RÉSUMÉ
Objective:To evaluate the application of a medical image software (RadiAnt) in anatomical measurements and precision craniotomy via suboccipital retrosigmoid sinus approach.Methods:A total of 43 inpatients who underwent craniocerebral CT venography (CTV) in our hospital from June 2020 to June 2021 were selected for the study; the CTV data of 35 patients was used to measure the spatial relations between transverse sigmoid sinus junction (TSSJ) and asterion; the preoperative planning in suboccipital retrosigmoid sinus craniotomy with the software was performed in the left 8 patients. Craniotomy time (subjected to exposure of venous sinus margin), venous sinus injury and incidence of complications within 2 weeks of craniotomy in these 8 patients were recorded.Results:(1) Anatomic measurement: for the left side, TSSJ was located at (0.89±0.33) cm lateral and (0.63±0.46) cm inferior to the asterion, and their direct distance was (1.15±0.42) cm; TSSJ was located at (0.76±0.49) cm interior and (1.97±0.52) cm superior to the starting point of the mastoid notch, and their direct distance was (2.18±0.49) cm; about 29% asterion were located superior to the transverse sinus, 37% were located on the surface of the transverse sinus, and 34% were located inferior to the transverse sinus. For the right side, TSSJ was located at (0.88±0.39) cm lateral and (0.64±0.43) cm inferior to the asterion, and their direct distance was (1.12±0.54) cm; TSSJ was located at (0.74±0.40) cm interior and (1.93±0.45) cm superior to the starting point of the mastoid notch, and their direct distance was (2.16±0.43) cm; about 26% asterion were located superior to the transverse sinus, 40% were located on the surface of the transverse sinus, and 34% were located inferior to the transverse sinus. (2) Preoperative planning and surgeries: in these 8 patients, the key-hole was located at (0.96±0.49) cm lateral and (0.53±0.18) cm inferior to the asterion, and (0.46±0.35) cm interior and (1.76±0.47) superior to the starting point of mastoid notch. The interior of sigmoid sinus was located (0.13±0.51) cm interior and (0.21±0.46) cm superior to the starting point of mastoid notch. The inferior of the transverse sinus was located (2.17±0.45) cm interior and (0.53±0.35) cm inferior to the asterion. An accurate localization of the real position of TSSJ, inferior of transverse sinus and interior of sigmoid sinus was performed in all 8 surgical patients. The distance between the margin of the bone window and the interior of sigmoid sinus was (3.5±1.0) mm, and the craniotomy time was (25.7±4.1) min; no sinus injury was noted. Post-operative CT showed good reposition of the bone flaps and less bone defect. There was no cerebrospinal fluid leakage or subcutaneous effusion during the 2 weeks of follow-up.Conclusion:Anatomical measurements and preoperative planning can be quickly finished with low cost with Radiant ?, which provides an efficient and safe method for accurate craniotomy via suboccipital retrosigmoid approach.