title: Impact of non-contrast enhanced volumetric MRI-based feeder localization in the treatment of spinal dural arteriovenous fistula.
abstract: BACKGROUND
  The preoperative localization of the feeder of spinal dural arteriovenous fistula (SDAVF) could simplify the diagnostic spinal angiographic procedure. Localization by non-contrast-enhanced MRI-based techniques is an attractive option. However, the usefulness of such an approach for evaluation of SDAVF has not yet been reported.
  
  
  OBJECTIVE
  To study the impact of non-contrast MRI-based feeder localization, followed by targeted spinal angiography, in the evaluation of SDAVF before endovascular intervention.
  
  
  METHODS
  Prospectively collected data were analyzed and the level of the feeder was localized preoperatively. The procedural time for targeted spinal angiography was calculated and compared with that of a historical cohort, who underwent routine spinal angiographic examination before the study period. Follow-up MRI was carried out to assess the reliability of this model for detection of occasional metachronous lesions that might be missed with this approach.
  
  
  RESULTS
  Seven patients underwent targeted spinal angiography during the study. The feeder level was accurately identified in five patients and was localized to one vertebral level in six patients. The correlation between MRI and DSA was statistically significant. The number of spinal levels assessed was fewer and overall procedure time was significantly shorter compared to historical cohort (58 min vs 162 min, respectively; p<0.001). Intervention was coupled with targeted angiography in two patients. Follow-up MRI demonstrated flow voids in one patient, who had recurrent fistula at one vertebral level below the previously embolized feeder.
  
  
  CONCLUSIONS
  The non-contrast MRI-based localization technique can reliably detect the level of feeder and help in therapeutic planning of SDAVF. The localization techniques potentially shorten the angiographic procedure and may facilitate simultaneous endovascular definitive treatment. Inclusion of follow-up MRI may be useful for detection of synchronous or metachronous lesions if a targeted approach is adopted. Additionally, this helps to identify failed endovascular therapy.
authors: Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India.
authors: Santhosh Kumar
authors: SK
authors: Kannath
authors: Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India.
authors: Bejoy
authors: B
authors: Thomas
authors: Achutha Menon Center for Health Sciences Studies, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India.
authors: P
authors: P
authors: Sankara Sarma
authors: Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum, Kerala, India.
authors: Jayadevan
authors: J
authors: Enakshy Rajan
mesh_terms: D000328:Adult; D000368:Aged; D015901:Angiography, Digital Subtraction; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging* / Q000601:surgery*; D004621:Embolization, Therapeutic; D057510:Endovascular Procedures / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013116:Spinal Cord; D013131:Spine / Q000000981:diagnostic imaging; D016896:Treatment Outcome
keywords: Fistula; Intervention; MRI; Spine