The accuracy of 1- and 3-mm slices in coronary calcium scoring using multi-slice CT in vitro and in vivo.
The accuracy of coronary calcium scoring using 16-row MSCT comparing 1- and 3-mm slices was assessed. A thorax phantom with calcium cylinder inserts was scanned applying a non-enhanced retrospectively ECG-gated examination protocol: collimation 12 x 0.75 mm; 120 kV; 133 mAs(eff). Thirty-eight patients were examined using the same scan protocol. Image reconstruction was performed with an effective slice thickness of 3 and 1 mm. The volume score, calcium mass and Agatston score were determined. Image noise was measured in both studies. The volume score and calcium mass varied less than the Agatston score. The overall measured calcium mass compared to the actual calcium mass revealed a relative difference of +2.0% for 1-mm slices and -1.2% for 3-mm slices. Due to increased image noise in thinner slices in the patient study (26.1 HU), overall calcium scoring with a scoring threshold of 130 HU was not feasible. Interlesion comparison showed significantly higher scoring results for thinner slices (all P<0.001). A similar accuracy comparing calcium scoring results of 1- and 3-mm slices was shown in the phantom study; therefore, the potentially necessary increase of the patient's dose in order to achieve assessable 1-mm slices with an acceptable image-to-noise-ratio appears not to be justified.
Mühlenbruch
Georg
G
Department of Diagnostic Radiology, University Hospital (RWTH) Aachen, Pauwelsstrasse 30, 52057 Aachen, Germany. gmuehlen@rad.rwth-aachen.de
Klotz
Ernst
E
Wildberger
Joachim E
JE
Koos
Ralf
R
Das
Marco
M
Niethammer
Matthias
M
Hohl
Christian
C
Honnef
Dagmar
D
Thomas
Christoph
C
Günther
Rolf W
RW
Mahnken
Andreas H
AH
D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000473:pathology; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005858:Germany; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000145:classification