Özgen Ali
1 Department of Radiology, Yeditepe University, İçerenköy Mahallesi, Hastane Yolu Sokak, Number 102-104, Ataşehir, Istanbul 34752, Turkey.
2 Department of Radiology, Memorial Hospitals Group, Istanbul, Turkey.
AJR Am J Roentgenol. 2017 Mar;208(3):603-608. doi: 10.2214/AJR.16.16774. Epub 2016 Dec 22.
The objective of this study was to determine the value of the T2-weighted multipoint Dixon technique as a single sequence in MRI of the sacroiliac joints for the diagnosis of active and chronic sacroiliitis.
The T2-weighted multipoint Dixon sequence with water-only, in-phase, opposed-phase, and fat-only images was added to a routine MRI protocol, which included T1-weighted, fat-saturated T2-weighted, and contrast-enhanced fat-saturated T1-weighted sequences, for imaging 73 patients. Images obtained as part of the routine protocol were reviewed first by two radiologists. Then, the T2-weighted multipoint Dixon images were reviewed separately. Signs of active inflammation detected on fat-saturated T2-weighted and contrast-enhanced fat-saturated T1-weighted images were compared with the water-only images. Signs of chronic sacroiliitis detected on T1-weighted images were compared with the fat-only, in-phase, and opposed-phase images. Contrast-to-noise ratios (CNRs) of all lesions were statistically analyzed. ANOVA and posthoc Tukey tests were used to compare CNR data.
The mean CNR of 34 lesions with bone marrow edema or osteitis was greater on the water-only images (CNR, 176) than on the fat-saturated T2-weighted images (CNR, 82) and the contrast-enhanced fat-saturated T1-weighted images (CNR, 56), and this difference in mean CNRs was statistically significant (p < 0.01). There were also statistically significant differences in CNRs between sequences (p < 0.01). The highest mean CNR for subchondral sclerosis in 23 lesions was noted on in-phase images, and the highest mean CNR for periarticular fat deposition in 29 lesions was noted on opposed-phase images. Qualitative analyses also revealed that T2-weighted multipoint Dixon images were superior in showing signs of both active and chronic sacroiliitis.
The T2-weighted multipoint Dixon sequence is superior to conventional MRI sequences in depicting diagnostic signs of active and chronic sacroiliitis and therefore may be used as a single sequence.
本研究的目的是确定T2加权多回波 Dixon技术作为骶髂关节MRI单一序列在诊断活动性和慢性骶髂关节炎中的价值。
将具有纯水、同相位、反相位和纯脂肪图像的T2加权多回波 Dixon序列添加到常规MRI检查方案中，该方案包括T1加权、脂肪抑制T2加权和对比增强脂肪抑制T1加权序列，对73例患者进行成像。作为常规检查方案一部分获得的图像首先由两名放射科医生进行评估。然后，分别对T2加权多回波 Dixon图像进行评估。将在脂肪抑制T2加权和对比增强脂肪抑制T1加权图像上检测到的活动性炎症征象与纯水图像进行比较。将在T1加权图像上检测到的慢性骶髂关节炎征象与纯脂肪、同相位和反相位图像进行比较。对所有病变的对比噪声比（CNR）进行统计学分析。采用方差分析和事后 Tukey检验比较CNR数据。
34例伴有骨髓水肿或骨炎的病变在纯水图像上的平均CNR（176）高于脂肪抑制T2加权图像（82）和对比增强脂肪抑制T1加权图像（56），且平均CNR的差异具有统计学意义（p<0.01）。序列间的CNR也存在统计学显著差异（p<0.01）。23例软骨下硬化病变在同相位图像上的平均CNR最高，29例关节周围脂肪沉积病变在反相位图像上的平均CNR最高。定性分析还显示，T2加权多回波 Dixon图像在显示活动性和慢性骶髂关节炎征象方面更具优势。
T2加权多回波 Dixon序列在描绘活动性和慢性骶髂关节炎的诊断征象方面优于传统MRI序列，因此可作为单一序列使用。
