Liver MRI – Planning and Positioning

Wednesday, September 28, 2016


Liver and Biliary System MRI Scan

Live and Biliary MRI is used to diagnose and study the following indications:
  • Focal lesions and staging of neoplasm in the liver
  • Benign hepatic disease, esp. hemangioma and focal nodular hyperplasia.
  • Hemachromatosis and Gallbladder disease.
  • Biliary ducts obstruction is also seen.
  • Evaluation of liver infiltrants such as iron and fats.

Equipment use in Upper Abdomen MRI Scan


  • Body coil volume torso array or multi-coil.
  • RC bellows
  • Ear plugs
  • Pre gating leads if necessary.

Patient Positioning:

The patient position is supine on the examination couch with the RC bellows is securely attached if needed. The longitudinal alignment light is in the midline of the patient, and horizontal light passes to the level of the 3rd lumbar vertebra, or the lower costal margin.


Suggested Protocol for liver and Biliary System MRI

Coranal Breath-hold technique T1 – Incoherent (spoiled)

This act as the localizer if three-plane localization is unavailable, or as a diagnostic sequence.  These slices are thick that relatively prescribed from the vertical alignment light, from the posterior abdominal muscles to the anterior abdominal wall, and horizontally from area of pubis symphysis to the diaphragm is included in the image.

abdomen mri
Coronal SE T1 weighted image through the
abdomen demonstrating slice prescription boundaries and
orientation for axial imaging of the liver.

Axia GRE T1 +/- in and out phase

As for coronal T1, except prescribe slices from the inferior margin of the liver to the diaphragm.
Delayed scan after contrast enhancement using chemical / Spectral presaturation technique are sometimes necessary to evaluate arterial and venous phases.

abdomen mri
Axial FSE T1 weighted image through
the liver.

Axial SE T2 or GRE T2

Slice planning is just the same with the axial T1.

 

Axial SE or Breath-hold incoherent (spoiled) GRE T1 + Contrast Media

Slice planning as for Axial T1.






abdomininal mri
Axial fast GRE T2* through the liver with contrast.



Additional Planning Liver MRI


MRCP – SS-FSE

MRCP is Magnetic Resonance Cholangiopancreatography it is a sequence which provides images in which only fluids-filled spaces such as the gall bladder and biliary ducts return signal. It is necessary to use very long TE’s and TRs to effectively nullify or eliminate the signal from all tissues except those that having a long T2 decay time. TEs in excess of 200 ms and TR of more than 10 s are required. If SS-FSE is unavailable then an FSE sequence may be substituted.

Coronal SS-FSE image of the gallbladder
(MRCP). Very long values of TR and TE were used to
acquire images in which only fluid is seen.

Diffusion Imaging

The use of real time imaging has application in the liver and biliary system. This includes biopsies and thermal ablations of the lesions under real time MR control. In addition, diffusion and perfusion techniques of the liver have been developed that may negate the use of contrast agents in the future. DWI images are overlaid onto T1 weighted acquisitions. The DWI image set provides pathology information, whereas the T1 weighted acquisition provides anatomical data. The images produced are not dissimilar to a PET / CT scan. In addition, diffusion tensor imaging used in conjunction with parallel imaging techniques enables differentiation of benign from malignant hepatic lesions and may also assist in the quantification of hepatic fibrosis.

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