex-specific and body mass index-specific cutoff values for sarcopenia and myosteatosis, respectively. The Cox proportional hazards model was used to determine the effect of sarcopenia and myosteatosis on overall survival. RESULTS: Sarcopenia was associated with age, body mass index, myosteatosis, malignancy, congestive heart failure, hemodialysis, and Fontaine 4 classification. Myosteatosis was associated with age, sarcopenia, type 2 diabetes mellitus, hypertension, chronic obstructive pulmonary disease, malignancy, congestive heart failure, ischemic stroke, and Fontaine 4 classification. Sarcopenia (hazard ratio [HR], 2.82; 95% confidence interval [CI], 2.05-3.86; P < .001) and myosteatosis (HR, 4.13; 95% CI, 3.03-5.63; P < .001) were both associated with reduced survival in univariable analysis. When adjusted for other prognostic markers, myosteatosis (HR, 2.09; 95% CI, 1.46-2.99; P < .001) was still associated with lower overall survival in the multivariable model, but sarcopenia (HR, 1.40; 95% CI, 0.97-2.01; P = .073) was not. CONCLUSIONS: Muscle depletion is independently associated with a poorer overall survival in patients with PAOD. Myosteatosis is a stronger predictor than sarcopenia, which indicates that quality is more important than quantity. Results should be interpreted with caution owing to missing data on medication usage.

A systematic review and meta-analysis of endovascular and surgical revascularization techniques in acute limb ischemia.

BACKGROUND: The initial treatment of patients with acute limb ischemia (ALI) remains undefined. The aim of this article was to compare the safety and effectiveness of catheter-driven thrombolysis (CDT) with surgical revascularization and evaluate the various fibrinolytic agents, endovascular, and pharmacochemical approaches that aim for thrombectomy. METHODS: PubMed, Embase, and the Cochrane Library were searched for studies on the management of ALI by means of surgical or endovascular recanalization, returning 520 studies. All randomized, controlled trials, nonrandomized prospective, and retrospective studies were included comparing treatment of ALI. RESULTS: Twenty-five studies, investigating a total of 4689 patients, were included for meta-analysis spread across nine different comparisons. No differences were found in limb salvage between thrombectomy and thrombolysis. More major vascular events were seen in the thrombolysis group (6.5% compared with 4.4% in the surgically treated group; odds ratio [OR], 0.33; 95% confidence interval [CI], 0.13-0.87; P = .02; I2 = 20%). Comparable limb salvage was found for high- and low-dose recombinant tissue plasminogen activator (r-tPA). No significant differences were found in major vascular event between low r-tPA (14%) and high r-tPA (10.5%; P = .13). The 30-day limb salvage rate was 79.7% for r-tPA treatment and 60.4% for streptokinase (OR, 3.14; 95% CI, 1.26-7.85; P = .01; I2 = 0%). AngioJet showed more limb salvage at 6 months compared with r-tPa (OR, 2.21; 95% CI, 1.17-4.18; P = .01; I2 = 0%). CONCLUSIONS: Both CDT and surgery have comparable limb salvage rates in patients with ALI; however, CDT is associated with a higher risk of hemorrhagic complications. No conclusions can be drawn regarding the risk of hemorrhagic complications regarding thrombolytic therapy by means of r-tPA, streptokinase, or urokinase. Insufficient data are available to conclude the preference of using a hybrid approach, ultrasound-accelerated CDT, heated r-tPA. or novel endovascular (rheolytical) thrombectomy systems. Future trials regarding ALI need to be constructed carefully, ensuring comparable study groups, and should follow standardized practices of outcome reporting.

Vascular access creation in octogenarians: The effect of age on outcomes.

BACKGROUND: The prevalence of end-stage renal disease is accelerating among older age groups. Patient-specific factors in the elderly patient group might advocate for a different vascular access creation approach, in which patency, risk of nonmaturation, and time to cannulation with accompanied prolonged catheter use should be of primary importance. The aim of this study was to determine which vascular access has the best outcomes and to determine whether age is associated with different outcomes after vascular access surgery. METHODS: Data were obtained from a prospectively maintained database of patients treated between November 2004 and December 2017. Two different patient groups were identified: the octogenarian group, consisting of patients aged ≥80 years; and the control group, consisting of all the other patients. A total of 694 vascular access procedures were included in this study, 65 in the octogenarian group and 629 in the control group. Primary, primary assisted, and secondary patency rates were calculated and compared between groups and vascular accesses. Multivariable analysis was used to determine whether age is an effect modifier in the association between type of vascular access and different patency outcomes. RESULTS: Mean follow-up was 23.2 months in the octogenarian group and 21.2 months in the control group (P = .210). No significant differences were found in patient survival, with a 5-year survival rate of 63.8% (±5.9%) in the octogenarian group and 57.2% (±2.2%) in the control group (P = .866). Within the octogenarian group, primary failure rate was highest in the radiocephalic arteriovenous fistula (AVF) patients, 42.1% (P = .006). Brachiocephalic AVF had significantly improved assisted patency compared with the other vascular accesses among the octogenarians (P = .016). Age was not an effect modifier in the association between type of vascular access and different patency outcomes. The adjusted analysis, corrected for octogenarian age, diabetes mellitus, hypertension, and sex, showed that brachiocephalic AVF was significantly associated with an increase in primary patency (hazard ratio, 0.70; 95% confidence interval, 0.54-0.90; P = .006) and primary assisted patency (hazard ratio, 0.58; 95% confidence interval, 0.39-0.86; P = .006) compared with other vascular accesses. CONCLUSIONS: The results of our study support primary placement of a brachiocephalic AVF in the octogenarian patient. A low primary failure rate was achieved with significant improved patency rates compared with the other vascular accesses.

Telemedicine in patients with peripheral arterial disease: is it worth the effort?

Introduction: For patients with peripheral arterial disease (PAD), the various components of telemedicine, such as telemonitoring, telecoaching, and teleconsultation, could be valuable in daily management. The objective of this review was to give an overview of the current use of telemedicine interventions in PAD. Areas covered: A literature search was performed for studies that evaluated patients with PAD of the aorto-pedal trajectory, who were monitored by telemedicine and acted upon accordingly. The primary outcome was health-related outcomes. The studies that were found focused mainly on wearable activity monitoring and telecoaching in PAD (n = 4) or wound monitoring after vascular surgery (n = 2). Main results indicate that telemedicine interventions are able to detect (post-operative) complications early, improve functional capacity and claudication onset time, and improve PAD patients' quality of life. Expert opinion: The use of telemedicine in PAD patients is still an under-explored area. Studies investigating the use of telemedicine in PAD are very limited and show varying results. Owing to its high potential in improving physical ability, lifestyle coaching, and timely detection of deterioration, future research should focus on proper implementation of telemedicine in PAD patients, including clinical and feasibility outcomes, effect on workload of nurses, and cost-efficiency.

Visual versus automated evaluation of chest computed tomography for the presence of chronic obstructive pulmonary disease.

BACKGROUND: Incidental CT findings may provide an opportunity for early detection of chronic obstructive pulmonary disease (COPD), which may prove important in CT-based lung cancer screening setting. We aimed to determine the diagnostic performance of human observers to visually evaluate COPD presence on CT images, in comparison to automated evaluation using quantitative CT measures. METHODS: This study was approved by the Dutch Ministry of Health and the institutional review board. All participants provided written informed consent. We studied 266 heavy smokers enrolled in a lung cancer screening trial. All subjects underwent volumetric inspiratory and expiratory chest computed tomography (CT). Pulmonary function testing was used as the reference standard for COPD. We evaluated the diagnostic performance of eight observers and one automated model based on quantitative CT measures. RESULTS: The prevalence of COPD in the study population was 44% (118/266), of whom 62% (73/118) had mild disease. The diagnostic accuracy was 74.1% in the automated evaluation, and ranged between 58.3% and 74.3% for the visual evaluation of CT images. The positive predictive value was 74.3% in the automated evaluation, and ranged between 52.9% and 74.7% for the visual evaluation. Interobserver variation was substantial, even within the subgroup of experienced observers. Agreement within observers yielded kappa values between 0.28 and 0.68, regardless of the level of expertise. The agreement between the observers and the automated CT model showed kappa values of 0.12-0.35. CONCLUSIONS: Visual evaluation of COPD presence on chest CT images provides at best modest accuracy and is associated with substantial interobserver variation. Automated evaluation of COPD subjects using quantitative CT measures appears superior to visual evaluation by human observers.

Whole-brain arterial spin labeling perfusion MRI in patients with acute stroke.

BACKGROUND AND PURPOSE: Perfusion MRI can be used to identify patients with acute ischemic stroke who may benefit from reperfusion therapies. The risk of nephrogenic systemic fibrosis, however, limits the use of contrast agents. Our objective was to evaluate the ability of arterial spin labeling (ASL), an alternative noninvasive perfusion technique, to detect perfusion deficits compared with dynamic susceptibility contrast (DSC) perfusion imaging. METHODS: Consecutive patients referred for emergency assessment of suspected acute stroke within a 7-month period were imaged with both ASL and DSC perfusion MRI. Images were interpreted in a random order by 2 experts blinded to clinical information for image quality, presence of perfusion deficits, and diffusion-perfusion mismatches. RESULTS: One hundred fifty-six patients were scanned with a median time of 5.6 hours (range, 3.0-17.7 hours) from last seen normal. Stroke diagnosis was clinically confirmed in 78 patients. ASL and DSC imaging were available in 64 of these patients. A perfusion deficit was detected with DSC in 39 of these patients; ASL detected 32 of these index perfusion deficits, missing 7 lesions. The median volume of the perfusion deficits as determined with DSC was smaller in patients who were evaluated as normal with ASL than in those with a deficit (median [interquartile range], 56 [10-116] versus 114 [41-225] mL; P=0.01). CONCLUSIONS: ASL can depict large perfusion deficits and perfusion-diffusion mismatches in correspondence with DSC. Our findings show that a fast 2½-minute ASL perfusion scan may be adequate for screening patients with acute stroke with contraindications to gadolinium-based contrast agents.