Fluoroscopy- and CT-Guided Gold Fiducial Marker Placement for Intraoperative Localization during Spinal Surgery: Review of 179 Cases at a Single Institution-Technique and Safety Profile.

BACKGROUND AND PURPOSE: Wrong-level spinal surgery, especially in the thoracic spine, remains a challenge for a variety of reasons related to visualization, such as osteopenia, large body habitus, severe kyphosis, radiographic misinterpretation, or anatomic variation. Preoperative fiducial marker placement performed in a dedicated imaging suite has been proposed to facilitate identification of thoracic spine vertebral levels. In this current study, we report our experience using image-guided percutaneous gold fiducial marker placement to enhance the accuracy and safety of thoracic spinal surgical procedures. MATERIALS AND METHODS: A retrospective review was performed of all fluoroscopy- or CT-guided gold fiducial markers placed at our institution between January 3, 2019, and March 16, 2022. A chart review of 179 patients was performed detailing the procedural approach and clinical information. In addition, the method of gold fiducial marker placement (fluoroscopy/CT), procedure duration, spinal level of the gold fiducial marker, radiation dose, fluoroscopy time, surgery date, and complications (including whether wrong-level surgery occurred) were recorded. RESULTS: A total of 179 patients (104 female) underwent gold fiducial marker placement. The mean age was 57 years (range, 12-96 years). Fiducial marker placement was performed by 13 different neuroradiologists. All placements were technically successful without complications. All 179 (100%) operations were performed at the correct level. Most fiducial markers (143) were placed with fluoroscopy with the most common location at T6-T8. The most common location for placement in CT was at T3 and T4. CONCLUSIONS: All operations guided with gold fiducial markers were performed at the correct level. There were no complications of fiducial marker placement.

Percutaneous CT-Guided Core Needle Biopsies of Head and Neck Masses: Review of 184 Cases at a Single Academic Institution, Common and Special Techniques, Diagnostic Yield, and Safety.

BACKGROUND AND PURPOSE: Percutaneous CT-guided core needle biopsies of head and neck lesions can be safely performed with vigilant planning. This largest-to-date single-center retrospective study evaluates multiple approaches with consideration of special techniques and examines the histopathologic yield. MATERIALS AND METHODS: Retrospective review of CT-guided core biopsies of head and neck lesions from January 1, 2010, to October 30, 2020, was performed. We recorded the following: patient demographics, sedation details, biopsy needle type and size, lesion location and size, approach, patient positioning, preprocedural intravenous contrast, proceduralists' years of experience, complications, and pathology results. RESULTS: One hundred eighty-four CT-guided core biopsies were evaluated. The initial diagnostic yield was 93% (171/184). However, of 43/184 (23%) originally "negative for malignancy" biopsies, 4 were eventually positive for malignancy via rebiopsy/excision, resulting in a 2% false-negative rate and an adjusted total diagnostic yield of 167/184 (91%). Biopsies were performed by 16 neuroradiologists with variable experience. The diagnostic yield was essentially the same: 91% (64/70) for proceduralists with ≤3 years' experience, and 90% (103/114) with >3 years' experience. The diagnostic yield was 93% (155/166) for lesions of >10 mm. The diagnostic yield per biopsy needle gauge was the following: 20 ga, 81% (13/16); 18 ga, 93% (70/75); 16 ga, 90% (64/71); and 14 ga, 91% (20/22). There were 4 asymptomatic hematomas, with none requiring intervention. CONCLUSIONS: Percutaneous CT-guided core needle biopsies are safe procedures for superficial and deep head and neck lesions with a high diagnostic yield. Careful planning and special techniques may increase the number of lesions accessible percutaneously while minimizing the risk of complications.

Time to Resolution of Inadvertent Subdural Contrast Injection during a Myelogram: When Can the Study Be Reattempted?

BACKGROUND AND PURPOSE: Inadvertent subdural contrast injections can occur during any myelogram. Currently, there are no guidelines defining when residual subdural iodinated contrast will be cleared and no longer interfere with subsequent procedure and imaging. We investigated the time to resolution of subdural contrast using a 2-day lateral decubitus digital subtraction myelogram and associated CT myelogram data in patients undergoing evaluation for spontaneous intracranial hypotension. MATERIALS AND METHODS: Retrospective review of 63 patients with lateral decubitus digital subtraction myelograms from September 4, 2018, to October 1, 2019, was performed. Patients with 2-day lateral decubitus digital subtraction myelograms on 2 consecutive days, with or without a same-day CT myelogram on day 1 and with a same-day CT myelogram on day 2, were included. Patients with next-day CT covering at least the abdomen and pelvis after either-day injection were also included. In cases of subdural injection, next-day CT scans were evaluated for residual subdural contrast. RESULTS: Of 49 included patients, 5 had subdural injection on day 1, with the second-day CT myelogram available for review. One of these 5 patients had subdural injections on 2 different days and subsequently had chest/abdomen/pelvis CTA a day after the second subdural injection. In all 6 cases of subdural injections, there was complete resolution of subdural contrast on the next-day CT, with the shortest time to resolution of approximately 20.5 hours (range, 20.5-28.5 hours). CONCLUSIONS: Our study suggests that resolution of inadvertently injected subdural contrast occurs within 1 day, and the myelogram can be reattempted as early as the next day.

Lateral Decubitus Digital Subtraction Myelography: Tips, Tricks, and Pitfalls.

Digital subtraction myelography is a valuable diagnostic technique to detect the exact location of CSF leaks in the spine to facilitate appropriate diagnosis and treatment of spontaneous spinal CSF leaks. Digital subtraction myelography is an excellent diagnostic tool for assessment of various types of CSF leaks, and lateral decubitus digital subtraction myelography is increasingly being used to diagnose CSF-venous fistulas. Lateral decubitus digital subtraction myelography differs from typical CT and fluoroscopy-guided myelograms in many ways, including equipment, supplies, and injection and image-acquisition techniques. Operators should be familiar with techniques, common pitfalls, and artifacts to improve diagnostic yield and prevent nondiagnostic examinations.