CT-guided quadratus femoris injection for ischiofemoral impingement.

OBJECTIVES: To describe the technique, efficacy, and safety of CT-guided quadratus femoris injection with corticosteroid and local anesthetic for the treatment of ischiofemoral impingement in a series of cases at our institution. METHODS: Cases of CT-guided quadratus femoris injections from 2000 to 2021 were identified in the enterprise-wide electronic medical record of our institution. Patient charts and our institutional picture archiving and communication system (PACS) were searched for demographics, pain level on a 0-10 scale before and immediately following the procedure, procedure technique, and follow-up outcomes if available. RESULTS: There were 13 cases among 12 patients with clinical and imaging findings of ischiofemoral impingement included in this study. Of the 12 patients, 10 were female and two were male. There were eight posterior approaches and five posterolateral approaches. Of the 13 cases, 11 resulted in immediate pain reduction. The median reduction in pain score was four (average 3.46, range 0-8.5). There was no statistically significant difference in pain reduction between the posterior approach cases and the posterolateral approach cases. No cases reported immediate complications or increases in pain score. Of the 12 cases, seven resulted in at least 1 month of pain relief, three had subsequent surgeries, and three had no follow-up. CONCLUSION: CT-guided quadratus femoris injection is safe and effective for treating ischiofemoral impingement. Further and larger scale study is needed to fully delineate differences in technique effectiveness. KEY POINTS: • CT-guided quadratus femoris injection is safe and effective for treating ischiofemoral impingement. • We found no statistically significant difference in pain reduction between the posterior approach and the posterolateral approach.

CSF-oma Identification With Nuclear Medicine Shunt-o-Gram.

A nuclear medicine shunt-o-gram is used to evaluate ventriculoperitoneal shunt patency and dispersion of radiotracer into the peritoneal cavity. A 73-year-old man presented with worsening memory, gait disturbance, and urinary incontinence. Shunt-o-gram revealed antegrade flow through the tubing and spillage into the peritoneal cavity without dispersion. CT confirmed a CSF-oma. Symptoms resolved after CSF-oma resection. Normal passage of radiotracer through the shunt without normal dispersion into the peritoneal cavity along with CT imaging correctly identified a CSF-oma. This is an unexpected complication of a shunt. Correct diagnosis on imaging likely saved this patient from unnecessary complete shunt revision.