J
Jyrki Ruohonen
Researcher at University of Oulu
Publications - 10
Citations - 253
Jyrki Ruohonen is an academic researcher from University of Oulu. The author has contributed to research in topics: Magnetic resonance imaging & Intervertebral disc. The author has an hindex of 9, co-authored 9 publications receiving 244 citations. Previous affiliations of Jyrki Ruohonen include Oulu University Hospital.
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Journal ArticleDOI
BOLD signal increase preceeds EEG spike activity—a dynamic penicillin induced focal epilepsy in deep anesthesia
Minna Mäkiranta,Jyrki Ruohonen,Kalervo Suominen,Jaakko Niinimäki,Eila Sonkajärvi,Vesa Kiviniemi,Tapio Seppänen,Seppo Alahuhta,Ville Jäntti,Osmo Tervonen +9 more
TL;DR: Development of focal epileptic activity can be detected as a BOLD signal change, even preceding the spike activity in scalp EEG, in this experimental model.
Journal ArticleDOI
Association between visual degeneration of intervertebral discs and the apparent diffusion coefficient.
Jaakko Niinimäki,Arto Korkiakoski,Outi Ojala,Jaro Karppinen,Jaro Karppinen,Jyrki Ruohonen,Marianne Haapea,Raija Korpelainen,Antero Natri,Osmo Tervonen +9 more
TL;DR: ADC measurements of intervertebral discs, at least with current technology, have limited clinical value, and there is considerable overlap between ADC values of normal and degenerated discs.
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Separation of physiological very low frequency fluctuation from aliasing by switched sampling interval fMRI scans
TL;DR: The VLF BOLD signal fluctuation in the occipital cortex is a true physiological fluctuation, not a result of signal aliasing.
Journal ArticleDOI
BOLD-contrast functional MRI signal changes related to intermittent rhythmic delta activity in EEG during voluntary hyperventilation-simultaneous EEG and fMRI study.
Minna Mäkiranta,Minna Mäkiranta,Jyrki Ruohonen,Kalervo Suominen,Eila Sonkajärvi,Timo Salomäki,Vesa Kiviniemi,Tapio Seppänen,Seppo Alahuhta,Ville Jäntti,Osmo Tervonen +10 more
TL;DR: IRDA due to HV in healthy volunteers represent a model with a clearly defined EEG pattern and an observable BOLD signal change, which seems to depict changes, which precede IRDA.
Journal ArticleDOI
In vivo quantification of delayed gadolinium enhancement in the nucleus pulposus of human intervertebral disc.
Jaakko Niinimäki,Outi Parviainen,Jyrki Ruohonen,Risto Ojala,Mauno Kurunlahti,Jaro Karppinen,Jaro Karppinen,Osmo Tervonen,Miika T. Nieminen +8 more
TL;DR: To quantify the delayed contrast agent enhancement in the nucleus pulposus of the intervertebral disc by means by T1 relaxation time measurements, and to correlate the enhancement with visual grading of disc degeneration.