Ultrashort TE MR imaging of bovine cortical bone: The effect of water loss on the T1 and T2* relaxation times

✍ Scribed by Nima Kokabi; Won Bae; Eric Diaz; Christine B. Chung; Graeme M. Bydder; Jiang Du

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 459 KB
• Volume: 66
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.22859

✦ Synopsis

The effects of water loss on the T 1 and T 2 * of bovine cortical bone were investigated using ultrashort echo time sequences with signals excited either by a short hard pulse or by two longer half pulses. Nine bovine femur samples were prepared and sequentially air-and oven-dried. On average 3.42% of bone by weight was lost after air-drying for 3 days, with another 5.98% of bone weight loss after oven-drying at 100°C for 24 h. T 1 and T 2 * were measured after every 1% decrease in weight, with 9-10% bone weight loss at the termination of the drying process. After both forms of drying, the overall T 1 decreased 33% from 153 6 18 ms to 102 6 17 ms when measured using the hard pulse and from 186 6 25 ms to 122 6 23 ms when using the half pulses. T 2 * decreased by 45-50% from 368 6 29 ms to 201 6 19 ms using the hard pulse and from 379 6 35 ms to 191 6 17 ms using the half pulses. A steady decrease of 26-31% was observed in both T 1 and T 2 * with the first 3-4% bone water loss after air-drying. Oven-drying at 100°C for 24 h resulted on an additional 4% T 1 reduction but 25% T 2 * reduction. Magn Reson Med 66:476-482, 2011. V