Purpose
Gadolinium-enhanced magnetic resonance angiography (MRA) is increasingly being used as the technique of choice for imaging the vascular system. This technique has several advantages over conventional digital subtraction angiography (DSA). MRA is non-invasive and does not require ionizing radiation. Moreover, the gadolinium contrast agent used has minimal renal effects; this renders the technique particularly useful in patients with concurrent renal failure. However, it has been recently reported that a serious adverse effect called nephrogenic systemic fibrosis (NSF) may occur after exposure to gadodiamide, an extracellular,...
Methods and Materials
Materials: Between November 2007 and July 2008, 31 consecutive patients who underwent MR portography at the University of Miyazaki Hospital were enrolled in this study. These included 20 men and 11 women patients, (mean age of 63.4 years; range, 21-80 years). The patient population is presented in Table 1. Methods: Magnetic resonance imaging (MRI) examination was performed using a 1.5-T system (EXCELART Vantage; TOSHIBA) with a body phased-array coil. SPIO- enhanced MR portography was performed using coronal respiratory-triggerd 3D true SSFP with the following parameters:...
Results
The CNRs before the administration of SPIO were 3.05 ± 1.12 in the main portal vein, 2.27 ± 1.40 in the right portal vein, 2.25 ± 1.46 in the left portal vein, 2.16 ± 1.24 in the ascending peripheral branch (P8 or P7), and 1.79 ± 1.19 in the descending peripheral branch (P5 or P6). After the administration of SPIO, these values significantly increased to 5.31 ± 1.57, 4.18 ± 1.15, 4.77 ± 1.81, 3.86 ± 1.51, 3.74 ± 1.53, respectively (Table 3). The qualitative...
Conclusion
The results of quantitative and qualitative analyses suggested that the spin labeling portography with SPIO was more effective than that without SPIO in depicting the portal vein. After SPIO administration, the background signal was considerably suppressed because of the decrease in the signal of the liver parenchyma. The increase in the vessel-to-liver contrast was also influenced by the T1 shortening effect. Therefore, the depiction of intrahepatic vessels, including the portal vein, was improved after SPIO administration. We speculate that the suppression of the background signal...
