両側性慢性硬膜下血腫

Bilateral Chronic Subdural Hematomas

Point

・CTで等吸収の慢性硬膜下血腫はしばしばみられ，とりわけ両側性のものを見逃さない注意が必要である．

・慢性硬膜下血腫と類似した画像所見を示す病態には，硬膜転移，肉芽腫性の諸疾患，肥厚性硬膜炎がある．

・小児では，慢性硬膜下血腫は虐待に起因することが稀でないことを念頭に置く．

　Chronic subdural hematomas（SDHs）do not infrequently present isodensity on CT. They should not be overlooked, particularly if bilateral. Therefore, checking for an abnormal mass effect and visualizing the cortical sulci in higher slices should be routine. In suspected cases, MRI can be a reliable tool for establishing the diagnosis. SDHs or subdural hygromas are often found in patients with intracranial hypotension, along with other findings such as thickened dural enhancement, enlarged dural sinuses, an anterior shift of the brainstem, inferior shift of the cerebellar tonsils, and others. In such cases, some techniques are indicated for visualizing cerebrospinal fluid leakage from the dural sac. Conditions with similar imaging findings, such as chronic SDHs, include dural metastases, several kinds of granulomatous disease, and hypertrophic pachymeningitis. Additionally, it is essential to consider child abuse when SDH is found in children.