Somatic mutations arising from the phosphoinositide 3–kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, a mediator of cell growth and angiogenesis, result in limb overgrowth and vascular anomalies; radiologists who are aware of the clinical-radiologic findings associated with limb overgrowth can suggest appropriate genetic testing to help guide decisions regarding endovascular therapy, surgery, and newly available oral medications. Congenital limb length discrepancy disorders are frequently associated with a variety of vascular anomalies and have unique genetic and phenotypic features. Many of these syndromes have been linked to sporadic somatic mosaicism involving mutations of the phosphoinositide 3–kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, which has an important role in tissue growth and angiogenesis. Radiologists who are aware of congenital limb length discrepancies can make specific diagnoses based on imaging findings. Although genetic confirmation is necessary for a definitive diagnosis, the radiologist serves as a central figure in the identification and treatment of these disorders. The clinical presentations, diagnostic and imaging workups, and treatment options available for patients with Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular anomalies, epidermal nevi, and scoliosis/spinal deformities) syndrome, fibroadipose vascular anomaly, phosphatase and t...

Obtaining arterial access is one of the most technically challenging aspects of pediatric angiography and endovascular interventions and requires detailed preprocedural planning, selection of an appropriate arterial access site, periprocedural optimization, use of US guidance for arterial puncture, and meticulous postaccess care.