Intramuscular hematomas on the psoas muscle are rare and usually occur as a result of trauma, iatrogenic etiology during lumbar surgery, rupture of the aortic aneurysm, and hematologic diseases. The incidence of spontaneous psoas muscle hematomas has slowly increased as a result of using anticoagulation and antiplatelet agents. Magnetic resonance (MR) imaging is a more sensitive option compared to computed tomography (CT) when diagnosing a hematoma. Coronal T2-weighted images are more useful. CT imaging is also useful to establish the rapid diagnosis of hematoma. When a prolonged prothrombin time and international normalized ratio and decrease platelet count are noted, psoas muscle hematomas should be considered, if there was no lesion in the spinal canal. Most hematomas resolve spontaneously without clinical complications if the hematoma is not large or it is not compressing the surrounding important structures, irrespective of cause.

Objective Subdural hematoma (SDH) primarily occurs in elderly patients. While most patients have good prognosis, some do not. Hematoma recurrence is one of the factors influencing prognosis. Moreover, some characteristic radiological factors may increase the recurrence rate. The aim of this study was to investigate whether the presence of trauma influenced radiological characteristics and hematoma recurrence in SDH patients treated with burr hole trephination. Methods From January 2012 to December 2014, we selected 83 patients diagnosed with unilateral SDH using computed tomography and/or magnetic resonance imaging. We divided the patients into 2 groups based on the presence of trauma. We compared the 2 groups with multiple parameters, such as patient factors, radiological characteristics, and recurrence rate. Results Patients who had a prolonged international normalized ratio (INR) were significantly more common in the non-traumatic SDH group (22.2%:55.2%, p =0.002). There was no statistical difference in radiological parameters between the 2 groups. The recurrence rate was marginally higher in the non-traumatic SDH group (14.8%:17.2%, p =0.502), but this difference was not statistically significant. Conclusion There were no statistically significant differences in the radiological findings, including brain atrophy, hematoma density, thickness of hematoma, and degree of midline shifting between the 2 groups. The associated trauma history may not influence recurrence. Anticoagulants medication influence INR prolongation, and commonly shown in non-traumatic group, but not statistically. INR prolongation was statistically more common in non-traumatic SDH patients than in traumatic SDH patients. INR prolongation is only a different characteristic between 2 groups.