Effect of tendon orientation on MR imaging signal intensity: a manifestation of the 'magic angle' phenomenon
| Autor: | Guillermo F. Carrera, L. D. Estkowski, James S. Hyde, I H Cox, J A Strandt, Scott J. Erickson |
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| Rok vydání: | 1991 |
| Předmět: |
Wrist Joint
Magic angle medicine.diagnostic_test Shoulder Joint Pulse (signal processing) business.industry Magnetic resonance imaging Wrist medicine.disease Magnetic Resonance Imaging Tendon Tendons medicine.anatomical_structure Nuclear magnetic resonance Tendinitis Orientation (geometry) medicine Humans Radiology Nuclear Medicine and imaging Ankle Artifacts business Ankle Joint |
| Zdroj: | Radiology. 181:389-392 |
| ISSN: | 1527-1315 0033-8419 |
| DOI: | 10.1148/radiology.181.2.1924777 |
| Popis: | To determine whether orientation in the static field may be responsible for the frequent occurrence of increased signal intensity within normal tendons at magnetic resonance (MR) imaging, seven healthy volunteers were imaged by means of a 1.5-T unit and standard clinical pulse sequences. The wrist, ankle, and shoulder regions were evaluated with local coils. Imaging was performed with tendon orientations ranging from 0 degree to 90 degrees in relation to the constant magnetic induction field (B0). Markedly increased intratendinous signal intensity was observed at the "magic angle" of 55 degrees, intermediate signal intensity was observed at 45 degrees and 65 degrees, and no signal intensity was observed at 0 degree and 90 degrees. Signal intensity was evident only when a short echo time was used. The authors believe that tendon orientation greatly affects tendon signal intensity in vivo. Increased signal intensity due to the magic angle effect may be misdiagnosed as tendinous degeneration, tendinitis, or frank tear. |
| Databáze: | OpenAIRE |
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