In vivo intravascular MR imaging: transvenous technique for arterial wall imaging.
OBJECTIVE
To determine, in vivo, the potential for transvenous magnetic resonance (MR) imaging of the arterial wall and to assess appropriate MR pulse sequences for this method.


METHODS
MR imaging was performed on 19 vessels (right renal artery, N = 9; left renal artery N = 2; external iliac artery, N = 4; abdominal aorta, N = 4) in nine swine. The animals were either low-density lipoprotein receptor knockout (N = 5) or Yucatan mini-pigs fed an atherogenic diet for 6 to 11 weeks (N = 4). The intravascular MR coil/guide wire (IVMRG) (Surgi-Vision, Gaithersburg, MD) was introduced via the external iliac vein into the inferior vena cava (IVC). The following electrocardiograph-gated MR pulse sequences were obtained: T1-weighted precontrast with and without fat saturation and T1-weighted postcontrast with fat saturation. Two observers scored wall signal and conspicuity and classified the vessel as normal, abnormal, or stented. Images were compared with histopathologic findings.


RESULTS
The T1-weighted precontrast without fat saturation, T1-weighted precontrast with fat saturation, and T1-weighted postcontrast images correlated with histopathologic findings in 12 of 15 vessels, eight of 10 vessels, and 14 of 16 vessels, respectively. Abnormal histopathologic findings included: arterial wall thickening (N = 3), arterial dissection (N = 2), focal fibrous plaque (N = 2), adherent thrombus (N = 1). The T1-weighted postcontrast images were not compromised by artifacts and had the highest score for vessel wall signal and conspicuity. T1-weighted precontrast images were compromised by chemical shift artifact and poor blood suppression. Negligible artifacts were created by the platinum stent.


CONCLUSIONS
The T1-weighted fat saturated postcontrast pulse sequence was superior to other sequences for transvenous MR imaging of the arterial wall.
Hofmann
Lawrence V
LV
Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins Medical Institutions, Blalock 545, 600 North Wolfe Street, Baltimore, Maryland 21287, USA. lhofmann@jhmi.edu
Liddell
Robert P
RP
Arepally
Aravind
A
Montague
Brian
B
Yang
Xiaoming
X
Bluemke
David A
DA
D000818:Animals; D001158:Arteries / Q000473:pathology*; D001161:Arteriosclerosis / Q000175:diagnosis* / Q000473:pathology; D016477:Artifacts; D003287:Contrast Media; D019786:Gadolinium DTPA; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D013552:Swine; D013556:Swine, Miniature
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA