KNEE ALIGNMENT SYSTEM (KAS) MRI Protocol

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Candace Haynes
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1 KNEE ALIGNMENT SYSTEM (KAS) MRI Protocol

2 Sample referral sticker Referral Sticker Insert here Corin 17 Bridge Street Pymble NSW Australia 2073 P: +61 (0) F: +61 (0) E: KNEE ALIGNMENT SYSTEM (KAS) MRI Protocol Contents 1. General Overview Pg 1 2. Acquisition Overview Pg Low Resolution Image Specifications (LR) Pg High Resolution Image Specifications (HD) Pg 4 3. File format and transfer Pg 7 4. Contact Pg 8

KNEE ALIGNMENT SYSTEM (KAS) Knee MRI Protocol This document contains the parameters and conditions to follow in order to obtain the desired quality of MRI images.

3 KNEE ALIGNMENT SYSTEM (KAS) Knee MRI Protocol This document contains the parameters and conditions to follow in order to obtain the desired quality of MRI images. These images are used to design a 3D model reconstruction of the knee joint in order to allow personalised preoperative planning and guides for the total knee replacement surgery. The following information concerns 1.5T or higher MRI. 1. General Overview We d like to focus on the knee joint cartilage visualisation, which is our main region of interest for the 3D model reconstruction. Attention: Images that do not conform to this protocol can NOT be accepted Here are the general requirements to apply to each patient s scan: The patient does not move during the whole exam; The coordinate system does not reset between scans; The 3 regions of interest to scan are: Hip Knee Ankle Phased array Knee coil Body Coil Body Coil Axial Sagittal Axial For any questions or clarification please contact your local Corin representative. 1 OPTWKIMF73 KAS MRI Protocol (Rev 1)

4 2. Acquisition Overview We d like to visualise the 3 anatomical areas with different levels of resolution an orientation. The acquisition of these areas is necessary to define the coordinate system for the implant positioning and to allow for the placement of the personalised guide. An amount of 3 scans are performed: One for the ankle region of interest with low resolution (LR) parameters and body coil. One for the knee region of interest with high definition (HD) parameters and dedicated knee coil. One for the hip region of interest with low resolution (LR) parameters and body coil. The 3 scan areas are scanned successively with the same coordinate system Take the ankle as origin Slices are parallel or perpendicular to the table. No oblique scan. Regions of interest should not be cut Name the protocol KAS Protocol. The scanning order is: 1. Ankle (LR) g 2. Knee (HD) g 3. Hip (LR) The origin of the coordinate should be displaced 10mm below the medial malleolus of the leg to be operated on. Between all scans, the coordinate system stay the same, it must not be reset. Use a localizer to find the regions of interest. If knee coil has to be removed after the HR scan do not reset coordinate system. The patient must not move between scans. It s recommened to use shimming. The acquisitions are made only on the leg needing surgery; the other leg should be as far away as possible. Place the patient so that the desired leg is at the isocenter. 2.1 Low Resolution Image Specifications (LR) Ankle/Hip common parameters: Slice thickness from 4 to 5mm; Spacing between slices is 2mm; Acquisition matrix of 256*256, no reconstruction; Region of interest visible on 20 slices; In phase TE; Do not allow patients to move between scans. Refer to Table 1. for Ankle and Hip Imaging specifications Refer to Table 2. for Low Resolution specific MRI parameters 2 OPTWKIMF73 KAS MRI Protocol (Rev 1)

Table 1: Ankle/Hip Imaging Specifications. Ankle Hip Region of Interest Coordinate System Set the coordinate system at the ankle joint. Do not reset coordinate system after ankle scan.

Capture from the heel to the distal part of Capture the entire femoral head of the the tibia (10cm above the ankle). Ensure the operative leg malleoli is captured of the operative leg.

5 Table 1: Ankle/Hip Imaging Specifications. Ankle Hip Region of Interest Coordinate System Set the coordinate system at the ankle joint. Do not reset coordinate system after ankle scan. Sequence 2D T1 fast spin echo sequence Plane Axial Axial FOV 260mm 360mm Weighting T1 weighted TR but a PD weighted TR T1 weighted TR would occur Saturation No saturation No saturation Anatomy Capture from the heel to the distal part of Capture the entire femoral head of the the tibia (10cm above the ankle). Ensure the operative leg malleoli is captured of the operative leg. Table 2: Low Resolution specific MRI parameters. Manufacturer GE Philips Siemens Toshiba Hitachi Sequence FSEXL TSE TSE FastSE PrimeFSE Options No Phase Wrap Fold Over Suppression Phase Oversampling Phase Wrap Suppression Anti Wrap 3 OPTWKIMF73 KAS MRI Protocol (Rev 1)

2.2 High Resolution Image Specifications (HD) 2.2.1 Knee Do not reset the coordinate system. Do not allow patients to move between scans.

6 2.2 High Resolution Image Specifications (HD) Knee Do not reset the coordinate system. Do not allow patients to move between scans. Use a 3D T1 spoiled gradient sequence, with fat saturation and/or water excitation, and the following parameters: Sagittal plane; ATR Orientation Gantry tilt 0 ; Slice thickness in regions of interest is 1mm; Slice increment is 1mm; Reconstruction matrix of 512*512; Pixel size to 0.4mm; Field of view (FOV) is 200mm; TR is T1 weighted, close to 20ms; TE is in phase, close to 7ms; Flip angle is close to 15 (refer to Table 3.); The complete heads of the knee joint bones are visible on 100 to 180 slices; Reduction: 1; Only use the options described in Table 3. High Resolution specific MRI parameters Scan the knee over 10cm on each side of the joint line. We want to see the entire anatomy of the bones in the joint: condyles, epicondyles and tibial tuberosity. A dedicated knee coil should be used in the majority of cases, the apex of the patella in its center. If phased array or flex type of coils, it must be positioned so the seams are posterior. 4 OPTWKIMF73 KAS MRI Protocol (Rev 1)

7 Table 3: High Resolution specific MRI parameters. Manufacturer GE Philips Siemens Toshiba Hitachi Sequence 3D T1 Vascular Fast TOF SPGR 3D T1 WATSc FFE 3D T1 VIBE 3D T1 RF Spoiled FE 3D T1 RSSG Flip Angle Bandwidth ~20 Default value Default value ~30 Options PURE Zip 512, ZIP 2 Whole gradient mode Fat Sat CLEAR ProSet Prescan Normalize Interpolation ON Normal gradient mode Distortion correction WE Weak Fat Sat Fine ON Averages 8channel coil or more : 1 Flex coil : 2 Body coil : 3 Strong Fat Sat Naturally Truncation ON WE For the 3D High Resolution Knee we d like to obtain these image characteristics: Black bone; Bright white cartilage; Well defined cartilage. Note: Refer to Table 4. for the Acceptance Criteria 5 OPTWKIMF73 KAS MRI Protocol (Rev 1)

8 Table 4: Acceptance Criteria Criteria Approve Reject Quality of scan 6 OPTWKIMF73 KAS MRI Protocol (Rev 1)

9 3. File format and transfer Note: Any problems with the imaging must be reported to your local Corin representative DICOM information All required MRI files (refer to Imaging Checklist on front page) should be saved in DICOM format and contain the following information: Patient name*, date of birth and gender Date of scan Operating surgeon Radiology practice name and location MRI machine model Note: *For patients in Australia, you may use the patient name *For patients in Europe, please use the Patient ID in the Patient surname field of the DICOM GenoMe ID in the Patient first name field of the DICOM Patient Identifier (ID) The Patient ID is an alphanumeric sequence in the format SURFIRYYYY where: SUR = first 3 letters of patient s surname FIR = first 3 letters of patient s first name YYYY = year of patient s date of birth Example: For patient John Smith DOB 19/08/1938 Patient ID = SMIJOH1938 GenoMe ID The GenoMe ID should be found in the referral. It is an alphanumeric sequence based on the patient gender and side of operative leg. The GenoMe ID is in the format GSXXXX where: G = M or F; gender is either M for male or F for female S = L or R; side of operative leg is either L for left or R for right XXXX = unique 4 digit integer Example: For a MALE patient whose LEFT leg is being operated on GenoMe ID = ML OPTWKIMF73 KAS MRI Protocol (Rev 1)

10 File transfer Three (3) methods of image transfer are available: Corin Portal Patient Archiving and Communication System (PACS) Mail images on a CD Electronic transfer of image data is the preferred method. Please contact your local Corin representative to set up access to one of the electronic file sharing methods listed above. Alternative means of image transfer must be discussed with your local Corin representative prior to sending images. If the referring surgeon requests a hardcopy or CD of the films, ensure that these are collected by the patient or sent directly to the referring surgeon. Do not send the hardcopy films to Corin. 4. Contact DICOM Images can be delivered at our Production Department by post mail to the address below or directly uploaded on our secured Corin Portal. For upload, images have to be compressed into one standard zip or rar file format. For any questions, additional information or remark, you can contact us at: Corin 17 Bridge Street Pymble NSW Australia 2073 P: +61 (0) F: +61 (0) E: KAS.customerservice@coringroup.com 8 OPTWKIMF73 KAS MRI Protocol (Rev 1)

11 1 Corin 17 Bridge Street Pymble NSW Australia 2073 P: +61 (0) F: +61 (0) E:

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