Pulmonary MR Angiography

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Pulmonary MR Angiography
Martin R. Prince with slides borrowed from
Tom Grist, MD Jorg Debatin, MD Jim Meaney,
MD Piotr Wielopolski, PhD Qian Dong, MD Ruth
Carlos, MD David Stafford-Johnson, MD Stefan
Schoenberg, MD Gus Bis, MD Vic Ferarri, MD Stefan
Reuhm, MD
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Pulmonary Embolism

• gt 600,000 per year
• 30 mortality
• Difficult to diagnosis
• V/Q - 64 indeterminate
• Angio is expensive risks
• CTA safer but nephrotoxicity
• Anticoagulation 7 risk of
• major complication

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MR Angiography Protocol
Coronal 3D GdMRA
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Pulmonary MRA Technique

• Sagittal Locator 1 min
• Coronal 3D Volume x 3 1.5 min
• Total imaging time lt3 min

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Prescribing Coronal 3D Volume

• Posterior to spinal cord
• Anterior to the ascending aorta
• Large FOV to prevent wrap
• No spoiling
• Fast scan for breath holding
• Thick slices 3-5 mm
• Zero interpolation (ZIP x 2)
• Gradient upgrade for short TR
• Partial Fourier Imaging
• Multiphase

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Injecting the Gadolinium

• 2 ml/sec (as fast as you can)
• 6-10 second scan delay for
• arterial phase
• equilibrium phase
• rest to catch breath
• equilibrium phase again
• ventilated patient suspend
• in max inspiration

Arterial Phase
Equilibrium Phase
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Acute Pulmonary Embolism
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Chronic Pulmonary Embolism
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Pulmonary EmbolismDiagnosis with MRA

• Author Year of pt Techniques Sensitivit
  y Specificity
• Grist 1993 20 TOF 92
  63
• Isoda 1995 18 3D Gd 80
  95
• Laissy 1995 28 TOF Gd 87
  95
• Wolff 1996 34 2D Gd 72
  94
• Meaney 1997 30 3D Gd 87
  97
• Gupta 1999 36 3D Gd 85
  96

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Diagnosis of Pulmonary Embolism with MRA (n30)
1 2 3 Sensitivity 100 87 75 Specifi
city 95 100 95 Meaney et al. NEJM
3661422-7, 1997.
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Diagnosis of Pulmonary Embolism with MRA (n36)
Reviewer 1 2 Sensitivity 92 7
7 Specificity 83 91 PPV 75 83 NPV
95 88 Gupta et al Radiology 1999 210353-359
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Shortness of Breath with cough in a 51-year-old
female
Magnification
Reformation
Coronal MIP
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Partial anomlous pulmonary venous return from the
right upper lobe
Magnification
Reformation
Coronal MIP
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46-year-old female with machinery murmur
Axial T1
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Patent Ductus Arteriosus
Axial T1
16
Pulmonic stenosis
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Summary

• 3D GdMRA useful
• Safe
• no nephrotoxicity
• no ionizing radiation
• no arterial catheterization
• Fast (30 second breath hold)
• Accurate
• Better with blood pool?

Blood pool agent MRA