Functional Magnetic Resonance Imaging with Arterial Spin Labeling: Techniques and Potential Clinical and Research Applications

PURPOSE: To describe technical methods for functional magnetic resonance imaging (fMRI) study with arterial spin labeling (ASL) compared to blood oxygenation level-dependent (BOLD) technique and discuss the potential of ASL for research and clinical practice. MATERIALS AND METHODS: Task-based (n = 1) and resting-state fMRI (rs-fMRI) (n = 20) were performed using ASL and BOLD techniques. Results of both techniques were compared. RESULTS: For task-based fMRI with finger-tapping, the primary motor cortex of the contralateral frontal lobe and the ipsilateral cerebellum were activated by both BOLD and ASL fMRI. For rs-fMRI of sensorimotor network, functional connectivity showed similar results between BOLD and ASL. CONCLUSION: ASL technique has potential application in clinical and research fields because all brain perfusion imaging, CBF measurement, and rs-fMRI study can be performed in a single acquisition.

Functional Magnetic Resonance Imaging with Arterial Spin Labeling: Techniques and Potential Clinical and Research Applications

PURPOSE: To describe technical methods for functional magnetic resonance imaging (fMRI) study with arterial spin labeling (ASL) compared to blood oxygenation level-dependent (BOLD) technique and discuss the potential of ASL for research and clinical practice. MATERIALS AND METHODS: Task-based (n = 1) and resting-state fMRI (rs-fMRI) (n = 20) were performed using ASL and BOLD techniques. Results of both techniques were compared. RESULTS: For task-based fMRI with finger-tapping, the primary motor cortex of the contralateral frontal lobe and the ipsilateral cerebellum were activated by both BOLD and ASL fMRI. For rs-fMRI of sensorimotor network, functional connectivity showed similar results between BOLD and ASL. CONCLUSION: ASL technique has potential application in clinical and research fields because all brain perfusion imaging, CBF measurement, and rs-fMRI study can be performed in a single acquisition.

Evaluation of Hippocampal Volume Based on Various Inversion Time in Normal Adults by Manual Tracing and Automated Segmentation Methods

PURPOSE: To investigate the value of image post-processing software (FreeSurfer, IBASPM [individual brain atlases using statistical parametric mapping software]) and inversion time (TI) in volumetric analyses of the hippocampus and to identify differences in comparison with manual tracing. MATERIALS AND METHODS: Brain images from 12 normal adults were acquired using magnetization prepared rapid acquisition gradient echo (MPRAGE) with a slice thickness of 1.3 mm and TI of 800, 900, 1000, and 1100 ms. Hippocampal volumes were measured using FreeSurfer, IBASPM and manual tracing. Statistical differences were examined using correlation analyses accounting for spatial interpretations percent volume overlap and percent volume difference. RESULTS: FreeSurfer revealed a maximum percent volume overlap and maximum percent volume difference at TI = 800 ms (77.1 +/- 2.9%) and TI = 1100 ms (13.1 +/- 2.1%), respectively. The respective values for IBASPM were TI = 1100 ms (55.3 +/- 9.1%) and TI = 800 ms (43.1 +/- 10.7%). FreeSurfer presented a higher correlation than IBASPM but it was not statistically significant. CONCLUSIONS: FreeSurfer performed better in volumetric determination than IBASPM. Given the subjective nature of manual tracing, automated image acquisition and analysis image is accurate and preferable.

Ictal Images of Simple Partial Status Epilepticus

No abstract available.

Assessment of Cerebral Vascular Reserve Capacity Prior to Carotid ArteryStenting: Brain Single Photon Emission Computed Tomography images and Magnetic Resonance Arterial Spin Labeling images

No abstract available.

A Study of Changes of Inversion Time Effect on Brain Volume of Normal Volunteers

PURPOSE: The objective of this study was to analyze the brain volume according to the brain image of healthy adults in the 20s taken with different inversion time (TI). MATERIALS AND METHODS: Brain images of healthy adults in the 20 s were acquired using magnetization prepared rapid acquisition gradient echo (MPRAGE) pulse sequence with 1.5 mm thickness of pieces and four inversion times (1100 ms, 1000 ms, 900 ms, 800 ms). The acquired brain images were analyzed to measure the volume of white matter (WM), gray matter (GM), intracranial volume (ICV). The statistical difference according to brain volume and gender was analyzed for each TI. RESULTS: The brain volume calculated using Freesurfer was WM=486.52+/-48.64 cm3 and GM=646.86+/-57.12 cm3 in mean when adjusted by mean ICV=1278.94+/-154.92 cm3. Men's brain volume(WM, GM, ICV) was larger than women's brain volume. In the intrarater reliability test, all of the intraclass correlation coefficients were high (0.992 for WM, 0.988 for GM, and 0.997 for ICV). In the repeated measures analysis of variance, GM and ICV did not show a significant difference at each TI (GM p=0.143, ICV p=0.052), but WM showed a significant (p=0.001). In the linear structure relation analysis, all of the Pearson correlation coefficients were high. CONCLUSION: WM, GM, and ICV indicated high reliability and solid linear structure relations, but WM showed significant differences at each TI. The brain volume of healthy adults in the 20s could be used in comparison with that of patients for reference purposes and to predict the structural change of brain. It would be needed to conduct additional studies to examine the contract, SNR, and lesion detection ability according to variable TI.