Repetitive Computed Tomography Perfusion for Detection of Cerebral Vasospasm–Related Hypoperfusion in Aneurysmal Subarachnoid Hemorrhage

Abstract

Background: Delayed cerebral infarction after aneurysmal subarachnoid hemorrhage (aSAH) still remains the leading cause of disability in patients that survive the initial ictus. It has been shown that CT perfusion (CTP) imaging can detect hypoperfused brain areas. The aim of this study was to evaluate if a single acute CTP examination at time of neurological deterioration is sufficient or if an additional baseline CTP increases diagnostic accuracy. Methods: Retrospective analysis of acute and baseline (within 24 hours after aneurysm treatment) CTP examinations of patients with neurological deterioration because of vasospasm-related hypoperfusion. Patients without clinical deterioration during the vasospasm period served as controls. The following CTP parameters were analyzed for predefined brain regions: time to drain (TTD), mean transit time, time to peak, cerebral blood flow and volume. Results: 33 patients with and 23 without neurological deterioration were included. Baseline CTP examination did not ameliorate diagnostic accuracy of the acute CTP examination in symptomatic patients. The same was true for inter-hemispheric comparison of perfusion parameters of the acute examination. The CTP parameter with the highest diagnostic yield was TTD of the symptomatic brain region (threshold value 4.7 sec, sensitivities 97 %, specificities 96 %). Conclusions: Acute CTP examination in case of suspected vasospasm-induced neurological deterioration after aSAH has the highest diagnostic accuracy to detect misery perfusion.

Inhaled Nitric Oxide Treatment for Aneurysmal SAH Patients With Delayed Cerebral Ischemia

“…Angiography and TCD sonography may not be able to detect iNO-induced changes in the microcirculation. CTP scans can detect and monitor cerebral hypoperfusion in SAH patients (71)(72)(73)(74) but since these scans were not done in all patients during iNO, the results should be interpreted with caution. Nevertheless, three of the four patients who had CTP scans during iNO had improved cerebral perfusion.…”

Routine use of perfusion computed tomography for the detection of delayed cerebral ischemia in unconscious patients after aneurysmal subarachnoid hemorrhage

“…According to our protocol, the first rPCT was performed the day after aneurysm obliteration as a baseline examination. However, the performance of PCT baseline examinations is not uncontested and there are indications in the literature that additional baseline PCTs are not needed in order to diagnose DCI [21]. Moreover, the rate of DCI findings at this stage is significantly lower than the rate during the high- risk phase.…”

“…However, PCT also has several disadvantages such as increased radiation exposure or contrast reactions, which may restrict the applicability. Although no profound guidelines for an appropriate use of PCT in aSAH patients have yet been defined, PCT imaging is broadly accepted in the event of a new neurological deficit or abnormalities in TCD or invasive neuromonitoring [21,23]. However, the value of routinely performed PCT (rPCT) in unconscious aSAH patients without any deterioration detected by the functional monitoring is still unknown.…”

Individualized Brain Tissue Oxygen-Monitoring Probe Placement Helps to Guide Therapy and Optimizes Outcome in Neurocritical Care

“…A confirmatory scan is recommended in clinical practice as well as in ongoing trials (BONANZA), and imposes a radiation exposure of 600-700 mGycm by itself if performed as a regular CT scan [1,45]. Of note, as an alternative to ptO 2 measurements in the diagnosis of vasospasms, angio-CT combined with perfusion-CT imaging is often used and imposes a radiation exposure of 3000-3400 mGycm [46][47][48].…”