Prompt: Generate a detailed medical x-ray image portraying a sagittal view of a human skull with a distinct focus on the brain. The x-ray should clearly display a coin embedded in the frontal lobe, and the overall image should convey a realistic x-ray effect, with attention to grayscale tones and transparency. Ensure that the x-ray emphasizes the skull's structure, including the outlines of the bones and the intricate details of the brain. Aim for a scientifically accurate and visually compelling representation.