Note: Please see pages ii , iii for a list of anatomic terms/abbreviations used throughout this book.

Book Format

Chapters are grouped into sections and are color coded according to the body region, with colors along the book’s edge for easy reference. The Expert Consult online version of the book includes bonus chapters and relevant videos.

The atlas starts with introductory chapters, including needle techniques, fluoroscopic and ultrasound pearls, and patient and radiation safety. The procedural techniques are arranged from the typically safer lumbosacral region procedures to the more complex cervical and atlanto-occipital region procedures. Towards the end of the Atlas, we include sections with interventions for structures that masquerade as spinal conditions.

A final appendix of reference tables has also been included, with an antiplatelet/anticoagulant discussion, a steroid equivalency table, a local anesthetic dose reference guide, an intrathecal contrast and dose reference, and suggestions for premedication for those with a history of contrast reactions. These tables are provided as a reference guide but may be subject to change as new studies and guidelines are published. While every attempt was made to provide evidence-based recommendations, each patient situation should be weighed individually.

This introductory chapter will assist the reader in making the most of this atlas. Image-guided interventional procedures can be performed more efficiently, accurately, and safely with consistent application of disciplined principles and consistent algorithmic methodology.

For each procedure, we provide relevant fluoroscopic and/or ultrasound images with anatomic diagrams and photographs for appropriate landmark identification. A consistent set of procedural views throughout the atlas is denoted by the icons shown below. The “setup” for each technique is demonstrated. Multiplanar imaging will also be emphasized. Ideal needle positioning before contrast injection, optimal and suboptimal contrast flow patterns (under fluoroscopy), and needle positions are shown. Most importantly, safety issues, anatomic concerns, common pitfalls, and “pearls” are highlighted.

Individual or combined introductions for each chapter, or set of chapters, are provided with associated bibliographies and references.

The list of collective anatomic terms/abbreviations is provided in the front matter of this atlas.

Trajectory View: “Setup Is Key”

The fluoroscopic trajectory view, which is also known as the hubogram, hub view, needle view, “ down-the-barrel,” or coaxial view, provides the initial orientation for needle placement and advancement. Because proper setup is so imperative, we cannot overemphasize this view’s importance. In this view, the interventionalist directly visualizes the needle’s path to the final target. Instead of estimating the needle’s trajectory, an unobstructed needle pathway is visualized, and an associated needle entry point is identified ( Fig. 1.1 ). An initial trajectory view can be identified for almost all procedures found in this atlas. The trajectory view is typically used only for initial setup and needle placement. On occasion, the trajectory view can also be one of the final multiplanar views and will be so indicated.

A sample page that demonstrates the fluoroscopic trajectory view; note the Trajectory View icons. The trajectory view provides the initial orientation for needle placement and advancement for almost all fluoroscopic procedures found in this atlas. Note how the fluoroscopic image ( top left ), radiopaque ( top right ), and radiolucent structures ( bottom left ) are shown for most figures in this atlas. When there is a safety view, it is outlined with a yellow banner, and the safety considerations are listed. In particular, radiolucent structures that should be avoided are shown and described. Note that we typically label the associated drawing and not the fluoroscopic image.

The setup is obtained by appropriately positioning the fluoroscope relative to the patient. The fluoroscopic image produced using this C-arm position will be depicted via the Trajectory View icon. The ease and timeliness of a procedure will be heavily dependent on an appropriate trajectory view setup.

For most trajectory and multiplanar fluoroscopic images found in this atlas, a similar format will be used. The top left picture will be the actual fluoroscopic image. To the right, a drawing with radiopaque structures (that you can see) is outlined and labeled. At the bottom, a drawing with radiolucent structures (that you cannot see) is outlined and labeled. The needle and hub are green in all atlas drawings. When there is a “safety view,” the safety considerations are listed. In particular, lucent structures that should be avoided are shown and described.

In the trajectory view, the needle is placed parallel to the direction of the fluoroscopic beam (i.e., perpendicular to the image intensifier’s surface), and a coaxial image of the needle is obtained ( Fig. 1.2 ). On initial placement, the needle should be advanced just deep enough so that it takes sufficient hold (i.e., purchase) in the soft tissues to remain in a stable position. A “hubogram” should be obtained early, before significantly advancing the needle along its trajectory . As intermittent fluoroscopic imaging confirms the needle advancement parallel to the fluoroscope beam, minor trajectory adjustments are made to maintain the needle shaft parallel to the X-ray beam.

To effectively use the trajectory view, the needle is placed parallel to the direction of the fluoroscopic beam (i.e., perpendicular to the image intensifier’s surface, the pink line simulated here), and a coaxial image of the needle is obtained. Static pictures are taken, and minor adjustments can still be made to keep the needle parallel to the X-ray beam.

In most cases, the hub view is only used to identify the needle starting point and trajectory angle relative to the patient. After the needle is advanced sufficiently to stay along its intended trajectory, additional multiplanar views are used for further advancement, as described later in this chapter. Occasionally, the trajectory view is also one of the final multiplanar views. For example, the lumbar zygapophyseal joint nerve block target (i.e., the “eye or eyebrow of the Scotty dog”) can be visualized on the oblique trajectory view. For most other procedures (e.g., the lumbar transforaminal epidural), the trajectory view is not used as one of the final multiplanar views.

Multiplanar Views

When the needle tip is perceived to be close to its target, a minimum of two (multiplanar) views is necessary to confirm its position. Only by obtaining two or more views can the needle tip position be accurately triangulated. It is important to confirm the needle tip position prior to contrast instillation to avoid obscuring the image and/or potential harm. Although the final views are typically the anteroposterior and lateral views, there are some procedures with other recommended multiplanar views (i.e., oblique) that we recommend for needle tip position and/or contrast confirmation. This will be described in the respective chapters.