ADPKD — Intracranial Aneurysm Screening

Genetic GNmedium

A 35-year-old woman with ADPKD has no personal history of subarachnoid hemorrhage (SAH). Her older sister was found to have an unruptured intracranial aneurysm (ICA) on incidental imaging. She requests guidance on ICA screening. Per KDIGO 2025, does she qualify for ICA screening, and what is the preferred imaging modality?

  1. A.All ADPKD patients should be screened annually with contrast-enhanced brain MRI, no family history criterion is required
  2. B.She qualifies for ICA screening due to her family history of ICA; the preferred modality is time-of-flight MRA without gadolinium enhancementCorrect
  3. C.She does not qualify, screening is only indicated for ADPKD patients with a prior personal SAH, not family history of ICA alone
  4. D.CT angiography with contrast is the preferred first-line screening modality, MRA lacks adequate sensitivity for aneurysms <5 mm

Explanation

KDIGO 2025 Recommendation 6.1.2: Recommends screening for ICA in people with ADPKD who have a personal history of SAH OR a positive family history of ICA, SAH, or unexplained sudden death, in those eligible for treatment and with a reasonable life expectancy (Grade 1D). This patient has a first-degree relative (sister) with a confirmed ICA → she has a positive family history of ICA → she qualifies for screening. ICA prevalence in ADPKD: ~12.9% (vs 2.9% in the general population). With a family history of ICA or SAH: ~17.1%. Rupture risk 3–7× higher than the general population. Preferred imaging modality (PP 6.1.10): Time-of-flight magnetic resonance angiography (TOF-MRA) without gadolinium enhancement. It detects flow-related signal without radiation or contrast, reliably identifies aneurysms ≥3 mm. High-resolution CT angiography (CTA) with contrast is an acceptable alternative. If high-risk and initial screen is negative: individualized re-screening every 5–10 years based on age, life expectancy, and risk factors. Modifiable risk factors for ICA in ADPKD: smoking (strong, PP 6.1.3) and uncontrolled hypertension (moderate, PP 6.1.4). Additional screening contexts (PP 6.1.6): de novo ADPKD, unknown family history, small number of ADPKD relatives, personal or familial extracerebral vascular phenotype. Thunderclap headache (worst headache of life, maximal intensity within 60 seconds) = EMERGENCY, CT scan immediately.

Why each option

A.
Incorrect. KDIGO 2025 does not recommend routine annual screening for all ADPKD patients. Screening is targeted to those with personal history of SAH or family history of ICA/SAH/unexplained sudden death.
B.
Correct. Family history of ICA qualifies her for screening (Rec 6.1.2). Preferred modality: TOF-MRA without gadolinium (PP 6.1.10). CTA is an alternative.
C.
Incorrect. KDIGO 2025 Rec 6.1.2 explicitly includes family history of ICA (not just SAH) as a screening criterion. A sister with confirmed ICA is a positive family history.
D.
Incorrect. TOF-MRA without gadolinium is the preferred modality (PP 6.1.10), it avoids radiation and contrast. CTA is acceptable as an alternative, not as the primary recommendation.

Reference: KDIGO 2025 ADPKD Guideline, Rec 6.1.2, PP 6.1.10; Kidney Int 2025;107(2S):S1–S239

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