無顯影劑磁振血管影像技術在腎動脈成像之初步研究

Detection of Renal artery by Using Non-Contrast-Enhanced MR Angiography with Time-Spatial Labeling Inversion Pulses: Preliminary Results

劉靜文(Jing-Wen Liu) ； 黃偉倫(Wei-Lun Huang) ； 林新傑(Hsin-Chieh Lin) ； 丘思穎(See-Ying Chiou) ； 李威興(Wei-Hsing Lee) ； 陳名聖(Ming-Sheng Chern) ； 呂坤木(Kun-Mu Lu) ； 陳良光(Liang-Kuang Chen)

《台灣應用輻射與同位素雜誌》 7卷2期 (2011/06) Pp. 75-81

https://doi.org/10.29832/TJARI.201106.0004

摘要

近年來的統計，腎臟病仍列在國人的十大死因當中，腎動脈狹窄是導致腎衰竭的重要原因之一，其形成的過程多爲動脈粥狀硬化造成血管壁的變化，長期甚至會導致嚴重的高血壓。在影像學檢查中，腎動脈磁振血管攝影因非侵入性及高診斷率，所以成爲優先考慮的方法，但是注射顯影劑對於腎功能異常或顯影劑過敏體質者，仍造成潛在的風險，因此，無顯影劑磁振血管影像技術便可望能解決此狀況。本研究收集20位受檢者，包括男性10例，女性10例，年齡34~53歲，平均年齡爲47歲。以Time-SLIP (Time-Spatial Labeling Inversion Pulse)技術，搭配3DTrue-SSFP (True-steady-state free-precession)波序，調整不同TI (Inversion Time)值進行測試研究，利用2位放射科醫師以4級評分法(four-point scale)評估腎動脈的MIP影像，另外測量影像訊雜比，評估原始影像的影像品質。研究結果顯示，在四組不同TI值(700、1000、1300、1600ms)的影像中，TI=1300ms可以獲得較佳的背景抑制效果，並且可顯示較多的腎動脈分支。根據本研究結果，我們可以證明，利用Time-SLIP技術搭配3D True-SSFP波序，應用在腎動脈血管檢查上，可獲得良好的影像品質。因此，無顯影劑磁振血管影像技術可作爲腎動脈血管的另一種檢查方式。

關鍵字

腎動脈磁振血管攝影 ； 無顯影劑磁振血管攝影 ； Time-SLIP ； 3D True-SSFP

並列摘要

Purpose: The purpose of this study is to demonstrate renal artery by using three-dimensional (3D) true Steady-State Free-Precession (SSFP) MR angiography with a novel time-spatial labeling inversion pulses (T-SLIP), and to optimize the acquisition protocol. Materials and Methods: Respiratory-gated 3D true SSFP scans were conducted in 20 subjects with different inversion time (TI) of T-SLIP, and the images was obtained at four different TIs of 700, 1000, 1300, 1600 msec. There are two quantitative ways to determine the imaging quality. First, two experienced radiologists reviewed the renal artery 3D images (MIP) with 4-points to score the different parameters. The other quantitative measurement is to calculate the signal-to-noise ratio (SNR) for renal artery images (2D). The SNR were calculated using the following formulas: SNR(subscript vessel)=SI(subscript vessel)/SD(subscript noise)，SI(subscript vessel). (SD(subscript noise): SD of signal values in the ROI at the Kidney as the noise). Results: For both readers, the average score of vascular signal in four groups: TI=700, 1000, 1300, 1600msec were 1.3, 3.3, 3.5, 2.6, respectively. And the SNR of renal artery signal in four groups were RRA(1st): 20.15±9.63, 30.18±13.29, 34.00±9.96, 25.71±6.37, LRA(1st): 23.90±9.53, 30.34±8.30, 33.39±5.62, 22.17±6.66, RRA(2nd): 21.65±7.04, 28.73±5.33, 36.21±7.02, 26.10±6.36, and LRA(2nd) 18.92±6.30, 31.25±6.84, 31.96±10.49, 21.34±6.65. Results indicated the TI of 1300 msec was the optimal parameter for best demonstration of renal artery (p＜0.05). (1(superscript st): Proximal segment of renal artery, 2(superscript nd): Main trunk of renal artery.) Conclusion: Non-contrast True SSFP scan with T-SLIP enabled demonstration of the renal artery with excellent imaging quality. By using T-SLIP with adequate parameters and protocol, it can be provide essential imaging information of renal artery morphology.

並列關鍵字

Renal MR angiography ； Non-contrast-enhance MR angiography ； 3D True-SSFP ； Time-SLIP