Bolus-chase Three-dimensional Contrast-enhanced Peripheral Arterial MR Angiography With Automatic Moving-table And Automated Trigger Technique In Aortoiliac Arteries And Lower Extremity Arteries

Purpose: Our study included three aspects: 1) To determine the optimal biphasic bolus rate based on automated table movement and bolus-chase technique for aortoiliac and lower extremity arteries of contrast-enhanced magnetic resonance angiography. 2) To improve the image quality in infrapopliteal arteries with combining body coil and biphasic injection protocol with higher matrix and different zero filling techniques.3) To evaluate the feasibility and convenience with three-station contrast-enhanced MR angiography in peripheral artery diseases by applying the biphasic injection protocol and higher matrix optimized mentioned above. Materials and methods: All examinations were performed on a 1.5T scanner (Signa, GE Medical Systems, Milwaukee,Wis) with a 3D fSPGR sequence. A body coil was used for signal transmission and reception. For all examinations, 0.2-0.25mmol/kg of gadopentetate dimeglumine (Magnevist, Schering, Guangzhou, China) was used. Precise injection rates were ensured by means of an automated power injector (Spectris; Medrad, Indianola, Pa). For bolus-chase MR angiography, commercially available software (SmartPrep; GE Medical Systems) was used.1) Eleven healthy volunteers were performed contrast-enhanced MR angiographic examinations in aortoiliac and lower extremity arteries in three-station techniques. A biphasic bolus protocol was designed, the first half of the contrast agent volume was injected at a rate of 2.0ml/sec, and the second half was injected at a rate of 1.0ml/sec in groupl, 0.8ml/sec in group2, 0.5ml/sec in group3, then was flushed with 20ml of saline at a rate of 2.0ml/sec. The imaging parameters for acquisition of the mask images were identical to those used for acquisition of the contrast-enhanced images: repetition time msec/echo time msec of 4.5-4.7/1.0-1.1, flip angle of 30(?), field of view of 44×44-39.6cm, 256×128-224 matrix, 34-42 sections, effective section thickness of 2.0-3.0mm, zero interpolation to 1.0- 1.5mm, acquition time in three station is 17 seconds, 19 seconds, 40 seconds, respectively. The entire artery tree from infrarenal aorta to dorsalis pedis artery were observed, and signal to noise ratio (SNR) and contrast to noise ratio (CNR) on all arteries were measured. Venous enhancement score was calculated by in region of interest. The qualitative and quantitative data of image quality were analyzed using a Student t test. Statistical significance was established at p<0.05. 2) Eleven...