Table of Contents
Perspectives
Review Article
General Contents
- The Brain Thermal Response as a Potential Neuroimaging Biomarker of Cerebrovascular Impairment
The authors evaluated the use of noninvasive MR thermometry in patients with cerebrovascular disease, and hypothesized that the presence of a measurable brain thermalresponse would reflect the tissue hemodynamic state. MR imaging and MR thermometry were performed in 10 patients undergoing acetazolamide challenge for chronic, anterior circulation steno-occlusive disease. Cerebrovascular reactivity was calculated with BOLD imaging and arterial spin-labeling methods. Brain temperature was calculated pre- and post-acetazolamide using previously established chemical shift thermometry. They observed significant, voxelwise quadratic relationships between cerebrovascular reactivity from BOLD imaging and the brain thermal response and baseline brain temperatures, concluding that brain thermal response is a potential noninvasive biomarker for cerebrovascular impairment.
- Arterial Spin-Labeling Perfusion MR Imaging Demonstrates Regional CBF Decrease in Idiopathic Normal Pressure Hydrocephalus
The authors assessed regional CBF in patients with idiopathic normal pressure hydrocephalus compared with healthy controls using the noninvasive quantitative arterial spin-labeling MR imaging technique. Twenty-one consecutive patients with NPH and 21 age- and sex-matched randomly selected healthy controls from a population registry were prospectively included. In patients with idiopathic NPH, perfusion was reduced in the periventricular white matter,lentiform nucleus, and thalamus compared with controls. They conclude that using pseudocontinuous ASL, they confirmed the findings of reduced perfusion in the periventricular white matter, basal ganglia, and thalamus in patients with idiopathic NPH previously observed with other imaging techniques.
- Angioarchitectures and Hemodynamic Characteristics of Posterior Communicating Artery Aneurysms and Their Association with Rupture Status
The authors studied 313 posterior communicating artery aneurysms (145 ruptured, 168 unruptured) with image-based computational fluid dynamics. Aneurysms were classified into different angioarchitecture types depending on the location of the aneurysm with respect to parent artery bifurcation. Ruptured aneurysms had higher, more concentrated, and more oscillatory wall shear stress distributions; stronger and more concentrated inflow jets; and more complex and unstable flow patterns compared with unruptured aneurysms. They conclude that high-flow intrasaccular hemodynamic characteristics, commonly found in bifurcation-type angioarchitectures, are associated with the posterior communicating artery aneurysm rupture status.
- Comparison of Clinical Outcomes of Intracranial Aneurysms: Procedural Rupture versus Spontaneous Rupture
This was a retrospective review of 1340 patients with 1595 unruptured saccular intracranial aneurysms that underwent endovascular coil embolization between February 2010 and December 2014. The clinical outcomes of patients with procedural rupture of saccular intracranial aneurysms were compared with those of 198 patients presenting with spontaneously ruptured aneurysms. Procedural rupture developed in 19 patients, and the morbidity related to procedural rupture was 26.3% with no mortality. Hunt and Hess scale grades and hospitalization days of patients with procedural rupture were equivalent to those of patients presenting with spontaneous aneurysm rupture. In multivariate analysis, spontaneous aneurysm rupture was a significant risk factor for worse clinical outcome. This study showed better clinical outcomes in the procedural-rupture group.
- Real-Time Motor Cortex Mapping for the Safe Resection of Glioma: An Intraoperative Resting-State fMRI Study
The authors conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type and tumor cavity, were studied. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. They conclude that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.
- Apparent Diffusion Coefficient Histograms of Human Papillomavirus–Positive and Human Papillomavirus–Negative Head and Neck Squamous Cell Carcinoma: Assessment of Tumor Heterogeneity and Comparison with Histopathology
One hundred five consecutive patients with primary oropharyngeal and oral cavity head and neck squamous cell carcinoma underwent MR imaging with anatomic and DWI sequences. The collected tumor voxels from the contoured ROIs provided histograms from which position, dispersion, and form parameters were computed. Histogram data were correlated with histopathology, p16-immunohistochemistry, and polymerase chain reaction for human papillomavirus DNA. Diffusion phenotypes of human papillomavirus–positive and human papillomavirus–negative head and neck squamous cell carcinomas showed significant differences, which reflect their distinct degree of tumor heterogeneity.
