This poster was previously presented in Spanish at the 2012 Congreso Nacional SERAM (Granada)
Type:
Educational Exhibit
Keywords:
Transplantation, Arteriosclerosis, Aneurysms, Imaging sequences, Technology assessment, Technical aspects, MR-Angiography, Vascular, Pelvis, Abdomen
Authors:
J. A. López García1, C. N. Perez Brito1, I. Gonzalez Garcia2, H. Valles Gonzalez2, F. J. Diaz Romero2; 1La Laguna (Tenerife)/ES, 2La Laguna/ES
DOI:
10.1594/ecr2013/C-0111
Background
In the early nineties nonenhanced MR angiographic sequences arise,
phenomenon based on the input or time-of-flight (TOF) and phase contrast of protons that move through the bloodstream.
They were used in the study of the renal arteries,
but the clinical application was not very extensive, prolonged acquisition times and image artifacts have generally limited their use.
From the second half of the nineties is developed contrast material– enhanced MRA,
using a 3D rapid gradient echo sequence and bolus intravenous gadolinium with short acquisition time,
this allows for obtaining the patient's respiratory pause,
which greatly reduces artifacts.
He became the technique of choice in patients with significantly impaired renal function and when in doubt with Doppler ultrasound diagnostic of the presence of renal artery stenosis.
In the second half of 2006 the gadolinium is associated with the nephrogenic systemic fibrosis.
In February 2007,
the European Medicines Agency (EMEA) contraindicated the use of gadolinium in patients who have a glomerular filtration rate of less than 30 ml/ min.,
in patients with acute renal failure and in the liver transplantation preoperatively.
Four months later,
a caution for its use in patients who have a glomerular filtration rate between 30 and 60 mL/min was added.
This changed the diagnostic algorithm.
However,
the evolution of the MRI technique in recent years: more potent and fast field gradients,
new forms of k-space sampling,
interpolation in the reconstruction of images,
new multi-channel phased array coils and parallel imaging,
have helped to the development of new sequences to visualized the vessels without intravenous contrast administration,
avoiding its potential adverse effects.