ABSTRACT
Congenital heart disease (CHD) is the most common congenital malformation.MRI plays an important role in evaluating postoperative cardiac function of CHD.The new technology of 4D flow can be used to encode phase flow coded cine based on 3 vertical dimensions at the same time.Meanwhile,4D flow can perform multi-parameter functional assessments of blood flow vector and peak flow velocity,also can visualize the structure and blood flow of the inner heart and the outer heart.The principle of 4D flow and its application in children with CHD were reviewed in this article.
ABSTRACT
4D Flow MRI is a new phase contrast MR technique,which can spatially encode velocity in three-direction,collect multi-directional blood flow data,and result in complex three-dimensional dynamic parameters.4D Flow MRI is more accurate and comprehensive than 2D phase contrast MRI and Doppler echocardiography.However,4D Flow MRI have some disadvantages,such as long scanning time,noise,etc.,which are the future key technical issues to be addressed.4D Flow MRI technology has a great potential in clinical applications,such as intracranial vascular diseases,cardiac magnetic resonance imaging,and other aspects of aortic diseases.Research advances in clinical application of 4D Flow MRI were reviewed in this paper.
ABSTRACT
Although digital subtraction angiography (DSA) has been used as the gold standard for the diagnosis of intracranial aneurysms, its clinical use is somewhat limited by its invasiveness, high medical cost and potential risk of nephrotoxicity. For the past three decades, the magnetic resonance angiography (MRA) techniques have been developed rapidly. As a non-invasive technique with high resolution ability, MRA can replace DSA for the diagnosis of intracranial aneurysms in most clinical situations. The time-of-flight MRA (TOF-MRA) carries a diagnostic sensitivity of up to 98.2%-98.7%for tiny intracranial aneurysms ( 5 mm) reaches as high as 100%. All the above mentioned MRA techniques can clearly display the intracranial aneurysms although their imaging characteristics and clinical applications are different from each other. This paper aims to make a brief review concerning the principles, clinical applications and recent progress of some MRA techniques.