CT angiography in highly calcified arteries: 2D manual vs. modified automated 3D approach to identify coronary stenoses.
BACKGROUND
Two-dimensional axial and manually-oriented reformatted images are traditionally used to analyze coronary data provided by multidetector-row computed tomography angiography (MDCTA). While apparently more accurate in evaluating calcified vessels, 2D methods are time-consuming compared with automated 3D approaches. The purpose of this study was to evaluate the performance of a modified automated 3D approach (using manual vessel isolation and different window and level settings) in a population with high calcium scores who underwent coronary half-millimeter 16-detector-row CT angiography (16 x 0.5-MDCTA).


METHODS
ECG-gated 16 x 0.5-MDCTA (16 x 0.5 mm cross-sections, 0.35 x 0.35 x 0.35 mm3 isotropic voxels, 400 ms rotation) was performed after injection of iopamidol (120-ml, 300 mg/ml) in 19 consecutive patients (11 male, 62+/-10 years-old). Native arteries were independently evaluated for >or=50%-stenoses using both manual 2D and modified automated 3D approaches. Stents and bypass grafts were excluded. Conventional coronary angiography was visually analyzed by 2 observers.


RESULTS
Median Agatston calcium score was 434. Sensitivities, specificities, positive and negative predictive values for detection of >or=50% coronary stenoses using the 2D and modified 3D approaches were, respectively: 74%/63%, 76%/80%, 45%/34%, and 91%/93% (p=NS for all comparisons). Overall diagnostic accuracies were 75 and 78%, respectively (p=NS). Uninterpretable vessels were, respectively: 37% (77/209) and 35% (73/209) - p=NS. Time to analyze a single study was 160+/-23 and 53+/-11 min, respectively (p<0.01).


CONCLUSIONS
This modified automated 3D approach is equivalent to and significantly less time consuming than the traditional manual 2D method for evaluation of >or=50%-stenoses by 16 x 0.5-MDCTA in native coronary arteries of patients with high calcium scores.
Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
Marco A S
MA
Cordeiro
Albert C
AC
Lardo
Marcelo S V
MS
Brito
Miguel A
MA
Rosário Neto
Maria H A
MH
Siqueira
José R
JR
Parga
Luiz F
LF
Avila
José A F
JA
Ramires
João A C
JA
Lima
Carlos E
CE
Rochitte
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002114:Calcinosis / Q000000981:diagnostic imaging*; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*