title: Incremental contribution of size ratio as a discriminant for rupture status in cerebral aneurysms:  comparison with size, height, and vessel diameter.
abstract: BACKGROUND
  Aneurysm size ratio (SR), variably defined as the ratio of dome height (H) or maximal dimension (D(max)) over average parent vessel diameter (PV) diameter, has been proposed as a promising aneurysm rupture status predictor.
  
  
  OBJECTIVE
  To evaluate the incremental contribution of SR to retrospective rupture status determination in a large high-resolution aneurysm database.
  
  
  METHODS
  Measurements were performed on catheter 3D-rotational angiographic volumetric datasets for 267 aneurysms (98 ruptured). SR was computed both as H/PV (SR1) and as D(max)/PV (SR2), and its discriminant performance was evaluated on the whole dataset, on aneurysm-type subsets (bifurcation [BIF] vs sidewall [SW]), and at specific aneurysm locations. Univariate and multivariate statistical analyses were performed by the use of area under the curve (AUC) of the receiver-operating characteristics.
  
  
  RESULTS
  Neither SR1 nor SR2 were statistically correlated to rupture status in the BIF group, where only PV (AUC = 0.61) achieved significance. All parameters were statistically significant in the combined group, but with modest performance (AUC range, 0.62-0.74). SR1 (AUC = 0.84) and SR2 (AUC = 0.78) were strong predictors in the SW group, similar to H (AUC = 0.83) and D(max) (AUC = 0.77). Multivariate statistics failed to support SR as an incremental independent parameter from PV, D(max), and H.
  
  
  CONCLUSIONS
  SR provides an uneven performance that depends strongly on the BIF/SW distribution of the data and is not useful for bifurcation lesions. In the SW subset, the incremental contribution of the SR over its H or D(max) individual component measurements could not be validated, suggesting prior findings of its utility to be the result of aneurysm-type selection bias.
authors: Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center, Boston, Massachusetts 02111, USA.
authors: Alexandra
authors: A
authors: Lauric
authors: Merih I
authors: MI
authors: Baharoglu
authors: Bu-Lang
authors: BL
authors: Gao
authors: Adel M
authors: AM
authors: Malek
mesh_terms: D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging* / Q000473:pathology*; D019540:Area Under Curve; D002533:Cerebral Angiography / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000473:pathology*; D011379:Prognosis; D012372:ROC Curve