Contrast‐enhanced magnetic resonance angiography of the lower extremities: Standard‐dose vs. high‐dose gadodiamide injection

Abstract

Purpose:To compare the efficacy and safety of two different doses (0.1 and 0.3 mmol/kg of body weight [BW]) of gadodiamide for contrast-enhanced magnetic resonance angiography (ce-MRA) of the lower extremities with intraarterial digital subtraction angiography (IA-DSA). Materials and Methods:A total of 30 patients with peripheral arterial occlusive disease underwent IA-DSA and ce-MRA from the aortic bifurcation down to the ankle. Patients were randomized to receive a total dose of 0.1 or 0.3 mmol/kg of BW gadodiamide (Omniscan, Amersham Buchler), administered intravenously as a series of three automatic bolus injections. Ce-MRA was performed with a 1.5-T system using a body phased-array coil, centered stepwise over the calf, thigh, and pelvic region. A fast T1-weighted, three-dimensional gradient-echo sequence was obtained before and after injection of the allocated dose. IA-DSA was performed using the Seldinger technique and a femoral approach. The vessels under investigation were divided into 31 segments, and ce-MRA and IA-DSA image sets were evaluated in a double-blind fashion for the presence of stenosis, presence of collateral vessels, vessel delineation, and overall image quality. Both dose groups were compared with regard to contrast index (CI) and signal-and contrast-to-noise ratios (SNR, CNR). The occurrence of adverse events or side effects was also documented. Sensitivity, specificity, and accuracy were calculated in relation to the results of stenosis grading.Results: A total of 26 patients were entered in the efficacy evaluation, while all 30 patients were included in the safety assessment. The sensitivity, specificity, and accuracy for the 0.1 and 0.3 mmol/kg dose groups were 78.8%/93.0%/ 88.9% vs. 60.2.%/91.5%/83.2%, respectively. The detection of collaterals was similar to IA-DSA for the 0.3 mmol/kg dose group (30.2% vs. 27.4%), but was lower in the 0.1 mmol/kg dose group (27.3% vs. 12.3%). The highdose gadodiamide injection proved to be superior to the 0.1 mmol/kg dose group with regard to vessel delineation and overall image quality (P ϭ 0.007 and P ϭ 0.002, respectively). The difference between the two dose groups regarding CI, SNR, and CNR was significant (P ϭ 0.0001), in favor of the 0.3 mmol/kg dose group. No adverse events were observed in any of the patients. Conclusion:Ce-MRA with gadodiamide is safe and efficacious. Comparison of two different doses with IA-DSA as the standard of reference showed that the 0.3 mmol/kg dose is superior to the standard 0.1 mmol/kg dose with respect to contrast enhancement, vessel delineation, image quality, and detection of collaterals. However, the 0.1 mmol/kg dose was superior to the high dose in the grading of stenosis.

Multicenter, Double-Blind, Randomized, Intraindividual Crossover Comparison of Gadobenate Dimeglumine and Gadopentetate Dimeglumine for MR Angiography of Peripheral Arteries

“…However, a drawback of contrast-enhanced MR angiography is insuffi cient contrast enhancement for accurate visualization and diagnosis if the contrast agent dose is too low (6)(7)(8)(9). This is particularly relevant in the peripheral runoff vasculature where vessels are smaller and highly susceptible to fl ow alterations in heavily diseased patients; it is also relevant if parallel imaging techniques are used because these techniques decrease the signal-to-noise ratio (SNR) ( 10 ).…”

MR angiography versus intra-arterial digital subtraction angiography of the lower extremities: activity-based cost analysis

“…For evaluation of each vascular region, we used three-dimensional (3-D) fast spin echo (FSE) T1-weighted sequences with the following parameters: TR= 6 ms, TE 1.5 ms, flip angle 35°, slice thickness 1.5 mm (3 mm with 1.5-mm overlap), field of view 430 mm, matrix 512×512, number of slices 70 and acquisition time 28 s. Overall acquisition time of successive sequences, including the time needed for two table moveIntroduzione L'angiografia mediante risonanza magnetica (Angio-RM) ha trovato negli ultimi anni applicazione sempre più ampia nella valutazione delle arteriopatie degli arti inferiori. I progressi tecnologici hanno fatto sì che tale indagine possa garantire una sensibilità ed una specificità elevate, utilizzando l'angiografia digitale come gold standard, pur se i lavori pubblicati riportano un range di percentuali assai ampio (sensibilità tra il 71% e il 100%, specificità tra il 63% e il 100%) [1][2][3][4][5][6][7][8][9][10][11]. Molti lavori hanno preso quindi in considerazione il suo apporto diagnostico ed hanno sottolineato i suoi benefici, per il trascurabile costo biologico.…”

“…Technological advancements have allowed this technique to provide high levels of sensitivity and specificity as compared with digital subtraction angiography (DSA) as the gold standard even though the reported ranges are extremely wide (sensitivity: 71%-100%, specificity: 63%-100%) [1][2][3][4][5][6][7][8][9][10][11]. Most papers have, therefore, considered its diagnostic contribution and emphasised its advantages of having a negligible biological cost.…”

A comparison of shimming techniques for optimizing fat suppression in MR mammography

“…Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) has been shown to be a very useful diagnostic tool in the detection and evaluation of many breast diseases (1)(2)(3)(4). The use of fat suppression is recommended for sequences that are used for assessment of contrast enhancement (5).…”