GE Overview Intro

GE Healthcare - MR Gadopiclenol (VUEWAY®) Protocols

Introduction

These magnetic resonance (MR) imaging protocols were developed by an expert consensus panel for use on General Electric (GE) MR imaging equipment and were developed for high-end platform scanners with multichannel phased array coils and parallel reconstruction capabilities. The protocols are divided into 3 sections:

The protocol parameters can generally be adapted to work with other software platforms or releases and hardware configurations, but may require small modifications that can be made by a knowledgeable and experienced MR technologist. Image acquisition times may increase in some circumstances.

These protocols provide field strength-specific parameters for 1.5T and 3.0T. Attention has also been given to patient preparation, exam streamlining, and making the best use of Vueway/Elucirem (gadopiclenol), a recently FDA-approved, high-relaxivity, extracellular gadolinium-based contrast agent (GBCA).

Each protocol contains a brief description of patient preparation, special notes on coil choice and placement, and suggestions for contrast dose, bolus rate, and timing when applicable.

The consensus panel consisted of the following experts in radiology:

    Aaron S. Field, MD, PhD, Thomas M. Grist, MD, FACR, Ali Pirasteh, MD, and Megan E. Vadnais, BSRT, (R)(MR) – University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
    Alessandro Furlan, MD, MMM, MRMD – University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania

Body MR Imaging Protocols

All body MR imaging protocols presented here were developed by Ali Pirasteh, MD, Alessandro Furlan, MD, MMM, MRMD, and Megan E. Vadnais, BSRT, (R)(MR) for 1.5T and 3.0T systems. Specific protocols include:

  • Abdomen
    • Generic Abdomen Pelvis
    • Appendicitis Noncontrast
    • MR Enterography
  • Liver
    • Liver/Pancreas Extracellular Agent
    • MRCP (MR Cholangiopancreatography)
    • Diffuse Liver Disease
  • Pelvis
    • Generic Pelvis
    • Gynecologic Cancer Staging
    • Gynecologic Pelvis
    • Uterine Anomaly
    • Rectal Cancer
    • Perianal Fistula
    • Prostate
  • Adrenal/Renal
    • Adrenal
    • Renal
  • ARDL (AIR Recon Deep Learning™) Optional Sequences

    General Notes

    • Intravenous access should be obtained with an 18- to 22-gauge needle
    • We suggest the use of a contrast injector and a saline flush of a minimum of 20 to 30 mL at the same injection rate as the contrast injection (1.5-2.0 mL/sec)
    • Contrast timing is extremely important for abdominal MR imaging, particularly for high-quality liver imaging. We recommend the use of fluoro-triggering or “SmartPrep” methods rather than the use of a timing bolus
    • Breath-holding is essential for good image quality for thoracic or abdominal MR imaging. Precontrast images should be used to ensure that the patient can both breath-hold adequately and understand the instructions. We recommend breath-holding at end-expiration (end tidal volume)
    • When parallel imaging is used, care must be taken to increase the field of view sufficiently to avoid residual aliasing artifact. This artifact is more often encountered in coronal imaging, which may require placing the arms over the head or elevating the arms by the patient’s side
    • Vueway (gadopiclenol; American College of Radiology [ACR] group II GBCA) is injected at a dose of 0.05 mmol/kg, which is half the dose of other extracellular agents. For body MR imaging, we recommend a maximum dose of 10 mL for gadopiclenol

    MR Angiography Protocols

    All protocols should use fluoro-triggered (FT) MR angiography (MRA) fluoroscopic imaging for bolus detection. MR angiography protocols presented here include 1.5T and 3.0T systems, and were developed by Thomas M. Grist, MD, FACR and Megan E. Vadnais, BSRT, (R)(MR) for the following procedures: 

    • Cardiac MRA
      • Cardiac Basic Anatomy and Function
      • Pulmonary Artery
      • Pulmonary Vein Mapping
    • Thoracic MRA
      • Thoracic Aorta MRA
      • Gated Thoracic Aorta
    • Abdominal MRA
      • Contrast-enhanced MRA Abdomen
      • Noncontrast-enhanced MRA Abdomen
      • Thoracoabdominal Aortic Aneurysm MRA
    • Peripheral MRA
      • Lower Extremity Contrast-enhanced Venography (CE MRV)
      • Runoff Abdomen to Lower Extremity MRA
      • Peripheral Runoff Noncontrast
      • Arteriovenous Malformation (AVM) Evaluation
    • ARDL (AIR Recon Deep Learning™) Optional Sequences

      The rationale for the patient preparation for contrast-enhanced MR angiography is based on a hypothetical generic patient. Individual protocols may include important variations and will be delineated in the specific protocol.

    General Notes

    • Intravenous access should be obtained with an 18- to 22-gauge needle, inserted preferably in the antecubital fossa. The right side is preferred (when possible) for thoracic or carotid MR angiography
    • Use respiratory bellows – gating parameters: 
      • R-R intervals = 2-3
      • Trigger point = 40%
      • Trigger window = 30%
      • Delay = minimum
    • The basic sequences recommended are intended to achieve both anatomic localization and high-quality anatomic imaging to complement the angiographic sequences that are performed. These include:
      • 3 plane localizer
      • Coronal single-shot fast spin-echo (FSE)
      • Axial T2 FSE (respiratory triggered)
      • 3D (three-dimensional) contrast-enhanced FT MR angiography (precontrast-practice breath-hold)
      • 3D contrast-enhanced FT MR angiography (postcontrast)
      • 3D contrast-enhanced FT MR angiography (2nd postcontrast)
      • Axial fast spoiled gradient-echo postcontrast fat-saturated
    • For MR angiography, we prefer to dilute the dose of the GBCA into a fixed volume of 30 mL and inject at a rate of 1.5-2.0 mL/sec
    • We suggest the use of a contrast injector and a saline flush of a minimum of 20 to 30 mL at the same injection rate as the contrast injection (1.5-2.0 mL/sec)
    • Breath-holding is essential for good image quality for thoracic or abdominal MR angiography. Precontrast images should be used to ensure that the patient can both breath-hold adequately and understand the instructions. We recommend breath-holding at end-expiration (end tidal volume)
    • When parallel imaging is used, care must be taken to increase the field of view sufficiently to avoid residual aliasing artifact. This artifact is more often encountered in coronal imaging, which may require placing the arms over the head or elevating the arms by the patient’s side
    • Vueway (gadopiclenol; ACR group II GBCA) is injected at a dose of 0.05 mmol/kg, which is half the dose of other extracellular agents. For MR angiography, we recommend a maximum dose of 10 mL for gadopiclenol

    Central Nervous System (CNS) MR Imaging Protocols

    Newer hardware and software platforms at both 1.5T and 3.0T allow efficient protocol options for a wide range of CNS indications. This section suggests multiple consensus methods for optimizing examination of patients undergoing MR imaging in the CNS. Core sequences in each protocol are identified, and their aggregate use constitutes a complete examination for each protocol. Alternative sequences of interest are included for emerging technologies, specific target anatomy, or subspecialty preference.

    1.5T and 3.0T CNS MR imaging protocols presented here were developed by Aaron S. Field, MD, PhD, and Megan E. Vadnais, BSRT, (R)(MR) for the following procedures:

    • Brain
      • Routine Adult Brain
      • Brain Neck Magnetic Resonance Angiography (MRA)/Magnetic Resonance Venography (MRV)
      • Motion Brain
      • Routine Stroke Brain
      • Hyperacute Stroke Brain
      • Tumor Brain
      • Multiple Sclerosis Brain
      • Pediatric Brain
      • Epilepsy Brain
    • Specialty Brain
      • Hydrocephalus Brain
      • Cerebrospinal Fluid Flow
      • Pituitary 1.5T and 3T
      • Cranial Nerves/Internal Auditory Canals
      • Vessel Wall
    • Head and Neck
      • Orbits
      • Soft Tissue Neck
      • Sinuses/Face
    • Spine
      • Cervical Spine
      • Lumbar Spine
      • Thoracic Spine
      • Routine Total Spine
      • Focused Total Spine
      • Specialty Spine
      • Brachial Plexus
      • Lumbar Plexus
    • ARDL (AIR Recon Deep Learning™) Optional Sequences

    General CNS Protocol Notes

    • Standard brain. There are multiple approaches to obtain various tissue parameter weightings at both 1.5T and 3.0T, such that “standard” imaging refers more to the general-purpose nature of the protocol rather than the core sequence choices. The core preferences of our consensus panel are indicated within each protocol
    • T1. Six techniques for obtaining T1-weighting are included: spin echo (SE), fast spin echo (FSE), T1 fluid-attenuated inversion recovery (T1-FLAIR), 3D IR-prepared FSPGR (BRAVO), 3D T1 CUBE, and magnetization transfer (MT)
      • SE is the T1 reference standard for image contrast at 1.5T, although the other sequences have unique advantages and are included as options. Due to T1 prolongation at 3.0T and associated loss of gray-white contrast, there is no consensus standard for T1-weighting, and many sites use inversion recovery preparation to restore tissue contrast
      • FSE, with its intrinsic MT effects, results in decreased gray-white contrast but may depict contrast enhancement to better advantage
      • T1-FLAIR and BRAVO are inversion prepared, facilitating excellent gray-white differentiation, but with the potential disadvantage of inconspicuous contrast enhancement due to the marked precontrast hypointensity of many lesions and subsequent isointensity to surrounding brain postcontrast
      • BRAVO, as a standard 3D sequence, has the key advantage of multiplanar reconstruction capability of the isotropic data sets, and excellent gray-white contrast desirable for most applications
      • T1 CUBE. This T1-weighted FSE-based volumetric sequence can be performed either before or after contrast. Beyond the usual 3D attributes (such as high resolution and multiplanar reconstructions), it has particular advantages postcontrast, where it provides black blood imaging, supports fat saturation, and shows outstanding tissue contrast for enhancing lesions. T1 CUBE is suitable for routine brain imaging as well as orbital, cranial nerve, and vessel wall imaging exams. Many sites now use T1 CUBE as a supplement to postcontrast T1 BRAVO and other sequences
      • MT is an optional feature that can be added to increase contrast enhancement conspicuity on SE imaging, but at the cost of increased SAR (specific absorption rate) and decreased gray-white distinction
    • T2. Most sites use FSE sequences rather than SE. PROPELLER is effective for dealing with patient motion, and is the primary FSE sequence used at many sites. Some users add fat saturation to T2 imaging as an option
    • T2-FLAIR. Improves lesion detection particularly at the brain-cerebrospinal fluid (CSF) interface. When done as the first sequence postinjection, postcontrast T2-FLAIR imaging effectively inserts a time delay for subsequent T1- weighted scans, which improves lesion detection on subsequent T1 imaging. The T2-FLAIR images also have some intrinsic T1 contrast that allows visualization of both edema and enhancement on one sequence for many lesions. Both 2D and 3D T2-FLAIR sequences are commonly performed, with the advantage of multiplanar reconstruction capability and fewer CSF pulsation artifacts of the 3D CUBE
    • Susceptibility. Due to the reduced susceptibility weighting of FSE methods, a T2*-GRE sequence can be added as an option to detect blood products and calcium. The SWAN sequence has been shown to more sensitively detect subtle areas of blood and calcium and has become a common protocol choice
    • Diffusion. Most brain protocols include a diffusion-weighted imaging (DWI) sequence that is useful for stroke, infection, and tumor imaging. Apparent diffusion coefficient maps should be included to assess T2 shine-through. In areas near the skull base or orbits, PROPELLER DWI can be a good option to reduce signal pile-up and geometric distortion artifacts
    • Perfusion. Dynamic susceptibility contrast, perfusion-weighted imaging is becoming increasingly important and can provide clinically significant information regarding blood volume and/or transit time for both stroke and tumor imaging. Arterial spin labeling is also an option for assessing cerebral blood flow at 3.0T, but must be obtained precontrast
    • Contrast. The protocols presented here do not list separate imaging sequences for postcontrast imaging; rather, the T1-weighted sequence of choice is typically repeated after contrast agent administration. Most neurologic sequences with contrast are acquired with at least a 3- to 5-minute delay after injection to optimize visualization of disorders of the blood-brain barrier. Some protocols use more than one sequence “family” postcontrast, such as T2-FLAIR, T1-BRAVO, and T1-CUBE Fat Sat due to their complementary information. Many centers prefer routinely acquiring such volumetric series postcontrast to facilitate retrospective multiplanar reconstructions, treatment planning, and neuronavigation applications. T2-FLAIR is an excellent complement to T1 series, and may be done first postcontrast to intentionally provide a time delay before the T1 series are acquired. The method of injection is not important in these cases, and manual injection is typically used. However, power injectors are needed for contrast-enhanced MR angiography and perfusion imaging. Rates of injection vary, but 4 to 5 mL/sec is standard for perfusion, and 1.5 to 2.0 mL/sec is used for MR angiography. Dosing of gadopiclenol is weight-based at 0.05 mmol/kg (half the dose of other extracellular agents) for most protocols aimed at standard extracellular fluid distribution. The dose for an individual injection may be lower for split-dose protocols (e.g., involving multiple first-pass MR angiography acquisitions), keeping overall dose within the standard 0.05 mmol/kg guideline. The ACR has recommended that the lowest dose feasible be used for diagnostic purposes; because standard dosing recommendations are mostly influenced by lean body mass, and extracellular fluid volume in fatty tissues is low, it is reasonable to cap the upper limit of gadopiclenol for heavier adults at 15 mL total (the largest single-dose vials and prefilled syringes are 15 mL).

    A useful contrast dose calculator ("GadCalc") is available at https://www.radiology.wisc.edu/contrastCorner/gadcalc.php and is also available for free download at the Apple and Droid App Stores.