Neurointervention.  2018 Mar;13(1):48-53. 10.5469/neuroint.2018.13.1.48.

Diagnosis of Cerebral Aneurysm Via Magnetic Resonance Angiography Screening: Emphasis on Legal Responsibility Increases False Positive Rate

• Cho SH
• Lee JY
• Ryu KH
• Suh DC

• KMID: 2424049
• DOI: http://doi.org/10.5469/neuroint.2018.13.1.48

Abstract

PURPOSE
False positive diagnoses of cerebral aneurysm via magnetic resonance angiography (MRA) screening may increase unnecessary cerebral catheter angiography. The purpose of this study was to investigate the effects of medical liability on medical decision-making during radiologic interpretation.
MATERIALS AND METHODS
We included 56 consecutive patients who were referred with suspected aneurysm based on MRA or computed tomography angiography (CTA) and showed no aneurysm on subsequent digital subtraction angiography (DSA). MRA and CTA were reviewed twice by two neuroradiology fellows who were blind as to whether the suspected lesions were true aneurysms or not. The second review was repeated after proposing that their decision was subject to legal liability and they would be responsible for medico-legal problems related to their diagnoses. Diagnostic differences based on each review were analyzed, focusing on changes in false positive diagnosis rates.
RESULTS
A total of 63 suspected aneurysmal lesions detected via MRA or CTA were found to be negative based on DSA. At first review, 32 lesions were diagnosed as true aneurysms by observer 1 and 27 by observer 2, corresponding to false positive rates of 51% and 43% respectively. At the second review, 39 lesions (62%) were diagnosed by observer 1, and 30 (48%) by observer 2. Thus, there was an overall increase in false positive aneurysm diagnosis of 11% for observer 1 and 5% for observer 2, after emphasizing their responsibilities in the context of medical litigation.
CONCLUSION
Concerns about medical liability could result in increased false positive diagnoses of cerebral aneurysms via MRA screening. Whether repeated follow-up of the suspected lesion or catheter angiographic confirmation is better with regard to long-term patient outcomes requires further study.

Keyword

Intracranial aneurysm; Junctional dilatation; Magnetic resonance angiography; Digital subtraction angiography

MeSH Terms

Aneurysm
Angiography
Angiography, Digital Subtraction
Catheters
Clinical Decision-Making
Diagnosis*
Follow-Up Studies
Humans
Intracranial Aneurysm*
Jurisprudence
Liability, Legal
Magnetic Resonance Angiography*
Mass Screening*

Figure

• 

  Fig. 1 False positive diagnosis of an aneurysm (arrows) in the right A1. (A) An aneurysm was suggested in the right A1 on 3D-TOF MRA. (B) There was no definite aneurysm on cerebral angiogram. (C) Three dimensional angiogram showed a mild dilatation of the proximal A1. There was neither abnormal vessel wall thickness (D) nor abnormal enhancement (E) on vessel wall MRI.

• 

  Fig. 2 Changes in diagnostic results from observer 1 (A) and observer 2 (B). Note increased false positive diagnosis rates of aneurysm after emphasizing the possibility of medical litigation (2nd review) in both observers

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