Anatomical Evaluation of the Dural Sinuses in the Region of the Torcular Herophili Using Three Dimensional CT Venography

Fukusumi, Akio; Okudera, Toshio; Takahashi, Shoki; Taoka, Toshiaki; Sakamoto, Masahiko; Nakagawa, Hiroyuki; Takayama, Katsutoshi; Kichikawa, Kimihiko; Iwasaki, Satoru

doi:10.1016/j.acra.2010.04.020

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Volume 17, Issue 9 , Pages 1103-1111, September 2010

Anatomical Evaluation of the Dural Sinuses in the Region of the Torcular Herophili Using Three Dimensional CT Venography

Akio Fukusumi, MD
- Department of Radiology, Takanohara Central Hospital, 1-3-3 Ukyo, Nara 631-0805, Japan
- Address correspondence to: A.F.
Toshio Okudera, MD
- Division of Neuroradiology, Hara-Doi Hospital, Fukuoka, Japan
Shoki Takahashi, MD
- Department of Diagnostic Radiology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
Toshiaki Taoka, MD
- Department of Radiology, Nara Medical University, Kashihara, Nara, Japan
Masahiko Sakamoto, MD
- Department of Radiology, Nara Medical University, Kashihara, Nara, Japan
Hiroyuki Nakagawa, MD
- Department of Radiology, Nara Medical University, Kashihara, Nara, Japan
Katsutoshi Takayama, MD
- Department of Radiology, Nara Medical University, Kashihara, Nara, Japan
Kimihiko Kichikawa, MD
- Department of Radiology, Nara Medical University, Kashihara, Nara, Japan
Satoru Iwasaki, MD
- Department of Diagnostic Imaging, Higashi-Osaka Municipal General Hospital, Higashi-Osaka, Osaka, Japan

Received 1 April 2010; accepted 22 April 2010. published online 12 July 2010.

Rationale and Objectives

The torcular herophili, or “confluence of the sinuses,” shows various configurations with other venous sinuses, as revealed by angiography. The aims of this study were to evaluate anatomic variations of this confluence and to assess their clinical relevance using three-dimensional (3D) computed tomographic (CT) venography.

Materials and Methods

The torcular herophili and its relevant venous sinuses were analyzed using 3D CT venography in 120 adults, consisting of 76 patients who were proven to have aneurysms and 44 patients who were proven to have no vascular malformations or aneurysms after the examinations. Three-dimensional CT venography was performed following the arterial phase of 3D CT angiography without any additional injection of contrast material. Three-dimensional volume-rendered venous images were reconstructed on a workstation and reviewed.

Results

The superior sagittal sinus (SSS) drained into the transverse sinus (TS) in four patterns: the SSS reached the centrally located confluence, where it divided into the bilateral TS (20.0%); the SSS was prematurely duplicated into the right and left limbs and drained into the same side TS (26.7%); the SSS drained exclusively into the right TS (44.2%); or the SSS drained exclusively into the left TS (9.2%). The draining pattern of the straight sinus was also classified into four types. The right TS was larger than the left TS. The right TS were higher compared to the left TS. Persistent occipital sinuses were recognized in 57.5% of the subjects. Finally, persistent falcial sinuses were seen in 2.5% of the subjects. A septum in the SSS and complicated venous channels in the confluence were each seen in only one case.

Conclusion

Three-dimensional CT venography is useful as a noninvasive method to evaluate the confluence and its relevant dural sinuses and can provide useful information for surgical intervention.

Key Words: Torcular herophili, confluence, dural venous sinus, three-dimensional CT venography