title: [16-row multidetector CT angiography of the aortoiliac system and lower extremity arteries: contrast enhancement and image quality using a standarized examination protocol].
abstract: OBJECTIVE
  To assess the degree of enhancement and image quality of 16-slice multidetector CT angiography (MDCTA) of pelvic and lower limb arteries with a monophasic contrast medium injection protocol.
  
  
  METHODS
  Fifty patients underwent a CT angiography of the pelvic and lower limb arteries using the following parameters: collimation 16 x 1.5 mm, rotation time 0.5 s, table feed 40 mm/sec, slice thickness 2 mm, reconstruction interval 1.2 mm, 100 ml Iomeprol 400 + 60 ml normal saline, flow rate 4 ml/s, bolus tracking (threshold of 250 DeltaHU in aorta). Arterial enhancement was measured in all arterial segments. Maximum intensity projections (MIP) together with axial images were reviewed by two radiologists (consensus). If the results were inconclusive for stenosis, additional curved multiplanar reformations (MPR) were performed.
  
  
  RESULTS
  The mean arterial enhancement values were aorta: 314 +/- 69, pelvis: 342 +/- 105, thigh: 347 +/- 139, calf: 231 +/- 109 DeltaHU. The image quality was judged as excellent in 346 (77.6 %), adequate in 76 (17 %), and inadequate in 24 (5.4 %, all but one in calf and foot) of 446 arterial territories. An override of the contrast bolus below the knee occurred in 2 patients rendering the calf arteries nondiagnostic. Venous enhancement occurred in 13 patients but this compromised the diagnostic assessment in only one case. Additional MPRs were required accurately to assess stenoses in 22 of 200 arterial levels in 16 patients with marked arterial calcifications.
  
  
  CONCLUSIONS
  16-slice MDCTA with a monophasic contrast bolus of Iomeprol 400 provided good arterial enhancement and diagnostic image quality in 94.6 % of the depicted arterial segments. The majority (67 %) of nondiagnostic segments were below the ankle. MPRs were required in patients with marked calcification for accurate assessment of stenosis.
authors.affiliation: Klinik und Poliklinik für Radiologie und Nuklearmedizin, Campus Benjamin Franklin, Charité -- Universitätsmedizin Berlin. Bernhard.Meyer@charite.de
authors.forename: B C
authors.initials: BC
authors.lastname: Meyer
authors.forename: C
authors.initials: C
authors.lastname: Ribbe
authors.forename: M
authors.initials: M
authors.lastname: Kruschewski
authors.forename: K-J
authors.initials: KJ
authors.lastname: Wolf
authors.forename: T
authors.initials: T
authors.lastname: Albrecht
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000592:standards
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol