Embodetect Eastern Finland Study Group

Imaging as an aid in understanding stroke etiology

Stroke is the leading cause of long-term disability, the second-leading cause of death, and a major consumer of healthcare resources worldwide. Embolism of cardiac origin is thought to account for around one fifth of ischemic strokes. Approximately 20–25% of all strokes are recurrent and the risk of recurrence can be reduced with early initiation of appropriate secondary prevention. Ischemic strokes without a well-defined etiology are labeled as cryptogenic, and account for 30–40% of all ischemic strokes.

Etiological work-up of stroke/transient ischemic attack (TIA) usually includes the parallel use of several imaging modalities that may be time-consuming and expensive when performed in separate sessions. 

Our study group investigates whether combined examination of the heart, aorta, and cervicocranial arteries with CT may improve the diagnosis of stroke etiology.

Most cardiac thrombi originate from the left atrial appendage (LAA). An enlarged LAA may predispose to blood coagulation due to slow flow velocity. The study also aims to assess whether LAA and/or left atrium volumetry is helpful in risk stratifications in patients with cryptogenic stroke.

We also investigate the role of inflammation markers and increased visceral fat, intrathoracic fat and pericardial fat in stroke pathogenesis.

Study group

Pirjo Mustonen / Adjunct Professor
Pirjo.Mustonen (at) ksshp.fi


Marja Hedman / Adjunct Professor
Marja.Hedman (at) kuh.fi

Pekka Jäkälä / Professor
Pekka.Jakala (at) kuh.fi

Mikko Taina / Senior Researcher
Mikko.Taina (at) kuh.fi

Sakari Simula / Senior Researcher
Sakari.Simula (at) esshp.fi

Kari Pulkki / Professor
Kari.Pulkki (at) uef.fi

Petri Sipola / Adjunct Professor
Petri.Sipola (at) kuh.fi

Ritva Vanninen / Professor Chairman
Ritva.Vanninen (at) kuh.fi
+358 44 717 3303

Doctoral students

Antti Muuronen, MD / Junior Researcher
 – visceral adipose tissue and inflammation markers
Antti.Muuronen ( at ) kuh.fi

Miika Korhonen, BM  M.Sc.(Tech.) / Junior Researcher 
– left atrial appendage morphology and automatized segmentation
Miika.Korhonen ( at ) kuh.fi

Juha Onatsu, MD / Neurologist 
– clinical perspectives and fife-year follow-up
Juha.Onatsu ( at ) kuh.fi


Jyrki Lötjönen
ICT for Health, VTT Technical Research Centre of Finland, Tampere, Finland

Juha Koikkalainen
ICT for Health, VTT Technical Research Centre of Finland, Tampere, Finland

Dissertations of the study group

Left atrial appendage volume in acute stroke
Taina, Mikko
Itä-Suomen yliopisto,2014
Publications of the University of Eastern Finland. Dissertations in Health Sciences.,243

Publications from the embodetect study group 

Taina M, Korhonen M, Haataja M, Muuronen A, Arponen O, Hedman M, Jäkälä P, Sipola P, Vanninen R. (2014) Morphological and Volumetric Analysis of Left Atrial Appendage and Left Atrium: Cardiac Computed Tomography-Based Reproducibility Assessment.PLoS ONE; 9(7): e101580. doi: 10.1371/journal.pone.0101580 (open access)

Taina M, Sipola P, Muuronen A, Hedman M, Mustonen P, Kantanen A-M, Jäkälä P, Vanninen R. (2014) Determinants of Left Atrial Appendage Volume in Stroke Patients without Chronic Atrial Fibrillation.PLoS ONE; 9(3): e90903. doi: 10.1371/journal.pone.0090903  (open access)

Taina M, Vanninen R, Hedman M, Jäkälä P, Kärkkäinen S, Tapiola T, Sipola P. (2013) Left Atrial Appendage Volume Increased in More Than Half of Patients with Cryptogenic Stroke.PLoS ONE; 8(11):doi:10.1371/journal.pone.0079519 (open access)

Sipola P, Hedman M, Onatsu J, Turpeinen A, Halinen M, Jäkälä P, Vanninen R. Computed Tomography and Echocardiography together Reveal More High-Risk Findings than Echocardiography Alone in the Diagnostics of Stroke Etiology. Cerebrovasc Dis 2013;35:521–530.

Sipola P, Hedman M, Jäkälä P, Karjalainen AM, Peuhkurinen K, Manninen H, Vanninen R. Prevalence of pulmonary embolism in patients with suspected cardioembolic ischemic stroke. J Thorac Imaging. 2011;26:32–35.

Simula S, Muuronen A, Taina M, Jäkälä P, Sipola P, Vanninen R, Hedman M. Effect of Middle Cerebral Artery Territory Ischemic Stroke on QT Interval. Journal of Stroke & Cerebrovascular Diseases 2014;23:717–23.

Selected publications on imaging of ischemic stroke

Zhang Z, Berg M, Ikonen A, Könönen M, Kälviäinen R, Manninen H, Vanninen R. Carotid stenosis degree in CT angiography: Assessment based on luminal area versus luminal diameter measurements. Eur Radiol 2005;15:2359–2365.

Berg M, Zhang Z, Ikonen A, Kälviäinen R, Manninen H, Vanninen R. Multidetector CT angiography in the assessment of carotid artery disease in symptomatic patients: Comparison with rotational angiography and DSA. AJNR Am J Neuroradiol 2005;26:1022–1034.

Liu Y, Karonen J, Vanninen R, Nuutinen J, Koskela A, Soimakallio S, Aronen H. Predictive value of phase contrast MRA in acute ischemic stroke: a series study with combined diffusion and perfusion MRI . Radiology 2004;23:517–527.

Zhang Z, Berg M, Ikonen A, Vanninen R, Manninen H. Carotid artery stenosis: Reproducibility of advanced 3D CT-angiography analysis methods. Eur Radiol 2004;14: 665–672.

Liu Y, Laakso M, Karonen J, Vanninen R, Nuutinen J, Soimakallio S, Aronen H. Apolipoprotein E polymorphism and acute ischemic stroke: A diffusion- and perfusion-weighted magnetic resonance imaging study. J Cerebral Blood Flow Metabolism 2002;22:1336–1342.

Karonen JO, Ostergaard L, Vainio P, Partanen K, Vanninen R, Vanninen E, Korhonen K, Haapamäki S, Liu Y, Roivainen R, Onatsu J, Nuutinen J, Könönen M, Sivenius J, Kuikka J, Aronen HJ. Diffusion and perfusion MR imaging in acute ischemic stroke: a comparison to SPECT.Comput Methods Programs Biomed. 2001;66:125–128.

Liu Y, Karonen J, Vanninen R, Ostergaard L, Perkiö J, Könönen M, Hämäläinen A, Vanninen E, Soimakallio S, Kuikka J, Aronen H. Cerebral hemodynamic changes in human acute stroke: a comparison of magnetic resonance perfusion weighted imaging with SPECT. J Cerebr Blood Flow Metab 2000;20:910–920.

Karonen J, Kuikka JT, Nuutinen J, Vanninen E, Vanninen R, Partanen K, Vainio P, Roivainen R, Sivenius J, Aronen H. Combined diffusion weighted magnetic resonance imaging and single photon emission computed tomography as a predictor of development in acute ischaemic stroke. Stroke 1999;30:1583–1590.

Räsänen H, Manninen H, Vanninen R, Vainio P, Berg M, Saari T. Mild carotid artery atherosclerosis: Assessment by 3D TOF MR angiography, with reference to intravascular US imaging and contrast angiography. Stroke 1999;30:827–833.

Vanninen R, Manninen H, Partanen K, Vainio P, Soimakallio S. Carotid artery stenosis: Clinical efficacy of MR phase-contrast flow quantification as an adjunct to MR angiography. Radiology 1995;194:459–467.

Vanninen R, Koivisto K, Tulla H, Manninen H, Partanen K. Hemodynamic effects of carotid endarterectomy by magnetic resonance flow quantification. Stroke 1995;26:84–89. 


Clinical Research Centre / UEF
Doctoral Programme of Clinical Research