Single Session of MR Coronary Angiography and Myocardial Perfusion Imaging Using a New Blood Pool Co

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Single Session of MR Coronary Angiography and
Myocardial Perfusion Imaging Using a New Blood
Pool Compound B-22956 (Gadocoletic Acid)
Initial Experience in a Porcine Model of
Coronary Artery Disease

• Jie Zheng, Debiao Li, Fabio Maggioni,
• Dana Abendschein, Orlando Simonetti, Gerhard
  Laub,
• J Paul Finn, Robert J Gropler, Friedrich M Cavagna

Zheng J et al, Investigative Radiology
200540604-613
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Diagnostic Decision Tree for Coronary Artery
Disease
300.-
Stress ECG
rule out CAD medication
13 m procedures/y
Ultrasound
400.-
POSITIVE NON DIAGNOSTIC
Radiation
Nuclear Medicine
4.4 m procedures/y
rule out CAD medication
Stress Perfusion Imaging
POSITIVE NON DIAGNOSTIC
Invasive
2.2 m procedures/y
X-Ray Coronary Angiography or IVUS
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Advantages of Cardiac MRI

• No radiation and minimal invasiveness (IV
  injection)
• 3-dimensional anatomic images (3D coronary artery
  and myocardial imaging)
• Comprehensive functional imaging - Myocardial
  mechanical work
• - Myocardial perfusion
• - Myocardial oxygenation
• - Myocardial Viability

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Challenges of Cardiac MRI

• Prone to cardiac and respiratory motions
• Low signal-to-noise ratio
• Low spatial resolution relative to motionless
  organs (brain, kidney, etc)

Intravascular or blood-pool contrast agents can
potentially overcome these limitations!
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New Experimental Contrast for MR Coronary
Angiography B-22956/1

• Low molecular weight Gd chelate with very high
• affinity for serum proteins

• Binding (0.5 mM) to HSA 0.6 mM 94 (80 )

• Binding (0.5 mM) to PSA 0.6 mM 90 (56 )

• Binding (0.5 mM) to MSA 0.6 mM 92 (81 )

• Apparent longitudinal relaxivity (0.5 mM in
  Seronorm)

r1 27 mM-1 s -1 (35 mM-1 s -1)
data in parenthesis are for MS-325, a protein
binding contrast agent undergoing Clinical Trials
and FDA approval
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MPR Images (Siemens Symphony 1.5T) after 0.125
mmol/kg Injection of B-22956/1 Res. 0.7 ? 0.7
? 0.7 mm3
RCA
1 min postcontrast
33 min postcontrast
17 min postcontrast
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3D MR Coronary Angiography in Pigs after
B-22956/1 (0.1 mmol/kg b.w.)
Volume Rendering
RCA
Res. 1.0 ? 1.0 ? 2.0 (1.0) mm3
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Myocardial Perfusion Imaging in Pig _at_ 1.5T
(IR-True FISP TR/TE/a 3.5/1.8/70)
Conventional Gadolinium (FDA approved MRI
contrast agent) 0.04 mmol/kg
2.4 s
5.6 s
8.0 s
14.4 s
17.6 s
20.8 s
B-22956/1 0.02 mmol/kg
2.7 s
6.4 s
9.1 s
16.4 s
20.0 s
23.6 s
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Materials and Methods

• Six Yucatan mini-swine (mean weight 18 kg)
• Coronary balloon angioplasty injury and
  atherogenic diet feeding
  atherosclerotic plaques in 2 or 3 coronary
  arteries
• X-ray angiography prior to MR scans
• MR precontrast coronary imaging
• Injection of 0.1 or 0.15 mmol/kg B-22956/1
  (Bracco)
• MR postcontrast scans (breath-holds (BH) and
  navigator-echo gated imaging (NAV))

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Pig 2 LCx, Mild Stenosis lt 50
LCx
LAD
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Pig 2 RCA, Moderate Stenosis 50-70
50-70
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Pig 1 RCA, High Grade Stenosis gt 95
RCA
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Pig 1 RCA, Perfusion High Grade Stenosis gt 95
Normal Perfusion in LAD
Low Perfusion in RCA
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Results

• Breath-hold and high-resolution navigator-echo
  gated scans could repeat after the contrast
  injection
• MR Coronary Angiography results qualitatively
  confirmed x-ray findings in terms of stenosis
  degree and locations
• Functional assessment of myocardial perfusion
  simultaneously

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Conclusions

• Availability of B-22956/1 will greatly
  facilitate the successful development of
  Magnetic Resonance Coronary Angiography and
  quantification of myocardial perfusion

• Clinical Trials are warranted to further assess
  the potential of this contrast agent