Valve and great vessel stenosis: assessment with MR jet velocity mapping
| Autor: | D B Longmore, Raad H. Mohiaddin, R. S. O. Rees, Dudley J. Pennell, J. Martinez, S. R. Underwood, Philip J. Kilner, David N. Firmin |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Adult
Heart Defects Congenital medicine.medical_specialty Heart Valve Diseases Arterial Occlusive Diseases Constriction Pathologic Signal Constriction Nuclear magnetic resonance medicine Humans Radiology Nuclear Medicine and imaging Heart valve Jet (fluid) medicine.diagnostic_test business.industry Turbulence Graft Occlusion Vascular Magnetic resonance imaging medicine.disease Magnetic Resonance Imaging Models Structural Stenosis medicine.anatomical_structure Great vessels Radiology business Blood Flow Velocity |
| Zdroj: | Radiology. 178:229-235 |
| ISSN: | 1527-1315 0033-8419 |
| Popis: | For measurement of poststenotic jet velocities with magnetic resonance (MR) imaging, the authors reduced the echo time (TE) of the field even-echo rephasing (FEER) velocity mapping sequence from 14.0 to 3.6 msec, so minimizing the problem of MR signal loss from turbulent fluid. In vitro use of rotating disk and stenotic flow phantoms confirmed that the 3.6-msec TE sequence enables accurate measurement of jet velocities of up to 6.0 m/sec (r = .996). Peak jet velocity measurements were made with MR imaging in 36 patients with stenosis of native heart valves (n = 9), conduits (n = 19), or Fontan connections (n = 2) or with aortic coarctation (n = 6). Peak velocity measurements made with MR imaging agreed well with measurements made with Doppler ultrasound (US), which were available in 18 cases (standard deviation = 0.2 m/sec). Velocity mapping with fast-echo MR imaging is likely to have considerable importance as a noninvasive means of locating and evaluating stenoses, particularly at sites inaccessible to US, but care must be taken to prevent errors caused by malalignment, signal loss, phase wrap, or partial-volume effects. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|