geoffrey dick b.app.sci. (med.rad.) rmit deputy chief radiographer angliss hospital, melbourne ct supervisor angliss hospital, melbourne

Transcription

1 ct intervention tips geoffrey dick b.app.sci. (med.rad.) rmit deputy chief radiographer angliss hospital, melbourne ct supervisor angliss hospital, melbourne sessional lecturer monash university department of medical imaging & radiation sciences vsnmt education committee member 1 /46

2 objectives patient preparation ctf radiation dose reduction techniques step by step set-up/guide 2 /46

3 patient preparation 3 /46

4 interventional success everyone has a specific job to do! patient must be cooperative radiographer nurse radiologist 4 /46

5 patient preparation informed consent specific instructions blood clotting results fasting (13) 5 /46

6 contraindications abnormal clotting patient on anti-coagulants uncontrollable movement non-compliant patient 6 /46

7 nurse preparation consent form preparation sterile equipment set-up drapes drugs needles etc. 7 /46

8 radiologist preparation get off the phone! 8 /46

9 radiographer preparation previous films/imaging correct patient position respiration inspiration expiration quiet breathing 9 /46

10 scan set-up localise lesion view previous imaging! determine most appropriate needle path low dose target localisation scan must include skin edge! 10 /46

11 site preparation puncture site determined triple check location check image table position table position on gantry VERY important 11 /46

12 ct fluoroscopy (ctf) dynamic imaging, developed in 1993 by toshiba (2) ~8 frames per second real-time method quick-check method dose to patient and radiologist/nurse 12 /46

13 ctf 13 /46

14 limiting ctf radiation dose kvp examination time ma remember, radiation dose is accumulative! 14 /46

15 15 /46

16 technique example 16 /46

17 1 CTF CHEAT SHEET set-up CTF hand controller and for switch select correct patient, ORGAN = CTF select PROTOCOL SELECTION diamond correctly position patient, with table low in the gantry and zero table select correct body area in GROUP A perform DUAL scanograms (can have GRID on patient) click CONFIRM and move patient to scan scan correct area (including skin surface) with sticky BIOPSY GRID in situ using laser lights to position GRID click FILMING tab current patient will be displayed hit F4 on the keyboard to bring up patient's image folder select image group that you want displayed select TOOL2 and INSET (places scanogram in corner of image) click on inset image with left mouse button and use middle mouse to move image and left/middle to magnify choose correct level, close INSET application hit F2 to bring up measurement tool and select LINE measurement tool measure needle skin entry point to target, F7 to screen save with measurement on the desired image click SCAN tab and QUIT EXAM select correct CTF protocol ensure CTF patient orientation is correct 17 /46

18 2 CTF CHEAT SHEET click and select 3 boxes at top of CTF screen hit F4 and load screen save from previous step click and select bottom box on CTF screen scroll through images to select correct table position that matches screen save hit F1 on the keyboard to bring up MANUAL MOVE enter table position of desired screen save, hit ENTER press orange table move button to move to CTF location turn on gantry laser lights and click STOP SCAN use SHARPIE to mark up correct needle entry point on patients body, using grid and laser enter table position of ~ +/-600, hit orange table move button to move table out of gantry if using "true" CTF radiologist enables hand controller inside room TYPE in desired CTF table location in MANUAL MOVE, hit ENTER press ORANGE table move/tilt button on keyboard to move table to correct position change SLICE thickness or EXPOSURE if required perform interventional procedure to move patient out UNLOCK table using hand controller or gantry controls and PUSH table/patient out of gantry re-lock table QUIT CTF, QUIT manual move table window, QUIT EXAM, NEXT PATIENT TRANSFER image with needle position/tip to PACS PRINT image with needle position/tip for referrer 18 /46

19 ctf operator dose 19 /46

20 20 /46

21 21 /46

22 22 /46

23 ctf operator dose 23 /46

24 24 /46

25 25 /46

26 pre icrp msv icrp msv ctf icrp msv icrp msv 26 /46 icrp msv icrp msv

27 volume one shot 27 /46

28 28 /46

29 29 /46

30 30 /46

31 31 /46

32 pre-scan dose radiation dose reduction for ctf-guided ESI is best achieved by minimising the dose from the preliminary planning lumbar spine ct scan (25) 32 /46

33 pre-scan dose kvp ma scan range change detector configuration? not a diagnostic scan, just a map 33 /46

34 34 /46

35 35 /46

36 36 /46

37 pre-scan pre-scan 37 /46 icrp msv icrp msv icrp msv icrp msv

38 previous case kvp (for pre-scan & ctf) noise/sd x 80 mm 0.5 x 40 mm scan range 38 /46

39 Artner et. al Conclusion: Radiation dose of CT-guided SI joint injections can be decreased to levels of pulsed fluoroscopy with a precise intra- articular needle placement using the low-dose protocol. The technique is simple to perform, fast, and reproducible. 39 /46

40 take home messages planning, planning, planning dose reduction concentrate understand 40 /46

41 thanks andrew wilson alison stubbs (cook medical) 41 /46

42 references 1. Letourneau, Janis G. Percutaneous Biopsy of Abdominal Masses. Interventional Radiology. Williams and Wilkins. Baltimore, pp Maher, Kieran. CT Fluoroscopy. RMIT Computed Tomography Short Course Notes, July VanSonnenberg E, Lin AS, Deutsch AL, Mattrey RF. Percutaneous Biopsy of Difficult Mediastinal, Hilar, and Pulmonary Lesions by Competed Tomographic Guidance and a Modified Coaxial Technique. Radiology 1983 (148): Klein JS, Salomon G, Stewart EA. Transthoracic Needle Biopsy with a Coaxially Placed 20-gauge Automated Cutting Needle: Results in 122 Patients. Radiology 1996 (198): Nashed Z, Klein JS, Zarka MA. Special Techniques in CT-Guided Transthoracic Needle Biopsy. AJR 1998 (171): Sheiman RG, Fey C, McNicholas M, Raptopoulos F. Possible Cause of Inconclusive Results on CT- Guided Thoracic and Abdominal Core Biopsies. AJR 1998 (170): Silverman SG, Tuncali K, Adams DF, Nawfel RD, Zou KH, Judy PF. CT Fluoroscopy-guided Abdominal Interventions: Techniques, Results, and Radiation Exposure. Radiology 1999 (212): /46

43 references 8. Kazerooni EA, Lim FT, Mikhail A, Martinez FJ. Risk of Pneumothorax in CT-guided Transthoracic Needle Aspiration Biopsy of the Lung. Radiology 1996 (198): Westcott JL, Rao N, Colley DP. Transthoracic Needle Biopsy of Small Pulmonary Nodules. Radiology 1997 (202): Sheafor DH, Paulson EK, Kliewer MA, DeLong DM, Nelson RC. Comparison of Sonographic and CT Guidance Techniques. AJR 2000 (174): Gobien RP, Stanley JH, Vujic I, Gobien BS. Thoracic Biopsy: CT Guidance of Thin-Needle Aspiration. AJR 1984 (142): Khouri NF, Stitik FP, Erozan YS, Gupta PK, Kim WS, Scott WW, Hamper UM, Mann RB, Eggleston JC, Baker RR. Transthoracic Needle Aspiration Biopsy of Benign and Malignant Lung Lesions. AJR 1985 (144): Tarver RD, Kreipke DL, Conces DJ, Becker GJ. Interventional Radiology of the Chest. Interventional Radiology. Williams and Wilkins. Baltimore, /46

44 references 14. Silverman SG, Bloom DA, Seltzer SE, Tempany CMC, Adams DF. Needle-Tip Localization During CT- Guided Abdominal Biopsy: Comparison of Conventional and Spiral CT. AJR 1992 (159): Nawfel RD, Judy PF, Silverman SG, Hooton S, Tuncali K, Adams DF. Patient and Personnel Exposure during CT Fluoroscopy-guided Interventional Procedures. Radiology 2000 (216): Cox JE, Chiles C, McManus CH, Aquino SL, Choplin RH. Transthoracic Needle Aspiration Biopsy: Variables That Affect Risk of Pneumothorax. Radiology 1999 (212): Daly B & Templeton PA. Real-time CT Fluoroscopy: Evolution of an Interventional Tool. Radiology 1999 (211): Swerdlow DR & Thaete FL. CT-Guided Core Biopsy of Difficult Lesions: A Modified Coaxial Approach. AJR 1994 (163): Daly B, Krebs TL, Wong-You-Cheong JJ, Wang SS. Percutaneous Abdominal and Pelvic Interventional Procedures Using CT Fluoroscopy Guidance. AJR 1999 (173): Harter LP, Moss AA, Golberg HI, Gross BH. CT-Guided Fine-Needle Aspirations for Diagnosis of Benign and Malignant Disease. AJR 1983 (140): /46

45 references 21. Alfidi RJ, Haaga JR, Meaney TF et al. Computed Tomography of the Thorax and Abdomen. Radiology 1975 (117): Westcott JL. Direct Percutaneous Needle Aspiration of Localized Pulmonary Lesions: Results in 422 Patients. Radiology 1980 (137): Chapman S & Nakielny R. A Guide To Radiological Procedures. Bailliere Tindal, London, Solomon, S. B., et al. (2002). "Robotically driven interventions: a method of using CT fluoroscopy without radiation exposure to the physician." Radiology 225(1): Hoang, J. K., et al. (2011). "Radiation dose exposure for lumbar spine epidural steroid injections: a comparison of conventional fluoroscopy data and CT fluoroscopy techniques." AJR Am J Roentgenol 197(4): Artner, J., F. Lattig, H. Reichel and B. Cakir (2012). "Effective radiation dose reduction in computed tomography-guided spinal injections: a prospective, comparative study with technical considerations." Orthop Rev (Pavia) 4(2): e Hayot M, Michaud A, Koechlin C, Caron MA, Leblanc P, Prefaut C, et al. Skeletal muscle microbiopsy: a validation study of a minimally invasive technique. The European respiratory journal. 2005;25(3): /46

46 references 27. Hayot M, Michaud A, Koechlin C, Caron MA, Leblanc P, Prefaut C, et al. Skeletal muscle microbiopsy: a validation study of a minimally invasive technique. The European respiratory journal. 2005;25(3): /46