Tsushima Y, Niemi P, Komu M, Dean P B, Haapanen A, Kormano M
Department of Diagnostic Radiology, Turku University Hospital, Finland.
Am J Nephrol. 1996;16(6):506-12. doi: 10.1159/000169051.
To determine whether T1- or T2-weighted sequences are more informative and practical in dynamic Gd-DTPA-enhanced MR imaging for the evaluation of renal blood flow and function.
Dynamic Gd-DTPA-enhanced MR imaging of the kidney was performed in 7 patients by either T1-weighted TurboFLASH (TR/TE/TI/FA = 9/4/27/8) or T2-weighted FLASH (TR/TE/FA = 32/22/10) sequences for comparison of the enhancement pattern. None of the subjects had a suspicion of renal dysfunction from laboratory data, and the absence of renal artery stenosis was confirmed by conventional angiography.
During the early phase, the marked signal increase in T1-weighted imaging in the renal cortex corresponded to a similar marked decrease in signal intensity in T2-weighted imaging. During the middle and late phases, the medulla was dramatically decreased in intensity on the T2-weighted imaging resulting in a good contrast between the cortex and medulla.
Both sequences may provide almost similar information about the renal cortical blood flow. However, T2-weighted dynamic MR imaging may be more informative than T1-weighted dynamic MR imaging about the concentrating ability in the renal medulla. A high concentration of Gd-DTPA in the tubular structure was suspected to cause a dramatic decrease in intensity in the medulla in T2-weighted imaging.
确定在动态钆喷酸葡胺增强磁共振成像中，T1加权序列还是T2加权序列在评估肾血流和功能方面更具信息价值和实用性。
对7例患者的肾脏进行动态钆喷酸葡胺增强磁共振成像，采用T1加权快速小角度激发序列（TR/TE/TI/FA = 9/4/27/8）或T2加权快速小角度激发序列（TR/TE/FA = 32/22/10）来比较强化模式。所有受试者实验室检查数据均未提示肾功能异常，且常规血管造影证实无肾动脉狭窄。
在早期，肾皮质T1加权成像中信号显著增加，而T2加权成像中信号强度有类似的显著降低。在中晚期，T2加权成像中髓质信号强度显著降低，从而使皮质与髓质之间形成良好对比。
两种序列在提供肾皮质血流信息方面可能几乎相似。然而，在肾髓质浓缩能力方面，T2加权动态磁共振成像可能比T1加权动态磁共振成像提供更多信息。怀疑肾小管结构中高浓度的钆喷酸葡胺导致T2加权成像中髓质信号强度显著降低。
