HEAD IMAGING - MRI Protocol Overview

    January 29 1999 Stay in Touch :-)
Preamble

These Protocols have been developed for a Siemens VISION B31D with EPI Overdrive. They are posted to the web for the information and consideration of other MRI users and are not intended to be absolutely prescriptive. All MRI examinations are conducted in a dynamic interactive mode, with changes being made as required.


Contents

General Preparation Dynamic Pituitary
Standard Head Multiple Sclerosis
CP Angle Temporal Lobe
Pituitary .
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General Preparation

Further Reading

Magnetic Resonance Imaging of the Brain. R Jager I Moseley Current Medical Literature London 1998 ISBN 185009 107 2
  


STANDARD HEAD
Used for general examination of the brain with no specific neurological symptoms. The technique should be modified with additional views or more topical slices if an unexpected lesion is discovered.

Sequences stored under Head/Standard_Brain_Exam

SCOUT 3 plane GRE localisers
PD + T2 AXIAL Turbo spin echo (TSE) axials. 5 mm thick with 50% gap

  • Position slices parallel to the line joining the Genu and Splenium of the Corpus Callosum.
  • Cover the brain from below the Foramen Magnum to the Vertex.
  • Sat band just below inferior slice and parallel to the slices
  • FLAIR AXIAL 5 mm slices 0.9 mm resolution FOV 230 mm

    T1 CORONAL Spin Echo coronals 5 mm thick with 50% gap

  • Position perpendicular to the line joining the Genu and Splenium of the Corpus Callosum.
  • Optional Sequences

    T1_Coronal_low-susceptibilty
    Use this sequence when the patient has metal in the FOV as the standard T1 uses a very low bandwidth.

    MP-RAGE isotropic T1
    Use this if there are multiple lesions, when you need 2 T1 views, or when needing a slice thickness less than 4 mm. Reconstruct images as required.

    Contrast

    Consider contrast for suspected intracranial tumours, where a known tumour has changed size.

    Post contrast, Scan 5 minutes after contrast. Use the MP-RAGE for most lesions except ? Lymphoma or in where there is a solitary metastases. In those cases use the SE sequence with a short TR and MTC

     Filming

     
    CEREBELLO-PONTINE ANGLE (CPA) PROTOCOL

    Intended to provide a detailed examination of the seventh and eight cranial nerves and the other C-P angle structures, especially for detecting acoustic neuromas. The fifth cranial nerve is included on imaging. General brain images are obtained to make the exam more comprehensive.

    Typical Indications

    Sequences stored under Head/ CP_ANGLE

    SCOUT Three plane low resolution scout

    PD + T2 AXIAL Full brain coverage TSE axials. 5 mm thick with 50% gap

  • Position slices parallel to the line joining the Genu and Splenium of the Corpus Callosum.
  • Cover the brain from below the Foramen Magnum to the Vertex.
  • Sat band just below inferior slice and parallel to the slices
  • CISS_Axial High resolution 3D bright fluid sequence to define the cochlea and semi-circular canals and outline the cranial nerves.

  • Centre on the Acoustic nerves, angle to place scan plane roughly parallel to the roof of the 4th ventricle.
  • Use MPR software to correct positional errors and display full length of the nerves. See the protocol notes describing  how to create & film CISS or MP-RAGE MPRs for Acoustic Nerves
  • Variations & Optional Sequences

    FILMING

    Brain Images
    20 format film. Film 19 images with annotated scout in bottom right corner.
    200 mm presented FOV (1.25 magnification)

    CP Angle Views
    12 format film 135 mm presented FOV

    1.5 magnification for CISS
    1.85 magnification for MP-RAGE
    Related Reading

    Fast Spin Echo MR Imaging of the Temporal Bone. Ric Harnsberger P91-93, Second International Conference on Magnetic Resonance Imaging 1995 Notes

    MRI of Cranial Nerves. Part 2. MRI DECISIONS Vol.4 No. 4 Pp.2-16
     


    PITUITARY FOSSA EXAMINATION
    Intended to detect sellar or parasellar lesions, to delineate intrusion into surrounding structures (optic chiasm, cavernous sinus, sphenoid sinus, frontal and temporal lobes, anterior brainstem, and to display any nasal cavity abnormality which may complicate a trans-sphenoidal surgical approach.

    Typical Indications

    Sequences stored under Head / Pituitary

    SCOUT Three plane low resolution scouts

    T2_CORONAL TurboSE T2 coronals positioned through the sella or lesion.

  • Place the rear slice through the Basilar artery.
  • Isotropic_MPRAGE Used for multi-planar reformatting.

    Optional Sequences

    PD+T2_BRAIN
    Sequence copied form the Standard brain examination for a general overview of the brain in patients with a non specific indication for Pituitary MRI

    T2_SAGITTAL
    For enhanced display of cystic lesions if they are not clearly visible on the MP RAGE images

    Multi-planar Reconstructions

    For more detailed instructions see "Creating & Filming MPRs for Pituitary Examinations"

    FILMING

    Related Reading:
    MRI of the Sella/Juxtasellar Region Part 1. Ann Osborn. MRI DECISIONS Vol. 4 No.6 Pp. 21-31
      
    Dynamic Contrast Pituitary
    To identify small (>3mm) secreting pituitary adenomas so that a partial resection of the pituitary may be used rather than total.

    Typical Indications

    Sequences stored under Head /Pituitary

    Preparation & Kit

    Set up the jelco with the extension tube filled with saline. The contrast is injected rapidly (2 ml/sec) at the beginning of the second scan, and followed by a saline flush of 5-10 mls.


    Contrast Doses (Half dose)

     
    40 kg 4 mls   80 kg 8 mls
    50 kg 5 mls   90 kg 9 mls
    60 kg 6 mls   100 kg 10 mls
    70 kg 7 mls   110 kg  11 mls

    Technique

    Perform a standard pituitary exam first unless done recently.

    Rapid_T1_Coronal_51297
    This is a series of TSE T1 coronal images intended to be used with a fast injection of half dose contrast. The injection is rapidly given at the start of the 2nd measurement. There is a 10 second pause between the first (precontrast) scan and the start of the continuous string of post contrast measurements to prepare the injector and give a countdown.

    Filming and Analysis.

    Low SNR means that lesions are hard to distinguish reliably by visual comparison. Images for a single patient must be presented consistently and filmed with the same window settings. Time curve graphs of the enhancement are produced to be able to objectively identify lesions.  
    Location 1 
    Pre contrast
    Location 2 Location 3
    36 sec post  
    (normal image or subtraction)
    . .
    1:48 post  
    (normal image or subtraction)
    . .
    3 min post  
    (normal image or subtraction)
    . .

    Time curve analysis

    Perform this analysis for each slice covering the gland.
    Review the images sequentially for any subjective appearance of delayed enhancement.  
    Location 1 
    3rd post contrast image with ROIs
    Location 2 
    3rd post contrast image with ROIs
    Location 3 
    3rd post contrast image with ROIs
    Graph of Time / Intensity curves Graph of Time / Intensity curves Graph of Time / Intensity curves

     
    MULTIPLE SCLEROSIS HEAD EXAMINATION

    Intended to detect M.S. plaques in the white matter anywhere in the brain.

    Typical Indications

    Sequences stored under Head / Demyelination

    SCOUT 3 plane GRE localisers
    Double_Echo_AXIAL Turbo spin echo (TSE) axials. 5 mm thick with 50% gap

  • Position slices parallel to the line joining the Genu and Splenium of the Corpus Callosum.
  • Cover the brain from below the Foramen Magnum to the Vertex.
  • Sat band just below inferior slice and parallel to the slices
  • Sagittal_FLAIR 5 mm slices 0.9 mm resolution FOV 230 mm

  • Position parallel to the corpus callosum
  • T1 CORONAL Spin Echo coronals 5 mm thick with 40% gap

  • Position perpendicular to the line joining the Genu and Splenium of the Corpus Callosum.
  • Filming

     
    TEMPORAL LOBE STUDY

    Intended to detect temporal lobe lesions which are likely to be the root course of complex partial seizures which have not responded to medication. The films may provide planning information for partial or full temporal lobectomy. Lesions could include tumour, scar, infarct, miscellaneous gliotic change or mesial temporal sclerosis. The examination must also screen for other lesions in the brain.

    Typical Indications

  • Temporal lobe epilepsy (TLE)
  • Complex partial seizures (CPS)
  • Mesial temporal sclerosis (MTS)
  • Short term memory loss (STM)
  • Partial seizures
  • Temporal focus on EEG
  •  
    Orthodontic Braces
    These are common in young TLE patients and will create substantial artefact even in axial views of the temporal lobes. Use the low susceptibility T1 sequence.
    You may need to repeat the sequence with half the acquisitions, 100% phase oversampling, and the phase running S-I to shift braces artefact from the temporal lobes as the standard T1 uses a very low bandwidth.

    Sequences stored under Head / Temporal_Lobe

    Scout 3 plane GRE localisers

    Sagittal Scout 3 sagittal FLASH images to help identify the line of the hippocampal grey matter.

    PD + T2 AXIAL Turbo spin echo (TSE) axials. 5 mm thick with 50% gap

  • Position slices parallel to the line joining the Genu and Splenium of the Corpus Callosum.
  • Cover the brain from below the Foramen Magnum to the Vertex.
  • Sat band just below inferior slice and parallel to the slices
  • T1 Isotropic MP-Rage (sagittal acquisition)

  • Run and create MPRs in the coronal and axial planes relative to the Hippocampus (see below)
  • T2 TSE Coronal 3 mm slices 0.65mm resolution

  • Position perpendicular to the line of the Hippocampal grey matter, cover form the anterior temporal horn to the abutment of the Hippocampus and the corpus callosum
  • FLAIR Coronal 5 mm slices 0.9 mm resolution FOV 230 mm

  • Position perpendicular to the line of the Hippocampal grey matter, cover form the anterior temporal horn to the abutment of the Hippocampus and the corpus callosum
  • Optional Sequences

    True IR Coronals
  • Position perpendicular to the line of the Hippocampal grey matter, cover form the anterior temporal horn to the abutment of the Hippocampus and the corpus callosum
  • True IR Axials

  • Position parallel to the line of the Hippocampal grey matter.

  •    

    REMAINING PROTOCOLS TO BE CONTINUED ....... later
    Check for more recent versions
    Greg Brown January 30 1999
     
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