title: Required temporal resolution for accurate thoracic aortic pulse wave velocity measurements by phase-contrast magnetic resonance imaging and comparison with clinical standard applanation tonometry.
abstract: Pulse wave velocity (PWV) is a biomarker for arterial stiffness, clinically assessed by applanation tonometry (AT). Increased use of phase-contrast cardiac magnetic resonance (CMR) imaging allows for PWV assessment with minor routine protocol additions. The aims were to investigate the acquired temporal resolution needed for accurate and precise measurements of CMR-PWV, and develop a tool for CMR-PWV measurements.
  
  
  
  Computer phantoms were generated for PWV = 2-20 m/s based on human CMR-PWV data. The PWV measurements were performed in 13 healthy young subjects and 13 patients at risk for cardiovascular disease. The CMR-PWV was measured by through-plane phase-contrast CMR in the ascending aorta and at the diaphragm level. Centre-line aortic distance was determined between flow planes. The AT-PWV was assessed within 2 h after CMR. Three observers (CMR experience: 15, 4, and <1 year) determined CMR-PWV. The developed tool was based on the flow-curve foot transit time for PWV quantification.
  
  
  
  Computer phantoms showed bias 0.27 ± 0.32 m/s for a temporal resolution of at least 30 ms. Intraobserver variability for CMR-PWV were: 0 ± 0.03 m/s (15 years), -0.04 ± 0.33 m/s (4 years), and -0.02 ± 0.30 m/s (<1 year). Interobserver variability for CMR-PWV was below 0.02 ± 0.38 m/s. The AT-PWV overestimated CMR-PWV by 1.1 ± 0.7 m/s in healthy young subjects and 1.6 ± 2.7 m/s in patients.
  
  
  
  An acquired temporal resolution of at least 30 ms should be used to obtain accurate and precise thoracic aortic phase-contrast CMR-PWV. A new freely available research tool was used to measure PWV in healthy young subjects and in patients, showing low intra- and interobserver variability also for less experienced CMR observers.
authors.affiliation: Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Karolina
authors.initials: K
authors.lastname: Dorniak
authors.affiliation: Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Clinical Physiology, Lund, Sweden.|Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
authors.forename: Einar
authors.initials: E
authors.lastname: Heiberg
authors.affiliation: Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Hellmann
authors.affiliation: Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Rawicz-Zegrzda
authors.affiliation: Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Wesierska
authors.affiliation: 1st Department of Cardiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Rafal
authors.initials: R
authors.lastname: Galaska
authors.affiliation: 2nd Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Sabisz
authors.affiliation: 2nd Department of Radiology, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Edyta
authors.initials: E
authors.lastname: Szurowska
authors.affiliation: Department of Noninvasive Cardiac Diagnostics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Maria
authors.initials: M
authors.lastname: Dudziak
authors.affiliation: Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Clinical Physiology, Lund, Sweden. erik.hedstrom@med.lu.se.|Lund University, Skane University Hospital, Department of Clinical Sciences Lund, Diagnostic Radiology, Lund, Sweden. erik.hedstrom@med.lu.se.
authors.forename: Erik
authors.initials: E
authors.lastname: Hedström
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001011:Aorta / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001795:Blood Pressure Determination / Q000379:methods*; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D063177:Pulse Wave Analysis / Q000379:methods*; D012372:ROC Curve; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Aorta; Applanation tonometry; Magnetic resonance imaging; Phase contrast; Pulse wave velocity; Temporal resolution