ABSTRACT
Objective To evaluate the relaxation rates and imaging effects of three MRI contrast agents gadopentetate dimeglumine(0.5 mol/L),gadodiamine and gadovist(1.0 mol/L) in the nervous system.Methods Relaxation rate differences between the three contrast agents were assessed using the GE Signa HDx 3.0 T MR scanner and phantom solutions of different albumin concentrations.Twenty leukemia patients whose initial scans had been conducted with the injection of a standard dose(0.5 mol/L)of gadopentetate dimeglumine as the contrast agent were recalled to have a follow-up scan for signs of brain infections with the same imaging protocols,except that a high concentration(1.0 mol/L)gadovist was used this time as the contrast agent.CNR and SNR in the ROI were measured for quantitative analysis.Results Changes in dosage of the three contrast agents produced no difference in intensity of the image signal for each phantom solution of a specific albumin concentration(5.0 g/L:P=0.35,6.5g/L:P =0.27,8.0 g/L:P=0.23).Two sets of scans of the leukemia patients showed that high concentration(1.0 mol/L)gadovist generated higher SNR and CNR in the ROI of the white matter,gray matter and vasculature than standard concentration(0.5 mol/L) gadopentetate dimeglumine(P＜ 0.05).Conclusions A half dose of high concentration(1.0 mol/L) gadovist generates better imaging enhancement than standard concentration(0.5 mol/L)gadopentetate dimegluminethe.Gadopentetate dimeglumine,gadodiamide and gadovist have no significant difference in relaxation rate.
ABSTRACT
Purpose To investigate the feasibility of T1 measurement using multi-slice inversion recovery turbo spin echo (IR-TSE) and variable flip angle three-dimensional fast low angle shot (3D FLASH) for full-joint coverage delayed gadolinium enhanced MRI of the cartilage. Materials and Methods MR phantoms using dilated gadolinium solution with different concentrations and ex vivo bovine cartilages were scanned using multi-slice IR-TSE and variable flip angle 3D FLASH sequences and the T1 values were calculated. The referring T1 value were obtained using single slice IR-TSE sequence. Results On phantom study, the correlation coefficiencies between multi-slice IR-TSE, 3D FLASH sequences and single slice IR-TSE was 1.000 and 0.997, respectively, where P<0.001 on ex vivo bovine cartilage study, the T1 values of the trypsin degraded species measured by single-slice, multi-slice IR-TSE and 3D-FLASH were significantly lower than the control species. The correlation coefficiency between single-slice and multi-slice IR-FSE on the control group, the trypsin degraded group and both was 0.821(P=0.012), 0.968(P=0.001), and 0.953(P=0.001) respectively. The correlation coefficiency between single-slice IR-FSE and 3D-FLASH on the trypsin degraded group, control group and both was 0.199(P=0.637), 0.757(P=0.030), and 0.775(P=0.001) respectively, where P<0.001. Conclusion Both Multi-slice IR-TSE and variable flip angle 3D-FLASH sequences can be applied for T1 measurement of the full joint cartilage.
ABSTRACT
With the increasing number of interventional angiographic procedures, iodinated contrast induced nephropathy has become an important cause of iatrogenic acute renal failure. Gadopentetate dimeglumine, gadolinium chelated by DTPA, are widely used in magnetic resonance imaging without adverse effect on renal function in patients with renal insufficiency. It also has sufficient radiographic density to allow visualization and has been described as an alternative contrast agent for angiography. Here we report a case of successful angioplasty using gadopentetate dimeglumine as a contrast agent in a patient with both renal artery stenosis and renal insufficiency. The patient had a history of iodinated contrast induced acute renal failure. Using this contrast agent, angioplasty was successfully performed and contrast induced acute renal failure did not occur after this procedure.