"Black bone" MRI: a partial flip angle technique for radiation reduction in craniofacial imaging
"Black bone" MRI: a partial flip angle technique for radiation reduction in craniofacial imaging
复制标题
DOI：
10.1259/bjr/95110289
复制
发表时间：
2012-03-01
影响因子：
2.6
通讯作者：
Golding, S. J.
中科院分区：
文献类型：
--
作者：
Eley, K. A.;Mcintyre, A. G.;Golding, S. J.
电离辐射的潜在有害影响继续突出。减少辐射的技术主要包括低剂量技术，而不是向非电离成像方法的转变。尽管CT扫描是辐射防护的关键解剖区域之一，但考虑到辐射敏感的晶状体和甲状腺，CT扫描仍经常用于头面部骨骼的成像。我们描述了一种低翻转角度梯度回波MRI序列，它在骨骼和其他组织之间提供高图像对比度，但降低单个软组织之间的对比度。这使得“黑骨”很容易与软组织的一致性区分开来。在保持8.6ms的重复时间和4.2ms的回声时间的情况下，提供脂肪和水的最佳抑制的翻转角度被确定为5度。使用体模获得直接的解剖学测量和可比的CT扫描，证实了该序列的生物统计学准确性。黑骨MRI测量值与直接解剖测量值之间的平均偏差为0.32 mm。因此，黑骨MRI有可能通过在成像面部骨骼时取代CT扫描来减少辐射暴露，尤其适用于年轻人的良性疾病成像。
The potential harmful effects of ionising radiation continue to be highlighted. Radiation reduction techniques have largely consisted of low-dose techniques rather than a shift to non-ionising methods of imaging. CT scanning is frequently employed for imaging the craniofacial skeleton despite being one of the key anatomical regions for radiation protection in view of the radiosensitive lens and thyroid gland. We describe a low flip angle gradient echo MRI sequence which provides high image contrast between bone and other tissues but reduces the contrast between individual soft tissues. This permits the "black bone" to be easily distinguished from the uniformity of the soft tissues. While maintaining a repetition time of 8.6 ms and an echo time of 4.2 ms, the flip angle which provided optimised suppression of both fat and water was identified to be 5 degrees. The biometric accuracy of this sequence was confirmed using a phantom to obtain direct anatomical measurements and comparable CT scanning. The average discrepancy between black bone MRI measurements and direct anatomical measurements was 0.32 mm. Black bone MRI therefore has the potential to reduce radiation exposure by replacing CT scanning when imaging the facial skeleton, with particular scope for imaging benign conditions in the young.