Sökning: "Pulsatility index"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden Pulsatility index.

  1. 1. Cerebral arterial pulsatility imaging using 4D flow MRI : methodological development and applications in brain aging

    Författare :Tomas Vikner; Anders Wåhlin; Anders Eklund; Jan Malm; Lars Nyberg; Susanne Schnell; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Magnetic resonance imaging; 4D flow MRI; medical image analysis; cerebral hemodynamics; arterial pulsatility; DCE MRI; blood-brain barrier; white matter lesions; perivascular spaces; cerebral small vessel disease; hippocampus; cognition; aging; biomedicinsk strålningsvetenskap; Biomedical Radiation Science;

    Sammanfattning : 4D flow magnetic resonance imaging (MRI) is increasingly recognizedas a versatile tool to assess arterial and venous hemodynamics. Cerebral arterial pulsatility is typically assessed by analyzing flow waveforms over the cardiac cycle, where flow amplitude is a function of cardiac output, central arterial stiffness, and cerebrovascular resistance and compliance. LÄS MER

  3. 2. Studies on Prostanoid Production in the Umbilicoplacental Circulation

    Författare :Pia Saldeen; Malmö Reproduktionsmedicin; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; gynaecology; Obstetrics; Umbilical; Thromboxane; Pulsatility Index; Prostacyclin; Pregnancy; Placenta; Peroxidation; Growth restriction; Endoperoxides; Endothelium; Doppler; Diabetes; sexualitet; reproduktion; andrologi; gynekologi; andrology; reproduction; sexuality; Obstetrik;

    Sammanfattning : The fetoplacental circulation is a low pressure system with a high vascular prostacyclin to thromboxane (Pc/Tx)synthesis ratio. In intrauterin growth restriction (IUGR) and diabetes the prostanoid balance may be altered. LÄS MER

  4. 3. Cerebral blood flow distribution, collateral function and pulsatility in healthy and in patients with symptomatic carotid stenosis  : a magnetic resonance imaging approach

    Författare :Laleh Zarrinkoob; Jan Malm; Anders Eklund; Khalid Ambarki; Sepideh Amin-Hanjani; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Aging; Arterial pulsatility; Carotid stenosis; Cerebral arteries; Cerebral blood flow; Cerebral collateral blood flow; Circle of Willis; Phase contrast magnetic resonance imaging;

    Sammanfattning : Background: For the detection and treatment of early cerebral vascular disease it is of paramount importance to first understand the normal physiology of the cerebral vasculature, and subsequently, to understand how and when pathology can develop from that. This is especially important as the population above 65 years of age is increasing and aging itself is an established risk factor for the development of cerebral vascular disease. LÄS MER

  5. 4. Maternal renal artery Doppler velocimetry in normal and hypertensive pregnancies

    Författare :Marius Kublickas; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :Atrial natriuretic factor Cyclicguanosine monophosphate Doppler ultrasoundKidney Modeling Preeclampsia Pregnancy Preg-nancy induced hypertension Pulsatility index Re-nal artery Renal blood flow Repeatability.Stockholm 1966;

    Sammanfattning : Background: The measurement of effective renal plasma flow (ERPF) by calculation of p-aminohippurate (PAH) clearance is an invasive, time-consuming procedure. In nonpregnant humans, the clearance of isotopes can be used to measure renal plasma flow, but the use of these radioactive substances during pregnancy is unsuitable. LÄS MER

  7. 5. Measurements in Idiopathic Normal Pressure Hydrocephalus : Computerized neuropsychological test battery and intracranial pulse waves

    Författare :Anders Behrens; Jan Malm; Anders Eklund; Eva Elgh; Niklas Lenfeldt; Marianne Juhler; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Hydrocephalus; Normal Pressure; Neuropsychological tests; Neuropsychology; Reliability and validity; Software; Dementia; intracranial pressure; spinal puncture; cerebrospinal fluid pressure; pulse pressure waves; Blood flow velocity; Middle cerebral artery; Pulsatility index; Neurology; neurologi;

    Sammanfattning : Idiopathic Normal Pressure Hydrocephalus (INPH) is a condition affecting gait, cognition and continence. Radiological examination reveals enlarged ventricles of the brain. A shunt that drains CSF from the ventricles to the abdomen often improves the symptoms. LÄS MER