Case Report: Arterial Spin Labeling Perfusion MRI Contribution for Clinical Implementation of Brain Disease

@#Currently, ASL is widely used as an additional breakthrough sequence in MRI due to acquiring reliable results. The case report aims to prove the efficacy and effectiveness of a quantitative method of ASL sequence through the calculation of the cerebral blood flow (CBF) on CBF maps in different cases. ASL sequence has been done on four patients with different cases. Then, the authors put 2 regions of interest (ROI) for measurement in normal and different regions on CBF maps and then calculated the average value result from CBF maps. ASL has been proven as a reliable and breakthrough sequence in MRI for detecting brain disease with a non-invasive method through the calculation of CBF value. ASL should be used as an additional protocol in brain examinations because it allows radiologists to assess the significance of CBF values using a quantitative method that is more reliable and non-invasiv

Assessment of changes in perfusion after radiotherapy for brain metastasis using three-dimensional arterial spin labeling / 中国肿瘤临床

Objective: This study aimed to quantitatively analyze changes in blood perfusion in brain metastases (BMs), normal brain areas, and peritumor edema areas during radiotherapy (RT) using three-dimensional arterial spin labeling (3D-ASL) in BMs patients. The associations between perfusion changes in the three brain regions and RT dose gradients need to be established to provide a reference for individualized RT for BMs patients. Methods: MR-simulated location images of 26 BMs patients before and after RT were collected (including enhanced T1W images and perfusion maps of 3D-ASL; BMs tumor target areas were identified using enhanced T1W images and perfusion information was obtained from 3D-ASL). The high signal areas of BMs on contrast-enhanced T1W images, normal brain areas, and peritumor edema areas were defined as regions of interest (ROIs). The changes and correlation of the mean maximum cross-sectional area and mean maximum cerebral blood flow (CBF) in BMs tumor target areas before and after RT were assessed. Changes in CBF values in the three ROIs under different dose gradients were analyzed. Results: The mean maximum cross-sectional area and CBF values of BMs decreased by 26.46% and 29.64%, respectively, after RT (both P50 Gy dose gradients were 33.75%, 24.61%, and 27.55%, respectively (all P50 Gy, the decreasing CBF rates after RT were 7.65%, 11.12%, 18.42%, 20.23%, 19.79%, and 17.89%, respectively (all P<0.05). The decreasing CBF rates in peritumor edema areas increased as dose gradients increased after RT. The perfusion changes in BMs after RT were more notable than those in normal brain areas and peritumor edema areas. Conclusions: Thus, 3D-ASL can objectively reflect changes in perfusion in BMs, normal brain areas, and peritumor edema areas. Based on changes in CBF, it is recommended to control the dose administered to normal brain areas to <30 Gy, whereas high doses

Evaluation of Tumor Blood Flow Using Alternate Ascending/Descending Directional Navigation in Primary Brain Tumors: A Comparison Study with Dynamic Susceptibility Contrast Magnetic Resonance Imaging

OBJECTIVE: Alternate ascending/descending directional navigation (ALADDIN) is a novel arterial spin labeling technique that does not require a separate spin preparation pulse. We sought to compare the normalized cerebral blood flow (nCBF) values obtained by ALADDIN and dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) in patients with primary brain tumors. MATERIALS AND METHODS: Sixteen patients with primary brain tumors underwent MRI scans including contrast-enhanced T1-weighted imaging, DSC perfusion MRI, and ALADDIN. The nCBF values of normal gray matter (GM) and tumor areas were measured by both DSC perfusion MRI and ALADDIN, which were compared by the Wilcoxon signed rank test. Subgroup analyses according to pathology were performed with the Wilcoxon signed rank test. RESULTS: Higher mean nCBF values of GM regions in the bilateral frontal lobe, temporal lobe, and caudate were detected by ALADDIN than by DSC perfusion MRI (p <0.05). In terms of the mean or median nCBF values and the mean of the top 10% nCBF values from tumors, DSC perfusion MRI and ALADDIN did not statistically significantly differ either overall or in each tumor group. CONCLUSION: ALADDIN tended to detect higher nCBF values in normal GM, as well as higher perfusion portions of primary brain tumors, than did DSC perfusion MRI. We believe that the high perfusion signal on ALADDIN can be beneficial in lesion detection and characterization.

Effects of " acupuncture on cerebral blood flow in patients with high risk of cerebral ischemic stroke based on ASL and PWI technique / 中国针灸

OBJECTIVE@#To observe the effects of "" acupuncture on cerebral blood flow in high-risk patients of cerebral ischemic stroke based on arterial spin labeling (ASL) and perfusion-weighted imaging (PWI), and to evaluate the clinical efficacy.@*METHODS@#A total of 180 patients with transient ischemic attacks (TIA) / minor ischemic stroke (MIS) were randomly divided into an acupuncture A group, an acupuncture B group and a medication group, 60 cases in each group. The patients in the acupuncture A group were treated with "" acupuncture at Baihui (GV 20), Fengfu (GV 16), Yamen (GV 15), Dazhui (GV 14), Shenzhu (GV 12), Zhiyang (GV 9), Mingmen (GV 4), Yaoyangguan (GV 3) and Jingjiaji (EX-B 2), once a day; the patients in the acupuncture B group were treated with identical acupoints but was given once every other day; the patients in the medication group were treated with oral administration of nimodipine tablets, 30 mg, three times daily. All the three groups were treated for four weeks. ASL and PWI, including relative cerebral blood volume (rCBV), relative cerebral blood flow (rCBF), relative mean transit time (rMTT) and relative time to peak (rTTP), were conducted before and after treatment; the changes of the test indexes were compared before and after treatment. The clinical efficacy of the three groups was compared.@*RESULTS@#Compared before treatment, the numbers of ASL normal perfusion in the 3 groups were significantly increased after treatment (all 0.05). Compared before treatment, rCBV and rCBF in the 3 groups were significantly increased after treatment (all 0.05). The total effective rate was 88.3% (53/60) in the acupuncture A group, 73.3% (44/60) in the acupuncture B group and 90.0% (54/60) in the medication group; the total effective rate in the acupuncture A group was superior to that in the acupuncture B group (0.05).@*CONCLUSION@#"" acupuncture could effectively improve the hypoperfusion of cerebral blood flow in patients with high risk of cerebral ischemic stroke, reduce the incidence of severe CIS; acupuncture for once a day is better than once every other day.

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.

Angiografía no contrastada con Arterial Spin Labeling / Non-contrast angioresonance with Arterial Spin Labeling

Introducción: La angiografía por resonancia magnética no contrastada realizada con "Arterial Spin Labeling" (ARM ASL) es un método diseñado para marcar los espines sanguíneos y así crear un contraste endógeno adecuado para evaluar territorios vasculares selectivamente sin la necesidad de aplicar medio de contraste intravenoso (compuestos de Gadolinio). Metodología: Se realizó un estudio descriptivo de una serie de casos, donde se describen los detalles técnicos y los resultados de la aplicación de la ARM ASL en equipos de 1.5 y 3 Tesla en voluntarios sanos. Resultados: Se observaron dos casos: Para la técnica angiográfica del primer caso (ASL "Flow-in") se usó un resonador de 3T, sincronización cardiaca, una secuencia b-SSFP 3D y un pre-pulso de inversión, este último para saturar los tejidos estáticos. El volumen de examen se ubicó en el plano axial teniendo la precaución de cubrir la anatomía vascular renal, lo cual se logra en la mayoría de los casos con 60 a 70 cortes de 2 mm solapados en 50 porciento, voxel de 2x1x1 mm y campo de visión (FOV) de 250x100 mm. El protocolo del segundo caso fue obtenido en un equipo de 1.5T, sin sincronización cardiaca, con un navegador respiratorio dia fragmático y con una secuencia coronal Turbo SE 3D después de aplicar dos pre-pulsos de marcación sanguínea, el primero similar al del caso anterior y el segundo, o pulso selectivo, para marcar el flujo del vaso de interés. Con este método (ASL "Flow-Out") sólo la sangre marcada emite señal. Conclusión: Las técnicas de angiografía b-SSFP 3D y Turbo SE 3D no contrastadas con pre-pulsos de ASL en 1.5 y 3T son alternativas disponibles y, por lo tanto, pueden considerarse como complemento a otros métodos de angiografía por resonancia magnética al momento de evaluar la patología vascular.

Introduction: Non-contrast magnetic resonance angiography using "Arterial Spin Labeling" (MRA ASL) is a technique designed to label blood spins and therefore create an endogenous contrast suitable for selectively evaluating vascular territories without intravenous contrast (Gadolinium compounds). Methodology: Technical details and results of the implementación of the MRA ASL using 1.5 and 3.0 Tesla systems in healthy volunteers is described. Results: Two cases were observed: for the angiographic technique of the first case (ASL "Flow-in") in a 3.0 T unit, cardiac synchronization (cardiac gating), a 3D b-SSFP sequence, and an inversion pre-pulse was used, the latter to saturate the static tissues. The examination volume was located in the axial plane taking care to cover the renal vascular anatomy, which is achieved in most cases with 60 to 70 2 mm slices overlapped in 50%, voxel of 2x1x1 mm and a field of vision (FOV) of 250 x100 mm. The protocol for the second case was obtained on a 1.5 T system, without cardiac gating, with a diaphragmatic respiratory navigator and a 3D Turbo SE coronal sequence after applying two pre-pulse blood saturation bands, the first similar to the previous case and the second, or selective pulse, to label the flow of the vessel of interest. With this method (ASL "Flow-Out") only the labeled blood emits a signal. Discussion: 3D b-SSFP and 3D Turbo SE non-contrast angiography techniques with ASL pre-pulses in 1.5 and 3T are available alternatives and, therefore, can be considered as a complement to other methods of magnetic resonance angiography when assessing vascular pathology.