Superficial- and deep-tissue temperature increases in anesthetized dogs during exposure to high specific absorption rates in a 1.5-T MR imager
| Autor: | William P. Shuman, A W Guy, D J Schaefer, David R. Haynor, G E Wesbey, Albert A. Moss |
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| Rok vydání: | 1988 |
| Předmět: |
medicine.diagnostic_test
Radio Waves Rf exposure business.industry Specific absorption rate Magnetic resonance imaging Absorption (skin) Magnetic Resonance Imaging Absorption Body Temperature Dogs Nuclear magnetic resonance Deep tissue medicine Animals Anesthesia Radiology Nuclear Medicine and imaging Irradiation business Biomedical engineering |
| Zdroj: | Radiology. 167:551-554 |
| ISSN: | 1527-1315 0033-8419 |
| DOI: | 10.1148/radiology.167.2.3357971 |
| Popis: | Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability. |
| Databáze: | OpenAIRE |
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