刀锋伪影校正技术在精神疾病患者海马MRI检查中的应用

为探讨磁共振刀锋伪影校正(BLADE)技术提升精神疾病患者海马磁共振图像质量的效果,本文分别使用结合了BLADE技术的BLADE T2WI TSE、BLADE T2WI FLAIR及传统T2WI TSE、T2WI FLAIR四种序列,对47例精神疾病患者和美国放射学院(ACR)标准模体在3.0 T磁共振成像(MRI)设备上分别进行常规海马斜冠状位扫描和ACR标准检测.患者的磁共振图像由2名放射科医师采用5分法对运动伪影、搏动伪影、颗粒度、海马磁共振图像质量进行评价,并应用Wilcoxon符号秩检验进行数据分析.模体图像通过识别图像的钻孔阵列和轮辐的数目,半定量评价各序列的高对比空间分辨力(HCSR)和低对比物体探测能力(LCD).结果表明相比传统序列,结合BLADE技术的序列能够明显改善海马磁共振图像的运动伪影、搏动伪影(p<0.001),提高图像质量(p<0.05);但在图像颗粒度方面,传统序列表现更优(p<0.001).ACR模体半定量分析显示,结合BLADE技术序列与传统序列相比,在LCD检测方面结果更优、在HCSR检测方面结果相同或略逊.本文推荐将BLADE技术应用于不合作的精神疾病患者海马的MRI检查.

Imaging Hippocampus of Mental Patients with BLADE Technique

BLADE is the commercial name of a spin-echo imaging technique that uses periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) k-space trajectory. In this study, the efficiency of using BLADE to improve hippocampal imaging in mental patients was assessed. The hippocampi of 47 mental patients were imaged on a 3.0 T scanner along the oblique coronal orientation using the T₂WI TSE and T₂WI FLAIR sequences with or without the use of BLADE. The same four sequences were also used to scan a standard American College of Radiology (ACR) phantom according to the ACR standards. The hippocampal images were scored by two radiologists using a 5-point scale, in terms of motion artifact, pulsation artifact, perceptive coarseness and image quality. The outcomes were compared between the sequences by two-sample Wilcoxon tests. The images of the phantom were evaluated semi-quantitatively for high contrast spatial resolution (HCSR) and low contrast object detection detectability (LCD) by counting the number of hole arrays and spokes that could be detected. The results showed that, compared to the conventional sequences, the sequences combined with BLADE technique showed significantly reduced motion and pulsation artifacts (p<0.001), improved image quality (p<0.05), but increased the perceptive coarseness (p<0.001). In the phantom experiments, the use of BLADE greatly improved the LCD, but had little effects on the HCSR. Based on these results, the BLADE technique is recommended for hippocampal imaging in mental patients with low compliance with the guidance.