Brain magnetic resonance imaging (MRI) overdetection & overtreatment
Rustam Al-Shahi Salman Professor of clinical neurology
MRC senior clinical fellow & honorary consultant neurologist
@BleedingStroke www.dcn.ed.ac.uk/rush …/bleedingstroke
What’s a brain incidentaloma?
Incidentalomas Biomarkers
How are brain incidentalomas detected?
Diagnosis Research
‘Monitoring’ Screening ‘health checks’
I wanted the neurologist to tell me it was straightforward…
but when I said to him, "I'm a mother, I just can't die,"
he replied "God, you've got two kids - I'm surprised you survived childbirth."
Brain incidentalomas: fortuitous or futile?
Diagnosis Research
Monitoring Screening ‘health checks’
Prevalence (%)
Incidental tumours 143
Condition NNS
Other incidental findings 50
Incidental brain findings (but not markers of cerebrovascular disease)
37
BMJ 2009;339:b3016
MRI incidentaloma frequency: meta-analysis
0 0.5 1 1.5 2 2.5 3 3.5
MRI incidentaloma frequency: meta-analysis
Prevalence (%) NNS
Arachnoid cyst 0.5 200
Aneurysm 0.35 286
Meningioma 0.3 345
Cavernous malformation 0.16 625
Arteriovenous malformation 0.05 2,000
Low grade glioma 0.05 2,000
BMJ 2009;339:b3016
Prevalence Incidence of bleeding /100,000/year
Aneurysm 2,051,200 5,833 (0.3%)
CCM 102,560 154 (0.2%)
AVM 32,050 327 (1%)
A reservoir of ticking timebombs in the UK
BMJ 2009;339:b3016, Stroke 2003;34:1163-9, Lancet Neurol 2011;10:626–36, JNNP 2007;78:1365-72
What’s worse, the treatment or the disease?
Aneurysm CCM AVM
Lancet Neurol 2014;13:59-66, Radiology 2012;263:828-35, Trials 2011;12:64
Unruptured intracranial aneurysms
• IPD meta-analysis
• Annual rupture risk = 1.4%
Untreated clinical course Treatment outcome • Systematic review of
endovascular coiling
• 1-month death/disability = 4.7%
One randomised controlled trial
– Trial of Endovascular Aneurysm Management (TEAM)
– Recruited 80 patients (of ~2 000 planned) 2006-2009
Risk of death/disability for unruptured aneurysm
Without treatment
1 year
5 years
After treatment
Lancet Neurol 2012;11:217-24, Neurology 2014;83:582-9, Acta Neurochirurgica 2013;155:643-9
Cerebral cavernous malformations
• Scottish population-based study
• Annual rupture risk = 0.5%
Untreated clinical course Treatment outcome • Systematic review
• 1-month death/stroke – Supratentorial = 8%
– Brainstem = 52%
No randomised controlled trials
Neurology 2014;83:582-9
Cerebral cavernous malformations
Log rank (Mantel Cox), chi-square = 5.9, df=1, p=0∙015
Outcome after surgery
Conservative management
Risk of death/stroke for CCM
Without treatment
1 year
5 years
After treatment
Neurology 2014 83:590-7, JAMA 2011;306:2011-9; Lancet 2014;383:614-21; JAMA 2014;311:1661-9
Arteriovenous malformations
• IPD meta-analysis
• Annual rupture risk = 1.3%
Untreated clinical course Treatment outcome • Systematic review
• Annual risk of death/stroke = 7%
Population-based cohort study adjusted HR 0·37 (95% CI 0·19–0·72)
RCT HR 0·27 (95% CI 0·14–0·54)
Risk of death/stroke for unruptured AVM
Without treatment
1 year
5 years
After treatment
Summary: incidentalomas on brain MRI
5-year rupture risk for most intracranial vascular incidentalomas:
treated > untreated ~5 years
~1% per year
Am J Roentgenol 2005;184:598-611
0 0 : 0 9 8 7 6 5 4 3 2 1 0 • RCTs of interventions
• Long-term balance?
• Detection prevention?
• Informed choice…
• Shared decisions…
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