Fig 1.
Flow diagram demonstrates patient’s recruitment and imaging finding of the double-track sign.
Fig 2.
Transverse sinus stenosis with double-track sign.
A 37-year old female patient with right transverse sinus stenosis. Hypointense on T1WI (A) and T2WI (B) demonstrated a chronic stage of thrombus, and double-track sign (arrow) was detected on axial Gd-enhanced T1WI (C). Transverse sinus stenosis was confirmed on MRV which showed a linear signal of blood flow in the right transverse sinus (D). (Time from MRI to MRV was 4.5 hours).
Fig 3.
Double-track sign and sinus recanalization.
A 42-year old male patient with left transverse sinus stenosis. Isointense on T1WI (A) and hypointense on T2WI (B) demonstrated an acute stage of thrombus. Double-track sign (arrow) was showed on axial Gd-enhanced T1WI (C). Transverse sinus stenosis was confirmed on MRV which showed a linear signal of blood flow in the left transverse sinus on MRV (D) (Time from MRI to MRV was 3 hours). Follow-up scan after 2 weeks of anticoagulation therapy showed that the stenosis was ameliorated than before on MRV (E), and the double-track sign disappeared on axial Gd-enhanced T1WI after the recanalization (F) (Time from MRI to MRV was 6 hours).
Fig 4.
Double-track sign and the varied signal of thrombus.
A 46-year old female patient with left transverse sinus stenosis. Hyperdensity of thrombus (cord sign) on non-contrast CT (A). Thrombus was isointense on T1WI (B) and hypointense on T2WI (C) which demonstrated an acute stage of thrombus. Double-track sign (arrow) was detected on axial Gd-enhanced T1WI (D). Severe stenosis was confirmed on MRV which showed a linear signal of blood flow in the left transverse sinus (E) (Time from MRI to MRV was 2.5 hours). No remission in headache in the patient after anticoagulant therapy for one week, and follow-up scan showed that the thrombus was hyperintense on T1WI (F) and hypointense on T2WI (G), which demonstrated an early sub-acute stage of thrombus. Transverse sinus stenosis was confirmed on DSA which showed the filling deficiency in the left transverse sinus (H) (Time from MRI to DSA was 3 hours).
Table 1.
Imaging findings of the double-track sign on axial Gd-enhanced T1WI compared to imaging diagnosis on DSA and MRV.
Table 2.
Sensitivity and specificity of the double-track sign on axial Gd-enhanced T1WI in the detection of transverse sinus stenosis.
Fig 5.
Transverse sinus occlusion without double-track sign.
A 38-year old male patient with right transverse sinus occlusion. The thrombus was hypointense on T1WI (A) and T2WI (B), and double-track sign was not observed in right transverse sinus on axial Gd-enhanced T1WI (C). Transverse sinus occlusion was confirmed on MRV which showed a lack of blood flow signal in the right transverse sinus (D) (Time from MRI to MRV was 2 hours).