Domain: Healthcare — Imaging Medicine
Target concept: Ultrasound Manifestations of Hydronephrosis

Video generation prompt: Ultrasound examination of patients with hydronephrosis to assess the dilation of the renal pelvis and calyces, as well as the thickness of the renal parenchyma.

Evaluation guide:
(i) Target concept: Real-time B-mode ultrasound visualization of hydronephrosis in vivo.
Minimum mechanism: Acoustic coupling between transducer and skin must generate a coherent, depth-resolved echo return pattern that resolves anatomically accurate renal structures with correct echogenicity hierarchy (anechoic fluid > hypoechoic parenchyma).
(ii)Storyline: Frame 1–2: Probe approaches flank skin surface. Frame 3–4: Probe establishes stable contact; real-time grayscale image begins rendering. Frame 5–7: Renal outline emerges; central anechoic pelvis becomes dominant feature. Frame 8–9: Branching anechoic calyces become resolved from pelvis. Frame 10: Hypoechoic parenchymal band fully encircles pelvis and calyces, enabling visual assessment of thickness. All structures remain in fixed spatial configuration under continuous probe contact and stable imaging plane.

Manual:
Experimental Procedure
1. Place ultrasound probe longitudinally over the patient"s flank region.
2. Apply gentle, steady pressure to achieve optimal acoustic coupling.
3. Observe real-time grayscale B-mode ultrasound image of the kidney.
Observation of Experimental Phenomena
- Anechoic (black) dilation of the renal pelvis appears centrally within the kidney.
- Anechoic (black) calyces branch outward from the pelvis.
- Hypoechoic (gray) renal parenchyma surrounds both pelvis and calyces; its thickness is assessable relative to pelvic dilation.
Summary of Experimental Principles
Hydronephrosis manifests sonographically as fluid-filled dilation of the renal pelvis and calyces due to urinary outflow obstruction; the degree of parenchymal thinning correlates with chronicity and severity.

Prompt Grounding rubric:
level_1: No ultrasound probe visible; no human torso or flank region shown; no real-time grayscale B-mode ultrasound image displayed; no renal anatomy (pelvis, calyces, parenchyma) identifiable in any frame.
level_2: Ultrasound probe is present but not contacting skin; torso/flank region is shown but without probe placement; grayscale image appears but contains no recognizable renal structure (e.g., only uniform noise, non-anatomic shapes, or non-renal organ); zero appearance of dilated pelvis or calyces.
level_3: Ultrasound probe is placed on flank region and maintains stable contact with skin surface; grayscale B-mode ultrasound image is continuously visible and contains a recognizable kidney outline; dilation of the renal pelvis is visually present as anechoic (black) central cavity; renal parenchyma is visible as hypoechoic (gray) tissue surrounding the pelvis.
level_4: All conditions for score 3 are satisfied; additionally, calyceal dilation is visibly present as multiple discrete anechoic (black) extensions branching from the central pelvis; renal parenchymal thickness is visibly preserved or reduced (i.e., parenchyma appears as continuous hypoechoic band adjacent to dilated pelvis/calyces), with no structural discontinuity or artifact obscuring this relationship.
level_5: All conditions for score 4 are satisfied; additionally, spatial relationship between structures is anatomically accurate: pelvis centrally located within kidney outline, calyces symmetrically radiating outward from pelvis, parenchyma uniformly encircling both pelvis and calyces; no extraneous objects (e.g., text overlays, arrows, color Doppler, measurement calipers) appear; viewpoint remains fixed on longitudinal or transverse renal plane throughout.

Scientific and Causal Correctness rubric:
level_1: No causal link between probe contact and image generation; ultrasound image shows impossible features (e.g., colored fluid in B-mode, pulsating blood vessels in static B-mode, bone-like echogenicity in renal parenchyma); pelvis appears hyperechoic or solid; calyces absent or fused into single shape; parenchyma missing or replaced by fluid signal.
level_2: Probe contacts skin but ultrasound image shows non-renal anatomy (e.g., liver, bladder, or muscle); pelvis appears as solid or mixed echogenicity rather than purely anechoic; calyces not discernible as separate structures; parenchyma appears identical in echogenicity and texture to pelvis; no contrast between them.
level_3: Probe contact correlates with appearance of real-time grayscale ultrasound image; pelvis appears anechoic (uniform black) and centrally located; calyces appear as discrete anechoic branches extending from pelvis; parenchyma appears as contiguous hypoechoic (gray) tissue surrounding pelvis and calyces; contrast between anechoic (pelvis/calyces) and hypoechoic (parenchyma) states is present.
level_4: All conditions for score 3 are satisfied; additionally, parenchymal thinning is visually evident when compared to normal reference proportion, i.e., hypoechoic parenchymal band is narrower than expected relative to size of dilated pelvis; no false artifacts mimic parenchymal loss (e.g., shadowing, reverberation, or dropout replacing true tissue).
level_5: All conditions for score 4 are satisfied; additionally, all state changes follow correct causal chain: probe contact → real-time B-mode image → identification of anechoic pelvis → identification of branching anechoic calyces → identification of surrounding hypoechoic parenchyma → visual assessment of parenchymal thickness relative to pelvic dilation; no contradictory echogenicity (e.g., no bright rim around pelvis, no internal echoes in calyces, no cystic appearance of parenchyma).

Spatiotemporal Consistency rubric:
level_1: Probe teleports across body; kidney image abruptly appears/disappears mid-sequence; sudden jump cuts or frame drops; drastic lighting shift (e.g., bright → dark) without motion; renal outline warps or fractures between frames; parenchyma/pelvis boundaries flicker or vanish intermittently.
level_2: Probe moves erratically with jerky motion; kidney outline deforms significantly across frames; pelvis or calyces change shape discontinuously (e.g., appears then vanishes then reappears larger); parenchyma loses continuity: gaps or tears appear in its hypoechoic band; background shifts (e.g., skin surface disappears/reappears).
level_3: Probe maintains steady contact and consistent orientation on flank; kidney outline remains stable in position and shape; pelvis and calyces appear as continuous anechoic regions without flicker or fragmentation; parenchyma remains a contiguous hypoechoic band surrounding them; no abrupt lighting, contrast, or perspective shifts.
level_4: All conditions for score 3 are satisfied; additionally, motion is smooth and biomechanically plausible: probe pressure causes subtle, gradual compression of subcutaneous tissue without sudden indentation or rebound; renal structures maintain fixed spatial relationships (e.g., calyces always originate from pelvis, never float independently); no inter-frame tearing or ghosting.
level_5: All conditions for score 4 are satisfied; additionally, temporal progression is strictly sequential and synchronous: probe contact precedes image appearance; pelvis becomes visible before calyces fully resolve; parenchymal boundaries emerge concurrently with calyceal definition; no lag, stutter, or desynchronization between probe motion and image update.