Novalis Stereotactic Radiosurgery for Spinal Dural Arteriovenous Fistula

motor weakness of grade IV in both legs and his anal tone was grade zero.Sensory changes, such as hypesthesia and analgesia were presented below the T9 level.About 14 years ago, he had pain in the left leg and was diagnosed with spinal arteriovenous malformation.At that time, magnetic resonance imaging (MRI) of the thoracolumbar spine revealed a vascular anomaly at the thoracolumbar level, and physicians performed spinal angiography for definite treatment.However, spinal angiography had failed three times in two other hospitals due to vasospasm and paraparesis.He recovered from these symptoms spontaneously, and he had not undergone any treatment thereafter.MRI in our hospital showed a vascular anomaly with enhancement at the T12, L1, and L2 levels (Fig. 1A).Axial images of the L1 level revealed a mass lesion, located on the left side of the intraspinal canal (Fig. 1B).We recommended selective spinal angiography, but the patient refused because of his experience, requesting a non-invasive technique for diagnosis and treatment.We planned SRS using the Novalis system (BrainLAB ® , Heimstetten, Germany).However, we required an alternative modality to selective spinal angiography for obtaining accurate information on diagnosis, level of the lesion, and follow-up after treatment.Thus, a three-dimensional volumetric sagittal timeresolved imaging of contrast kinetics (TRICKS) abdominal magnetic resonance angiography (MRA) using 1.5T MRI system were performed in quiet respiration (TR/TE/flip=4.2/1.1/45°,FOV