Subtraction MRA techniques subtract MR signal from noncontrast-enhanced MR images from a contrast-enhanced MRA, resulting in improved visualization of vascular structures as soft tissue signal is removed [31]. There may also be value in the use of noncontrast MRA as an anatomic survey before performing contrast-enhanced MRA to facilitate planning of field of view and contrast bolus timing [32]. MRA Area of Interest Without IV Contrast Numerous noncontrast-enhanced MRA sequences are also available, relying on the speed of blood flow (flow- dependent) and subject to signal loss in vessels with slow blood flow. Flow-independent noncontrast-enhanced MRA sequences produce bright blood or dark blood pool images and enable imaging a larger field of view. Noncontrast MRA images may incorporate longer scan times and therefore produce higher spatial resolution images Soft Tissue Vascular Anomalies-Child [33]. Noncontrast MRA does not provide dynamic flow information provided by contrast-enhanced MRA. Furthermore, although time-of-flight cannot be used to characterize soft tissue components, it does show the feeding and draining vessels of a fast-flow VM [34]. MRI Area of Interest Without and With IV Contrast MRI area of interest without and with IV contrast as the initial imaging modality for vascular lesion such as tumor or malformation may be helpful as the initial imaging examination and may be performed contemporaneously with US to investigate a soft tissue mass or skin discoloration. MRI findings typically show a lobulated and often infiltrative soft tissue mass with T1 hypointense and T2 hyperintense signal, variable vascular flow voids, variable patterns of enhancement, and possibly phleboliths, depending upon the type of lesion. The addition of MRA may be beneficial to making a definitive diagnosis [31].
Soft Tissue Vascular Anomalies Vascular Malformations and Infantile Vascular Tumors Non CNS Child. Subtraction MRA techniques subtract MR signal from noncontrast-enhanced MR images from a contrast-enhanced MRA, resulting in improved visualization of vascular structures as soft tissue signal is removed [31]. There may also be value in the use of noncontrast MRA as an anatomic survey before performing contrast-enhanced MRA to facilitate planning of field of view and contrast bolus timing [32]. MRA Area of Interest Without IV Contrast Numerous noncontrast-enhanced MRA sequences are also available, relying on the speed of blood flow (flow- dependent) and subject to signal loss in vessels with slow blood flow. Flow-independent noncontrast-enhanced MRA sequences produce bright blood or dark blood pool images and enable imaging a larger field of view. Noncontrast MRA images may incorporate longer scan times and therefore produce higher spatial resolution images Soft Tissue Vascular Anomalies-Child [33]. Noncontrast MRA does not provide dynamic flow information provided by contrast-enhanced MRA. Furthermore, although time-of-flight cannot be used to characterize soft tissue components, it does show the feeding and draining vessels of a fast-flow VM [34]. MRI Area of Interest Without and With IV Contrast MRI area of interest without and with IV contrast as the initial imaging modality for vascular lesion such as tumor or malformation may be helpful as the initial imaging examination and may be performed contemporaneously with US to investigate a soft tissue mass or skin discoloration. MRI findings typically show a lobulated and often infiltrative soft tissue mass with T1 hypointense and T2 hyperintense signal, variable vascular flow voids, variable patterns of enhancement, and possibly phleboliths, depending upon the type of lesion. The addition of MRA may be beneficial to making a definitive diagnosis [31].