Department of Radiology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China.
Department of Rheumatology, Nanjing Drum Tower Hospital, Affiliated Hospital of Nanjing University Medical School, Nanjing, China.
J Magn Reson Imaging. 2019 Jan;49(1):101-108. doi: 10.1002/jmri.26194. Epub 2018 Aug 13.
Conventional magnetic resonance (MR) imaging is limited in providing sufficient information on microstructure or in quantitatively evaluating certain inflammation processes. Functional MR sequences such as diffusion kurtosis imaging (DKI) might help to evaluate the sacroiliac joint in ankylosing spondylitis (AS) patients.
To explore the application of DKI in evaluating the disease activity of AS.
Prospective.
Forty-four patients with a diagnosis of AS according to the Assessment in SpondyloArthritis International Society (ASAS) criteria.
FIELD STRENGTH/SEQUENCE: 3.0T MRI including the DKI sequence (b = 0, 500, 1000, 1500, 2000 s/mm ).
Two-independent-samples t-test and one-way analysis of variance (ANOVA) were used to compare the DKI parameters among different groups, and post-hoc Scheffe's method was adopted. Receiver operating characteristic (ROC) analysis and Spearman's rank correlation were performed to test the diagnostic performance of DKI parameters in distinguishing different activity grades and the correlation between them, respectively.
AS disease activity was evaluated according to the Ankylosing Spondylitis Disease Activity Score (ASDAS), and four disease activity states were chosen by consensus: inactive disease and moderate, high, and very high disease activity. The three cutoffs selected to separate these states were: 1.3, 2.1, and 3.5 units, respectively.
The corrected ADC (D) and apparent diffusion coefficient (ADC) values of sacroiliac joints in the active group were significantly higher, while the the kurtosis of diffusion (K value) value was significantly lower than those of the inactive group (all P < 0.001). The D value performed best in distinguishing different activity grades (all P < 0.001). The D and ADC values correlated positively, while the K value correlated negatively, with activity grade significantly (r = 0.918, 0.798, and -0.765, respectively; all P < 0.001).
DKI of sacroiliac joints might be useful to evaluate the disease activity of AS.
2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:101-108.
常规磁共振成像（MR）在提供关于微观结构的充分信息或定量评估某些炎症过程方面存在局限性。功能磁共振序列，如扩散峰度成像（DKI），可能有助于评估强直性脊柱炎（AS）患者的骶髂关节。
探讨 DKI 在评估 AS 疾病活动度中的应用。
前瞻性。
根据评估强直性脊柱炎国际协会（ASAS）标准诊断为 AS 的 44 例患者。
磁场强度/序列：3.0T MRI 包括 DKI 序列（b=0、500、1000、1500、2000 s/mm）。
采用两独立样本 t 检验和单因素方差分析（ANOVA）比较不同组之间的 DKI 参数，采用事后 Scheffe 法。采用受试者工作特征（ROC）分析和 Spearman 秩相关分别检验 DKI 参数在区分不同活动度等级和两者之间相关性的诊断性能。
根据强直性脊柱炎疾病活动度评分（ASDAS）评估 AS 疾病活动度，通过共识选择四种疾病活动状态：无疾病活动和中度、高度和极高疾病活动。选择三个截断值来区分这些状态：分别为 1.3、2.1 和 3.5 个单位。
活动组骶髂关节校正 ADC（D）和表观扩散系数（ADC）值明显升高，而扩散峰度（K 值）值明显降低（均 P<0.001）。D 值在区分不同活动度等级方面表现最佳（均 P<0.001）。D 值和 ADC 值与活动度呈正相关，而 K 值与活动度呈负相关（r 值分别为 0.918、0.798 和-0.765，均 P<0.001）。
骶髂关节 DKI 可能有助于评估 AS 的疾病活动度。
2 技术功效：2 级 J. Magn. Reson. Imaging 2019；49：101-108.
