Value Of Mean Hounsfield Unit In Predicting Acute Epidural Hematoma Expansion

Objective(s): Hematoma expansion(HE)often indicates poor prognosis in patients with intracranial hemorrhage.We retrospectively collected data including imaging data from patients with acute epidural hematoma.The mean Hounsfield unit(HU)and minimum Hounsfield unit(HU)of hematoma were calculated by 3D slicer software to investigate the value of mean Hounsfield unit of hematoma in predicting hematoma expansion in traumatic intracranial hematoma,and to determine the critical Hounsfield unit suitable for predicting hematoma expansion.The possible factors affecting the Hounsfield unit of hematoma were analyzed.To provide an objective and generally applicable index based on non-contrast computed tomography(NCCT/CT)in the diagnosis and treatment of patients at risk for hematoma expansion in future clinical work to assess the risk of hematoma expansion and guide personalized anti-hematoma expansion therapy for patients.Methods: According to the inclusion and exclusion criteria,a total of 108 patients with acute epidural hematoma admitted to our hospital from March 2017 to May 2022 were retrospectively collected.The gender,age,GCS score,mode of injury,time from injury to the first CT scan,red blood cell count,hemoglobin volume,mean corpuscular hemoglobin content,INR and other information were collected to obtain NCCT images.All images were scanned in our hospital.Hematoma was segmented in3 D slicer software.The volume of hematoma,mean Hounsfield unit,and lowest Hounsfield unit were calculated.Through the statistical software SPSS 27.0,the dependent variable was whether hematoma expansion occurred,univariate and multivariate analysis were performed for the above indicators to investigate the effect of each indicator on hematoma expansion.Taking the Hounsfield unit of hematoma as the dependent variable,the main factors affecting the Hounsfield unit of hematoma were explored,and a receiver operating curve was established to determine the optimal Hounsfield unit cut-off value of hematoma for predicting hematoma expansion.Results: Finally,108 patients were statistically analyzed,the median hematoma volume was 8.7(4.1,19.9)m L,the mean Hounsfield unit value of hematoma was64.36 ± 5.24 HU,the mean lowest Hounsfield unit value was 36.05 ± 11.66 HU,44 patients(40.7%)developed HE and 64 patients(59.3%)did not develop HE.Univariate analysis showed that GCS score,time from injury to first CT scan,mean and minimum Hounsfield unit of hematoma had an effect on hematoma expansion.,the mean Hounsfield unit of hematoma in the HE group was lower than the mean Hounsfield unit in the group without HE(t = 5.257,p < 0.001).Multivariate logistic regression analysis showed the mean Hounsfield unit(OR = 0.881,95% CI0.781–0.992,p = 0.037),GCS score(OR = 0.727,95% CI 0.598–0.884,p = 0.001),and the time from injury to the first CT scan(OR = 0.820,95% CI 0.698–0.963,p =0.016)were independent risk factors for acute epidural hematoma expansion.The mean Hounsfield unit of hematoma and the first CT scan time(r = 0.529,p < 0.001),GCS score(r = 0.300,p = 0.002),and mean corpuscular hemoglobin content(r =0.262,p = 0.006)was positively correlated,and the optimal Hounsfield unit cut-off value for predicting hematoma expansion was determined to be 64 HU by a receiver operating curve,which had a sensitivity of 0.781 and a specificity of 0.727,at this time,area under the curve AUC was 0.776(95% CI 0.684–0.868,p < 0.001).Conclusion(s): The mean Hounsfield units of hematoma,GCS score,and the time from injury to first CT scan are independent risk factors for the expansion of acute epidural hematoma.The optimal cut-off value of mean Hounsfield unit for predicting the expansion of hematoma is 64 HU,and the risk of expansion is higher when the mean Hounsfield unit are less than 64 HU.The Hounsfield units of hematoma are positively correlated with the mean corpusular hemoglobin content(MCH),and the higher the MCH,the larger the Hounsfield units of hematoma.In clinical practice,we can identify patients at risk of hematoma expansion by measuring the mean Hounsfield unit of hematoma,so that anti-hematoma expansion therapy can be targeted to improve the prognosis of patients and reduce the risk of death.