Extensive pneumatized air cells causing susceptibility artifacts in the petrosus part of the ICA.
BACKGROUND
3D-Time-of-flight magnetic-resonance-angiography (TOF MRA) is an established method in vessel analysis. However, many artifacts that occur may lead to a false diagnosis. This retrospective study evaluates the coherence of MR artifacts to extensive pneumatized air cells surrounding the internal carotid artery (ICA) in the petrosus part of the temporal bone.


METHODS
Patients who received 3D-TOF MRA and multidetector helical computed tomography (CT) angiography were registered from April 2012 to April 2013. Of these patients, both ICAs in the petrosus part were analyzed. Vertical maximum intensity projection (MIP) artifacts were graduated as normal, mild to moderate, and severe artifacts. The distinction of the vertical part of the pneumatized air cells was also categorized in three groups, regarding the circumference of the ICA in pneumatization ≤ 90°, between 90° and 180°, and ≥ 180°.


RESULTS
A total of 203 vessels were collected for analysis. The more extensive the pneumatized air cells were present, the more band-like artifacts and pseudostenosis at the vertical portion of the petrosus part of the ICA were registered.


CONCLUSIONS
Careful examination of the source images and evaluation of the size of the pneumatized air cells with CT scan are essential to avoid false positive diagnosis in the distal petrosus part of the ICA.
Division of Neuroradiology, Department of Radiology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria.
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MR
McCoy
Division of Neuroradiology, Department of Radiology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria. e.broussalis@salk.at.|Department of Neurology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria. e.broussalis@salk.at.|Research Institute for Neurointervention, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria. e.broussalis@salk.at.
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Broussalis
Department of Neurology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria.|Research Institute for Neurointervention, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria.
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M
Killer
Division of Neuroradiology, Department of Radiology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria.
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J
Steinbacher
Division of Neuroradiology, Department of Radiology, Paracelsus Medical University Salzburg, Ignaz-Harrer-Strasse 79, 5020, Salzburg, Austria.
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Klausner
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000388:Air; D016477:Artifacts; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D003951:Diagnostic Errors / Q000517:prevention & control*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010579:Petrous Bone / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
ICA artifacts; ICA-pseudostenosis; MR artifacts; Petrosus part of the ICA; Pneumatization and artifacts; TOF MRA