Influence of MRI Follow-Up on Treatment Decisions during Standard Concomitant and Adjuvant Chemotherapy in Patients with Glioblastoma: Is Less More?

MRI is the gold standard for treatment response assessments for glioblastoma. However, there is no consensus regarding the optimal interval for MRI follow-up during standard treatment. Moreover, a reliable assessment of treatment response is hindered by the occurrence of pseudoprogression. It is unknown if a radiological follow-up strategy at 2-3 month intervals actually benefits patients and how it influences clinical decision making about the continuation or discontinuation of treatment. This study assessed the consequences of scheduled follow-up scans post-chemoradiotherapy (post-CCRT), after three cycles of adjuvant chemotherapy [TMZ3/6], and after the completion of treatment [TMZ6/6]), and of unscheduled scans on treatment decisions during standard concomitant and adjuvant treatment in glioblastoma patients. Additionally, we evaluated how often follow-up scans resulted in diagnostic uncertainty (tumor progression versus pseudoprogression), and whether perfusion MRI improved clinical decision making. Scheduled follow-up scans during standard treatment in glioblastoma patients rarely resulted in an early termination of treatment (2.3% post-CCRT, 3.2% TMZ3/6, and 7.8% TMZ6/6), but introduced diagnostic uncertainty in 27.7% of cases. Unscheduled scans resulted in more major treatment consequences (30%; p < 0.001). Perfusion MRI caused less diagnostic uncertainty (p = 0.021) but did not influence treatment consequences (p = 0.871). This study does not support the current pragmatic follow-up strategy and suggests a more tailored follow-up approach.

The Correlation of In Vivo MR Spectroscopy and Ex Vivo 2-Hydroxyglutarate Concentration for the Prediction of Isocitrate Dehydrogenase Mutation Status in Diffuse Glioma.

Isocitrate dehydrogenase (IDH) mutation status is an important biomarker in the glioma-defining subtype and corresponding prognosis. This study proposes a straightforward method for 2-hydroxyglutarate (2-HG) quantification by MR spectroscopy for IDH mutation status detection and directly compares in vivo 2-HG MR spectroscopy with ex vivo 2-HG concentration measured in resected tumor tissue. Eleven patients with suspected lower-grade glioma (ten IDH1; one IDHwt) were prospectively included. Preoperatively, 3T point-resolved spectroscopy (PRESS) was acquired; 2-HG was measured as the percentage elevation of Glx3 (the sum of 2-HG and Glx) compared to Glx4. IDH mutation status was assessed by immunochemistry or direct sequencing. The ex vivo 2-HG concentration was determined in surgically obtained tissue specimens using gas chromatography-mass spectrometry. Pearson correlation was used for assessing the correlation between in vivo MR spectroscopy and ex vivo 2-HG concentration. MR spectroscopy was positive for 2-HG in eight patients, all of whom had IDH1 tumors. A strong correlation (r = 0.80, p = 0.003) between 2-HG MR spectroscopy and the ex vivo 2-HG concentration was found. This study shows in vivo 2-HG MR spectroscopy can non-invasively determine IDH status in glioma and demonstrates a strong correlation with ex vivo 2-HG concentration in patients with lower-grade glioma.

Ventricle contact may be associated with higher 11C methionine PET uptake in glioblastoma.

PURPOSE: Ventricle contact is associated with a worse prognosis and more aggressive tumor characteristics in glioblastoma (GBM). This is hypothesized to be a result of neural stem cells located around the lateral ventricles, in the subventricular zone. 11C Methionine positron emission tomography (metPET) is an indicator for increased proliferation, as it shows uptake of methionine, an amino acid needed for protein synthesis. This study is the first to study metPET characteristics of GBM in relation to ventricle contact. METHODS: A total of 12 patients with IDH wild-type GBM were included. Using MRI, the following regions were determined: primary tumor (defined as contrast enhancing lesion on T1) and peritumoral edema (defined as edema visible on FLAIR excluding the enhancement). PET parameters in these areas were extracted using PET fused with MRI imaging. Parameters extracted from the PET included maximum and mean tumor-to-normal ratio (TNRmax and TNRmean) and metabolic tumor volume (MTV). RESULTS: TNRmean of the primary tumor showed significantly higher values for the ventricle-contacting group compared to that for the non-contacting group (4.44 vs 2.67, p = 0.030). Other metPET parameters suggested higher values for the ventricle-contacting group, but these differences did not reach statistical significance. CONCLUSION: GBM with ventricle contact demonstrated a higher methionine uptake and might thus have increased proliferation compared with GBM without ventricle contact. This might explain survival differences and should be considered in treatment decisions.

Value of screening and follow-up brain MRI scans in patients with metastatic melanoma.

BACKGROUND: Novel treatments make long-term survival possible for subsets of patients with melanoma brain metastases. Brain magnetic resonance imaging (MRI) may aid in early detection of brain metastases and inform treatment decisions. This study aimed to determine the impact of screening MRI scans in patients with metastatic melanoma and follow-up MRI scans in patients with melanoma brain metastases. METHODS: This retrospective cohort study included patients diagnosed with metastatic melanoma or melanoma brain metastases between June 2015 and January 2018. The impact of screening MRI scans was evaluated in the first 2 years after metastatic melanoma diagnosis. The impact of follow-up MRI scans was examined in the first year after brain metastases diagnosis. The number of MRI scans, scan indications, scan outcomes, and changes in treatment strategy were analyzed. RESULTS: In total, 116 patients had no brain metastases at the time of the metastatic melanoma diagnosis. Twenty-eight of these patients (24%) were subsequently diagnosed with brain metastases. Screening MRI scans detected the brain metastases in 11/28 patients (39%), of which 8 were asymptomatic at diagnosis. In the 96 patients with melanoma brain metastases, treatment strategy changed after 75/168 follow-up MRI scans (45%). In patients treated with immune checkpoint inhibitors, the number of treatment changes after follow-up MRI scans was lower when patients had been treated longer. CONCLUSION(S): Screening MRI scans aid in early detection of melanoma brain metastases, and follow-up MRI scans inform treatment strategy. In patients with brain metastases responding to immune checkpoint inhibitors, treatment changes were less frequently observed after follow-up MRI scans. These results can inform the development of brain imaging protocols for patients with immune checkpoint inhibitor sensitive tumors.

Quantifying effects of radiotherapy-induced microvascular injury; review of established and emerging brain MRI techniques.

Microvascular changes are increasingly recognised not only as primary drivers of radiotherapy treatment response in brain tumours, but also as an important contributor to short- and long-term (cognitive) side effects arising from irradiation of otherwise healthy brain tissue. As overall survival of patients with brain tumours is increasing, monitoring long-term sequels of radiotherapy-induced microvascular changes in the context of their potential predictive power for outcome, such as cognitive disability, has become increasingly relevant. Ideally, radiotherapy-induced significant microvascular changes in otherwise healthy brain tissue should be identified as early as possible to facilitate adaptive radiotherapy and to proactively start treatment to minimise the influence on these side-effects on the final outcome. Although MRI is already known to be able to detect significant long-term radiotherapy induced microvascular effects, more recently advanced MR imaging biomarkers reflecting microvascular integrity and function have been reported and might provide a more accurate and earlier detection of microvascular changes. However, the use and validation of both established and new techniques in the context of monitoring early and late radiotherapy-induced microvascular changes in both target-tissue and healthy tissue currently are minimal at best. This review aims to summarise the performance and limitations of existing methods and future opportunities for detection and quantification of radiotherapy-induced microvascular changes, as well as the relation of these findings with key clinical parameters.

Accuracy of Intraoperative Computed Tomography in Deep Brain Stimulation-A Prospective Noninferiority Study.

INTRODUCTION: Clinical response to deep brain stimulation (DBS) strongly depends on the appropriate placement of the electrode in the targeted structure. Postoperative MRI is recognized as the gold standard to verify the DBS-electrode position in relation to the intended anatomical target. However, intraoperative computed tomography (iCT) might be a feasible alternative to MRI. MATERIALS AND METHODS: In this prospective noninferiority study, we compared iCT with postoperative MRI (24-72 hours after surgery) in 29 consecutive patients undergoing placement of 58 DBS electrodes. The primary outcome was defined as the difference in Euclidean distance between lead tip coordinates as determined on both imaging modalities, using the lead tip depicted on MRI as reference. Secondary outcomes were difference in radial error and depth, as well as difference in accuracy relative to target. RESULTS: The mean difference between the lead tips was 0.98 ± 0.49 mm (0.97 ± 0.47 mm for the left-sided electrodes and 1.00 ± 0.53 mm for the right-sided electrodes). The upper confidence interval (95% CI, 0.851 to 1.112) did not exceed the noninferiority margin established. The average radial error between lead tips was 0.74 ± 0.48 mm and the average depth error was determined to be 0.53 ± 0.40 mm. The linear Deming regression indicated a good agreement between both imaging modalities regarding accuracy relative to target. CONCLUSIONS: Intraoperative CT is noninferior to MRI for the verification of the DBS-electrode position. CT and MRI have their specific benefits, but both should be considered equally suitable for assessing accuracy.

Perfusion MRI in treatment evaluation of glioblastomas: Clinical relevance of current and future techniques.

Treatment evaluation of patients with glioblastomas is important to aid in clinical decisions. Conventional MRI with contrast is currently the standard method, but unable to differentiate tumor progression from treatment-related effects. Pseudoprogression appears as new enhancement, and thus mimics tumor progression on conventional MRI. Contrarily, a decrease in enhancement or edema on conventional MRI during antiangiogenic treatment can be due to pseudoresponse and is not necessarily reflective of a favorable outcome. Neovascularization is a hallmark of tumor progression but not for posttherapeutic effects. Perfusion-weighted MRI provides a plethora of additional parameters that can help to identify this neovascularization. This review shows that perfusion MRI aids to identify tumor progression, pseudoprogression, and pseudoresponse. The review provides an overview of the most applicable perfusion MRI methods and their limitations. Finally, future developments and remaining challenges of perfusion MRI in treatment evaluation in neuro-oncology are discussed. Level of Evidence: 3 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2019;49:11-22.

The relation between flocculus volume and tinnitus after cerebellopontine angle tumor surgery.

PURPOSE: Chronic tinnitus is a common symptom after cerebellopontine angle (CPA) tumor removal. Sometimes, the tinnitus is gaze-modulated. In that case, patients can change the loudness or pitch of their tinnitus by ocular movements. During tumor removal by a retrosigmoid craniotomy, the cerebellar flocculus is manipulated by the surgical approach to access the tumor. The flocculus has been associated with tinnitus in rats, and is involved in eye-gaze control. This suggests that the flocculus may have a role in gaze-modulated tinnitus after CPA tumor removal. In order to investigate this hypothesis, the relation between the flocculus volume and the characteristics of postoperative tinnitus was studied. RESULTS: A single-center cohort of 51 patients completed a questionnaire after CPA tumor removal. The questionnaire asked for the effect of eye movements on tinnitus and included the Tinnitus Functional Index (TFI). Tinnitus was present in 36 patients (71% of 51), of which 29 (81% of 36) described gaze-modulation. The median TFI was 22 (range 0-85). A postoperative MRI-scan of sufficient quality was available in 34 cases. The volumes of the (para)flocculi ipsilateral and contralateral to the surgery, and the ratio of these volumes were similar between patients with and without tinnitus. The TFI correlated with the volume of both ipsi- and contralateral (para)flocculus (rs(23) = .516, p = .008 and rs(23) = .430, p = .032). The ipsilateral-to-contralateral volume ratio of the (para)flocculi volumes was significantly lower in patients that could modulate the loudness of their tinnitus by eye gaze, compared to patients that could not (t(23) = 3.337, p = .003). CONCLUSIONS: The lack of a relation between flocculus volumes and the presence of tinnitus, combined with the significant correlation between tinnitus severity and flocculus volumes, suggests that the flocculus may not be the primary source of tinnitus, but is likely to mediate tinnitus severity. The reduced ipsi-to-contralateral volume ratio in patients with gaze-modulated tinnitus suggests that atrophy of the flocculus on the surgery side triggers cross-modal interactions leading to modulation of tinnitus.

Functional MRI for Treatment Evaluation in Patients with Head and Neck Squamous Cell Carcinoma: A Review of the Literature from a Radiologist Perspective.

PURPOSE OF REVIEW: To show the role of functional MRI in patients treated for head and neck squamous cell carcinoma. RECENT FINDINGS: MRI is commonly used for treatment evaluation in patients with head and neck tumors. However, anatomical MRI has its limits in differentiating between post-treatment effects and tumor recurrence. Recent studies showed promising results of functional MRI for response evaluation. SUMMARY: This review analyzes possibilities and limitations of functional MRI sequences separately to obtain insight in the post-therapy setting. Diffusion, perfusion and spectroscopy show promise, especially when utilized complimentary to each other. These functional MRI sequences aid in the early detection which might improve survival by increasing effectiveness of salvage therapy. Future multicenter longitudinal prospective studies are needed to provide standardized guidelines for the use of functional MRI in daily clinical practice.

Incidence of Tumour Progression and Pseudoprogression in High-Grade Gliomas: a Systematic Review and Meta-Analysis.

BACKGROUND: High-grade gliomas are the most common primary brain tumours. Pseudoprogression describes the false appearance of radiation-induced progression on MRI. A distinction should be made from true tumour progression to correctly plan treatment. However, there is wide variation of reported pseudoprogression. We thus aimed to establish the incidence of pseudoprogression and tumour progression in high-grade glioma patients with a systematic review and meta-analysis. METHODS: We searched PubMed, Embase and Web of Science on the incidence of pseudoprogression and tumour progression in adult high-grade glioma patients from 2005, the latest on 8 October 2014. Histology or imaging follow-up was used as reference standard. Extracted data included number of patients with worsening of imaging findings on T1 postcontrast or T2/FLAIR, pseudoprogression and tumour progression. Study quality was assessed. Heterogeneity was tested with I 2 . Pooling of the results was done with random models using Metaprop in STATA (StataCorp. Stata Statistical Software. College Station, TX: StataCorp LP). RESULTS: We identified 73 studies. MRI progression occurred in 2603 patients. Of these, 36% (95% confidence interval [CI] 33-40%) demonstrated pseudoprogression, 60% (95%CI 56-64%) tumour progression and unknown outcome was present in the remaining 4% of the patients (range 1-37%). CONCLUSION: This meta-analysis demonstrated for the first time a notably high pooled incidence of pseudoprogression in patients with a form of progression across the available literature. This highlighted the full extent of the problem of the currently conventional MRI-based Response Assessment in Neuro-Oncology (RANO) criteria for treatment evaluation in high-grade gliomas. This underscores the need for more accurate treatment evaluation using advanced imaging to improve diagnostic accuracy and therapeutic approach.

Subventricular Zone Involvement Characterized by Diffusion Tensor Imaging in Glioblastoma.

BACKGROUND: Glioblastomas have a poor prognosis, possibly because of a subpopulation of therapy-resistant stem cells within the heterogeneous glioblastoma. Because the subventricular zone is the main source of neural stem cells, we aimed at characterizing the subventricular zone using diffusion tensor imaging (DTI) to show subventricular zone involvement in glioblastoma. METHODS: We prospectively included 93 patients with primary glioblastomas who underwent preoperative DTI. The nonenhancing high fluid-attenuated inversion recovery (FLAIR) signal was used to describe the infiltrative tumor margin. We used a 5-mm margin surrounding the lateral ventricles to define the subventricular zone. The subventricular zone with high FLAIR was compared with the subventricular zone without high FLAIR, control high FLAIR outside the subventricular zone and control contralateral normal-appearing white matter. Normalized DTI parameters were calculated and compared between the different regions. RESULTS: The subventricular zone with high FLAIR showed increased isotropic p values compared with the subventricular zone without high FLAIR (t126 = 3.9; P < 0.001) and control regions (t179 = 1.9; P = 0.046). Anisotropic q and fractional anisotropy values were lower in regions with high FLAIR compared with the subventricular zone without high FLAIR (t181 = 11.6, P < 0.001 and t184 =12.4, P < 0.001, respectively). CONCLUSION: DTI data showed that the subventricular zone is involved in glioblastoma with increased isotropic p values in the subventricular zone with high FLAIR, indicating tumor infiltration.

Diagnostic accuracy of magnetic resonance imaging techniques for treatment response evaluation in patients with head and neck tumors, a systematic review and meta-analysis.

BACKGROUND: Novel advanced MRI techniques are investigated in patients treated for head and neck tumors as conventional anatomical MRI is unreliable to differentiate tumor from treatment related imaging changes. PURPOSE: As the diagnostic accuracy of MRI techniques to detect tumor residual or recurrence during or after treatment is variable reported in the literature, we performed a systematic meta-analysis. DATA SOURCES: Pubmed, EMBASE and Web of Science were searched from their first record to September 23th 2014. STUDY SELECTION: Studies reporting diagnostic accuracy of anatomical, ADC, perfusion or spectroscopy to identify tumor response confirmed by histology or follow-up in treated patients for head and neck tumors were selected by two authors independently. DATA ANALYSIS: Two authors independently performed data extraction including true positives, false positives, true negatives, false negatives and general study characteristics. Meta-analysis was performed using bivariate random effect models when ≥5 studies per test were included. DATA SYNTHESIS: We identified 16 relevant studies with anatomical MRI and ADC. No perfusion or spectroscopy studies were identified. Pooled analysis of anatomical MRI of the primary site (11 studies, N = 854) displayed a sensitivity of 84% (95%CI 72-92) and specificity of 82% (71-89). ADC of the primary site (6 studies, N = 287) showed a pooled sensitivity of 89% (74-96) and specificity of 86% (69-94). LIMITATIONS: Main limitation are the low, but comparable quality of the included studies and the variability between the studies. CONCLUSIONS: The higher diagnostic accuracy of ADC values over anatomical MRI for the primary tumor location emphases the relevance to include DWI with ADC for response evaluation of treated head and neck tumor patients.

Diagnostic accuracy of magnetic resonance imaging techniques for treatment response evaluation in patients with high-grade glioma, a systematic review and meta-analysis.

OBJECTIVE: Treatment response assessment in high-grade gliomas uses contrast enhanced T1-weighted MRI, but is unreliable. Novel advanced MRI techniques have been studied, but the accuracy is not well known. Therefore, we performed a systematic meta-analysis to assess the diagnostic accuracy of anatomical and advanced MRI for treatment response in high-grade gliomas. METHODS: Databases were searched systematically. Study selection and data extraction were done by two authors independently. Meta-analysis was performed using a bivariate random effects model when ≥5 studies were included. RESULTS: Anatomical MRI (five studies, 166 patients) showed a pooled sensitivity and specificity of 68% (95%CI 51-81) and 77% (45-93), respectively. Pooled apparent diffusion coefficients (seven studies, 204 patients) demonstrated a sensitivity of 71% (60-80) and specificity of 87% (77-93). DSC-perfusion (18 studies, 708 patients) sensitivity was 87% (82-91) with a specificity of 86% (77-91). DCE-perfusion (five studies, 207 patients) sensitivity was 92% (73-98) and specificity was 85% (76-92). The sensitivity of spectroscopy (nine studies, 203 patients) was 91% (79-97) and specificity was 95% (65-99). CONCLUSION: Advanced techniques showed higher diagnostic accuracy than anatomical MRI, the highest for spectroscopy, supporting the use in treatment response assessment in high-grade gliomas. KEY POINTS: • Treatment response assessment in high-grade gliomas with anatomical MRI is unreliable • Novel advanced MRI techniques have been studied, but diagnostic accuracy is unknown • Meta-analysis demonstrates that advanced MRI showed higher diagnostic accuracy than anatomical MRI • Highest diagnostic accuracy for spectroscopy and perfusion MRI • Supports the incorporation of advanced MRI in high-grade glioma treatment response assessment.

Surgical Accuracy of 3-Tesla Versus 7-Tesla Magnetic Resonance Imaging in Deep Brain Stimulation for Parkinson Disease.

BACKGROUND: In deep brain stimulation (DBS), accurate placement of the lead is critical. Target definition is highly dependent on visual recognition on magnetic resonance imaging (MRI). We prospectively investigated whether the 7-T MRI enabled better visualization of targets and led to better placement of leads compared with the 1.5-T and the 3-T MRI. METHODS: Three patients with PD (mean, 55 years) were scanned on 1.5-, 3-, and 7-T MRI before surgery. Tissue contrast and signal-to-noise ratio were measured. Target coordinates were noted on MRI and during surgery. Differences were analyzed with post-hoc analysis of variance. RESULTS: The 7-T MRI demonstrated a significant improvement in tissue visualization (P < 0.005) and signal-to-noise ratio (P < 0.005). However, no difference in the target coordinates was found between the 7-T and the 3-T MRI. CONCLUSIONS: Although the 7-T MRI enables a significant better visualization of the DBS target in patients with PD, we found no clinical benefit for the placement of the DBS leads.

Increasing levels of TNFalpha are associated with increased brain perfusion.

OBJECTIVE: Recent reports of animal models have shown that growth factors have stimulating effect on brain perfusion via the development of blood vessels. However, studies on the effect of growth factors on brain perfusion in humans are lacking. The aim of our study was to prospectively investigate in humans the relation between growth factors and brain perfusion. METHODS: We analyzed circulating levels of vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating growth factor (GM-CSF), tumor necrosis factor alpha (TNFalpha) and basic fibroblast growth factor (bFGF) in 121 consecutive patients (99 men and 22 women, age 58+/-10 years) who were enrolled in a prospective cohort study of patients with symptomatic atherosclerotic disease. In all patients regional cerebral blood flow (rCBF; in mL/min/100g) measurements were performed with arterial spin labeling magnetic resonance imaging. Cerebrovascular risk factors were assessed by means of a questionnaire and physical, ultrasonographic and laboratory examination. RESULTS: Increasing levels of TNFalpha were significantly associated with a higher rCBF (beta=7.0; 95% confidence interval 0.7; 13.9), independent of the presence of cerebrovascular risk factors. No significant association was found for VEGF, GM-CSF and bFGF. CONCLUSIONS: Increasing levels of TNFalpha are associated with increased rCBF, independent of the presence of cerebrovascular risk factors.

Effect of cerebrovascular risk factors on regional cerebral blood flow.

PURPOSE: To prospectively investigate which cerebrovascular risk factors are related to regional cerebral blood flow (rCBF), as measured noninvasively with arterial spin-labeling (ASL) magnetic resonance (MR) imaging, in a large group of patients with symptomatic atherosclerotic disease. MATERIALS AND METHODS: Ethics committee approval and informed consent were obtained. One hundred thirty consecutive patients (107 men, 23 women; mean age, 58 years +/- 10 [standard deviation]) with symptomatic atherosclerotic disease were included in the study. Cerebrovascular risk factors (body mass index, carotid artery stenosis, diabetes mellitus, hyperhomocysteinemia, hyperlipidemia, hypertension, and smoking) were assessed by means of a questionnaire and physical, ultrasonographic, and laboratory examinations. The control group consisted of 10 subjects (eight men, two women; mean age, 58 years +/- 15) without symptomatic atherosclerotic disease. rCBF measurements were performed with ASL MR imaging. The effects of the individual cerebrovascular risk factors on the rCBF were assessed by using linear regression analysis. RESULTS: Hypertension was significantly associated with higher rCBF (adjusted beta = 6.5 mL/min/100 g; 95% confidence interval: 1.4 mL/min/100 g, 11.7 mL/min/100 g). Hyperhomocysteinemia was significantly related to lower rCBF (adjusted beta = -7.4 mL/min/100 g; 95% confidence interval: -12.7 mL/min/100 g, -2.1 mL/min/100 g). No significant associations between rCBF and the other cerebrovascular risk factors were found. CONCLUSION: In patients with symptomatic atherosclerotic disease, hypertension is related to higher rCBF and hyperhomocysteinemia is related to lower rCBF.

Altered flow territories after carotid stenting and carotid endarterectomy.

BACKGROUND: The hemodynamic effects of carotid angioplasty with stent placement (CAS) on the collateral blood supply and on the regional cerebral blood flow (rCBF) have not been established. Recently, arterial spin-labeling (ASL) magnetic resonance imaging (MRI) has been introduced as the first method to quantify the actual territorial contribution of individual collateral arteries as well as to noninvasively measure rCBF. This study investigated alterations in flow territories and rCBF in patients with symptomatic internal carotid artery (ICA) stenosis and compared them with healthy control subjects. In addition, we investigated whether possible differences in flow territories and rCBF were present between patients undergoing CAS and patients undergoing carotid endarterectomy (CEA). METHODS: The study included 24 consecutive patients (15 men and 9 women; age 67+/-9 years) with symptomatic ICA stenosis. CAS was performed in 12 patients, and 12 patients underwent CEA. Flow territory mapping and rCBF measurements were performed with ASL MRI before intervention and 1 month after. The control group consisted of 40 subjects (25 men and 15 women; age 67+/-8 years). RESULTS: The flow territory of the ipsilateral ICA in patients with ICA stenosis was smaller, and the territories of the contralateral ICA and vertebrobasilar arteries were larger compared with control subjects (P<.05). After CAS, rCBF in the ipsilateral hemisphere increased from 60.2+/-16.9 mL/(min.100 g) to 68.9+/-9.2 mL/(min.100 g) (P<.05). Differences in flow territories and rCBF between patients and control subjects disappeared after CAS. Changes in flow territories and rCBF were similar in patients who underwent CAS or CEA. CONCLUSIONS: CAS results in a normalization of the territorial distribution and rCBF, as assessed by ASL MRI. The degree of improvement is similar to that seen after CEA.

Hemodynamic effect of carotid stenting and carotid endarterectomy.

BACKGROUND: Carotid angioplasty with stent placement (CAS) may offer an alternative treatment to carotid endarterectomy (CEA). However, in contrast to CEA, which has been shown to normalize impaired cerebral hemodynamics, the effects of CAS remain unclear. To investigate alterations in cerebral hemodynamics, we prospectively studied patients undergoing CAS and compared them with a group of similar patients undergoing CEA. METHODS: Twenty-three patients undergoing CAS for recently symptomatic internal carotid artery (ICA) stenosis were prospectively studied. Volume flow in the ICAs and basilar artery (BA) were measured with magnetic resonance volume flow quantification before CAS and 1 month after. The results were compared with those in 13 similar patients undergoing CEA and 40 control subjects without ICA stenosis. RESULTS: After CAS, volume flow in the ipsilateral ICA increased from 114 +/- 17 to 231 +/- 17 mL/min (P < .001), and total volume flow (ICAs plus BA) increased from 495 +/- 24 to 552 +/- 28 mL/min (P < .05). No significant changes were seen in the contralateral ICA and BA after CAS. Total volume flow and flow in the stenosed ICA normalized after CAS compared with control subjects. Volume flow values similarly improved after CEA. CONCLUSIONS: CAS results in a normalization of impaired cerebral hemodynamics, as assessed by magnetic resonance volume flow measurements. The degree of improvement is similar to that seen after CEA.