"DCE","ASL"

PURPOSE: This prospective study aimed to investigate the correlation between two perfusion methods: arterial spin labeling (ASL) and dynamic contrast enhanced (DCE) technique in patients with nasopharyngeal carcinoma (NPC) and to optimize ASL protocol. MATERIALS AND METHODS: Forty-five newly diagnosed NPC patients underwent MR examinations with both 3D pseudo-continuous ASL (pCASL) and DCE-MRI sequences. Tumor blood flow (TBF) derived in pCASL with three post-labeling delay (PLD) times (i...

PURPOSE: To investigate the correspondence between arterial spin labeling (ASL) flow-sensitive alternating inversion recovery (FAIR) and ferumoxytol DCE MRI for the assessment of placental intervillous perfusion. METHODS: Ten pregnant macaques in late second trimester were imaged at 3 T using a 2D ASL FAIR, with and without outer-volume saturation pulses used to control the bolus width, and a 3D ferumoxytol DCE-MRI acquisition. The ASL tagged/control pairs were averaged, subtracted, and normalized to create perfusion ratio maps...

OBJECTIVES: We evaluated the vascularity of retained products of conception (RPOC) using arterial spin-labeling magnetic resonance imaging (ASL-MRI) to clarify the clinical feasibility of this approach. MATERIALS AND METHODS: A pulsed-continuous ASL sequence with echo-planar imaging (EPI) acquisitions was used. Ten consecutive patients with RPOC were enrolled. All ASL images were evaluated visually and semiquantitatively and compared with the findings of Doppler ultrasound (US) and dynamic contrast-enhanced MRI (DCE-MRI)...

Recent improvements in arterial spin labeled (ASL) and vastly undersampled dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) acquisitions are providing a new opportunity to explore the routine use of quantitative perfusion imaging for evaluation of a variety of abdominal diseases in clinical practice. In this review, we discuss different approaches for the acquisition and data analysis of ASL and DCE MRI techniques for quantification of tissue perfusion and present various clinical applications of these techniques in both neoplastic and non-neoplastic conditions in the abdomen...

PURPOSE: To develop and validate a method for measuring murine single-kidney glomerular filtration rate (GFR) using dynamic contrast-enhanced MRI (DCE-MRI). METHODS: This prospective study was approved by the Institutional Animal Care and Use Committee. A fast longitudinal relaxation time (T1 ) measurement method was implemented to capture gadolinium dynamics (1 s/scan), and a modified two-compartment model was developed to quantify GFR as well as renal perfusion using 16...

This pilot study investigates the construction of an Adaptive Neuro-Fuzzy Inference System (ANFIS) for the prediction of the survival time of patients with glioblastoma multiforme (GBM). ANFIS is trained by the pharmacokinetic (PK) parameters estimated by the model selection (MS) technique in dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) data analysis, and patient age. DCE-MRI investigations of 33 treatment-naïve patients with GBM were studied. Using the modified Tofts model and MS technique, the following physiologically nested models were constructed: Model 1, no vascular leakage (normal tissue); Model 2, leakage without efflux; Model 3, leakage with bidirectional exchange (influx and efflux)...

PURPOSE: To evaluate arterial spin labeling (ASL) perfusion and dynamic contrast-enhanced (DCE) perfusion in glioma grading according to the previous WHO classification of 2007, as well as concerning isocitrate dehydrogenase (IDH) mutation status and ATRX expression as required by the new WHO 2016 brain tumor classification. METHODS: The mean values of Ktrans, Kep, Ve, and Vp by DCE perfusion, and cerebral blood flow (CBF) by ASL perfusion were assessed retrospectively in 40 patients with initial glioma diagnosis...

Extravascular extracellular space (ve ) is a key parameter to characterize the tissue of cerebral tumors. This study introduces an artificial neural network (ANN) as a fast, direct, and accurate estimator of ve from a time trace of the longitudinal relaxation rate, ΔR1 (R1  = 1/T1 ), in DCE-MRI studies. Using the extended Tofts equation, a set of ΔR1 profiles was simulated in the presence of eight different signal to noise ratios. A set of gain- and noise-insensitive features was generated from the simulated ΔR1 profiles and used as the ANN training set...

PURPOSE: In pharmacokinetic analysis of Dynamic Contrast Enhanced MRI data, a descriptive physiological model should be selected properly out of a set of candidate models. Classical techniques suggested for this purpose suffer from issues like computation time and general fitting problems. This article proposes an approach based on Artificial Neural Networks (ANNs) for solving these problems. METHODS: A set of three physiologically and mathematically nested models generated from the Tofts model were assumed: Model I, II and III...

PURPOSE: To propose and validate a method for accurately quantifying renal plasma flow (RPF) with arterial spin labeling (ASL). MATERIALS AND METHODS: The proposed method employs a tracer-kinetic approach and derives perfusion from the slope of the ASL difference signal sampled at multiple inversion-times (TIs). To validate the method's accuracy, we performed a HIPAA-compliant and IRB-approved study with 15 subjects (9 male, 6 female; age range 24-73) to compare RPF estimates obtained from ASL to those from a more established dynamic contrast-enhanced (DCE) MRI method...

OBJECTIVE: To assess alterations in perfusion and liver function in the concanavalin A (ConA)-induced mouse model of acute liver failure (ALF) using two magnetic resonance imaging (MRI)-based methods: dynamic contrast-enhanced MRI (DCE-MRI) with Gd-EOB-DTPA contrast agent and arterial spin labelling (ASL). MATERIALS AND METHODS: BALB/c mice were studied using a 9.4 T MRI system. The IntraGateFLASH(TM) and FAIR-EPI pulse sequences were used for optimum mouse abdomen imaging...

CLINICAL/METHODICAL ISSUE: Separate assessment of respiratory mechanics, gas exchange and pulmonary circulation is essential for the diagnosis and therapy of pulmonary diseases. Due to the global character of the information obtained clinical lung function tests are often not sufficiently specific in the differential diagnosis or have a limited sensitivity in the detection of early pathological changes. STANDARD RADIOLOGICAL METHODS: The standard procedures of pulmonary imaging are computed tomography (CT) for depiction of the morphology as well as perfusion/ventilation scintigraphy and single photon emission computed tomography (SPECT) for functional assessment...

CLINICAL/METHODICAL ISSUE: Magnetic resonance imaging (MRI) is recognized for its superior tissue contrast while being non-invasive and free of ionizing radiation. Due to the development of new scanner hardware and fast imaging techniques during the last decades, access to tissue and organ functions became possible. One of these functional imaging techniques is perfusion imaging with which tissue perfusion and capillary permeability can be determined from dynamic imaging data. STANDARD RADIOLOGICAL METHODS: Perfusion imaging by MRI can be performed by two approaches, arterial spin labeling (ASL) and dynamic contrast-enhanced (DCE) MRI...

UNLABELLED: Arterial spin-labeled (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) have been proposed to quantitatively assess vascularity in renal cell carcinoma (RCC). However, there are intrinsic differences between these 2 imaging methods, such as the relative contribution of vascular permeability and blood flow to signal intensity for DCE MRI. We found a correlation between ASL perfusion and the DCE-derived volume transfer constant and rate constant parameters in renal masses > 2 cm in size and these measures correlated with microvessel density in clear cell RCC...

This article reviews the most relevant state-of-the-art magnetic resonance (MR) techniques, which are clinically available to investigate brain diseases. MR acquisition techniques addressed include notably diffusion imaging (diffusion-weighted imaging (DWI), diffusion tensor imaging (DTI), and diffusion kurtosis imaging (DKI)) as well as perfusion imaging (dynamic susceptibility contrast (DSC), arterial spin labeling (ASL), and dynamic contrast enhanced (DCE)). The underlying models used to process these images are described, as well as the theoretic underpinnings of quantitative diffusion and perfusion MR imaging-based methods...

PURPOSE: To assess the correlation between flow-sensitive alternating inversion recovery (FAIR) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the measurement of spinal bone marrow (SBM) perfusion; in addition, to assess for an optimized inversion time (TI) as well as the reproducibility of SBM FAIR perfusion. MATERIALS AND METHODS: The optimized TI of a FAIR SBM perfusion experiment was carried out on 14 volunteers; two adjacent vertebral bodies were selected from each volunteer to measure the change of signal intensity (ΔM) and the signal-to-noise ratio (SNR) of FAIR perfusion MRI with five different TIs...

INTRODUCTION: The ability to ascertain information pertaining to peripheral perfusion through the analysis of tissues' temporal reaction to the inflow of contrast agent (CA) was first recognized in the early 1990's. Similar to other functional magnetic resonance imaging (MRI) techniques such as arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) MRI, dynamic contrast-enhanced MRI (DCE-MRI) was at first restricted to studies of the brain. Over the last two decades the spectrum of ailments, which have been studied with DCE-MRI, has been extensively broadened and has come to include pathologies of the heart notably infarction, stroke and further cerebral afflictions, a wide range of neoplasms with an emphasis on antiangiogenic treatment and early detection, as well as investigations of the peripheral vascular and musculoskeletal systems...

Perfusion MRI has the potential to provide pathophysiological biomarkers for the evaluating, staging and therapy monitoring of prostate cancer. The objective of this study was to explore the feasibility of noninvasive arterial spin labeling (ASL) to detect prostate cancer in the peripheral zone and to investigate the correlation between the blood flow (BF) measured by ASL and the pharmacokinetic parameters K(trans) (forward volume transfer constant), kep (reverse reflux rate constant between extracellular space and plasma) and ve (the fractional volume of extracellular space per unit volume of tissue) measured by dynamic contrast-enhanced (DCE) MRI in patients with prostate cancer...

Cerebral blood flow (CBF) and blood-brain barrier (BBB) permeability by arterial spin labeling (ASL)- and dynamic contrast enhanced (DCE)-magnetic resonance imaging (MRI), respectively were repeatedly measured under either halothane (N  =  5) or isoflurane (N  =  5) anesthesia in a rat stroke model of embolic occlusion of middle cerebral artery (MCA). Cerebral blood flow measurements were made after MCA embolization, following intravenous recombinant tissue plasminogen activator (rtPA) treatment at 3 hours post-ictus and again at 48 hours...

OBJECTIVES: To investigate the reproducibility of arterial spin labelling (ASL) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and quantitatively compare these techniques for the measurement of renal blood flow (RBF). METHODS: Sixteen healthy volunteers were examined on two different occasions. ASL was performed using a multi-TI FAIR labelling scheme with a segmented 3D-GRASE imaging module. DCE MRI was performed using a 3D-FLASH pulse sequence...