Morphological characteristics of ruptured intracranial aneurysms: A comparative study between CTA and DSA

Eftychia Kapsalaki, Alexandros G. Brotis, Giorgos Karagiorgas, Maria Karmen Kyparissi, Thanasis Paschalis, Konstantinos Fountas, Aristotelis P. Mitsos


Purpose: To study the agreement between digital subtraction angiography (DSA) and computed tomographic angiography (CTA) measurements on the aneurysmal neck and sac of ruptured intracranial aneurysms (IAs).

Material and Methods: Through a retrospective agreement analysis of all consecutive patients who reached our Tertiary Hospital with aneurysmal subarachnoid haemorrhage, we measured the intra-class correlation, Lin’s concordance correlation and Bland-Altman analysis estimates on the maximal neck and sac diameters. We included patients who underwent both CTA and DSA in the period between 2012 and 2018. All CTA examinations were acquired using one of two CT scanners: a Toshiba Aquilion 16 CT scanner and a multi-detector Philips Ingenuity 128 CT scanner.

Results: Thirty-two patients (mean age of 55 years) and an equal number of IAs fulfilled our eligibility criteria. Most IAs (87.5%) were located at the anterior circulation. Based on CTA measurements, the inter-observer agreement of the CTA was “weak” regarding the neck diameter, and ranged from “strong” (2D-CTA) to “very-strong” (3D-CTA) regarding the sac measurements. Based on DSA readings, the 2D-CTA was more precise than 3D-CTA regarding the neck (overestimated by 0.91 mm and 0.94 mm, respectively) and the sac diameters (overestimated by 0.49 and 0.51 mm, respectively). Accordingly, the mean normalised smallest detectable differences (MNSDD) of 2D-CTA were 0.93 mm and 0.41 mm for the neck and sac, respectively. Likewise, the MNSDD regarding 3D-CTA were 0.93 mm and 0.36 mm for the neck and sac, respectively.

Conclusions: CTA is an imaging modality, which seems to describe the size of a ruptured IA sac accurately, but fails to delineate the morphology of the aneurysmal neck. CTA seems to overestimate the aneurysm neck, and thus, it is probably inferior to DSA in the decision-making process for the management of ruptured IAs of the anterior circulation.


Intracranial aneurysm/diagnosis; DSA; CTA; Observer variation

Full Text:



Connolly ES, Rabinstein AA, Carhuapoma JR, et al. Guidelines for the management of aneurysmal subarachnoid hemorrhage. Stroke 2012; 43: 1711–1737. doi:10.1161/STR.0b013e3182587839.

Steiner T, Juvela S, Unterberg A, et al. European Stroke Organization Guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage. Cerebrovasc Dis 2013; 35: 93–112. doi:10.1159/000346087.

Yoon NK, McNally S, Taussky P, et al. Imaging of cerebral aneurysms: a clinical perspective. Neurovascular Imaging 2016; 2: 6.

Philipp LR, McCracken DJ, McCracken CE, et al. Comparison between CTA and Digital Subtraction Angiography in the diagnosis of ruptured aneurysms. Neurosurgery 2017; 80: 769–777. doi:10.1093/neuros/nyw113.

Li M, Zhu Y, Song H, et al. Subarachnoid hemorrhage in patients with good clinical grade: Accuracy of 3.0-T MR Angiography for detection and characterization. Radiology 2017; 284: 191–199. doi:10.1148/radiol.2017161469.

Kim HJ, Yoon DY, Kim ES, et al. Intraobserver and interobserver variability in CT angiography and MR angiography measurements of the size of cerebral aneurysms. Neuroradiology 2017; 59: 491–497.

Heit JJ, Gonzalez RG, Sabbag D, et al. Detection and characterization of intracranial aneurysms: a 10-year multidetector CT angiography experience in a large center. J Neurointerv Surg 2016; 8: 1168–1172. doi:10.1136/neurintsurg-2015-012082.

Cunli Y, Khoo LS, Lim PJ, et al. CT angiography versus digital subtraction angiography for intracranial vascular pathology in a clinical setting. Med J Malaysia 2013; 68: 415–423.

Cohen JF, Korevaar DA, Altman DG, et al. STARD 2015 guidelines for reporting diagnostic accuracy studies: Explanation and elaboration. BMJ Open 2016; 6.

Whiting PF, Rutjes AWS, Westwood ME, et al. Quadas-2: A revised tool for the quality assessment of diagnostic accuracy studies. Ann Intern Med 2011; 155: 529–536.

Fisher CM, Kistler JP, Davis JM. Relation of cerebral vasospasm to subarachnoid hemorrhage visualized by Computerized Tomographic scanning. Neurosurgery 1980; 6: 1–9. doi:10.1227/00006123-198001000-00001.

Shrout PE, Fleiss JL. Intraclass correlations: Uses in assessing rater reliability. Psychol Bull 1979; 86: 420–428. doi:10.1037/0033-2909.86.2.420.

Lin LI. A concordance correlation coefficient to evaluate reproducibility. Biometrics 1989; 45: 255–268.

Feng D, Baumgartner R, Svetnik V. A robust Bayesian estimate of the Concordance Correlation Coefficient. J Biopharm Stat 2015; 25: 490–507. doi:10.1080/10543406.2014.920342.

Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet (London, England) 1986; 1: 307–310. Accessed March 1, 2019.

R Core Team. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria, 2018. Available online at

Schober P, Boer C, Schwarte LA. Correlation Coefficients. Anesth Analg 2018; 126: 1763–1768. doi:10.1213/ ANE.0000000000002864.

McBride GB. A proposal for Strength-of-Agreement criteria for Lin’S Concordance Correlation Coefficient. New Zealand 2005. ttp:// Accessed March 1, 2019.

Chen L, Xu M, Zou Y, et al. Clinical study of the role of 64-Slice CT Cerebral Angiography in Aneurysmal Subarachnoid Hemorrhage. Cell Biochem Biophys 2014; 69: 573–575. doi:10.1007/s12013-014-9834-6.

Donmez H, Serifov E, Kahriman G, et al. Comparison of 16-row multislice CT angiography with conventional angiography for detection and evaluation of intracranial aneurysms. Eur J Radiol 2011; 80: 455–461. doi:10.1016/j.ejrad.2010.07.012.

El Khaldi M, Pernter P, Ferro F, et al. Detection of cerebral aneurysms in nontraumatic subarachnoid haemorrhage: role of multislice CT angiography in 130 consecutive patients. Radiol Med 2007; 112: 123–137. doi:10.1007/s11547-007-0126-8.

van Stralen KJ, Dekker FW, Zoccali C, et al. Measuring agreement, more complicated than it seems. Nephron Clin Pract 2012; 120: c162–167. doi:10.1159/000337798.

Watson PF, Petrie A. Method agreement analysis: A review of correct methodology. Theriogenology 2010; 73: 1167–1179. doi:10.1016/j.theriogenology.2010.01.003.

Vetter TR, Schober P. Agreement analysis. Anesth Analg 2018; 126: 2123–2128. doi:10.1213/ANE.0000000000002924.

Altman DG, Royston P. The cost of dichotomising continuous variables. BMJ 2006; 332: 1080.1. doi:10.1136/bmj.332.7549.1080.

Chappell ET, Moure FC, Good MC, et al. Comparison of computed tomographic angiography with digital subtraction angiography in the diagnosis of cerebral aneurysms: A meta-analysis. Neurosurgery 2003; 52: 624–631.

Menke J, Larsen J, Kallenberg K. Diagnosing cerebral aneurysms by computed tomographic angiography: Meta-analysis. Ann Neurol 2011; 69: 646–654.

Westerlaan HE, van Dijk JMC, Jansen-van der Weide MC, et al. Intracranial aneurysms in patients with subarachnoid hemorrhage: CT Angiography as a primary examination tool for diagnosis—Systematic review and meta-analysis. Radiology 2011; 258: 134–145.

Franklin B, Gasco J, Uribe T, et al. Diagnostic accuracy and inter-rater reliability of 64-multislice 3D-CTA compared to intra-arterial DSA for intracranial aneurysms. J Clin Neurosci 2010; 17: 579–583.

You C, Sun H, Ma J, et al. Diagnosing residual or recurrent cerebral aneurysms after clipping by computed tomographic angiography: Meta-analysis. Neurol India 2013; 61: 51.

Chen X, Liu Y, Tong H, et al. Meta-analysis of computed tomography angiography versus magnetic resonance angiography for intracranial aneurysm. Med (United States) 2018; 97.

Lubicz B, Levivier M, Francois O, et al. Sixty-Four-Row Multisection CT Angiography for detection and evaluation of ruptured intracranial aneurysms: Interobserver and intertechnique reproducibility. Am J Neuroradiol 2007; 28: 1949–1955. doi:10.3174/ajnr.A0699.

Zhang LJ, Wu SY, Niu JB, et al. Dual-energy CT angiography in the evaluation of intracranial aneurysms: Image quality, radiation dose, and comparison with 3D rotational digital subtraction angiography. AJR Am J Roentgenol 2010; 194: 23–30.

Zhang H, Hou C, Zhou Z, et al. Evaluating of small intracranial aneurysms by 64-Detector CT Angiography: A comparison with 3-Dimensional rotation DSA or surgical findings. J Neuroimaging 2014; 24: 137–143. doi:10.1111/j.1552-6569.2012.00747.x.

Chen L, Xu M, Zou Y, et al. Clinical study of the role of 64-Slice CT cerebral angiography in aneurysmal subarachnoid hemorrhage. Cell Biochem Biophys 2014; 69: 573–575. doi:10.1007/s12013-014-9834-6.



  • There are currently no refbacks.