Objective

To evaluate the feasibility of in-vivo quantitative susceptibility mapping (QSM) of the human kidney.

Methods

An axial single-breath-hold 3D multi-echo sequence (acquisition time 33 s) was completed on a 3 T-MRI-scanner (Magnetom Prisma, Siemens Healthineers, Erlangen, Germany) in 19 healthy volunteers. Graph-cut-based unwrapping combined with the T₂*-IDEAL approach was performed to remove the chemical shift of fat and to quantify QSM of the upper abdomen. Mean susceptibility values of the entire, renal cortex and medulla in both kidneys and the liver were determined and compared. Five subjects were measured twice to examine the reproducibility. One patient with severe renal fibrosis was included in the study to evaluate the potential clinical relevance of QSM.

Results

QSM was successful in 17 volunteers and the patient with renal fibrosis. Anatomical structures in the abdomen were clearly distinguishable by QSM and the susceptibility values obtained in the liver were comparable to those found in the literature. The results showed a good reproducibility. Besides, the mean renal QSM values obtained in healthy volunteers (0.04 ± 0.07 ppm for the right and − 0.06 ± 0.19 ppm for the left kidney) were substantially higher than that measured in the investigated fibrotic kidney (− 0.43 ± − 0.02 ppm).

Conclusion

QSM of the human kidney could be a promising approach for the assessment of information about microscopic renal tissue structure. Therefore, it might further improve functional renal MR imaging.

中文翻译：

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人体肾脏定量药敏图 (QSM) 的可行性

客观的

评估人肾脏体内定量药敏图（QSM）的可行性。

方法

19 名健康志愿者在 3 T-MRI 扫描仪（Magnetom Prisma，Siemens Healthineers，Erlangen，Germany）上完成了轴向单屏气 3D 多回波序列（采集时间 33 秒）。执行基于图形切割的展开与 T ₂ *-IDEAL 方法相结合，以消除脂肪的化学位移并量化上腹部的 QSM。确定并比较了肾脏和肝脏中整个肾皮质和髓质的平均敏感性值。五名受试者被测量两次以检查再现性。一名患有严重肾纤维化的患者被纳入研究，以评估 QSM 的潜在临床相关性。

结果

QSM 在 17 名志愿者和肾纤维化患者中取得了成功。QSM 可以清楚地区分腹部的解剖结构，并且在肝脏中获得的敏感性值与文献中发现的值相当。结果显示出良好的重现性。此外，在健康志愿者中获得的平均肾脏 QSM 值（右侧为 0.04 ± 0.07 ppm，左侧为 - 0.06 ± 0.19 ppm）显着高于在研究的纤维化肾脏中测量的值（- 0.43 ± - 0.02 ppm）。

结论

人体肾脏的 QSM 可能是评估有关微观肾组织结构信息的有前途的方法。因此，它可能会进一步改善功能性肾脏 MR 成像。