SIR 2024
General IR
Anna M. Sorensen, MD, MSc (she/her/hers)
Resident
University of Wisconsin Hospital and Clinics
Financial relationships: Full list of relationships is listed on the CME information page.
Annie M. Zlevor (she/her/hers)
Medical Student
University of Wisconsin School of Medicine and Public Health
Financial relationships: Full list of relationships is listed on the CME information page.
Meridith A. Kisting, MA (she/her/hers)
Research Assistant
University of Wisconsin Hospitals and Clinics
Financial relationships: Full list of relationships is listed on the CME information page.
Allison Couillard, MD
Resident
University of Wisconsin Hospitals and Clinics
Disclosure information not submitted.
Timothy J. Ziemlewicz, MD
Associate Professor of Radiology
University of Wisconsin Hospital and Clinics
Disclosure information not submitted.
Giuseppe V. Toia, MD, MS
Assistant Professor
University of Wisconsin Hospital and Clinics
Disclosure information not submitted.
J. Louis Hinshaw, MD
Professor
University of Wisconsin School of Medicine and Public Health
Disclosure information not submitted.
Lindsay Stratchko, DO
Assistant Professor
University of Wisconsin-Madison
Disclosure information not submitted.
Perry Pickhardt, MD
Professor
University of Wisconsin Hospitals and Clinics
Disclosure information not submitted.
Marcia Foltz, RN
Registered Nurse
University of Wisconsin Hospitals and Clinics
Disclosure information not submitted.
Walter W. Peppler, PhD
Professor
University of Wisconsin School of Medicine and Public Health
Disclosure information not submitted.
Fred T. Lee, Jr., MD
Professor of Radiology, Biomedical Engineering, and Urology
University Of Wisconsin
Financial relationships: Full list of relationships is listed on the CME information page.
Erica M. Knavel Koepsel, MD (she/her/hers)
Assistant Professor of Radiology
University of Wisconsin-Madison
Disclosure information not submitted.
(1) Review the equipment, procedural steps, and indications for percutaneous needle placement using electromagnetic CT navigation (E-CTN) via a pictorial case-based approach. (2) Outline the advantages of E-CTN. (2) Understand the disadvantages and pitfalls of E-CTN to avoid procedural error and ensure diagnostic adequacy.
Background: There is increased demand for CT-guided procedures, sometimes in relatively challenging anatomic locations. The recent introduction of several new CT navigation (CTN) tools may help overcome some of the limitations of historical CT guidance techniques. CTN systems combine the advantages of conventional CT guidance and CT Fluoroscopy (CTF) for more advanced percutaneous needle placement. E-CTN systems specifically use electromagnetic sensors placed on the patient and needle, combined with fiducials placed within the scan field to localize a needle which is then superimposed onto a CT dataset for real-time needle guidance. Advantages of E-CTN over conventional CT/CTF guidance include the ability to use virtually any puncture angle, with a recent report showing 50% of E-CTN procedures were performed at an angle greater than 10 degrees {1}. E-CTN is also highly efficient due to the need for fewer average check scans when compared to conventional CT guidance (3 checks vs. 9) {1}. Despite the diagnostic-level images used for E-CTN, the mean reported effective radiation dose to the physician was very low compared to CTF (0.4 vs 1.2 microGy) {1}. Considerations when utilizing CTN tools include an initial learning curve, less accurate needle position if the needle bends or becomes displaced from the guide, or if the fiducial gets displaced or the patient changes position.
Clinical Findings/Procedure Details: This exhibit will include a pictorial review of how E-CTN is set up, as well as utilize saliant cases to highlight the advantages and indications of E-CTN for percutaneous needle placement. Important pitfalls and considerations will also be highlighted using a pictorial format to aid interventionalists in utilizing E-CTN.
Conclusion and/or Teaching Points: E-CTN affords the interventionalist many advantages; including real-time needle tracking using a contemporaneous high-quality CT dataset with the patient in the treatment position, reduced radiation to the physician, facilitation of procedures outside of the gantry plane, fewer helical scans during needle placement, and needle guidance based on diagnostic-quality CT datasets. An understanding of the disadvantages and considerations when using E-CTN will help the interventionalist avoid errors and ensure diagnostic adequacy.