Intramedullary pneumorrhachis following a cervical epidural steroid injection

Nontraumatic Pneumorrhachis and Intraforaminal Gas, Presumed Intravascular, Is Occasionally Detected in Dogs Undergoing Computed Tomography Angiography Without Immediate Complications

Pneumorrhachis is a rare condition in human and veterinary medicine, defined as gas within the vertebral canal. Iatrogenic causes are the most common source of nontraumatic PR reported in humans. PR has been recognized in dogs undergoing routine CT. This study aims to identify the cause, prevalence, and distribution of PR and intraforaminal gas in dogs undergoing CT and identify any immediate post-CT complications. The medical records of dogs who underwent CT of the thorax, abdomen, and pelvis were retrospectively reviewed. Dogs were excluded if they presented with a history of trauma, neurologic deficits, recent surgery, or epidural injection. PR and intraforaminal gas were identified as present or absent and quantified subjectively. Patient positioning, intravenous catheter location, and complications in the 24 h following CT were recorded. 50/263 (19%) dogs with PR met the inclusion criteria. All dogs with PR had CT performed in sternal recumbency. Catheters were evenly distributed in laterality of placement, yet PR was predominantly right-sided (74%). The volume of gas identified was mild (87%) or moderate (13%). An increase in the amount of PR in postcontrast images was documented in 13 cases (20%). Intraforaminal gas was identified in 16.3% of dogs, and 88.4% had right-sided intraforaminal gas. No dogs developed neurologic deficits 24 h post-CT. The prevalence of PR and intraforaminal gas in this study was significantly higher than previously documented. Intravascular right-sided gas is proposed to be secondary to the ipsilateral location of the azygous vein and of no clinical significance.

Image Segmentation-Based Cervical Spine MRI Images to Evaluate the Treatment of Patients with Chronic Pain

The objective of this research was to investigate the application effect of cervical spine magnetic resonance imaging (MRI) image segmentation algorithm guidance in the treatment of chronic pain with cervical epidural puncture. A total of 72 patients with chronic pain were selected and divided into a cervical spine MRI image-guided group (group A) and a blind puncture group with traditional experience (group B). The results showed that the puncture time of group A was $9.9\pm 8.2$ (min), while that of group B was $15.2\pm 8.9$ (min), so the puncture time of patients in group A was significantly shorter than that of group B ( $P<0.05$ ). The incidences of pain at the puncture site of patients in group A and group B were 6% and 10%, respectively. The incidence of pain at the puncture site in group A was significantly lower than that in group B ( $P<0.05$ ). The success rate of the first puncture in group A was 78%, and that in group B was 54%. The success rate of the first puncture in group A was significantly higher than that in group B ( $P<0.05$ ). The complication rate of group A was 22.22%, and that of group B was 80.56%. The incidence of complications in group A was significantly lower than that in group B ( $P<0.05$ ). In addition, there was no significant difference in the puncture depth between the two groups ( $P>0.05$ ). In summary, the guidance of cervical spine MRI image segmentation algorithm can reduce the time and times of puncture and improve the success rate of puncture, thereby reducing the incidence of postoperative complications.