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Published on: December 16, 2021
Features of "false positive" unruptured intracranial aneurysms on screening magnetic resonance angiography
Minsu Jang1, Jang Hun Kim1,2, Jin Woo Park1
1Department of Neurosurgery, Armed Forces Capital Hospital, Seongnam-si, Gyeonggi-do, Republic of Korea.
Background:
Physicians can find it challenging to decide whether confirmative digital subtraction angiography (DSA) should be performed in patients who present with "suspicious small aneurysm-like structures" on magnetic resonance angiography (MRA). Factors associated with "false positive aneurysms on MRA" (FPAMs)," which are finally confirmed as negative on DSA, have rarely been reported. This study aimed to identify the clinical or radiologic clues indicative of FPAM on DSA.
Methods:
Patients who had undergone DSA between 2016 and 2019 for suspicious aneurysm-like structures < 5 mm in size on MRA were enrolled. Patient demographics and the details regarding the geometry of the structures were retrospectively reviewed. Univariate and multivariate logistic regression analyses were conducted to identify the associated factors. Receiver operating characteristic curve analysis was performed to assess the clinical implications.
Results:
Of the 107 suspicious structures, 46 were indicated as being false positive on DSA (42.96%). Location (positive on C7 and negative on C5-6 ICA) and lower dome to neck ratio were found to be significant parameters in the multivariate analysis. The dome to neck ratio threshold value was 0.99.
Conclusion:
Suspicious aneurysm-like structures located not on C5-6 but on C7 ICA and having wide neck morphologies (dome to neck ratio < 0.99) are highly likely to be negative on DSA.
Insights
Magnetic resonance angiography (MRA) may show suspicious small aneurysm-like structures. Wide necked structures (dome to neck ratio < 0.99) on C7 internal carotid artery (ICA) are likely false positives on digital subtraction angiography (DSA).
Area of Science:
- Neuroradiology
- Vascular imaging
- Cerebrovascular disease
Background:
- Magnetic resonance angiography (MRA) can detect small aneurysm-like structures.
- Distinguishing true aneurysms from false positives on MRA is challenging.
- Digital subtraction angiography (DSA) is often used for confirmation.
Purpose of the Study:
- To identify clinical and radiological indicators of false positive aneurysms on MRA (FPAMs).
- To reduce unnecessary invasive DSA procedures.
- To improve diagnostic accuracy in cerebrovascular imaging.
Main Methods:
- Retrospective review of 107 patients undergoing DSA for MRA-detected structures < 5 mm (2016-2019).
- Analysis of patient demographics and aneurysm geometry.
- Logistic regression and ROC curve analysis to identify predictive factors.
Main Results:
- 42.96% of suspicious MRA findings were false positives on DSA.
- Location (C7 vs. C5-6 internal carotid artery) and dome to neck ratio were significant.
- A dome to neck ratio < 0.99 was a key indicator.
Conclusions:
- Suspicious structures on C7 ICA with wide necks (dome to neck ratio < 0.99) are likely FPAMs.
- These findings suggest DSA may not be necessary in select cases.
- Helps in optimizing diagnostic pathways for cerebrovascular abnormalities.
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