Zalewski NL, et al. - The current study characterizes a unique pattern of spinal cord gadolinium enhancement on magnetic resonance imaging (MRI) in spinal dural arteriovenous fistula (sDAVF). In a large control group of patients with other myelopathy, this unique gadolinium enhancement pattern in sDAVF was not seen. For patients with an sDAVF, identifying the missing-piece sign on MRI could potentially result in earlier time to angiography with improved outcomes.

Methods

• In this retrospective evaluation, researchers involved pretreatment MRIs from 80 subjects referred to the Mayo Clinic, Rochester, MI from January 1, 1997 through December 31, 2017, with a confirmed diagnosis of sDAVF and a control group of 144 patients with alternative confirmed myelopathy diagnoses.
• All study participants had a neurologic evaluation at the Mayo Clinic.
• Evidence of at least 1 focal geographic nonenhancing area within a long segment of intense holocord gadolinium enhancement (termed the missing-piece sign) on MRI was the main outcome.

Results

• According to the findings, out of 51 patients with an sDAVF and a pretreatment MRI with gadolinium enhancement, 44 (86%) had intraparenchymal contrast enhancement, and 19 of these patients (43%) showed the characteristic missing-piece sign.
• Of these 19 subjects, symptom onset occurred at a median age of 67 years (range, 27-80 years); 15 patients were men.
• It was observed that progressive myelopathy features affecting the lower extremities occurred during a median of 33 months (range, 1-84 months).
• It was noted that 11 patients (58%) received an alternative diagnosis before confirmation of sDAVF.
• Findings revealed that tortuous flow voids were present on T2-weighted MRI in 13 of 19 patients.
• To confirm the diagnosis, more than 1 digital subtraction angiogram was needed for five patients.
• No patients from the control group exhibited the missing-piece sign.