Kwok Wingchi Edmund, You Zhigang, Monu Johnny, He Hua
Department of Imaging Sciences, University of Rochester, Rochester, New York, USA.
Department of Epidemiology, Tulane University School of Public Health and Tropic Medicine, New Orleans, Louisiana, United States.
J Clin Imaging Sci. 2019 May 24;9:19. doi: 10.25259/JCIS-20-2019. eCollection 2019.
High-resolution images of finger joints with chemical-shift elimination can be obtained using an interleaved water-fat (IWF) sequence. This study assessed IWF imaging of finger joints in the delineation of bone structures by comparing images of cadaver fingers with those of microcomputed tomography (CT) that served as a standard reference.
IWF images with spatial resolution of 176 µ × 176 µ × 300 µ were obtained from the distal and proximal interphalangeal joints of two cadaver finger specimens using a custom-built radiofrequency receive coil at 1.5T. Regular three-dimensional gradient-echo (GRE) images were also acquired with similar parameters and compared with the IWF images to evaluate the effects of chemical shift. Micro-CT scans were obtained and served as the standard reference. The image data were reviewed by two experienced musculoskeletal radiologists in consensus. The delineation of normal joint structures and abnormalities in the finger specimens as revealed by the magnetic resonance imaging (MRI) and micro-CT images were compared. The IWF and regular GRE images were assigned scores 0-3 for the depiction of apparent marginal bone defects, with zero being the same in appearance to the micro-CT image and three as having minimal resemblance to it. Statistical analysis of the scoring results was conducted to compare the two MRI techniques.
The high-resolution IWF images provided accurate delineation of bone and calcified structures as seen in micro-CT. The thickness of subchondral bone was depicted similarly on the IWF water + fat and the micro-CT images but not on the regular GRE images. The regular GRE sequence showed false marginal bone defects not observed with IWF and micro-CT. In addition, the IWF water-only images facilitated the identification of bone cyst by revealing its water content.
High-resolution IWF imaging should be useful for the early diagnosis and treatment assessment of arthritis and should also benefit basic research in the pathophysiology of the disease.
使用交错水脂（IWF）序列可获得消除化学位移的手指关节高分辨率图像。本研究通过将尸体手指图像与作为标准参考的微型计算机断层扫描（CT）图像进行比较，评估IWF成像在手指关节骨结构描绘中的应用。
使用定制的射频接收线圈，在1.5T条件下从两个尸体手指标本的远侧和近侧指间关节获取空间分辨率为176µ×176µ×300µ的IWF图像。还使用类似参数采集常规三维梯度回波（GRE）图像，并与IWF图像进行比较，以评估化学位移的影响。进行微型CT扫描并作为标准参考。图像数据由两位经验丰富的肌肉骨骼放射科医生共同审核。比较磁共振成像（MRI）和微型CT图像显示的手指标本中正常关节结构和异常的描绘情况。IWF和常规GRE图像在描绘明显的边缘骨缺损方面被赋予0 - 3分，0分表示与微型CT图像外观相同，3分表示与微型CT图像相似度最低。对评分结果进行统计分析以比较两种MRI技术。
高分辨率IWF图像能准确描绘微型CT所见的骨和钙化结构。IWF水 + 脂图像和微型CT图像上软骨下骨的厚度描绘相似，但常规GRE图像上则不然。常规GRE序列显示出IWF和微型CT未观察到的假边缘骨缺损。此外，IWF仅水图像通过显示骨囊肿的含水量有助于其识别。
高分辨率IWF成像应有助于关节炎的早期诊断和治疗评估，也应有利于该疾病病理生理学的基础研究。
