Applications of magnetic resonance imaging for cardiac stem cell therapy.
BACKGROUND
The latest generation of interactive cardiac magnetic resonance (MR) scanners has made cardiac interventions with real-time MRI possible. To date, cardiac MRI has been mostly applied to measure myocardial perfusion, viability, and regional function, but now the application of cardiac MRI can be extended to cardiovascular interventions. The purpose of this article is to illustrate the potential of MRI in stem cell therapy for cardiac restoration.


METHODS
We have applied MRI to (1) interactively target myocardial injections with a novel stem cell delivery catheter, and to compare gadolinium/blue dye injections to pathology; (2) assess myocardial perfusion with MR first pass imaging in an infarct model treated with stem cell therapy versus control animals; (3) measure regional functional changes using myocardial tissue tagging in the same animals.


RESULTS
We were able to demonstrate the feasibility and safety of myocardial injections under MR fluoroscopy. The intramyocardial distribution of the blue dye at necropsy correlated well with the extent of gadolinium, as detected with a three-dimensional inversion recovery MR pulse sequence for late enhancement immediately after contrast injection. Preliminary results show that myocardial perfusion reserve and regional wall motion improved in the stem-cell-treated group, compared to a control group.


CONCLUSIONS
These preliminary results suggest that (1) injections into the LV myocardium can be performed under real-time MRI guidance using a directed catheter approach, and (2) regional myocardial perfusion and function, measured with MRI, both improve after stem cell therapy. This ongoing study demonstrates the potential of MRI for image-guided interventions, combined with detailed evaluation of anatomy, function, perfusion, and viability.
Cardiovascular MRI Section, University of Minnesota, Minneapolis, Minnesota, USA.
Carsten
C
Rickers
Robert
R
Gallegos
Ravi Teja
RT
Seethamraju
Xiaoen
X
Wang
Cory
C
Swingen
Avinash
A
Jayaswal
Eric P
EP
Rahrmann
Zachary J
ZJ
Kastenberg
Christina E
CE
Clarkson
Richard
R
Bianco
Tim
T
O'Brian
Catherine
C
Verfaillie
R Morton
RM
Bolman
Norbert
N
Wilke
Michael
M
Jerosch-Herold
D000818:Animals; D001011:Aorta / Q000473:pathology / Q000601:surgery; D006328:Cardiac Catheterization; D003287:Contrast Media / Q000008:administration & dosage; D003326:Coronary Circulation / Q000502:physiology; D004195:Disease Models, Animal; D004285:Dogs; D005471:Fluoroscopy; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008955:Models, Cardiovascular; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000166:cytology; D032383:Myocytes, Cardiac / Q000000981:diagnostic imaging* / Q000637:transplantation*; D011856:Radiographic Image Enhancement; D033581:Stem Cell Transplantation; D013552:Swine
D003287:Contrast Media; D019786:Gadolinium DTPA