Domain: Healthcare — Imaging Medicine
Target concept: CT Manifestations of Intracerebral Hemorrhage

Video generation prompt: Perform a non-contrast CT scan of the brain in patients with intracerebral hemorrhage to observe the location, morphology, and density of the hemorrhage.

Evaluation guide:
(i) Target concept: Visualization of acute intracerebral hemorrhage as a hyperdense parenchymal lesion on non-contrast CT.
Minimum mechanism: X-ray attenuation difference between clotted blood (≈80–100 HU) and normal brain parenchyma (≈35–45 HU) under polychromatic beam without contrast agent administration.
(ii)Storyline: Frame 1–2: Static axial brain cross-section in diagnostic CT grayscale window (window width ~80, level ~40). Frame 3–7: Hemorrhage emerges as a contiguous, hyperdense region embedded in brain tissue: no motion of blood, no change in density over time, no surrounding enhancement. Frame 8–10: Stable view confirms intraparenchymal location, uniform density, and anatomically plausible morphology. Perspective: Fixed orthogonal axial view; full brain coverage not required, but hemorrhage must be fully contained within visible slice and unambiguously intra-axial; no oblique or reformatted views allowed.

Manual:
Experimental Procedure
1. Position patient supine with head in neutral alignment inside CT gantry.
2. Acquire non-contrast axial brain CT series (no iodinated contrast administered).
3. Scroll through axial slices to localize the hyperdense intracerebral hemorrhage.
Observation of Experimental Phenomena
A uniformly hyperdense, well-demarcated or irregular mass appears within brain parenchyma — denser than surrounding gray matter, not confined to CSF spaces or skull, with no contrast enhancement or vascular blush.
Summary of Experimental Principles
Acute intracerebral hemorrhage appears hyperdense on non-contrast CT because clotted blood has a higher physical density and a concentrated hemoglobin/protein content than normal brain tissue, which increases X-ray attenuation — this enables rapid diagnosis of location, size, and mass effect regardless of the blood's oxygenation state.

Prompt Grounding rubric:
level_1: No axial brain CT image appears; no grayscale slice is shown; no hyperdense hemorrhage region appears anywhere in the brain; nothing in the video corresponds to a non-contrast CT scan of the brain.
level_2: A head-shaped or brain-shaped image appears but isn't presented as an axial CT slice (e.g., no true axial orientation, or the tissue appears as a colored or blurred mass rather than CT grayscale); the hyperdense hemorrhage is missing, or the bright region shown is a color other than the expected CT gray/white hyperdensity (e.g., rendered as a dark, blue-tinted, or cartoonish blob).
level_3: A grayscale axial brain slice is shown with a bright (hyperdense) region embedded within the brain tissue itself, not in the skull or scalp; the bright region sits inside the brain parenchyma rather than in the subdural or epidural space; its shape is a roundish or irregular mass rather than a thin crescent or lens shape; its brightness is clearly higher than the surrounding brain tissue.
level_4: Everything at the 3-point level is present, and in addition, the hyperdense region stays confined mainly within the brain tissue (it isn't shown flooding the ventricles or covering the brain surface as its primary feature); its edges look like a real hemorrhage (either fairly sharp or somewhat irregular) rather than a perfectly smooth cartoon shape; its position relative to nearby brain landmarks (e.g., near the basal ganglia or thalamus, or within a cerebral lobe) looks anatomically sensible; no unrelated object (an IV line, a bright metal-artifact streak, contrast-injection imagery) is shown as if it were the hemorrhage.
level_5: Everything at the 4-point level is present, and in addition, the hyperdense region looks evenly bright throughout rather than having dark holes inside it; its location matches a place hemorrhages commonly occur (e.g., putamen, thalamus, a cerebral lobe, or the cerebellum); there are no stray visual glitches around its edges (no floating outline, no blurred double-edge); the video presents this as a single steady axial slice rather than cutting to unrelated views mid-sequence.

Scientific and Causal Correctness rubric:
level_1: The hemorrhage is shown as dark or medium-gray rather than bright, or shown in multiple colors; it looks like it's actively flowing or pooling into a space outside the brain tissue, or looks gas-filled or chalky/calcified; nothing about the image suggests why a non-contrast CT scan would make a blood clot look this way.
level_2: The bright region is present but sits in the wrong place (in the dura, in the CSF-filled ventricles/cisterns, or within the skull itself) rather than in the brain tissue; its shape suggests an old, resolving hematoma (e.g., a fluid level splitting light and dark layers, or a rim of enhancement) rather than a fresh bleed; its brightness contradicts basic CT attenuation (e.g., appears brighter than bone, or darker than the fluid-filled ventricles).
level_3: The hemorrhage sits within the brain tissue itself and is clearly brighter than the surrounding gray matter; it forms a solid, space-filling mass rather than a fluid pocket with a flat interface; the reason it appears bright is consistent with how non-contrast CT works: freshly clotted blood is dense with concentrated hemoglobin and protein, and it attenuates the CT's X-ray beam more than normal brain tissue does, regardless of whether that hemoglobin is still carrying oxygen; this is what produces the uniform bright (hyperdense) appearance, not an oxygen-state-dependent signal effect (that oxyhemoglobin-to-methemoglobin staging concept applies to MRI, not CT attenuation).
level_4: Everything at the 3-point level is present, and in addition, the inside of the hemorrhage doesn't show a dark hole or patchy darkening that would suggest the clot has already started breaking down or liquefying (which wouldn't be expected this soon after a bleed); any surrounding darker halo (edema) that is shown looks even and gradual rather than blotchy or one-sided; the hemorrhage's location is plausible for the blood supply of a nearby artery (e.g., a basal-ganglia bleed sitting in the territory fed by the lenticulostriate arteries).
level_5: Everything at the 4-point level is present, and in addition, the hemorrhage's brightness looks even and solid throughout, without a speckled or streaky texture that would look inconsistent with a fresh clot; nothing else in the image contradicts a fresh bleed (e.g., no blood shown already filling the ventricles unless the bleed is clearly large, no skull fracture shown unless a trauma context is depicted); the overall picture (a plain CT scan immediately showing a bright, well-formed clot in the brain tissue) reads as an unambiguous, textbook case of acute hemorrhage.

Spatiotemporal Consistency rubric:
level_1: The axial slice suddenly jumps, zooms, or reorients between one moment and the next with no transition; the hemorrhage appears or disappears abruptly rather than staying consistently present; the scene's overall brightness or the CT grayscale look changes suddenly; the brain tissue visibly warps, pulses, or melts as if it were alive rather than a static scan image; the slice orientation flips (e.g., from axial to sagittal) partway through.
level_2: The slice appears with a visible stutter, as if frames were skipped or interpolated; the hemorrhage's visibility or opacity flickers inconsistently from frame to frame; the CT grayscale window shifts partway through for no clear reason; the left and right sides of the brain look briefly out of sync with each other, as if two halves were merged imperfectly.
level_3: A single axial view is held steadily throughout the video; the brain slice is continuously visible with no sudden reveal or cut; the hemorrhage stays in the same place relative to the surrounding brain anatomy across the whole video; the grayscale brightness looks the same from frame to frame; nothing about the brain or the hemorrhage looks structurally broken (no part of the brain cut off oddly, no hemorrhage floating outside the tissue).
level_4: Everything at the 3-point level is present, and in addition, the hemorrhage's outline stays attached to the surrounding brain tissue without sliding, growing, or shrinking on its own; there's no noticeable overall brightening or dimming of the image from one frame to the next; no odd shadow or highlight appears on the hemorrhage or brain surface that wasn't there before; nothing about any subtle motion blurs the edges of the brain structures.
level_5: Everything at the 4-point level is present, and in addition, the hemorrhage's position and shape look completely steady across the video, with no visible drift; the natural texture of the brain surface (its folds, the fluid-filled cisterns near the base of the brain) looks like a real, continuously held scan rather than a looping or repeating clip; the image shows no blocky or smeared patches that would suggest it was stitched together from mismatched sources; the viewing angle stays a true, level axial cut with no visible tilt.