Contrast-enhanced thoracic 3D-MR angiography in infants and children.
OBJECTIVE
To optimise breath-hold contrast-enhanced MR angiography (MRA) in infants and children with suspected congenital heart or thoracic vessel malformation.


METHODS
Thirty-nine children (median age 1 year) were examined, using five different ultrafast MRA sequences with a TR between 3.2 and 5.0 ms and the contrast agent meglumine gadoterate. A test injection was used to determine contrast travel time. Different parameters for contrast injection were evaluated. Signal-to-noise ratio (SNR) measurements were performed and image quality and injection timing were evaluated.


RESULTS
MRA was successful in all patients and image quality was considered very good in 52%. Adequate SNR was achieved with no significant differences between the MR sequences. SNR decreased only 25-30% between subsequent scans. The mean contrast dose was 0.23 mmol/kg. The mean scan time was 12.5 +/- 3.8 s; the shorter scan times made dynamic examinations possible with high temporal resolution. Highest spatial resolution was obtained with TR 4.6/5.0 sequences.


CONCLUSIONS
A contrast dose of 0.2 mmol/kg b.w. is recommended with an injection rate of 0.5 to 1.2 ml/s, depending on patient size and scan time. The scan delay time should equal the contrast travel time for optimal vessel enhancement. In the future, contrast-enhanced MRA may be a potential alternative to angiocardiography in infants and children.
Holmqvist
C
C
Department of Diagnostic Radiology, University Hospital, Lund, Sweden.
Larsson E-M
Ståhlberg
F
F
Laurin
S
S
D000293:Adolescent; D001013:Aorta, Thoracic / Q000002:abnormalities; D002648:Child; D002675:Child, Preschool; D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D005260:Female; D006330:Heart Defects, Congenital / Q000175:diagnosis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000008:administration & dosage*; D009942:Organometallic Compounds / Q000008:administration & dosage*; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000002:abnormalities; D013909:Thorax / Q000098:blood supply*; D014652:Vascular Diseases / Q000151:congenital / Q000175:diagnosis*
D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine