ORTHOBALTIC CT SCAN PROTOCOL FOR ANATOMICAL 3D RECONSTRUCTION

ORTHOBALTIC CT SCAN PROTOCOL FOR ANATOMICAL 3D RECONSTRUCTION

CONTENT HIP JOINT 3D RECONSTRUCTION... 3 PELVIS 3D RECONSTRUCTION... 4 KNEE JOINT 3D RECONSTRUCTION... 5 SHOULDER 3D RECONSTRUCTION... 6 SKULL 3D RECONSTRUCTION... 7 INTERNAL ORGANS, VASCULAR STRUCTURES, RIBS AND SPINE 3D RECONSTRUCTION... 8

The quality of CT data is the essential part of creating accurate anatomical individual 3D reconstruction model and patient matching implant. Consequently, it is very important to follow this protocol with recommendations when scanning a patient. Please read it carefully and do not hesitate to contact Baltic Orthoservice on +370 37 473970 or info@balticimplants.eu with any questions or concerns related scanning procedure. General notes This scanning protocol should be followed for scans that are going to be used to create virtual three-dimensional models of patient s anatomical structures. This protocol is substantiated with experimental research, during which a scanner LightSpeed VCT (64 Slice) was used; and with literature research and analysis as well. Protocol consists of recommended CT parameter values, so it is advisable to consult a radiological specialist before scaning. Baltic Orthoservice understands concerns about keeping the radiation dose to patients as low as reasonably achievable, therefore please apply these guidelines as appropriate to your patients. If it s not possible to follow scan protocol instructions, please by all means contact us before scanning. General guidelines Gantry tilt must be 0 during the scan. A high resolution 512 x 512 pxl matrix should be used whenever possible. Recommended voltage: 120 kv. Align the patient in a way that prevents as many artifacts as possible in the images. Patient should be lying on the back fully straight; both legs nicely mutually aligned so that knee patellas (if possible) are parallel to scanning table; no unnatural tilt or lift of the pelvis area; arms folded upward away from the pelvis. Patient must remain completely still during entire scan procedure. Image distortion from patient motion can damage the accuracy of a virtual model, therefore images with motion artifacts will not be accepted. If patient motion occurs, the scan must be restarted. We require to archive entire original study (not reformatted!). All slices must be contiguous or overlapping. Entire original study (axial images) must be archived in uncompressed DICOM format on CD or DVD. It is also possible to transfer image data via computer network (for example, using www.wetransfer.com service). Otherwise contact our technicians.

HIP JOINT 3D RECONSTRUCTION Patient s legs are fully straight parallel to the scanning table Anterior surface of the knee patellas should be as parallel to scanning table as possible Feet are perpedicular to scanning table Arms folded upward away from the pelvis Start: top to illiac crest Ending: ending slice at least few centimeters below the lesser trochanter If it is required to evaluate fermur anetversion angle, distal femur condyles must be in the scanning zone. Slice thickness: 0.625 mm Voltage: 80 ma (for patient without metallic implants), 99 ma (for patient with metallic implants) or closest parameter value Field of view: at least 38 cm (depending on patient size) Algorithm: BONE

PELVIS 3D RECONSTRUCTION Patient s legs are fully straight parallel to the scanning table Anterior surface of the knee patellas should be as parallel to scanning table as possible Feet are perpedicular to scanning table Arms folded upward away from the pelvis Start: top to illiac crest Ending: Ending slice just below iscial tuberosity Slice thickness: 0.625 mm Voltage: 80 ma (for patient without metallic implants), 99 ma (for patient with metallic implants) or closest parameter value Field of view: At least 38 cm (depending on patient size) Algorithm: BONE

KNEE JOINT 3D RECONSTRUCTION Patient s legs are fully straight parallel to the scanning table Anterior surface of the knee patellas should be as parallel to scanning table as possible Feet are perpedicular to scanning table Start: not less than 10 cm above knee joint Ending: Ending slice 5cm below tibial tuberosity Slice thickness: 0.625 mm Voltage: 80 ma (for patient without metallic implants), 99 ma (for patient with metallic implants) or closest parameter value Field of view: at least 28 cm (depending on patient size) Algorithm: BONE

SHOULDER 3D RECONSTRUCTION Patient s legs are fully straight parallel to the scanning table Central facial line must coincide with sagittal plane Palms facing upwards Start: Above acromion process Ending: 15cm below the head of humerus Slice thickness: less or equal to 1.000 mm Voltage: 80 ma (for patient without metallic implants), 99 ma (for patient with metallic implants) or closest parameter value Field of view: less or equal to 25 cm (depending on patient size) Algorithm: BONE

SKULL 3D RECONSTRUCTION Occlusal plane should be parallel to the gantry (image plane) Central facial line must coincide with sagittal plane Start: at least 3 cm above highest point of the skull Ending: few centimeters below the lowest point of the mandible Slice thickness: 0.625 mm Voltage: 60 80 ma Field of view: is chosen depending on patient size and should include external patient s contour and whole area of interest. However, FOV should not exceed 30 cm Algorithm: BONE

INTERNAL ORGANS, VASCULAR STRUCTURES, RIBS AND SPINE 3D RECONSTRUCTION Patient s legs are fully straight parallel to the scanning table Occlusal plane should be parallel to the gantry (image plane) Palms facing upwards Start: Above acromion process. If interest of area includes cervical vertebrae, start must be above the first vertebra, including craniovertebral junction Ending: below coccyx Slice thickness: less or equal to 2.500 mm If the area of interest is smaller, slice thickness must be less or equal to 1.000 mm Voltage: 60 120 ma Field of view: is chosen depending on patient size and should include external patient s contour and whole area of interest. Algorithm: BONE (for bone structures reconstruction), STANDARD or SOFT TISSUE, depending on tissue or structure type to be used for 3D reconstruction. If 3D reconstruction of aorta aor other vascular structures is required, perform CT angiogram (CTA) with specific contrast agents.