CT-Fluoroscopic Cervical Transforaminal Epidural Steroid Injections: Extraforaminal Needle Tip Position Decreases Risk of Intravascular Injection.

BACKGROUND AND PURPOSE: Cervical transforaminal epidural steroid injections are commonly performed for temporary pain relief or diagnostic presurgical planning in patients with cervical radiculopathy. Intravascular injection of steroids during the procedure can potentially result in cord infarct, stroke, and even death. CT-fluoroscopy allows excellent anatomic resolution and precise needle positioning. This study sought to determine the safest needle tip position during CT-guided cervical transforaminal epidural steroid injection as determined by the incidence of intravascular injection. MATERIALS AND METHODS: We retrospectively evaluated procedural imaging for consecutive single-site CT-fluoroscopic cervical transforaminal epidural steroid injection performed during a 13-month period. Intravascular injections were identified and classified by volume, procedure phase, vessel type, and needle tip position relative to the targeted neural foramen. ANOVA, Wilcoxon, or Pearson χ(2) testing was used to assess differences among groups as appropriate. RESULTS: Intravascular injections occurred in 49/201 (24%) procedures. Of the intravascular injections, 13/49 (27%) were large, 10/49 (20%) were small, and 26/49 (53%) were trace volume. Sixteen of 49 (33%) intravascular injections occurred with a trial contrast dose; 27/49 (55%), with a steroid/analgesic cocktail; and 6/49 (12%), with both. Twenty-seven of 49 (55%) intravascular injections were likely venous, 22/49 (45%) were indeterminate, and none were likely arterial. The intravascular injection rate was significantly lower (P < .001) for the extraforaminal needle position (8/82, 10%) compared with junctional (27/88, 31%) and foraminal (14/31, 45%) needle tip positions. CONCLUSIONS: An extraforaminal needle position for CT-guided cervical transforaminal epidural steroid injection decreases the risk of intravascular injection and therefore may be safer than other needle tip positions.

Image-guided percutaneous disc sampling: impact of antecedent antibiotics on yield.

AIM: To evaluate the effect of antecedent antimicrobial therapy on diagnostic yield from percutaneous image-guided disc-space sampling. MATERIALS AND METHODS: A retrospective review of the electronic health records of all patients who underwent image-guided percutaneous sampling procedures for suspected discitis/osteomyelitis over a 5-year period was performed. One hundred and twenty-four patients were identified. Demographics, medical history, and culture results were recorded as well as duration of presenting symptoms and whether antecedent antibiotic therapy had been administered. RESULTS: Of the 124 patients identified who underwent image-guided percutaneous disc-space sampling, 73 had received antecedent antibiotic treatment compared with 51 who had not. The overall positive culture rate for the present study population was 24% (n=30). The positive culture rate from patients previously on antibiotics was 21% (n=15) compared with 29% (n=15) for patients who had not received prior antibiotic treatment, which is not statistically significant (p=0.26). Eighty-six percent (n=63) of patients who had antecedent antibiotics received treatment for 4 or more days prior to their procedure, whereas 14% (n=10) received treatment for 1-3 days prior to their procedure. The difference in culture positivity rate between these two groups was not statistically significant (p=0.43). Culture results necessitated a change in antibiotic therapy in a third of the patients who had received antecedent antibiotic therapy. CONCLUSION: Antecedent antibiotic therapy, regardless of duration, did not result in significantly diminished diagnostic yield from percutaneous sampling for suspected discitis/osteomyelitis. The present results suggest that percutaneous biopsy may nonetheless yield positive diagnostic information despite prior antimicrobial therapy. If the diagnostic information may impact choice of therapeutic regimen, percutaneous biopsy should still be considered in cases where there is a history of prior antimicrobial therapy.

Diffusivity measurements differentiate benign from malignant lesions in patients with peripheral neuropathy or plexopathy.

BACKGROUND AND PURPOSE: Peripheral nerve disorders caused by benign and malignant primary nerve sheath tumors, infiltration or compression of nerves by metastatic disease, and postradiation neuritis demonstrate overlapping features on conventional MR imaging but require vastly different therapeutic approaches. We characterize and compare diffusivities of peripheral nerve lesions in patients undergoing MR neurography for peripheral neuropathy or brachial or lumbosacral plexopathy. MATERIALS AND METHODS: Twenty-three patients, referred for MR neurography at our institution between 2003 and 2009 for a peripheral mononeuropathy or brachial or lumbosacral plexopathy and whose examinations included DWI, received a definitive diagnosis, based on biopsy results or clinical and imaging follow-up, for a masslike or infiltrative peripheral nerve or plexus lesion suspicious for tumor. Mean ADC values were determined within each lesion and compared across 3 groups (benign lesions, malignant lesions, and postradiation changes). RESULTS: Both ANOVA and Kruskal-Wallis tests demonstrated a statistically significant difference in ADC values across the 3 groups (P = .000023, P = .00056, respectively). Post hoc pair-wise comparisons showed that the ADC within malignant tumors differed significantly from that within benign tumors and postradiation changes. ADC within benign tumors and postradiation changes did not differ significantly from each other. CONCLUSIONS: DWI may be highly effective for the differentiation of benign from malignant peripheral nerve masslike or infiltrative lesions.