Keywords:
Bones, Artificial Intelligence, Pelvis, CT, Computer Applications-Virtual imaging, Surgery, Prostheses, Trauma
Authors:
M. Feeney1, M. Galea1, K. Phan2, A. Hardidge1; 1VIC/AU, 2NSW/AU
DOI:
10.26044/ranzcr2019/R-0093
Methods and materials
A retrospective series of CT pelvis studies were selected at random from existing studies performed at Austin Health. The following selection criteria were employed:
1.Studies were performed within the last 36 months;
2.Patients were aged between 65 and 75 at the time of the study;
3.Patients could not have bony malignancy of the pelvis, or the femur;
4. Patients could not have metalware in-situ.
Serial studies were assessed for eligibility by an unblinded assessor until 10 female and 10 male studies that met criteria were obtained. These studies were subsequently anonymised and randomised by assigning a them a number between 1 and 20. A blinded assessor who could only see the number assigned to each study then performed the same sequence of steps to each study using the CT viewer of Phillips Intellispace portal. The steps were as follows:
1.Axial slices were utilised to view the study in a 3D volume rendering application.
2.The window width and window level (WW/WL) were adjusted to increased and decreased in magnitude to remove all bone except the most dense portions such that only the thickest portion of the iliac wing remained on view.
3.The pelvis was rotated to a postero-lateral oblique view to bring that thickest portion of the iliac wing into profile to allow for measurement.
4.Measurement from ASIS to the iliac spine corresponding to the thickest portion, as well as from the pubic symphysis to the ASIS, and the pubic symphysis to the thickest portion of the iliac wing.
5.The following angles were then calculated:
-Coronal plane angle: degrees aimed medially from the drilling point of the tubercle of the iliac crest, in reference to a line from the pubic symphysis to central sacrum.
-Sagittal plane angle: degrees aimed posteriorly from the drilling point of the tubercle of the iliac crest in reference to a line from the ASIS to pubic symphysis.