Elste V, Wagner S, Taupitz M, Pfefferer D, Kresse M, Hamm B, Berg R, Wolf K J, Semmler W
Universitätsklinikum Benjamin Franklin Radiologische Klinik, Freie Universität Berlin, Germany.
Acad Radiol. 1996 Aug;3(8):660-6. doi: 10.1016/s1076-6332(96)80193-0.
We investigated the influence of muscular activity and regional body temperature changes on the accumulation of intravenously (i.v.) administered, dextran-coated superparamagnetic iron oxide (SPIO) particles in the lymph nodes of rats.
Four groups of rats (N = 21) were used. Five rats were allowed to move freely after i.v. contrast administration (group 1). In another five rats, muscular inactivity (group 2) was induced during i.v. injection of SPIO particles and for up to 2 hr thereafter by anesthesia. In seven rats (likewise anesthetized), the contrast agent was administered while the extremities of one side of the body were warmed in a water bath for 2 hr (group 3). The rats in groups 1-3 received 100 mumol Fe/kg of the contrast agent. Four rats not given SPIO particles served as the control group (group 4). The lymph nodes of all animals were removed 24 hr after SPIO administration and were embedded in an agar matrix for magnetic resonance imaging at 1.5 T using a proton-density-weighted spin-echo (PD-SE) sequence and a T2*-weighted gradient-recalled echo (T2* GRE) sequence.
Signal loss varied widely among the different lymph nodes in group 1. A pronounced signal reduction was observed in the mesenteric (PD-SE = 20 +/- 6%, T2* GRE = 55 +/- 19%), iliac (PD-SE = 13 +/- 13%, T2* GRE = 44 +/- 24%), and popliteal (PD-SE = 24 +/- 7%, T2* GRE = 70 +/- 11%) lymph nodes and only a moderate reduction in the mandibular (PD-SE = 4 +/- 7%, T2* GRE = 42 +/- 15%), axillary (PD-SE = 0 +/- 4%, T2* GRE = 8 +/- 7%), and inguinal (PD-SE = 5 +/- 5%, T2* GRE = 34 +/- 18%) lymph nodes. The least pronounced signal loss occurred in the peripheral lymph nodes of group 2, ranging from 0 +/- 3% for PD-SE sequences and 10 +/- 11% for T2* GRE sequences to 13 +/- 15% for PD-SE sequences and 41 +/- 19% for T2* GRE sequences. In group 3, the uptake of contrast material in the peripheral lymph nodes of the hyperthermal side was significantly more pronounced than on the contralateral side (p < .01), and the contrast agent was distributed more evenly to the different lymph node groups than in group 1.
Muscular activity and regional hyperthermia markedly influence the accumulation of SPIO particles in different lymph node groups in rats. These findings must be considered in preclinical studies and in the clinical administration of MR lymphography.
我们研究了肌肉活动和局部体温变化对静脉注射葡聚糖包被的超顺磁性氧化铁（SPIO）颗粒在大鼠淋巴结中蓄积的影响。
使用四组大鼠（N = 21）。五组大鼠在静脉注射造影剂后自由活动（第1组）。另外五组大鼠在静脉注射SPIO颗粒期间及之后长达2小时通过麻醉诱导肌肉不活动（第2组）。在七组大鼠（同样麻醉）中，在将身体一侧的肢体在水浴中加热2小时的同时给予造影剂（第3组）。第1 - 3组大鼠接受100 μmol Fe/kg的造影剂。四只未给予SPIO颗粒的大鼠作为对照组（第4组）。在给予SPIO后24小时取出所有动物的淋巴结，并嵌入琼脂基质中，使用质子密度加权自旋回波（PD - SE）序列和T2 *加权梯度回波（T2 * GRE）序列在1.5 T下进行磁共振成像。
第1组不同淋巴结之间的信号丢失差异很大。在肠系膜淋巴结（PD - SE = 20 ± 6%，T2 * GRE = 55 ± 19%）、髂淋巴结（PD - SE = 13 ± 13%，T2 * GRE = 44 ± 24%）和腘淋巴结（PD - SE = 24 ± 7%，T2 * GRE = 70 ± 11%）中观察到明显的信号降低，而在下颌淋巴结（PD - SE = 4 ± 7%，T2 * GRE = 42 ± 15%）、腋窝淋巴结（PD - SE = 0 ± 4%，T2 * GRE = 8 ± 7%）和腹股沟淋巴结（PD - SE = 5 ± 5%，T2 * GRE = 34 ± 18%）中仅观察到中度降低。第2组外周淋巴结中信号丢失最不明显，PD - SE序列为0 ± 3%，T2 * GRE序列为10 ± 11%至PD - SE序列为13 ± 15%，T2 * GRE序列为41 ± 19%。在第3组中，热侧外周淋巴结中造影剂的摄取明显比另一侧更明显（p <.01），并且造影剂在不同淋巴结组中的分布比第1组更均匀。
肌肉活动和局部热疗显著影响SPIO颗粒在大鼠不同淋巴结组中的蓄积。在临床前研究和磁共振淋巴造影的临床给药中必须考虑这些发现。
