Dual‐energy X‐ray absorptiometry for detecting neurogenic pulmonary edema in a mouse model of subarachnoid hemorrhage

Abstract

Abstract Murine subarachnoid hemorrhage (SAH) induced using the filament perforation method is a useful in vivo experimental model to investigate the pathophysiological mechanisms in the brain underlying SAH. However, identifying mice with comorbid acute neurogenic pulmonary edema (NPE), a life‐threatening systemic consequence often induced by SAH, in this model is difficult without histopathological investigations. Herein, we present an imaging procedure involving dual‐energy X‐ray absorptiometry (DXA) to identify NPE in a murine model of SAH. We quantified the lung lean mass (LM) and compared the relationship between micro‐computed tomography (CT) evidence of Hounsfield unit (HU) values and histopathological findings of PE. Of the 85 mice with successful induction of SAH by filament perforation, 16 (19%) had NPE, as verified by postmortem histology. The DXA‐LM values correlate well with CT‐HU levels (r = 0.63, p < 0.0001). Regarding the relationship between LM and HU in mice with post‐SAH NPE, the LM was positively associated with HU values (r2 = 0.43; p = 0.0056). A receiver operating characteristics curve of LM revealed a sensitivity of 87% and specificity of 57% for detecting PE, with a similar area under the curve as the HU (0.79 ± 0.06 vs. 0.84 ± 0.07; p = 0.21). These data suggest that confirming acute NPE using DXA‐LM is a valuable method for selecting a clinically relevant murine NPE model that could be used in future experimental SAH studies.

Keywords

• dual‐energy X‐ray absorptiometry
• mouse model
• neurogenic pulmonary edema
• subarachnoid hemorrhage