SDMRad

 Radiological Findings, Disease course and Management

 

                                   MRI Brain 

                                                            

                                                                              T1W   

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                                                                                  T2W

 

 

  

 

 

 

                                                                        

 

 

                 DWI                                         GRE

 

 

 

 

            

                                         

 

 

 

                                       FLAIR

 

 

 

 

 

 

 

 

  

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Findings

• Areas of diffusion restriction noted in the right temporal region – suggestive of acute infarct.

• There is evidence of T2 heterogenously hyperintense,T1 iso to hypointense areas which  show blooming on gradient sequence suggestive of hemorrhage within the infarct.

• Hemorrhage approximately measures 4.8 x 3.2 x 3.4cm (AP X TR X CC)

• Perihemorrhagic edema is seen causing mass effect on the surrounding brain parenchyma and temporal horn of right lateral ventricle.  However, no significant midline shift 

• Venous sinuses :  Loss of flow voids noted in the sigmoid sinus, transverse sinus and jugular bulb on the right side – suggestive of thrombosis

 

Diagnosis

Hemorrhagic infarct in the right temporal region, with cerebral venous sinus thrombosis as described above.

 

Disease course management

Patient was managed conservatively

Follow-up after 2 weeks: Patient improved

   

​Discussion

Cerebral venous thromboses and infarcts are rare but associated with serious consequences prompt diagnosis and treatment. 

Venous thrombosis may be

• spontaneous or

• secondary to trauma, infection or as a complication of surgery.

Risk factors

• Transient states of hypercoagulability from dehydration, oral contraceptives, and pregnancy or

• Permanent hypercoagulability from genetic causes 

Cerebral veins are thin, valveless structures that do not contain smooth muscle.

Venous infarcts occur due to obstruction of the venous system by

• thrombus or

• external compression 

Rise in venous pressure results in cortical edema and the appearance of vasogenic edema on imaging. As the venous pressure continues to rise, it ultimately leads to cytotoxic edema.

When there is a rapid rise in venous pressure, the friable valveless venous vasculature is unable to withstand the pressure, leading to parenchymal hemorrhage.

Imaging Findings

Hyperdense sinus or T1-hyperintense sinus

• Noncontrast CT: A hyperdense sinus may be the only sign of a thrombosed dural sinus in the absence of venous infarction

• CT or MR venogram: filling defect within the sinus

• MRI of the brain: T1 hyperintense thrombus or

                         loss of T2 flow void effect within the dural sinus

• Gradient echo sequence: may demonstrate susceptibility hypointensity                                within the thrombosed venous sinus 

Cerebral edema

• Gyral swelling: effacement of the adjacent sulci 

                    Gray-white differentiation relatively preserved                                 frequently accentuated with the presence of vasogenic                         edema

• Vasogenic edema: T2 hyperintensity of the subcortical and periventricular                     white matter with sparing of the cerebral cortex.

• Arterial infarct: cytotoxic edema with blurring of the gray and white                        matter interface from edema

• Diffusion-weighted sequence (DWI):Differentiation of vasogenic and                                            cytotoxic edema in a venous infarction                     Cytotoxic edema:restricted diffusion

                       Vasogenic edema:T2 shine through 

 

Hemorrhage

• Location: typically cortical or paramedian not confined to a typical arterial vascular territory   

 

References

• Lu, A., Shen, P. Y., Dahin, B. C., Nidecker, A. E., Nundkumar, A., & Lee, P. S. (n.d.). Cerebral venous thrombosis and infarct: Review of imaging manifestations. Retrieved September 16, 2016, from http://appliedradiology.com/articles/cerebral-venous-thrombosis-and-infarct-review-of-imaging-manifestations