Size and location of ruptured and unruptured intracranial aneurysms measured by 3-dimensional rotational angiography

Surg Neurol. 2006 Jan;65(1):18-25; discussion 25-7. doi: 10.1016/j.surneu.2005.05.019.


Objective: The aim of the study was to report about accurate size and location of a consecutive series of ruptured and unruptured aneurysms taking the complex 3-dimensional (3D) anatomy and parent vessel morphology into consideration by using the newly developed 3D rotational angiography (3D-RA).

Methods: One hundred eighteen consecutive patients with 155 saccular intracranial aneurysms were included in the study and received 3D-RA reconstructions for measurement of maximal height and width of the aneurysmal sac. Statistical evaluation compared values for ruptured (n = 83) and unruptured (n = 72) aneurysms.

Results: Mean height and width of unruptured aneurysms were 5.7 and 5.7 mm; of ruptured aneurysms, 6.7 and 6.1 mm (not significant, P = .7 for height and P = .9 for width). The majority of ruptured aneurysms, 81.9% and 59%, were smaller than 10 and 7 mm; likewise, 81.9% and 68.1% of unruptured aneurysms were smaller than 10 and 7 mm. The difference in frequency of small (<10/<7 mm) aneurysms between unruptured and ruptured aneurysms was not significant (P = 1.0 and .32, respectively). The majority (69.4%) of small ruptured aneurysms (<7 mm) were located in the anterior circulation. Most ruptured aneurysms were in the size group 4 to 6 mm in height and 2 to 4 mm in width, and a critical threshold size for aneurysm rupture could not be identified.

Conclusions: An automated calibration procedure applied to all images and excellent visualization of aneurysm and parent vessel morphology using 3D-RA allow accurate size measurement of intracranial aneurysms which may be smaller than previously thought. Small aneurysm (<7 mm), also in the anterior circulation, should be carefully evaluated for treatment.

Publication types

  • Clinical Trial

MeSH terms

  • Aneurysm, Ruptured / diagnostic imaging*
  • Aneurysm, Ruptured / pathology
  • Calibration
  • Cerebral Angiography / instrumentation
  • Cerebral Angiography / methods*
  • Female
  • Humans
  • Imaging, Three-Dimensional / instrumentation
  • Imaging, Three-Dimensional / methods*
  • Intracranial Aneurysm / diagnostic imaging*
  • Intracranial Aneurysm / pathology
  • Male
  • Middle Aged
  • Subarachnoid Hemorrhage / diagnostic imaging
  • Subarachnoid Hemorrhage / pathology