Coronary 64-slice computed tomographic angiography models employing aortic root and selective catheter directed contrast enhancement in swine: technical feasibility and preliminary results using 3D and 4D reconstructions.
OBJECTIVE
The technical feasibility of combining catheter directed coronary enhancement and multidetector computed tomographic angiography (MD-CTA) is presented in a swine model at various cardiac and injection rates.


METHODS
A 64-slice CT scanner was used under animal IRB approval in four sedated swine. Common femoral venous/arterial access with a 5 Fr micropuncture kit was ultrasound guided. Investigational 5 Fr diffusion-tip pigtail [aortic root (AR)-MD-CTA] and conventional 5 Fr coronary [selective (S)-MD-CTA] catheters were positioned on the CT table with c-arm fluoroscopy. AR-MD-CTA commenced 1-2 s after injection of 50 cc Visipaque mixed with 50 cc NS at 6 cc/s (n=3), 8 cc/s (n=5) or 10 cc/s (n=7) (HR=120, 100, 90, 80 or 65 bpm). S-MD-CTA (right and left, n=4) (HR= 90, 80, or 65 bpm) commenced 1-2 s after injection of 5 cc Visipaque mixed with 5 cc NS (1 cc/s). IV-MD-CTA (n=4) (HR=80 bpm) commenced 5 or 10 s after aortic peak density with 100 cc Visipaque (5 cc/s) and 50 or 75 cc NS (5 cc/s) flush. Conventional angiography (n=2) used standard protocol. MD-CTA was performed with the following parameters: collimation 0.6 mm, tube rotation time 0.3 s, table feed/rotation 3.8 mm, scan time 10-12 s, tube voltage 120 kVp, effective mAs 850, pitch 0.2, FOV 109-123 mm, slice thickness/increment 0.6 mm/0.3 mm, kernel B25 f smooth. Ex vivo imaging (64-slice CT, n=3) was also performed. Post-processing consisted of coronary peak densities, 3D-MIP's and 4D projections.


RESULTS
Catheter directed MD-CTA was feasible at all injection rates at and below 100 bpm and yielded higher peak coronary attenuation values than IV-enhanced studies. Definition and clarity of the tributary and distal anatomy was also higher than IV-enhanced CTA.


CONCLUSIONS
Catheter directed MD-CTA can be performed by retrofitting the current CT scanner with a portable c-arm fluoroscopy unit. S and AR MD-CTA provide high coronary anatomy definition and luminal attenuation without obscuring cardiac chamber signal and with the least iodinated contrast volume.
Bis
Kostaki G
KG
Department of Radiology, William Beaumont Hospital, Royal Oak, MI 48073, USA. kbis@beaumont.edu
Shetty
Anil N
AN
Brewington
Stacy
S
Arpasi
Paul
P
Kosuri
Rajani
R
Stein
Wendy
W
Lauer
Michael
M
O'Neill
William
W
D000818:Animals; D001027:Aortography / Q000379:methods; D006328:Cardiac Catheterization; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods; D003331:Coronary Vessels / Q000033:anatomy & histology; D005240:Feasibility Studies; D005260:Female; D006321:Heart / Q000033:anatomy & histology; D006331:Heart Diseases / Q000175:diagnosis; D021621:Imaging, Three-Dimensional; D011857:Radiographic Image Interpretation, Computer-Assisted; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*; D014283:Triiodobenzoic Acids
D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol