Tag: CT angiography

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Detection of impending perfusion deficits by intraoperative computed tomography (iCT) in aneurysm surgery of the anterior circulation

Acta Neurochirurgica (2021) 163:3501–3514

The aim of our study was to evaluate the additional benefit of intraoperative computed tomography (iCT), intraoperative computed tomography angiography (iCTA), and intraoperative computed tomography perfusion (iCTP) in the intraoperative detection of impending ischemia to established methods (indocyanine green videoangiography (ICGVA), microDoppler, intraoperative neuromonitoring (IONM)) for initiating timely therapeutic measures.

Methods Patients with primary aneurysms of the anterior circulation between October 2016 and December 2019 were included. Data of iCT modalities compared to other techniques (ICGVA, microDoppler, IONM) was recorded with emphasis on resulting operative conclusions leading to inspection of clip position, repositioning, or immediate initiation of conservative treatment strategies. Additional variables analyzed included patient demographics, aneurysm-specific characteristics, and clinical outcome.

Results Of 194 consecutive patients, 93 patients with 100 aneurysms received iCT imaging. While IONM and ICGVA were normal, an altered vessel patency in iCTA was detected in 5 (5.4%) and a mismatch in iCTP in 7 patients (7.5%). Repositioning was considered appropriate in 2 patients (2.2%), where immediate improvement in iCTP could be documented. In a further 5 cases (5.4%), intensified conservative therapy was immediately initiated treating the reduced CBP as clip repositioning was not considered causal. In terms of clinical outcome at last FU, mRS0 was achieved in 85 (91.4%) and mRS1-2 in 7 (7.5%) and remained mRS4 in one patient with SAH (1.1%).

Conclusions Especially iCTP can reveal signs of impending ischemia in selected cases and enable the surgeon to promptly initiate therapeutic measures such as clip repositioning or intraoperative onset of maximum conservative treatment, while established tools might fail to detect those intraoperative pathologic changes.

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Anatomic Features of Paraclinoid Aneurysms

Neurosurgery 81:949–957, 2017

Paraclinoid aneurysms are among the most challenging aneurysms to treat. Computed tomography (CT) angiography helps in evaluating the radiological characteristics of these aneurysms next to bony structures.

OBJECTIVE: To present the CT angiography characteristics of paraclinoid aneurysms in order to better understand such pathology.

METHODS: The study examined CT angiography-based anatomical characteristics obtained retrospectively from 136 patients with 144 paraclinoid aneurysms selected from single-defined catchment populations in Finland. We examined the diameters of the parent artery (internal carotid artery), the location of the aneurysm, its dimensions (width, height, neck), and aneurysm wall irregularity.

RESULTS:We analyzed 144 paraclinoid aneurysms in 136 patients admitted to the hospital during 2000-2014.Multivariable analysis reveals that rupture aneurysms have the following radiological features: aneurysm larger than 5 mm in diameter (P = .006), irregular wall (P = .046), superior location, larger aspect ratio (P = .039), and neck wider than parent artery (P < .001).

CONCLUSION: Smaller diameter of the internal carotid artery and superior location, as well as a large and irregular aneurysm wall, are radiological characteristics of ruptured paraclinoid aneurysms, which CT angiography can measure easily.

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Vascular complications of penetrating brain injury

Vascular complications penetrating BI

J Neurosurg 121:1275–1283, 2014

The authors conducted a study to compare the sensitivity and specificity of helical CT angiography (CTA) and digital subtraction angiography (DSA) in detecting intracranial arterial injuries after penetrating traumatic brain injury (PTBI).

Methods. In a retrospective evaluation of 48 sets of angiograms from 45 consecutive patients with PTBI, 3 readers unaware of the DSA findings reviewed the CTA images to determine the presence or absence of arterial injuries. A fourth reader reviewed all the disagreements and decided among the 3 interpretations. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTA were calculated on a per-injury basis and in a subpopulation of patients with traumatic intracranial aneurysms (TICAs).

Results. Sensitivity of CTA for detecting arterial injuries was 72.7% (95% CI 49.8%–89.3%); specificity, 93.5% (95% CI 78.6%–99.2%); PPV, 88.9% (95% CI 65.3%–98.6%); and NPV, 82.9% (95% CI 66.4%–93.4%). All 7 TICAs were correctly identified by CTA. Sensitivity, specificity, PPV, and NPV of CTA in detecting TICAs were 100%. To compare agreement with DSA, the standard of reference, confidence scores categorized as low, intermediate, and high probability yielded an overall effectiveness of 77.8% (95% CI 71.8%–82.9%).

Conclusions. Computed tomography angiography had limited overall sensitivity in detecting arterial injuries in patients with PTBI. However, it was accurate in identifying TICAs, a subgroup of injuries usually managed by either surgical or endovascular approaches, and non-TICA injuries involving the first-order branches of intracranial arteries.

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