Purpose
The two main non-invasive imaging modalities for the evaluation of renal artery diseases are CT angiography (CTA) and contrast-enhanced MR angiography (CE-MRA).
It has been well described that iodine-based contrast agents can cause deterioration in renal function associated with contrast-induced nephropathy (1,2).
Gadolinium-enhanced MR imaging had increasingly replaced CT angiography in patients with reduced renal function before the strong association between Nefrogenic Systemic Fibrosis (NSF) and gadolinium was reported in 2006 (1,2,3).
For these reason,
unenhanced MR angiography may be a better approach to prevent...
Methods and Materials
Unenhanced-MRA was performed in 24 patients (14 men; mean [±SD] age,
54 ± 17 years) with clinical suspicion of main renal artery disease.
Two radiologists independently evaluated the ability of U-MRA for depiction of the renal arteries and detection of the main renal artery disease by comparing the results with the gold standard tests: CE-MRA (14 patients) and Digital Subtraction Arteriography (DSA) (8 patients).
All examinations were performed with a 1.5 T GE Hdxt MR system.
Unenhanced-MRA was perform using a respiratory-triggered 3D fat saturated...
Results
Nineteen of the 24 patients underwent Unenhanced-MRA successfully.
Blurring artifacts secondary to respiratory motion resulted in not assessable image quality in three patients (Fig.
3) and in one patient,
the artifacts were caused by an aortic stent.
Unenhanced-MRA failed to identify a renal transplant artery because the vessel was oriented perpendicularly to the acquisition plane.
It was the only allograft studied.
A total of 38 main renal arteries were evaluated.
Four main renal arteries could not be evaluated as a result of a stent implantation...
Conclusion
Unenhanced-MRA is a reliable diagnostic method to depict normality and stenosis in the main renal arteries.
The presence of arterial stent or thrombosis prevents unenhanced-MRA assessment.
Segmental renal artery disease cannot be adequately depicted with unenhanced-MRA in all cases.
Unenhanced-MRA can be used as an alternative to enhanced techniques in patients with renal insufficiency.
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Unenhanced MR Angiography: Techniques and clinical applications...