Background and Purpose: The primary aim of this study was to investigate the diagnostic accuracy and time frames for neurological and transcranial color-coded sonography (TCCS) assessments in a prehospital ‘911’ emergency stroke situation by using portable duplex ultrasound devices to visualize the bilateral middle cerebral arteries (MCAs). Methods: This study was conducted between May 2010 and January 2011. Patients who had sustained strokes in the city of Regensburg and the surrounding area in Bavaria, Germany, were enrolled in the study. After a ‘911 stroke code’ call had been dispatched, stroke neurologists with expertise in ultrasonography rendezvoused with the paramedic team at the site of the emergency. After a brief neurological assessment had been completed, the patients underwent TCCS with optional administration of an ultrasound contrast agent in cases of insufficient temporal bone windows or if the agent had acute therapeutic relevance. The ultrasound studies were performed at the site of the emergency or in the ambulance during patient transport to the admitting hospital. Relevant timelines, such as the time from the stroke alarm to patient arrival at the hospital and the duration of the TCCS, were documented, and positive and negative predictive values for the diagnosis of major MCA occlusion were assessed. Results: A total of 113 patients were enrolled in the study. MCA occlusion was diagnosed in 10 patients. In 9 of these 10 patients, MCA occlusion could be visualized using contrast-enhanced or non-contrast-enhanced TCCS during patient transport and was later confirmed using computed tomography or magnetic resonance angiography. One MCA occlusion was missed by TCCS and 1 atypical hemorrhage was misdiagnosed. Overall, the sensitivity of a ‘field diagnosis’ of MCA occlusion was 90% [95% confidence interval (CI) 55.5–99.75%] and the specificity was 98% (95% CI 92.89–99.97%). The positive predictive value was 90% (95% CI 55.5–99.75%) and the negative predictive value was 98% (95% CI 92.89–99.97%). The mean time (standard deviation) from ambulance dispatch to arrival at the patient was 12.3 min (7.09); the mean time for the TCCS examination was 5.6 min (2.2); and the overall mean transport time to the hospital was 53 min (18). Conclusion: Prehospital diagnosis of MCA occlusion in stroke patients is feasible using portable duplex ultrasonography with or without administration of a microbubble contrast agent. Prehospital neurological as well as transcranial vascular assessments during patient transport can be performed by a trained neurologist with high sensitivity and specificity, perhaps opening an additional therapeutic window for sonothrombolysis or neuroprotective strategies.

Meairs S, Culp W: Microbubbles for thrombolysis of acute ischemic stroke. Cerebrovasc Dis 2009;27(suppl 2):55–65.
del Zoppo GJ, Higashida RT, Furlan AJ, Pessin MS, Rowley HA, Gent M: Proact: A phase II randomized trial of recombinant pro-urokinase by direct arterial delivery in acute middle cerebral artery stroke. PROACT investigators. Prolyse in acute cerebral thromboembolism. Stroke 1998;29:4–11.
Costalat V, Machi P, Lobotesis K, Maldonado I, Vendrell JF, Riquelme C, Mourand I, Milhaud D, Heroum C, Perrigault PF, Arquizan C, Bonafe A: Rescue, combined, and stand-alone thrombectomy in the management of large vessel occlusion stroke using the Solitaire device: a prospective 50-patient single-center study: timing, safety, and efficacy. Stroke 2011;42:1929–1935.
Roth C, Mielke A, Siekmann R, Ferbert A: First experiences with a new device for mechanical thrombectomy in acute basilar artery occlusion. Cerebrovasc Dis 2011;32:28–34.
Alexandrov AV, Molina CA, Grotta JC, Garami Z, Ford SR, Alvarez-Sabin J, Montaner J, Saqqur M, Demchuk AM, Moye LA, Hill MD, Wojner AW: Ultrasound-enhanced systemic thrombolysis for acute ischemic stroke. N Engl J Med 2004;351:2170–2178.
Daffertshofer M, Gass A, Ringleb P, Sitzer M, Sliwka U, Els T, Sedlaczek O, Koroshetz WJ, Hennerici MG: Transcranial low-frequency ultrasound-mediated thrombolysis in brain ischemia: increased risk of hemorrhage with combined ultrasound and tissue plasminogen activator: Results of a phase II clinical trial. Stroke 2005;36:1441–1446.
Tsivgoulis G, Eggers J, Ribo M, Perren F, Saqqur M, Rubiera M, Sergentanis TN, Vadikolias K, Larrue V, Molina CA, Alexandrov AV: Safety and efficacy of ultrasound-enhanced thrombolysis: a comprehensive review and meta-analysis of randomized and nonrandomized studies. Stroke 2010;41:280–287.
Teuschl Y, Brainin M: Stroke education: Discrepancies among factors influencing prehospital delay and stroke knowledge. Int J Stroke 2010;5:187–208.
Mikulik R, Goldemund D, Reif M, Brichta J, Neumann J, Jarkovsky J, Kryza J: Calling 911 in response to stroke: no change following a four-year educational campaign. Cerebrovasc Dis 2011;32:342–348.
Saver JL: Time is brain-quantified. Stroke 2006;37:263–266.
Holscher T, Schlachetzki F, Zimmermann M, Jakob W, Ittner KP, Haslberger J, Bogdahn U, Boy S: Transcranial ultrasound from diagnosis to early stroke treatment. 1. Feasibility of prehospital cerebrovascular assessment. Cerebrovasc Dis 2008;26:659–663.
Seidel G, Meairs S: Ultrasound contrast agents in ischemic stroke. Cerebrovasc Dis 2009;27(suppl 2):25–39.
Sauerbruch S, Schlachetzki F, Bogdahn U, Valakiene J, Holscher T, Harrer JU: Application of transcranial color-coded duplex sonography in stroke diagnosis. Curr Med Imaging Rev 2009;5:39–54.
Zanette EM, Fieschi C, Bozzao L, Roberti C, Toni D, Argentino C, Lenzi GL: Comparison of cerebral angiography and transcranial Doppler sonography in acute stroke. Stroke 1989;20:899–903.
The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group: Tissue plasminogen activator for acute ischemic stroke. . N Engl J Med 1995;14:1581–1587.
Wilson MH, Levett DZ, Dhillon S, Mitchell K, Morgan J, Grocott MP, Imray C: Stroke at high altitude diagnosed in the field using portable ultrasound. Wilderness Environ Med 2011;22:54–57.
Collis J, Manasseh R, Liovic P, Tho P, Ooi A, Petkovic-Duran K, Zhu Y: Cavitation microstreaming and stress fields created by microbubbles. Ultrasonics 2010;50:273–279.
Daffertshofer M, Fatar M: Therapeutic ultrasound in ischemic stroke treatment: Experimental evidence. Eur J Ultrasound 2002;16:121–130.
Molina CA, Ribo M, Rubiera M, Montaner J, Santamarina E, Delgado-Mederos R, Arenillas JF, Huertas R, Purroy F, Delgado P, Alvarez-Sabin J: Microbubble administration accelerates clot lysis during continuous 2-mHz ultrasound monitoring in stroke patients treated with intravenous tissue plasminogen activator. Stroke 2006;37:425–429.
Holscher T, Raman R, Ernstrom K, Parrish J, Le DT, Lyden PD, Mattrey RF: In vitro sonothrombolysis with duplex ultrasound: First results using a simplified model. Cerebrovasc Dis 2009;28:365–370.
O’Donnell MJ, Xavier D, Liu L, Zhang H, Chin SL, Rao-Melacini P, Rangarajan S, Islam S, Pais P, McQueen MJ, Mondo C, Damasceno A, Lopez-Jaramillo P, Hankey GJ, Dans AL, Yusoff K, Truelsen T, Diener HC, Sacco RL, Ryglewicz D, Czlonkowska A, Weimar C, Wang X, Yusuf S: Risk factors for ischaemic and intracerebral haemorrhagic stroke in 22 countries (the Interstroke Study): A case-control study. Lancet 2010;376:112–123.
Hynynen K, McDannold N, Martin H, Jolesz FA, Vykhodtseva N: The threshold for brain damage in rabbits induced by bursts of ultrasound in the presence of an ultrasound contrast agent (Optison). Ultrasound Med Biol 2003;29:473–481.
Hynynen K, McDannold N, Vykhodtseva N, Jolesz FA: Non-invasive opening of BBB by focused ultrasound. Acta Neurochir Suppl 2003;86:555–558.
Schlachetzki F, Holscher T, Koch HJ, Draganski B, May A, Schuierer G, Bogdahn U: Observation on the integrity of the blood-brain barrier after microbubble destruction by diagnostic transcranial color-coded sonography. J Ultrasound Med 2002;21:419–429.
Stroick M, Alonso A, Fatar M, Griebe M, Kreisel S, Kern R, Gaud E, Arditi M, Hennerici M, Meairs S: Effects of simultaneous application of ultrasound and microbubbles on intracerebral hemorrhage in an animal model. Ultrasound Med Biol 2006;32:1377–1382.
Ziegler V, Rashid A, Muller-Gorchs M, Kippnich U, Hiermann E, Kogerl C, Holtmann C, Siebler M, Griewing B: Mobile computing systems in preclinical care of stroke. Results of the Stroke Angel initiative within the BMBF project PerCoMed (in German). Anaesthesist 2008;57:677–685.
Walter S, Kostpopoulos P, Haass A, Helwig S, Keller I, Licina T, Schlechtriemen T, Roth C, Papanagiotou P, Zimmer A, Viera J, Korner H, Schmidt K, Romann MS, Alexandrou M, Yilmaz U, Grunwald I, Kubulus D, Lesmeister M, Ziegeler S, Pattar A, Golinski M, Liu Y, Volk T, Bertsch T, Reith W, Fassbender K: Bringing the hospital to the patient: first treatment of stroke patients at the emergency site. PLoS One 2010;5:e13758.
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