MRI of slow flow in artificial duct in swine.
Our aim was to evaluate whether it is possible to visualize slow flow within a small catheter placed inside a living animal. We used a flow-sensitive, single-shot turbo spin-echo (SS-TSE) MRI sequence, developed in house, based on diffusion-weighted (DW) techniques. Four anesthetized pigs were used as models. A plastic catheter was surgically placed within the common bile duct (CBD). To mimic flow, the catheter was filled with Ringer's acetate and connected to a pump. b factors (s/m(2)) of 0, 6, and 12, with flow velocities raging from 0 to 1.32 cm/s, were used. A total of 375 images were obtained and examined. After correction for bowel movement artifacts, all images displayed the catheter on zero flow. With a flow of 0.66 cm/s or higher, no images displayed the catheter with a b factor of 6 or 12. On the slower flow velocities, it was variable whether the catheter was visible or not, but at b=6 and flow 0.17 cm/s all catheters were viewable. This method made it possible to perform a semiquantitative evaluation of flow velocities in vivo, dividing flow into three groups.
Hellund
Johan Castberg
JC
Department of Radiology, Ullevaal University Hospital, 0407 Oslo, Norway. j.c.hellund@ioks.uio.no
Labori
Knut Jørgen
KJ
Bjørnbeth
Bjørn Atle
BA
Gjesdal
Kjell Inge
KI
Geitung
Jonn Terje
JT
D014670:Ampulla of Vater / Q000503:physiopathology; D000818:Animals; D016477:Artifacts; D002408:Catheters, Indwelling; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods*; D003135:Common Bile Duct / Q000503:physiopathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008365:Manometry / Q000379:methods*; D015588:Observer Variation; D010183:Pancreatic Ducts / Q000503:physiopathology*; D012680:Sensitivity and Specificity; D013552:Swine