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Abel Po-Hao Huang, Jui-Chang Tsai, Lu-Ting Kuo, Chung-Wei Lee, Hong-Shiee Lai, Li-Kai Tsai, Sheng-Jean Huang, Chien-Min Chen, Yuan-Shen Chen, Hao-Yu Chuang and Max Wintermark

Object

Currently, perfusion CT (PCT) is a valuable imaging technique that has been successfully applied to the clinical management of patients with ischemic stroke and aneurysmal subarachnoid hemorrhage (SAH). However, recent literature and the authors' experience have shown that PCT has many more important clinical applications in a variety of neurosurgical conditions. Therefore, the authors share their experiences of its application in various diseases of the cerebrovascular, neurotraumatology, and neurooncology fields and review the pertinent literature regarding expanding PCT applications for neurosurgical conditions, including pitfalls and future developments.

Methods

A pertinent literature search was conducted of English-language articles describing original research, case series, and case reports from 1990 to 2011 involving PCT and with relevance and applicability to neurosurgical disorders.

Results

In the cerebrovascular field, PCT is already in use as a diagnostic tool for patients suspected of having an ischemic stroke. Perfusion CT can be used to identify and define the extent of the infarct core and ischemic penumbra core, and thus aid patient selection for acute reperfusion therapy. For patients with aneurysmal SAH, PCT provides assessment of early brain injury, cerebral ischemia, and infarction, in addition to vasospasm. It may also be used to aid case selection for aggressive treatment of patients with poor SAH grade. In terms of oncological applications, PCT can be used as an imaging biomarker to assess angiogenesis and response to antiangiogenetic treatments, differentiate between glioma grades, and distinguish recurrent tumor from radiation necrosis. In the setting of traumatic brain injury, PCT can detect and delineate contusions at an early stage. In patients with mild head injury, PCT results have been shown to correlate with the severity and duration of postconcussion syndrome. In patients with moderate or severe head injury, PCT results have been shown to correlate with patients' functional outcome.

Conclusions

Perfusion CT provides quantitative and qualitative data that can add diagnostic and prognostic value in a number of neurosurgical disorders, and also help with clinical decision making. With emerging new technical developments in PCT, such as characterization of blood-brain barrier permeability and whole-brain PCT, this technique is expected to provide more and more insight into the pathophysiology of many neurosurgical conditions.

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Shin-Joe Yeh, Sung-Chun Tang, Li-Kai Tsai, Chung-Wei Lee, Ya-Fang Chen, Hon-Man Liu, Shih-Hung Yang, Yu-Lin Hsieh, Meng-Fai Kuo and Jiann-Shing Jeng

OBJECTIVE

Pediatric and adult patients with moyamoya disease experience similar clinical benefits from indirect revascularization surgeries, but there are still debates about age-related angiographic differences of the collaterals established after surgery. The goal of this study was to assess age-related differences on ultrasonography before and after indirect revascularization surgeries in moyamoya patients, focusing on some ultrasonographic parameters known to be correlated with the collaterals supplied by the external carotid artery (ECA).

METHODS

The authors prospectively included moyamoya patients (50 and 26 hemispheres in pediatric and adult patients, respectively) who would undergo indirect revascularization surgery. Before surgery and at 1, 3, and 6 months after surgery, the patients underwent ultrasonographic examinations. The ultrasonographic parameters included peak-systolic velocity (PSV), end-diastolic velocity (EDV), resistance index (RI), and flow volume (FV) measured in the ECA, superficial temporal artery (STA), and internal carotid artery on the operated side. The mean values, absolute changes, and percentage changes of these parameters were compared between the pediatric and adult patients. Logistic regression analysis was used to clarify the determinants affecting postoperative EDV changes in the STA.

RESULTS

Before surgery, the adult patients had mean higher EDV and lower RI in the STA and ECA than the pediatric group (all p < 0.05). After surgery, the pediatric patients had greater changes (absolute and percentage changes) in the PSV, EDV, RI, and FV in the STA and ECA (all p < 0.05). The factors affecting postoperative EDV changes in the STA at 6 months were age (p = 0.006) and size of the revascularization area (i.e., revascularization in more than the temporal region vs within the temporal region; p = 0.009). Pediatric patients who received revascularization procedures in more than the temporal region had higher velocities (PSV and EDV) in the STA than those who received revascularization within the temporal region (p < 0.05 at 1–6 months), but such differences were not observed in the adult group.

CONCLUSIONS

The greater changes of these parameters in the STA and ECA in pediatric patients than in adults after indirect revascularization surgeries indicated that pediatric patients might have a greater increase of collaterals postoperatively than adults. Pediatric patients who undergo revascularization in more than the temporal region might have more collaterals than those who undergo revascularization within the temporal region.

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Oral Presentations

2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010