Diagnostic value of non-enhanced computed tomography in identifying location of ruptured cerebral aneurysm in patients with aneurysmal subarachnoid haemorrhage

Abstract

Background. In patients with SAH and multiple aneurysms, the ruptured lesion must be identified to prevent recurrent bleeding. Aim of the study. To assess the diagnostic value of non-enhanced computed tomography (NECT) in identifying the rupture site in patients with subarachnoid haemorrhage (SAH) and multiple aneurysms. Material and methods. We included patients with SAH revealed by NECT and multiple aneurysms detected on computed tomography angiography (CTA) in whom a ruptured aneurysm was identified during neurosurgery. Two radiologists predicted the location of the ruptured aneurysm based on the distribution of the SAH and location of intracerebral haematoma (ICH) by NECT. Results. Eighty-three patients with a mean age of 55.7 ± 14.4 years were included. Ruptured aneurysms were significantly larger (mean size 7.7 ± 4.7 mm) than unruptured aneurysms (mean size 5.9 ± 4.5 mm; p = 0.014). Interobserver agreement was 0.86 (p < 0.001). Overall sensitivity and specificity of radiological prediction were 78.3% (95% CI, 68.6%-87.1%) and 96.4% (95% CI, 94.3%-97.8%) respectively. Overall PPV and NPV were 78.3% (95% CI, 67.6%-86.3%) and 96.8% (95% CI, 94.8%-98.1%) respectively. The sensitivity and PPV for aneurysms in the anterior communicating, anterior, and middle cerebral arteries appeared to be significantly higher than in other locations (p = 0.015 and 0.019 respectively). Analysis of independent predictive factors of correct radiological location revealed that ICH predisposes to a correct radiological diagnosis with an odds ratio of 8.57 (95% CI, 1.07-68.99; p = 0.03). Conclusions. NECT has a high diagnostic value in identifying the source of bleeding in patients with multiple aneurysms for anterior circulation aneurysms, especially with coexisting ICH. For other locations, NECT is not reliable enough to base treatment decisions upon.

Why SWI? The sensitivity of susceptibility weighted imaging in aneurysmal subarachnoid haemorrhage in the chronic phase

“…Ruptured aneurysm localisation rates on NECT and digitally subtracted angiograms vary from 52% to 80%, with studies reporting high sensitivities in localising anterior communicating, anterior cerebral and middle cerebral artery aneurysms. 21 , 22 , 23 , 24 In these studies, performed in the acute phase, the haemorrhage pattern was identified and causative aneurysm prediction was performed. As the current study was performed in the chronic phase of ASAH, SWI was able to detect haemosiderin distal to the areas of the initial haemorrhage load, thus creating complexity in the localisation of the maximum site of haemosiderin.…”

“…Maximum haemosiderin staining in the Sylvian cisterns was seen with ipsilateral middle cerebral (PPV = 31.25%), posterior communicating (PPV = 50%) and distal internal carotid arteries aneurysms (PPV = 18.75%) and hence was not specific for ruptured MCA aneurysms as observed in previous studies in the acute phase. 21 , 22 , 23 , 24 This is thought to be related to CSF flow dynamics and deposition of haemosiderin. Figure 6 demonstrates an example of localised haemosiderin and haematoma related to the Sylvian fissure.…”

Interobserver reliability of computed tomography angiography in the assessment of ruptured intracranial aneurysm and impact on patient management

“…Aneurysm detection could be expected by assessing the distribution of SAH, the site of the largest clot, the difference in attenuation, and the presence of mural calcification. A recent study performed on patients with SAH and multiple cerebral aneurysms found that NCCT can identify the source of bleeding with high accuracy for ACA, ACom, and MCA aneurysms, especially with the presence of intracranial hemorrhage (ICH)[ 10 ]. Our results showed excellent inter-observer agreement for detecting acute hydrocephalus with a variable degree of acute ventricular dilation, yet only 15% of our cases need management by EVD.…”

Significance of aneurysm wall enhancement on high-resolution vessel wall magnetic resonance imaging in clinical management of patients with intracranial aneurysms

“…However, small aneurysms remain the cause of a significant percentage of aneurysmal SAH [4]. Up to 30% of patients with acute aneurysmal SAH have multiple intracranial aneurysms [5,6]. Correct identification of a ruptured aneurysm in this condition is crucial for treatment planning.…”