顱骨切除術成果與效果之影像評估

Abstract

顱骨切除術是最常見的腦部手術之一，主要是希望藉由移除部份的顱骨，使得因外傷或中風而腫脹的腦部有膨脹的空間，避免因為顱內壓上而導致腦部的進一步傷害。雖然有很多研究認為顱骨切除術對改善預後非常有效，卻也有一些研究認為此手術無明顯效果。 有鑑於此，我們認為應該有量化的指標在影像學上評估顱骨切除術的成果與效果。我們提出顱骨切除成果的指標為顱骨切除體積與顱骨切除表面積，兩者也可說是減壓努力的指標。除了由電腦計算之外，我們也可以利用簡單的公式加以估算顱骨切除的體積與面積。由於相對容易，我們認為有關顱骨切除術的研究皆應該將切除的體積或面積當作常規的指標。 我們提出的減壓效果指標包括：中線回返量，顱容積增量和腦體積增量。這些指標與減壓努力指標有正相關，與時間也有相關性。除了由電腦計算之外，中線回返量較容易由影像上直接量出。 我們發現這些指標和許多臨床因素有相關性。這些減壓努力和效果指標和術後顱內壓和神經學結果也有關聯，值得進一步探討。

Craniectomy is one of the most common cranial surgeries. The object of this procedure is basically to provide an extra space for the swollen brain by removing part of the skull, and therefore reducing the intracranial pressure and avoiding secondary injuries to the brain. The most common indications of craniectomy are severe head injuries and large infarcts. Many studies showed positive effects of craniectomy for neurological outcomes, but there were some studies showing no effect. We propose some quantitative image parameters for evaluation of decompressive efforts and decompressive effects. The former includes the craniectomy volume and surface area. In addition to the computerized measurement, the craniectomy volume and area can also be estimated by simple formulas. It is so simple that the estimation of craniectomy volume or area should be considered a routine in every craniectomy study. The parameters for decompressive effects include the midline return, potential cranial capacity increment, and actual brain volume increment. These parameters also correlate with decompressive efforts and are actually functions of time. In addition to the computerized measurement, the midline return can be readily measured manually. We observed some correlation between these parameters and many clinical variables. They also correlated with the postoperative intracranial pressure and neurological outcome. Further studies should be done to clarify the clinical significance.