title: MR imaging of thrombi using EP-2104R, a fibrin-specific contrast agent: initial results in patients.
abstract: This study was an initial phase II trial in humans of molecular magnetic resonance (MR) imaging for improved visualization of thrombi in vessel territories potentially responsible for stroke using a new fibrin-specific contrast agent (EP-2104R). Eleven patients with thrombus in the left ventricle (n = 2), left or right atrium (n = 4), thoracic aorta (n = 4) or carotid artery (n = 1) as verified by an index examination (ultrasound, computed tomograpy, or conventional MR) were enrolled. All MR imaging was performed on 1.5 T whole-body MR-system using an inversion-recovery black-blood gradient-echo sequence. The same sequence was performed before and 2-6 h after low-dose intravenous administration of 4 mumol/kg EP-2104R. Two investigators assessed image quality and signal amplification. Furthermore, contrast-to-noise ratios (CNR) between the clot and the blood pool/surrounding soft tissue before and after administration of the contrast agent were compared using Student's t-test. MR imaging and data analysis were successfully completed in 10 patients. No major adverse effects occurred. On enhanced images, thrombi demonstrated high signal amplification, typically at the clot surface, with a significantly increased contrast in comparison to the surrounding blood pool and soft tissue (CNR for clot vs. blood pool, unenhanced and enhanced: 6 +/- 8 and 29 +/- 14; CNR for clot vs. soft tissue, unenhanced and enhanced: 0 +/- 4 and 21 +/- 13; P < 0.01 for both comparisons). EP-2104R allows for molecular MR imaging of thrombi potentially responsible for stroke. High contrast between thrombus and surrounding blood and soft tissues can be achieved with enhanced imaging.
authors.affiliation: Department of Diagnostic Radiology, University Hospital, Technical University (RWTH) Aachen, Aachen, Germany. spuenti@rad.rwth-aachen.de
authors.forename: Elmar
authors.initials: E
authors.lastname: Spuentrup
authors.forename: Rene M
authors.initials: RM
authors.lastname: Botnar
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Wiethoff
authors.forename: Tareq
authors.initials: T
authors.lastname: Ibrahim
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kelle
authors.forename: Marcus
authors.initials: M
authors.lastname: Katoh
authors.forename: Murat
authors.initials: M
authors.lastname: Ozgun
authors.forename: Eike
authors.initials: E
authors.lastname: Nagel
authors.forename: Josef
authors.initials: J
authors.lastname: Vymazal
authors.forename: Phil B
authors.initials: PB
authors.lastname: Graham
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
authors.forename: David
authors.initials: D
authors.lastname: Maintz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000493:pharmacokinetics; D005260:Female; D005337:Fibrin / Q000378:metabolism; D005682:Gadolinium / Q000493:pharmacokinetics; D006331:Heart Diseases / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000493:pharmacokinetics; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000209:etiology; D013927:Thrombosis / Q000150:complications / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; C503783:EP-2104R; D010455:Peptides; D005337:Fibrin; D005682:Gadolinium