Intravenous flat-detector computed tomography angiography for symptomatic cerebral vasospasm following aneurysmal subarachnoid hemorrhage

Comparative diagnostic efficacy of cranial CT, CTA, and DSA in subarachnoid hemorrhage management: A systematic review and meta-analysis

INTRODUCTION

Subarachnoid hemorrhage (SAH) is a critical medical condition associated with high morbidity and mortality rates. Timely and accurate diagnosis is crucial for optimal patient outcomes. Cranial computed tomography (CT), computed tomography angiography (CTA), and digital subtraction angiography (DSA) are commonly used imaging modalities for diagnosing SAH, but their comparative diagnostic efficacy remains debated.

METHODS

A systematic review and meta-analysis was conducted to evaluate the diagnostic performance of cranial CT, CTA, and DSA in identifying SAH. PubMed, Google scholar, Cochrane Library databases were searched for relevant studies published up to January 2024. Pooled sensitivity, specificity, and the summary receiver operating characteristic (SROC) curve were calculated using Review Manager 5.4.

RESULTS

A total of 31 studies involving 10,287 patients were included in the analysis. The pooled sensitivity of cranial CT for detecting SAH was 94.7 % (95 % Confidence Interval, CI) with a specificity of 98.3 % (95 % CI). CTA demonstrated a pooled sensitivity of 94.1 % (95 % CI) and specificity of 93.4 % (95 % CI). DSA showed a pooled sensitivity of 87.7 % (95 % CI) and specificity of 95.8 % (95 % CI). The SROC curve demonstrated discriminatory ability for all modalities.

CONCLUSION

Cranial CT, CTA, and DSA are valuable imaging modalities for diagnosing SAH, with high sensitivity and specificity. Cranial CT serves as an initial screening tool, while CTA offers superior sensitivity in detecting aneurysmal SAH. DSA remains essential in specific clinical scenarios. Further prospective studies are needed to validate these findings and refine diagnostic guidelines for SAH.

Computed Tomography Angiography Compared with Computed Tomography Perfusion in the Diagnosis of Cerebral Vasospasm: A Systematic Review and Meta-Analysis

INTRODUCTION

Cerebral vasospasm (CV) is a serious complication after subarachnoid hemorrhage; however, swift identification can be challenging. Computed tomography perfusion (CTP) directly measures tissue perfusion and may better screen for CV compared with other modalities. This systematic review summarizes studies assessing the diagnostic performance of computed tomography angiography (CTA) and CTP in identifying CV.

METHODS

The search strategy drew from English language publications in the PubMed, Embase, Medline, and Cochrane databases from January 1996 to September 2021. Diagnosis of CV by digital subtraction angiography was the reference standard. Pooled sensitivity, specificity, positive predictive values (PPV), negative predictive values (NPV), positive likelihood ratios, negative likelihood ratios, and summary receiver operating characteristic curve were calculated. The methodological index for nonrandomized studies tool was employed to assess the quality of the studies.

RESULTS

The search generated 22 studies. Seven CTA studies and 6 CTP investigations provided sufficient data for meta-analysis. Following pooled estimates, CTA carried a sensitivity of 0.76 (95% confidence interval [CI], 0.72-0.80), specificity of 0.93 (95% CI, 0.92-0.95), PPV of 0.77 (95%, 0.76-0.79), and NPV of 0.81 (95%, 0.79-0.82). CTP carried a sensitivity of 0.86 (95%, 0.81-0.92), specificity of 0.97 (95%, 0.95-0.98), PPV of 0.94 (0.89-0.98), and NPV of 0.94 (0.91-0.97). Using the methodological index for nonrandomized studies tool, the evidence was rated as overall moderate quality.

CONCLUSIONS

This meta-analysis on the diagnostic performance of CTA and CTP in identifying CV suggests that CTP may carry greater diagnostic accuracy compared with CTA. The clinical significance of this difference should be delineated through future prospective studies.

Flat-Detector CT to Quantify Response to Intra-Arterial Spasmolytic Therapy for Cerebral Vasospasm

BACKGROUND AND PURPOSE

Cerebral vasospasm in the setting of subarachnoid hemorrhage causes morbidity and mortality due to delayed cerebral ischemia and permanent neurological deficits. Vasospasm treatment includes intra-arterial injection of a spasmolytic during cerebral angiography. To evaluate effectiveness, neurointerventionalists subjectively examine a posttreatment cerebral angiogram to determine change in vessel diameter or increase in microvascular perfusion. Flat-detector computed tomography (FDCT) scanner has the ability to quantitatively measure cerebral blood volume (CBV) within the parenchyma and detect a quantitative change following treatment.

METHODS

This is a prospective study at a single institution between October 5, 2017 and June 3, 2019 that examines CBV studies from the Artis Q biplane (Siemens). Regions of interest were made in various territories to measure the CBV within the parenchyma before and after treatment with the spasmolytic verapamil. All instances of vasospasm involved vasculature within the left middle cerebral artery or internal carotid artery. The Wilcoxon signed-rank test was used to determine significance before and after treatment.

RESULTS

Our cohort consists of 6 patients who underwent Digital Subtraction Angiography (DSA) and FDCT scans for cerebral vasospasm within the left hemisphere. After intra-arterial injection of 20 mg of verapamil, average increases in blood volume were 59%, 22%, and 24% for the temporal, frontal, and parietal lobes, respectively. P-values associated were .03. We also observed decrease in the mean arterial blood pressure and transcranial Doppler values after treatment.

CONCLUSION

In conclusion, FDCT could measure the effectiveness of a change in CBV from infusion of verapamil in the setting of cerebral vasospasm. The authors believe quantifying the change allows for reassurance of improvement of cerebral vasospasm.

The Effect of Fenestration of Lamina Terminalis on the Vasospasm and Shunt-Dependent Hydrocephalus in Patients Following Subarachnoid Haemorrhage

BACKGROUND AND AIMS

SAH (Sub Arachnoid Haemorrhage) is a life threatening that is associated with complications such as vasospasm and shunt-dependent hydrocephalus. The purpose of this study was to assess the effect of FLT (Fenestration of Lamina Terminalis) on the incidence of vasospasm and shunt-dependent hydrocephalus in ACoA (Anterior Communicating Artery) aneurismal in SAH.

MATERIALS AND METHODS

The data of 50 ruptured ACoA aneurism patients were selected during the year 2001-2009 admitted to Imam Hussein hospital, Tehran, IR. In a randomized double-blind trial patients assigned in two group {with fenestration (FLT, n=25), without fenestration (No FLT, n=25)}. All patients underwent craniotomy by a single neurosurgeon. Patient's age, sex, Hunt-Hess grade, Fisher grade, vasospasm, presence of hydrocephalus and incidences of shunt-dependent hydrocephalus were compared between groups.

RESULTS

There were no significant differences among groups in relation to demographic characteristics, neurological scale scores (Hunt-Hess grade) and the severity of the SAH (Fisher grade) (p>0.05). The rate of hydrocephalus on admission, were 24% and 16% in FLT and no FLT group respectively (p>0.05). The shunt placement postoperatively in FLT and no FLT group were 16% and 12% respectively (p>0.05). The clinical vasospasm was 20% and 24% in FLT and no FLT group respectively (p>0.05).

CONCLUSION

Despite FLT can be a safe method there were not significant differences of FLT on the incidence of vasospasm and shunt-dependent hydrocephalus. A systematic evaluation with multisurgeon, multicentre and with greater sample size to disclose reality is suggested.