Evidence-based recommendations for musculoskeletal kinematic 4D-CT studies using wide area-detector scanners: a phantom study with cadaveric correlation.
METHODS
To establish evidence-based recommendations for musculoskeletal kinematic 4D-CT on wide area-detector CT.


METHODS
In order to assess factors influencing image quality in kinematic CT studies, a phantom consisting of a polymethylmethacrylate rotating disk with round wells of different sizes was imaged with various acquisition protocols. Cadaveric acquisitions were performed on the ankle joint during motion in two different axes and at different speeds to allow validation of phantom data. Images were acquired with a 320 detector-row CT scanner and were evaluated by two readers.


RESULTS
Motion artefacts were significantly correlated with various parameters (movement axis, distance to centre, rotation speed and volume acquisition speed) (p < 0.0001). The relation between motion artefacts and distance to motion fulcrum was exponential (R20.99). Half reconstruction led to a 23 % increase in image noise and a 40 % decrease in motion artefacts. Cadaveric acquisitions confirmed phantom data. Based on these findings, high tube rotation speed and half reconstruction are recommended for kinematic CT. The axis of motion significantly influences image artefacts and should be considered in patient training and evaluation of acquisition protocol suitability.


CONCLUSIONS
This study provides evidence-based recommendations for musculoskeletal kinematic 4D-CT.


CONCLUSIONS
• Motion artefacts can hamper the quality and interpretation of dynamic joint studies • The recommendations presented here help increase image quality • Patient training and preparation can be improved • The artefact-free distance concept helps protocol adaptation and comparison.
Service D'imagerie Guilloz, CHRU-Nancy Hôpital Central, Nancy, F-54000, France. ped_gt@hotmail.com.
Pedro Augusto
PA
Gondim Teixeira
Service D'imagerie Guilloz, CHRU-Nancy Hôpital Central, Nancy, F-54000, France.
Anne-Sophie
AS
Formery
IADI U947, Université de Lorraine, Nancy, F-54000, France.|INSERM, CIC-IT 1433, Nancy, F-54000, France.
Gabriela
G
Hossu
IDCmem, 10 passage de liège, 54000, Nancy, France.
Daniel
D
Winninger
Service de radiologie, Hôpital de Mercy, 57085, Metz, France.
Toufik
T
Batch
Medical Imaging Department, Legouest Military Instruction Hospital, 27 Avenue de Plantières, BP 90001, 57077, Metz Cedex 3, France.
Alban
A
Gervaise
Service D'imagerie Guilloz, CHRU-Nancy Hôpital Central, Nancy, F-54000, France.
Alain
A
Blum
D000368:Aged; D000843:Ankle Joint / Q000000981:diagnostic imaging*; D016477:Artifacts; D001696:Biomechanical Phenomena; D002102:Cadaver; D019317:Evidence-Based Medicine; D056973:Four-Dimensional Computed Tomography / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D006801:Humans; D007592:Joint Diseases / Q000000981:diagnostic imaging; D008297:Male; D009068:Movement / Q000502:physiology*; D019047:Phantoms, Imaging
Evidence-based practice; Four-dimensional computed tomography; Joint kinematics; Motion artefacts; Multidetector computed tomography