OBJECTIVE:Although intracranial arterial aneurysms (IAAs) of childhood are usually idiopathic, it is possible that underlying arteriopathy escapes detection when using conventional diagnostic tools. Quantitative arterial tortuosity (QAT) has been studied as a biomarker of arteriopathy. The authors analyzed cervicocerebral QAT in children with idiopathic IAAs to assess the possibility of arteriopathy. METHODS:Cases were identified by text-string searches of imaging reports spanning the period January 1993 through June 2017. QAT of cervicocerebral arterial segments was measured from cross-sectional studies using image-processing software. Other imaging and clinical data were confirmed by retrospective electronic record review. Children with idiopathic IAAs and positive case controls, with congenital arteriopathy differentiated according to aneurysm status (with and without an aneurysm), were compared to each other and to healthy controls without vascular risk factors. RESULTS:Cervicocerebral QAT was measured in 314 children: 24 with idiopathic IAAs, 163 with congenital arteriopathy (including 14 arteriopathic IAAs), and 127 healthy controls. QAT of all vertebrobasilar segments was larger in children with IAAs (idiopathic and arteriopathic forms) (p < 0.05). In children with congenital arteriopathy without an aneurysm, QAT was decreased for the distal cervical vertebral arteries and increased for the supraspinal vertebral artery relative to healthy children. QAT of specific cervicocerebral segments correlated with IAA size and rupture status. CONCLUSIONS:Cervicocerebral QAT is a biomarker of arteriopathy in children with IAA, even in the absence of other disease markers. Additional findings suggest a correlation of cervicocerebral QAT with IAA size and rupture status and with the presence of IAA in children with congenital arteriopathy.

Background and Purpose: Quantitative arterial tortuosity (QAT) has been reported as an imaging biomarker of arteriopathy in pediatric arterial ischemic stroke (AIS) due to dissection and transient cerebral arteriopathy. We sought to determine if QAT abnormalities are present in cryptogenic pediatric AIS patients. Methods: Children with non-cardiogenic non-traumatic AIS and normal case controls who underwent MRA of the head and/or neck were identified by retrospective electronic medical record review. Patients with pre-existing clinical risk factors for AIS were excluded. The remaining cases were classified according to stroke subtype. The study population consisted of cryptogenic stroke cases. Patients with AIS due to spontaneous dissection were compared as positive case controls. Patients considered to have Bow Hunter’s Physiology (BHP), and normal case controls were also compared. QAT indices of 5 cervicocerebral arterial segments were measured in all patients using automated image processing software, and differences between groups were analyzed. Results: In normal children, QAT of the cervicocerebral arteries showed significant age-related variability, but no sex-related differences. In pediatric patients with cryptogenic stroke, QAT indices of the cervicocerebral arteries were significantly different relative to normal case controls (p<0.05), and similar to those measured in positive case controls with spontaneous dissection. The cervicocerebral QAT indices of pediatric AIS patients with BHP were not significantly different than those measured in normal controls. Conclusions: QAT is a specific and independent biomarker of arteriopathy in otherwise cryptogenic pediatric AIS, even when conventional clinical or imaging biomarkers of arteriopathy are absent. QAT shows promise as an independent diagnostic criterion for arteriopathy in children with AIS.

Neuroblastoma is the most common extracranial solid malignancy in children. Historically, neuroblastoma has been staged using the International Neuroblastoma Staging System (INSS), which relies on surgical staging. This is problematic because surgical resection can vary among surgeons and tumors and occurs at interval times from diagnosis. In 2009 the International Neuroblastoma Risk Group (INRG) created a new staging system that relies on preoperative imaging for staging. The INRG staging system consists of 20 image-defined risk factors (IDRF) across multiple organ systems, which help predict surgical outcomes/adequacy of resection and can be combined with clinical data to provide up-front risk stratification. The purpose of this review is to describe both the INSS and INRG staging systems and their limitations and to illustrate the definitions and IDRFs that comprise the INRG staging system.

Background and Purpose-Quantitative arterial tortuosity (QAT) is a ratio of vessel length between 2 points to the shortest linear distance between same points. QAT has been reported as an imaging biomarker of arteriopathy in pediatric arterial ischemic stroke (AIS) because of dissection and transient cerebral arteriopathy. We sought to determine whether QAT abnormalities are present in other subtypes of pediatric AIS. Methods-Children with AIS-absent conventional biomarkers of arteriopathy and case-controls who underwent magnetic resonance angiography were classified by stroke mechanism. The primary study population consisted of cryptogenic AIS cases. AIS with bow hunter physiology and cardiogenic emboli were also evaluated. AIS because of nontraumatic dissection served as positive controls. Patients without vascular risk factors served as negative controls. Segmental QAT of cervicocerebral arteries were measured using automated image processing and differences between groups analyzed. Results-In negative controls, QAT showed significant age-related variability for most arterial segments. Positive controls showed significantly increased QAT of the distal extracranial vertebral arteries (VAs) and decreased QAT of the intracranial VA relative to negative controls. Cryptogenic stroke and bow hunter physiology cases were similar to positive controls showing increased QAT of the distal extracranial VA and decreased QAT of the intracranial VA relative to negative controls. Cardioembolic stroke cases were similar to negative controls showing decreased QAT of the distal extracranial VA and increased QAT of the intracranial VA relative to positive controls. Conclusions-Pediatric cryptogenic stroke is frequently associated with cervicocerebral arteriopathies expressing altered QAT. QAT may be a diagnostic biomarker of arteriopathy in pediatric AIS.