title: Helical CT angiography with maximum intensity projection in the assessment of aortic coarctation after surgery.
abstract: OBJECTIVE
  The value of CT angiography and three-dimensional (3D) reconstructions was investigated in the postoperative care after surgical repair of aortic coarctation and compared with conventional angiography.
  
  
  METHODS
  Twenty-five patients referred because of suspicion of stenosis in the area of former coarctation were prospectively studied with CT angiography and catheter angiography. We determined the morphometric and morphologic findings such as aortic diameter, stenosis, aneurysm, intimal flaps, circumscribed pouch, or arteriosclerotic plaques with 3D reconstructions, using maximum-intensity-projection (MIP) technique and catheter angiography. The results of both techniques were compared. The ratio of the narrowest diameters of the former coarctation and the descending aorta was correlated with the systolic pullback blood pressure gradient in all patients.
  
  
  RESULTS
  The former coarctation was normal in 11 patients, (44%), group A; narrowed in 12 children (48%), group B; and dilated in two children (8%), group C. An intimal flap and a circumscribed pouch were delineated in four subjects. MIP reconstructions and catheter angiography revealed identical results regarding the classification into groups A, B, C; intimal flaps; and circumscribed pouches. Statistical analysis revealed good correlation between the narrowest aortic diameters measured on MIP reconstructions and catheter angiography, whereas no correlation between the systolic pullback blood pressure gradient and the diameter ratio of the former coarctation and the descending aorta was found.
  
  
  CONCLUSIONS
  CT angiography and 3D reconstructions using MIP represent a reliable noninvasive technique to replace diagnostic catheter angiography in the postoperative care of patients with coarctation and provide the clinician with valuable information concerning further invasive procedures.
authors.affiliation: Department of Radiology, University Hospital Graz, Auenbruggerplatz 9, A-8036 Graz, Austria.
authors.forename: G J
authors.initials: GJ
authors.lastname: Schaffler
authors.forename: E
authors.initials: E
authors.lastname: Sorantin
authors.forename: R
authors.initials: R
authors.lastname: Groell
authors.forename: A
authors.initials: A
authors.lastname: Gamillscheg
authors.forename: E
authors.initials: E
authors.lastname: Maier
authors.forename: H
authors.initials: H
authors.lastname: Schoellnast
authors.forename: R
authors.initials: R
authors.lastname: Fotter
mesh_terms: D000293:Adolescent; D001017:Aortic Coarctation / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed