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MRI of the renal arteries David A. Bluemke, M.D., Ph.D., FAHA - - PowerPoint PPT Presentation
MRI of the renal arteries David A. Bluemke, M.D., Ph.D., FAHA - - PowerPoint PPT Presentation
MRI of the renal arteries David A. Bluemke, M.D., Ph.D., FAHA Director, Radiology and Imaging Sciences NIH Clinical Center Senior Investigator, NHLBI, NIDDK Bethesda, Maryland, USA Disclosures Off-label use: gadolinium enhanced MRI of the
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Screening for Renal Artery Stenosis: Screening for Renal Artery Stenosis:
- low morbidity - no
contrast reactions
- rapid exam - 15
minutes
- low nephrotoxicity
compared to iodine agents
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3D Gadolinium Renal MRA 3D Gadolinium Renal MRA
Study Study Yr Yr # arteries # arteries Sens. Sens. Spec. Spec.
Korst et al. ‘00 92 100% 85% De Cobelli ‘00 103 94% 93% Thornton ‘99 87 100% 98% Thornton ‘99 138 88% 92% Hany ‘98 235 93% 90% Bakker ‘98 121 97% 92% De Cobelli ‘97 105 100% 97% Postma ‘97 74 100% 96% Hany ‘97 78 93% 98%
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Fluoroscopic MRA trigger Fluoroscopic MRA trigger
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Fluoroscopic MRA trigger Fluoroscopic MRA trigger
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MRA: Venous phase MRA: Venous phase
3d VIBE, SPGR MRA: 2nd run
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MRA - Aorta MRA - Aorta
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- 3D aquisition,
2mm slice thickness
- 0.15 mmol/kg
gad @ 2ml/sec
- Automated
timing bolus
- 15 sec breath-
hold
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Renal MRA ?
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Renal MRA
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Renal MRA: data analysis Renal MRA: data analysis
- MIP image
- most
common “data reduction” method
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MRA - reformat MRA - reformat
coronal coronal axial axial sagittal sagittal
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MRA - reformat
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MRA - reformat
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3T Renal MRA
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3T Renal MRA 3T Renal MRA
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MRA - reformat MRA - reformat
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Eccentric plaque - MIP pitfall Eccentric plaque - MIP pitfall
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Volume Rendering Volume Rendering
- retains “3d”
information
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MR angiogram: accurate/ rapid anatomy MR angiogram: accurate/ rapid anatomy
Maximum intensity projection and surface displays Maximum intensity projection and surface displays
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Aorto-enteric fistula repair, aneurysm Aorto-enteric fistula repair, aneurysm
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Courtesy of Paul Finn, UCLA
Dynamic MRA (TREAT)
Renal MRA: Aneurysm
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MRA - variant anatomy MRA - variant anatomy
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MRA - document variant anatomy MRA - document variant anatomy
- Early arterial
branching
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MRA: variant anatomy MRA: variant anatomy
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Pitfall Pitfall
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Pitfall - susceptibility Pitfall - susceptibility
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Pitfall Pitfall - stent
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Pitfall: adenoma Pitfall: adenoma
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Pitfall: adenoma Pitfall: adenoma
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Pitfall: adenoma Pitfall: adenoma
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Renal MRA: size matters Renal MRA: size matters
- 3D renal size
- Is there
sufficient renal mass for revascular- ization?
- > 1 cm L/R
renal size difference
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Renal Artery MRA: disadvantages? Renal Artery MRA: disadvantages?
- tendency to overestimate
(calcification, turbulence)
- “unsuccessful” exams (2%-4%)
- lower sensitivity for accessory
vessels, or intra-renal abnormalities
- pacemakers, claustrophobia
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Female, long standing hypertension Female, long standing hypertension
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“ “Hypertension” Hypertension”
Fibromuscular Fibromuscular dysplasia dysplasia
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Fibromuscular dysplasia Fibromuscular dysplasia
CA CA MRA MRA
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Pressure gradient Pressure gradient
- By convention,
50% stenosis “physiologically significant”
- Experimentally,
70-80% required for a pressure gradient
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MRA: Phase contrast MRA: Phase contrast
- Improved
specificity for stenosis detection
- After 3D
MRA
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Eccentric plaque - MIP pitfall Eccentric plaque - MIP pitfall
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Phase contrast
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Renal MRA: phase contrast Renal MRA: phase contrast
Mild stenosis phase contrast
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3T Renal MRA: phase contrast 3T Renal MRA: phase contrast
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3T Renal abnormality
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Renal transplant Renal transplant
Increasing creatinine:
- Vascular insufficiency?
- Rejection?
- Concern for NSF
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Renal transplant- Renal transplant- multiple multiple reformations reformations
3D volume Targeted MIP Oblique MIP - early branching
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Renal transplant Renal transplant
“Normal” anastomotic narrowing
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1 90+ Normal kidney function but urine or other abnormalities point to kidney disease 2 60-89 Mildly reduced kidney function, urine or other abnormalities point to kidney disease 3 30-59 Moderately reduced kidney function
- Prior gadolinium administration
- Severe renal failure, dialysis
Associations with NSF
Stage GFR Description
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- Prior gadolinium administration
- Severe renal failure, dialysis
- Pro-inflammatory events
- surgery
- infection
- trauma
Associations with NSF
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- 1. Noncontrast time of flight MRA
- 2. 3T MRA: 50% reduction of contrast dose
- 3. Contrast agent with increased relaxivity
(Multihance); allows dose reduction
- 4. both (2) and (3)
Gadolinium MRA: options in at Gadolinium MRA: options in at risk patients risk patients
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Gadolinium MRA: Time of Gadolinium MRA: Time of Flight Flight
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Steady State Free Precession Steady State Free Precession (SSFP) (SSFP) TrueFISP, NATIVE TrueFISP, NATIVE
- Blood is imaged as
a fluid (long T2* time) using a balanced GRE sequence
- ECG and navigator
gated
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Steady State Free Precession Steady State Free Precession (SSFP): TrueFISP, NATIVE (SSFP): TrueFISP, NATIVE
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Steady State Free Precession Steady State Free Precession (SSFP): TrueFISP, NATIVE (SSFP): TrueFISP, NATIVE
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Multihance, 3T Multihance, 3T
0.08 mmol/kg 0.08 mmol/kg
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Multihance, 3T Multihance, 3T
5 cc 5 cc
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Renal MRA (3T): with 3d T1
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Acknowledgements
- Christine Lorenz, PhD, Steve Shea,
Christine Lorenz, PhD, Steve Shea, PhD, Siemens PhD, Siemens
- Paul Finn, MD, UCLA
Paul Finn, MD, UCLA
- Gerhard Laub, PhD, Siemens
Gerhard Laub, PhD, Siemens
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