Spleen Volume Change Predicts 45-Day Mortality in Neurocritical Care: A Prospective Cohort Study

Splenic volume was measured at baseline and at 72 hours using the Butterfly iQ+ handheld ultrasound (Butterfly Network, Inc.) in abdominal preset mode. Certified POCUS operators obtained spleen length, width, and depth in standard orthogonal planes. Volumes were calculated using the prolate ellipsoid formula (length × width × depth × 0.523), a validated method in ultrasound volumetric studies. ΔSpleen was defined as the 72-hour value minus the baseline value.