Time‐resolved MR angiography of renal artery stenosis in a swine model at 3 Tesla using gadobutrol with digital subtraction angiography correlation

Abstract

Purpose: To establish the minimum dose required for detection of renal artery stenosis using high temporal resolution, contrast enhanced MR angiography (MRA) in a porcine model. Materials and Methods:Surgically created renal artery stenoses were imaged with 3 Tesla MR and digital subtraction angiography (DSA) in 12 swine in this IACUC approved protocol. Gadobutrol was injected intravenously at doses of 0.5, 1, 2, and 4 mL for time-resolved MRA (1.5 Â 1.5 mm 2 spatial resolution). Region of interest analysis was performed together with stenosis assessment and qualitative evaluation by two blinded readers.Results: Mean signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were statistically significantly less with the 0.5-mL protocol (P < 0.001). There were no statistically significant differences among the other evaluated doses. Both readers found 10/12 cases with the 0.5-mL protocol to be of inadequate diagnostic quality (k ¼ 1.0). All other scans were found to be adequate for diagnosis. Accuracies in distinguishing between mild/insignificant (<50%) and higher grade stenoses (>50%) were comparable among the higher-dose protocols (sensitivities 73-93%, specificities 62-100%). Conclusion:Renal artery stenosis can be assessed with very low doses ($0.025 mmol/kg bodyweight) of a high concentration, high relaxivity gadolinium chelate formulation in a swine model, results which are promising with respect to limiting exposure to gadolinium based contrast agents.

Nonenhanced ECG-gated quiescent-interval single shot MRA: Image quality and stenosis assessment at 3 tesla compared with contrast-enhanced MRA and digital subtraction angiography

“…Due to the overall lengthy acquisition time of QISS‐MRA and the resulting time constraints, acquisitions were not repeated if poor image quality was detected in the present study. In contrast to CE‐MRA effects of poor bolus timing such as insufficient arterial contrast enhancement are not of concern; although, such effects are eliminated through use of dynamic CE‐MRA techniques . Although potential cost savings related to a lack of gadolinium chelate dose used for unenhanced MRA could be possible, this may be offset by longer scan acquisition times required and accompanying reductions in patient throughput.…”

MR angiography of carotid artery aneurysms in a porcine model at 3 tesla: Comparison of two different macrocyclic gadolinium chelates and of dynamic and conventional techniques

“…Experiences with high temporal resolution TWIST MRA from initial dose finding experiments using gadobutrol and gadoterate meglumine demonstrated that the total amount of Gd could be reduced to 1/5 of the typical (∼ 0.1 mmol/kg) dose for a CE‐MRA performed under clinical conditions. This dose‐finding study was performed using gadobutrol as the contrast media in a porcine model of renal artery stenosis (13). Transferring the observations of that preliminary study resulted in total injected volumes of 1 mL of gadobutrol and 2 mL of gadoterate meglumine for the high temporal resolution TWIST scan.…”

Consecutive Acquisition of Time-resolved Contrast-enhanced MR Angiography and Perfusion MR Imaging with Added Dose of Gadolinium-based Contrast Agent Aids Diagnosis of Suspected Brain Metastasis

“…Furthermore, assessment of Gdbased contrast agents with higher relaxivity as well as imaging at 3T could be warranted as possible ways to reduce the total amount of contrast agent injected, particularly in patients at risk for developing NSF. [17][18][19][20] In conclusion, consecutive acquisition of TCMRA and PWI using a supplementary injection of a Gdbased contrast agent can facilitate preoperative diŠerential diagnosis in patients with suspected brain metastasis. This method also increases the number and conspicuity of lesions detected in patients with suspected metastatic disease to the brain.…”