Thayyil Sudhin, Cleary Jon O, Sebire Neil J, Scott Rosemary J, Chong Kling, Gunny Roxanna, Owens Catherine M, Olsen Oystein E, Offiah Amaka C, Parks Harold G, Chitty Lyn S, Price Anthony N, Yousry Tarek A, Robertson Nicola J, Lythgoe Mark F, Taylor Andrew M
Centre for Cardiovascular Imaging, University College London (UCL) Institute of Child Health and Great Ormond Street Hospital for Children, London, UK.
Lancet. 2009 Aug 8;374(9688):467-75. doi: 10.1016/S0140-6736(09)60913-2.
Conventional whole-body MRI at 1.5 T does not provide adequate image quality of small fetuses, thus reducing its potential for use as an alternative to invasive autopsy. High-field whole-body MRI at 9.4 T provides good images of small animals. We therefore compared the diagnostic usefulness of high-field MRI with conventional MRI for post-mortem examination of human fetuses.
We did whole-body MRI at 9.4 T and 1.5 T on 18 fetuses of less than 22 weeks' gestation, using three-dimensional T(2)-weighted fast-spin echo sequences, before doing invasive autopsy. Images obtained with MRI for each system were compared with the findings of invasive autopsy in a blinded manner. Tissue contrast of 14 different regions was compared on 1.5 T and 9.4 T images that were provided by paediatric radiologists separately and in a random order, and image quality was scored on a four-point scale. The primary endpoint was diagnostic accuracy.
Spatial resolution, tissue contrast, and image quality of all organ systems were much better with high-field MRI than with conventional MRI. All structural abnormalities that were detected with invasive autopsy and internal examination of visceral organs were also detected with high-field MRI, whereas conventional MRI was not diagnostically useful in 14 (78%) cases.
Whole-body high-field MRI is a feasible option for post-mortem examination of human fetuses, and can provide good tissue characterisation even in small fetuses (5 g). The use of MRI at 9.4 T might be helpful in the development of a minimally invasive perinatal autopsy system.
Department of Health Policy Research Programme, British Heart Foundation, National Institute of Health Research, Higher Education Funding Council for England, Biotechnology and Biological Sciences Research Council, Engineering and Physical Sciences Research Council, Great Ormond Street Hospital, University College London (UCL) Institute of Child Health, UCL Hospital, and UCL.
1.5T的传统全身MRI无法提供小胎儿的足够图像质量，从而降低了其作为侵入性尸检替代方法的应用潜力。9.4T的高场全身MRI能提供小动物的良好图像。因此，我们比较了高场MRI与传统MRI在人类胎儿尸检中的诊断效用。
在进行侵入性尸检前，我们使用三维T2加权快速自旋回波序列，对18例妊娠少于22周的胎儿进行了9.4T和1.5T的全身MRI检查。将每个系统MRI获得的图像与侵入性尸检的结果进行盲法比较。由儿科放射科医生分别以随机顺序提供1.5T和9.4T图像，比较14个不同区域的组织对比度，并按四分制对图像质量进行评分。主要终点是诊断准确性。
高场MRI的所有器官系统的空间分辨率、组织对比度和图像质量均明显优于传统MRI。侵入性尸检和内脏器官内部检查发现的所有结构异常在高场MRI中也能检测到，而传统MRI在14例（78%）病例中诊断无用。
全身高场MRI是人类胎儿尸检的可行选择，即使在小胎儿（5g）中也能提供良好的组织特征。使用9.4T的MRI可能有助于开发微创围产期尸检系统。
卫生政策研究计划部、英国心脏基金会、国家卫生研究院、英格兰高等教育资助委员会、生物技术和生物科学研究委员会、工程和物理科学研究委员会、大奥蒙德街医院、伦敦大学学院儿童健康研究所、伦敦大学学院医院和伦敦大学学院。
