CAJ | 학술논문

目的探讨3.0 T血氧水平依赖功能MRI(fMRI-BOLD)技术在碘对比剂大鼠肾脏损害评价中的应用价值.方法 29只SD大鼠分别于注入碘对比剂前、注入碘对比剂碘普胺后20 min、24 h、48 h、72 h不同时间点进行常规MR序列及BOLD序列扫描;注入碘对比剂前作为对照组.BOLD序列扫描图像在工作站处理后,测量大鼠肾脏皮质、外髓及内髓的T2*值,计算表观自旋-自旋弛豫率(R2*值)(R2*值=1/T2 *值).对照组大鼠双肾不同部位R2*值的比较采用方差分析,对照组和实验组不同时间、不同部位右肾和左肾R2*值的比较采用t检验.结果对照组大鼠左、右肾脏外髓R2*值[分别为(31.76±2.73)/s和(32.77±3.07)/s]均高于相应皮质[分别为(30.20±3.48)/s和(28.84±3.11)/s]及内髓[分别为(29.54±2.42)/s和(28.37±2.80)/s],F值分别为3.357和14.961,P值均＜0.05.左肾和右肾内髓、外髓和皮质的R2*值差异均无统计学意义(P值均＞0.05).注入碘对比剂后不同时间点,以外髓R2*值变化明显.在注射对比剂20 min时,肾脏外髓R2*值最高[右肾和左肾分别为(44.58±3.13)/s和(43.57±3.84)/s],24 h后R2*值逐渐降低[右肾和左肾分别为(42.89±3.40)/s和(42.07±4.82)/s].内髓及皮质R2*值仅表现为轻微改变.结论 R2*值能反映出大鼠肾脏皮、髓质氧分压的变化,判断髓质缺血缺氧程度.BOLD成像技术能反映肾脏皮髓质氧代谢情况,评估肾脏损害程度,是一种简单、可行及重复性较好的方法.
목적 탐토3.0 T혈양수평의뢰공능MRI(fMRI-BOLD)기술재전대비제대서신장손해평개중적응용개치.방법 29지SD대서분별우주입전대비제전、주입전대비제전보알후20 min、24 h、48 h、72 h불동시간점진행상규MR서렬급BOLD서렬소묘;주입전대비제전작위대조조.BOLD서렬소묘도상재공작참처리후,측량대서신장피질、외수급내수적T2*치,계산표관자선-자선이예솔(R2*치)(R2*치=1/T2 *치).대조조대서쌍신불동부위R2*치적비교채용방차분석,대조조화실험조불동시간、불동부위우신화좌신R2*치적비교채용t검험.결과 대조조대서좌、우신장외수R2*치[분별위(31.76±2.73)/s화(32.77±3.07)/s]균고우상응피질[분별위(30.20±3.48)/s화(28.84±3.11)/s]급내수[분별위(29.54±2.42)/s화(28.37±2.80)/s],F치분별위3.357화14.961,P치균＜0.05.좌신화우신내수、외수화피질적R2*치차이균무통계학의의(P치균＞0.05).주입전대비제후불동시간점,이외수R2*치변화명현.재주사대비제20 min시,신장외수R2*치최고[우신화좌신분별위(44.58±3.13)/s화(43.57±3.84)/s],24 h후R2*치축점강저[우신화좌신분별위(42.89±3.40)/s화(42.07±4.82)/s].내수급피질R2*치부표현위경미개변.결론 R2*치능반영출대서신장피、수질양분압적변화,판단수질결혈결양정도.BOLD성상기술능반영신장피수질양대사정황,평고신장손해정도,시일충간단、가행급중복성교호적방법.
Objective To evaluate blood oxygen level-dependent (BOLD) MRI on assessing renal damage after injection of iodine contrast medium with a 3.0 T system. Methods Routine MRI examination,including T1WI and T2WI, and BOLD MRI were performed in 29 SD rats with a 3.0 T system before the injection of iodine contrast agent and 20 min, 24 h, 48 h, 72 h after the injection, respectively. T2 * and R2 * ( = 1/T2 * ) measurements were obtained in the cortex, inner and outer medulla of kidney,respectively. The results obtained before contrast agent administration were considered as the self-controls.AVONA test were used for the comparison of R2 * values in different parts of both kidneys before contrast agent administration. Two-sample t test was used to compare R2 * values before and at each time point after contrast agent administration, and R2 * values in different parts of the kidneys. Results Before contrast agentadministration, R2 * values in outer medulla in both sides of kidney [R2 *left oM = (31.76 ± 2.73 ) / s,R2 * right OM = (32.77±3.07) /s] were higher than those in cortex [R2 * left c=(30.20±3.48) /s,R2 * right c = (28.84 ±3.11 )/s] and in inner medulla [ R2 * letf IM = (29.54 ± 2.42) /s, R2 * right IM =(28.37±2.80) /s ] ( F = 3.357 and 14.961, P＜ 0.05 ). There was no statistical significance in R2 *values in the three parts between left and right kidney, including cortex, outer and inner medulla (P＞0.05). After contrast agent administration, R2* values in outer medulla changed obviously, which reached to the peak values at 20 minutes after contrast agent administration [R2* left OM = ( 43.57 ± 3.84 )/s,R2*right OM= (44.58±3.13) /s] and dropped from 24 hours [R2*left OM = (42.07 ±4.82) /s,R2* right OM = (42.89±3.40) /s]. R2* values in inner medulla and cortex only presented slight changes.Conclusion R2* values reflected the changes of oxygen content in renal cortex and medulla quantitatively,which helped for detecting medullar ischemia and hypoxia. BOLD MR imaging could offer a feasible method for evaluating oxygen metabolism and renal injury in cortex and medulla.