Relationship of aortic bifurcation with sacropelvic anatomy: Application to anterior lumbar interbody fusion.

INTRODUCTION: Various sacropelvic parameters such as the pelvic Incidence (PI) are used to predict ideal lumbar lordosis and aid surgical planning. The objective of this study was to establish the relationship between the location of the aortic bifurcation from the sacral promontory and sacropelvic measures including the PI. MATERIALS AND METHODS: One hundred sixty five computed tomography (CT) scans obtained for major trauma including the entire spine were identified. Sacropelvic parameters including PI, sacral anatomic orientation, pelvic thickness (PTH), and sacral table angle were measured. Aortic bifurcation was identified on sagittal and coronal imaging and the distance from the sacral promontory (bifurcation-promontory distance [BPD]) measured (mm). RESULTS: Mean age of the cohort was 44.3 years (SD 18.5; range 16-88 years); 61.8% male. The mean PI was 49.2° (SD 10.2°; range 30°-80°). The mean BPD was 66.4 mm (SD 13.1 mm; range 38.3-100 mm). In the majority, the bifurcation was at the level of the L4 vertebral body (72.7%). Only age (r = -.389; p < .0001) and PTH (r = .172; p = .027) correlated with the BPD to a significant degree. PI did not correlate with BPD (r = .061; p = .435). Linear regression analysis provided the following predictive equation: BPD = 34.3 mm + 0.30 × PTH. CONCLUSION: This study demonstrates a lack of any meaningful correlation between sagittal pelvic parameters and the distance of the aortic bifurcation from the sacral promontory. Surgical planning for fusion surgery in the lumbar spine should include assessment of spinopelvic parameters and if anterior access to the lumbar disc(s) necessary, vascular anatomy should be carefully assessed independent of these measures.

SMART (Stroke-Like Migraine Attacks After Radiation Therapy) Syndrome: A Case Study with Imaging Supporting the Theory of Vascular Dysfunction.

BACKGROUND SMART (Stroke-like Migraine Attacks after Radiation Therapy) syndrome is an uncommon delayed complication of cerebral radiotherapy. Less than 50 cases have been reported in the literature since it was first described in 1995. On average, presentation is about 20 years after radiotherapy, and patients commonly present with headaches, complex seizures, and stroke-like symptoms. The exact pathophysiology of the disease remains poorly understood, but one theory suggests radiation-induced vascular dysfunction. CASE REPORT We present one such case of a 28-year-old man who presented to our Emergency Department with a gradually progressive severe headache and right-sided weakness developing over a few hours. MRI played a central role in the diagnosis of SMART syndrome, with serial studies demonstrating and supporting the theory of vascular dysfunction. The condition is usually self-limiting, and most patients achieve complete recovery of symptoms, as did ours. Its optimal management remains unclear. CONCLUSIONS Better understanding of the imaging findings in SMART syndrome may help differentiate it from tumor recurrence, cerebral infections, or vasculitis. Because the diagnosis of this condition portends a significantly better prognosis and substantially alters patient expectation and management, it is important that clinicians are aware of the usual delayed presentation, symptomology, and imaging findings.