The present study was designed to assess the efficacy of ultrasound (US) and computed tomographic (CT)-guided injection techniques versus conventional blind technique for various nerve blocks of the head in one-humped camel cadavers. Eighteen cadaver heads of adult one-humped camels enrolled were randomly assigned to blind (n=6), US-guided (n=6), and CT-guided (n=6) injections of mental, infraorbital, supraorbital and retrobulbar nerves. Injections were made with 2.5 mL of lidocaine HCl mixed with equal volume of Iopaminol contrast agent. Injection criteria (needle localization, correct penetration, difficulty of injection and performance time) were assessed, scored and statistically compared among three techniques of injection. Collectively, the summation of injection criteria scores showed a significant increase (P<0.05) in the US and CT-guided nerve block injection techniques compared with the blind technique. Imaging-guided injection could precisely discriminate each target nerve (sensitivity: 72.2-94.4%; specificity: 27.8-83.3%; odds ratio: 6.5-85; CI: 15.03-389; P<0.0001). The highest specificity for imaging-guided nerve block injection technique was 83.3% for US and CT-guided techniques, whilst the lowest specificity was recorded for CT versus US-guided technique (27.8%). In conclusion, the US and CT-guided injection techniques offers considerable advantages for characterization of the anatomical landmarks, needle placement and selectivity of the head nerve block technique which is difficult to obtained using conventional blind technique.

Key words: Camel, Computed tomography, Imaging, Nerve block, Ultrasonography