Linear accuracy and reliability of volume data sets acquired by two CBCT-devices and an MSCT using virtual models: a comparative in-vitro study.
OBJECTIVE
To discriminate clinically relevant aberrance, the accuracy of linear measurements in three-dimensional (3D) reconstructed datasets was investigated.


METHODS
Three partly edentulous human skulls were examined. Landmarks were defined prior to acquisition. Two CBCT-scanners and a Quad-slice CT-scanner were used. Actual distances were physically measured with calipers and defined as a reference. Subsequently, from digital DICOM datasets, 3D virtual models were generated using maximum intensity projections (MIPs). Linear measurements were performed by semi-automated image analysis. Virtual and analogue linear measurements were compared using repeated measurements in a mixed model (p ≤ 0.05).


RESULTS
No significant difference was found among all of the digital measurements when compared to one another, whereas a significant difference was found in matched-pairs analysis between CBCT and calipers (p = 0.032). All digitally acquired data resulted in lower mean values compared to the measurements via calipers. A high level of inter-observer reliability was obtained in the digital measurements (inter-rater correlation = 0.988-0.993).


CONCLUSIONS
The reconstructed datasets led to highly consistent values among linear measurements. Yielding sub-millimeter precision, these modalities are assumed to reflect reality in a clinically irrelevant altered manner. During data acquisition and evaluation, a maximum of precision must be achieved.
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Johannes
J
Wikner
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Henning
H
Hanken
b 2 Medical Biometry and Epidemiology, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Christine
C
Eulenburg
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Max
M
Heiland
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Alexander
A
Gröbe
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Alexandre Thomas
AT
Assaf
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Björn
B
Riecke
a 1 Department of Oral and Maxillofacial Surgery, University Medical Center Hamburg Eppendorf , Hamburg, Germany.
Reinhard E
RE
Friedrich
D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D002508:Cephalometry / Q000295:instrumentation / Q000706:statistics & numerical data*; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000706:statistics & numerical data*; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging; D016555:Matched-Pair Analysis; D061330:Multidetector Computed Tomography / Q000706:statistics & numerical data*; D015588:Observer Variation; D015203:Reproducibility of Results; D012886:Skull / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data; D014584:User-Computer Interface
C-arm; computed tomography (CT); cone beam computed tomography (CBCT); maximum intensity projection (MIP); multiplanar reconstructions (MPR); three-dimensional (3D)