Geometric parameters on MRA source images to differentiate small Proximal Posterior communicating artery aneurysms
Yun Ji Kim1, Dae Young Yoon1, Eun Soo Kim2
1Department of Radiology, Kangdong Seong-Sim Hospital, Hallym University College of Medicine, Seoul, South Korea.
Background And Purpose:
We aimed to assess the accuracy of magnetic resonance angiography (MRA) in the differentiation of small aneurysms versus infundibular dilations (IDs) at the internal carotid artery-posterior communicating artery (ICA-PComA) junction, emphasizing the role of MRA axial source images.
Methods:
This retrospective study consisted of 83 focal arterial protrusions at ICA-PComA junction in 76 patients who underwent both MRA and digital subtraction angiography (DSA)/3-dimensional rotational angiography (3DRA). The diagnostic performance of MRA for differential diagnosis of aneurysm from ID was calculated using DSA/3DRA interpretation as the standard of reference. In addition, long-axis diameter, short-axis diameter, long-axis diameter/short-axis diameter (L/S) ratio, and angle of lesion (angle of the long-axis of lesion with respect to the x-axis) measured on MRA source images were compared between aneurysms and IDs.
Results:
Sensitivity, specificity, and accuracy of MRA for distinguishing aneurysms from IDs were 74.4% (57.9-87.0%) to 76.9% (60.7-88.9%), 93.2% (81.3-98.6%) to 95.5% (84.5-99.4%), and 85.5% (76.1-92.3%), respectively. Significant differences were found for the long-axis diameter (P < .001), short-axis diameter (P < .001), L/S ratio (P < .05), and angle of the lesion (P < .001) on MRA axial source images between aneurysms and IDs. The angle of the lesion had the highest discriminatory ability (area under the curve = .966 [.902-.994]) to differentiate aneurysms from IDs. An angle of lesion >60° was 89.7% (75.8-97.1%) sensitive and 100% (92.0-100.0%) specific for diagnosis of aneurysm.
Conclusions:
MRA is a useful imaging modality for distinguishing between aneurysm and ID at the ICA-PComA junction. Furthermore, geometric parameters on MRA axial source images can provide added value in their differentiation.
Insights
Magnetic resonance angiography (MRA) accurately differentiates small internal carotid artery aneurysms from infundibular dilations. MRA
Area of Science:
- Neuroradiology
- Vascular Imaging
- Medical Diagnostics
Background:
- Distinguishing small aneurysms from infundibular dilations (IDs) at the internal carotid artery-posterior communicating artery (ICA-PComA) junction is clinically important.
- Magnetic resonance angiography (MRA) is a key imaging modality, but its accuracy in this differentiation requires assessment.
Purpose of the Study:
- To evaluate the accuracy of MRA in differentiating small aneurysms from IDs at the ICA-PComA junction.
- To determine the role of MRA axial source images in this diagnostic process.
Main Methods:
- Retrospective analysis of 83 arterial protrusions in 76 patients who underwent both MRA and digital subtraction angiography (DSA)/3-dimensional rotational angiography (3DRA).
- Comparison of MRA-derived geometric parameters (diameters, L/S ratio, angle) between aneurysms and IDs, using DSA/3DRA as the reference standard.
Main Results:
- MRA demonstrated good diagnostic performance with sensitivity, specificity, and accuracy ranging from 74.4% to 95.5%.
- Significant differences in long-axis diameter, short-axis diameter, L/S ratio, and lesion angle were observed between aneurysms and IDs on MRA axial source images (P < .001).
- The angle of the lesion showed the highest discriminatory ability (AUC = .966), with an angle >60° being highly sensitive and specific for aneurysm diagnosis.
Conclusions:
- MRA is a valuable tool for differentiating aneurysms from IDs at the ICA-PComA junction.
- Geometric measurements from MRA axial source images, particularly the lesion angle, enhance diagnostic accuracy.
