Departments of Radiology and Bioengineering and Department of Radiology, Rady Children's Hospital, University of California-San Diego, 200 W Arbor Dr, San Diego, CA 92103, USA.
Radiology. 2010 Mar;254(3):837-45. doi: 10.1148/radiol.09081743.
To image cartilage-bone interfaces in naturally occurring and experimentally prepared human cartilage-bone specimens at 3 T by using ultrashort echo time (TE) (UTE) and conventional pulse sequences to (a) determine the appearance of the signal intensity patterns and (b) identify the structures contributing to signal intensity on the UTE MR images.
This study was exempted by the institutional review board, and informed consent was not required. Five cadaveric (mean age, 86 years +/- 4) patellae were imaged by using proton density-weighted fat-suppressed (repetition time msec/TE msec, 2300/34), T1-weighted (700/10), and UTE (300/0.008, 6.6, with or without dual-inversion preparations at inversion time 1 = 135 msec and inversion time 2 = 95 msec) sequences. The UTE images were compared with proton density-weighted fat-suppressed and T1-weighted images and were evaluated by two radiologists. To identify the sources of signal on the UTE images, samples including specific combinations of tissues (uncalcified cartilage [UCC] only, calcified cartilage [CC] and subchondral bone [bone] [CC/bone], bone only; and UCC, CC, and bone [UCC/CC/bone]) were prepared and imaged by using the UTE sequence.
On the UTE MR images, all patellar sections exhibited a high-intensity linear signal near the osteochondral junction, which was not visible on protein density-weighted fat-suppressed or T1-weighted images. In some sections, focal regions of thickened or diminished signal intensity were also found. In the prepared samples, UCC only, CC/bone, and UCC/CC/bone samples exhibited high signal intensity on the UTE images, whereas bone-only samples did not.
These results show that the high signal intensity on UTE images of human articular joints originates from the CC and the deepest layer of the UCC, without a definite contribution from subchondral bone. UTE sequences may provide a way of evaluating abnormalities at or near the osteochondral junction. (c) RSNA, 2010.
通过使用超短回波时间(UTE)和常规脉冲序列,对自然发生和实验制备的人软骨-骨标本的软骨-骨界面进行成像,以(a)确定信号强度模式的外观,以及(b)确定在 UTE MR 图像上产生信号强度的结构。
本研究获得了机构审查委员会的豁免,并且不需要获得知情同意。对 5 个尸体(平均年龄 86 岁 +/- 4 岁)的髌骨进行了质子密度加权脂肪抑制(重复时间毫秒/TE 毫秒,2300/34)、T1 加权(700/10)和 UTE(300/0.008,6.6,带有或不带有反转时间 1 = 135 毫秒和反转时间 2 = 95 毫秒的双反转准备)序列成像。将 UTE 图像与质子密度加权脂肪抑制和 T1 加权图像进行比较,并由两位放射科医生进行评估。为了确定 UTE 图像上信号的来源,制备了包括组织的特定组合(仅未钙化软骨[UCC]、钙化软骨[CC]和软骨下骨[骨][CC/骨]、仅骨;以及 UCC、CC 和骨[UCC/CC/骨])的样本,并使用 UTE 序列对其进行了成像。
在 UTE MR 图像上,所有髌骨切片在软骨-骨交界处附近均显示高强度线性信号,而在质子密度加权脂肪抑制或 T1 加权图像上则不可见。在一些切片中,还发现了局部区域的信号强度增厚或减弱。在制备的样本中,仅 UCC、CC/骨和 UCC/CC/骨样本在 UTE 图像上显示出高信号强度,而仅骨样本则没有。
这些结果表明,人关节的 UTE 图像上的高信号强度源自 CC 和 UCC 的最深层,而软骨下骨没有明确的贡献。UTE 序列可能为评估软骨-骨交界处或其附近的异常提供一种方法。(c)RSNA,2010 年。