64-Slice Spiral Computed Tomographic Angiography Of Venous Of Posterior Cranial Fossa And Clinical Application

Objective: Although cranial surface landmark is commonly used to determine the location of intracranial venous sinus during posterior fossa surgery, its localization is not accurate in clinics. In this study, we introduced a subtraction computed tomography angiography (CTA) technique and observed the anatomical relationship between venous sinus in posterior fossa and cranial surface landmarks using three-dimensional (3D) reformation. The reliability of applying conventional anatomical landmarks to locate venous sinus was also evaluated, providing anatomical evidence for opening location in posterior fossa surgery.Methods: We retrospectively reconstructed transverse sinus (TS), sigmoid sinus (SS) and cranial imaging from 100 patients undergoing head CTA examination. Subtraction CTA data been merged with nonenhanced data and then cranium transparency was adjusted to 50% on 3D volume rendering, indicating the anatomical relationship between surface landmarks of cranium and torcular, TS, and SS.Results: The asterion was located directly over the transverse - sigmoid sinus junction (TSST) in 81% cases, 15% inferior to TSST, 4% superior to TSST, and asterion was mainly distributed on the TS side of TSST, namely the distant end of TS. Superior nuchal line (SNL) had complex relation with line drawn from the zygoma root to the inion (LZI), and SNL could not completely represent the trend of LZI. In addition, SNL showed complicated anatomical relationship to TS, and SNL was unsuitable to locate TS position. In proximal-end of TS, majority of LZI was located on TS line. However, most LZI was gradually positioned below TS line as TS moved outwards. Almost half of line drawn from the squamosal-parietomastoid suture junction to the inion (LSPI) and line drawn from the asterion to the inion (LAI) shared the same trend with TS.Conclusion: CTA technique precisely displayed the anatomical relations between venous sinus in posterior fossa and cranial surface landmarks. The anatomical relation between venous sinus and surface landmarks of cranium significantly varied among individuals, so it is not accurate to determine deep parts location merely using surface landmarks. In this investigation, 3D imaging reformation technique was employed to accurately and rapidly observe the anatomical relationship between venous sinus in posterior fossa and cranial surface landmarks, providing valuable reference regarding individual anatomical data for posterior fossa surgery.Objective: To provide the anatomic of the jugular bulb and related anatomical structure for surgical treatment and imaging diagnosis, to discuss the display capabilities and advantages of subtraction technique of computed tomographic angiography (CTA) to the jugular bulb and to provide the anatomic of the jugular bulb and related anatomical structure for surgical treatment and imaging diagnosis.Methods: Dual-energy technology of synchronous scan with 64-row CT was applied, which was at first plain scan and volume scan of arteriovenous CTA to show the integral cerebral. Retrospective three-dimensional reconstruction of the jugular bulb and related structure was carried on 110 cases of head or head-and-neck CTA examination. Their spatial anatomical characters were observed and analyzed on the views of volume rendering(VR) and multiplanar reformation(MPR) by convention and subtraction CTA.Results: There were two type of jugular bulb, i.e. flat(56.8%) and upward bulge(43.2%). The detection rate of high jugular bulb was 6.36%. The average distance(±standard deviation) between the jugular bulb and the internal auditory canal on the right side was 6.72±2.71 mm, on the lift was 7.71±3.15 mm. When the jugular bulb reached or exceeded the floor of the internal auditory canal(10.5%), it was defined as a high jugular bulb , 78.3% of high jugular bulb were found in females. The jugular bulb was higher on the right side than its companion. The distance between the jugular bulb and the internal auditory canal was longer on the left side, and the distance is decrease with increasing of high of jugular bulb. The drainage forms of transverse sinus ware in relation to the shape of jugular bulb, but it was irrespective of the high of the jugular bulb.Conclusions The subtraction technique could display not only jugular bulb clearly with the rate of 100%, but also the anatomy of the jugular bulb and related structure was observed on the views of volume rendering(VR) and multiplanar reconstruction(MPR) by convention and subtraction CTA, and the high jugular bulb and jugular bulb diverticulum could be diagnosed. Subtraction CTA is a feasible and effective method for jugular bulb imaging. The CTA delineated the anatomic details of the jugular bulb and the relationship of jugular bulb and internal auditory canal, and provide valuable information to imaging diagnosis and surgery of this area.Objective: To explore and delineate the mastoid foramen and the mastoid emissary vein for clinical operation.Methods: A total of 67 images of mastoid emissary vein canaliculus(MEVC) were obtained by three-dimensional reconstruction after CT angiography of head and neck, to determine the position of the mastoid foramen and to observe mastoid emissary vein canaliculus.Results: The number and location of mastoid foramen and the MEVC are variant, The external aperture is more than the internal aperture of MEVC obviously. The external aperture of MEVC mainly located at the range of 1.5 cm backward connecting line between asterion to mastoidale, exactly located at neighboring middle point of right side of asterion around 1.5 cm. The internal aperture of MEVC mainly located at the range of 1 cm forward connecting line between asterion to mastoidale, Most of them located at the range around 1 cm of vertical line of crossed midpoint of connecting line between asterion to mastoidale as well . As discussed range is the shadow of the mastoid emissary vein.Conclusions: There are complicated anatomical variations in the mastoid foramen and the mastoid emissary vein,which can be finely evaluated by CT angiography.