Although MRI is generally considered high yield for evaluating lesion extent and often can distinguish between the various types of vascular malformations and soft-tissues masses, its evaluation of flow dynamics and intralesional vascular anatomy is limited when compared with MRA [3]. MRA Extremity MRA has emerged as the preferred modality for assessing vascular malformations, particularly in patients with a vascular murmur and suspected high-flow malformation, due to its exceptional ability to delineate inflow and outflow anatomy noninvasively. Time-resolved MRA has been reported to rival conventional angiography for the portrayal of both functional flow dynamics and anatomic detail [9]. Combined conventional and dynamic contrast-enhanced MRA has a reported sensitivity of 83% and specificity of 95% for the differentiation of venous and nonvenous malformations [24]. Furthermore, MRA protocols typically include conventional high soft-tissue contrast T1 and T2 sequences which accurately assess the internal characteristics and extent of vascular malformations. This modality can also assess for and characterize other possible soft-tissue masses which may be included in the clinical differential diagnosis [6,7]. One potential weakness of time-resolved MRA is its underestimation of shunt volumes in vascular malformations which may be better evaluated with arteriography [7]. Arteriography Extremity Arteriography offers high temporal and spatial resolution images of the vascular anatomy associated with high- flow lesions such as arteriovenous malformations, including the inflow and outflow vessels as well as intralesional shunting [5,7]. Although the presence of a vascular murmur increases the suspicion of a high-flow Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list.
Clinically Suspected Vascular Malformation of the Extremities. Although MRI is generally considered high yield for evaluating lesion extent and often can distinguish between the various types of vascular malformations and soft-tissues masses, its evaluation of flow dynamics and intralesional vascular anatomy is limited when compared with MRA [3]. MRA Extremity MRA has emerged as the preferred modality for assessing vascular malformations, particularly in patients with a vascular murmur and suspected high-flow malformation, due to its exceptional ability to delineate inflow and outflow anatomy noninvasively. Time-resolved MRA has been reported to rival conventional angiography for the portrayal of both functional flow dynamics and anatomic detail [9]. Combined conventional and dynamic contrast-enhanced MRA has a reported sensitivity of 83% and specificity of 95% for the differentiation of venous and nonvenous malformations [24]. Furthermore, MRA protocols typically include conventional high soft-tissue contrast T1 and T2 sequences which accurately assess the internal characteristics and extent of vascular malformations. This modality can also assess for and characterize other possible soft-tissue masses which may be included in the clinical differential diagnosis [6,7]. One potential weakness of time-resolved MRA is its underestimation of shunt volumes in vascular malformations which may be better evaluated with arteriography [7]. Arteriography Extremity Arteriography offers high temporal and spatial resolution images of the vascular anatomy associated with high- flow lesions such as arteriovenous malformations, including the inflow and outflow vessels as well as intralesional shunting [5,7]. Although the presence of a vascular murmur increases the suspicion of a high-flow Supporting Documents The evidence table, literature search, and appendix for this topic are available at https://acsearch. acr.org/list.