A GE Revolution CT scanner (GE Healthcare,
Milwaukee,
US) with 16 cm detector was used.
Scan parameters were 120kV,
30mAs,
slice thickness 0.6,
collimation 160 mm and rotation time 0,28s.
Standard reconstruction algorithm was used.
After scanning the study was viewed on the CT work station,
selecting the best 2D,
3D and 4D images showing pathology.
Figure 1 shows (on the same coronal image) the location of two of the sagittal 4D reconstructions best showing the pathology.
The patient was prior to the 4D CT told to repeat the exact movement reproducing the reduced ROM,
making it possible to plan how to best place the patient properly on the CT table,
in order to perform the desired movement within the scanner.
During the repeated elbow movement,
continuous scanning was performed.
Figure 2 shows how the patient was placed in prone superman position during the scan.
The elbow to be examined rested on a piece of cloth,
while pillows were used to support the patient.
The examination started with the elbow in a semi-extended,
neutral position.
Since there was both restricted extension and flexion of the elbow,
the patient was told to first extend and then flex the joint during the CT-scan.
The examination started using countdown,
where the radiographer started the scan just prior to the patient starting the elbow movement.
To avoid artefacts from trembling,
the joint ROM was to be performed during a time of 6-7 seconds.
A clock placed on the CT table was used to help the patient to do the movement within that timeframe.
The patient,
an earlier athlete,
had some years ago sustained several injuries to the elbow,
resulting in OA.
Prior to surgery in 2014 and 2016,
and as follow up,
a total of three conventional CT scans was performed prior to this 4D CT scan.
On examination at time of the 4D CT,
the patient had ROM of 20-112,
pro-/supination: 49/91.