Publications by authors named "K R Thulborn"
Background And Objectives: Moyamoya disease (MMD) is a rare noninflammatory disorder involving progressive intracranial vasculopathy and impaired cerebral blood flow in the anterior circulation, resulting in stroke and cognitive impairment. We aimed to characterize cognitive impairment and the possible predictive value of sociodemographic and clinical characteristics of adults with MMD.
Methods: This cross-sectional study examined neurocognitive performance in a group of 42 consecutive adult patients (mean age = 40.
The cell volume fraction (CVF) of the human brain is high (~82%) and is preserved across healthy aging while the brain declines in volume. These two observations, supported by several independent techniques, suggest that CVF is an important structural parameter. A new biophysical model is presented that incorporates CVF into the Goldman equation of classical membrane electrophysiology.
View Article and Find Full Text PDFArticle Synopsis
- - A novel method was created for reconstructing high-quality sodium MRI images from noisy and limited data, utilizing a combination of motion-compensated generalized series and sparse models for improved denoising and resolution.
- - The method showed significant advancements in spatial resolution and signal-to-noise ratio (SNR) compared to existing reconstruction techniques, demonstrating its effectiveness through simulations and tests on both phantoms and real patients.
- - The new approach successfully produced detailed tissue sodium concentration maps that enhance the detection of small tumors and improve the assessment of tumor responses to treatment, illustrating its potential clinical applications.
Quantitative measurement of the tissue sodium concentration (TSC) provides a metric for tissue cell volume fraction for monitoring tumor responses to therapy and neurodegeneration in the brain as well as applications outside the central nervous system such as the fixed charge density in cartilage. Despite the low detection sensitivity of the sodium MR signal compared to the proton signal and the requirement for a long repetition time to minimize longitudinal magnetization saturation, acquisition time has been reduced to less than 10 min for a nominal isotropic voxel size of 3.3 mm with the improved acquisition efficiency of twisted projection imaging (TPI) at 9.
View Article and Find Full Text PDFPurpose: Spatial and temporal patterns of response of human glioblastoma to fractionated chemoradiation are described by changes in the bioscales of residual tumor volume (RTV), tumor cell volume fraction (CVF), and tumor cell kill (TCK), as derived from tissue sodium concentration (TSC) measured by quantitative sodium MRI at 3 Tesla. These near real-time patterns during treatment are compared with overall survival.
Experimental Design: Bioscales were mapped during fractionated chemoradiation therapy in patients with glioblastomas ( = 20) using TSC obtained from serial quantitative sodium MRI at 3 Tesla and a two-compartment model of tissue sodium distribution.