Fetal MR imaging of posterior intracranial dural sinus thrombosis: a report of three cases with variable outcomes.
BACKGROUND
Thrombosis of fetal intracranial dural sinuses is a rare entity. A specific type of midline dural sinus thrombosis (DST) at the torcular Herophili with extension into the superior sagittal sinus (SSS) was initially seen on fetal US and was referred to fetal MRI for definite diagnosis and better delineation.


OBJECTIVE
Retrospective comparison to medical literature of three cases, diagnosed at our institution, of midline fetal DST with MR imaging findings and clinical outcomes.


METHODS
We reviewed MRI findings on T2-weighted images of our three cases of fetal midline DST and clinical outcomes of these fetuses and compared our findings to medical literature. The MR imaging and clinical findings of our cases extend over 6 years. They consist of three pregnant women, 31-39 years of age each with a single fetus, with fetal MR imaging performed at different gestational ages (GA). Case 1 the MR imaging was performed at 21 5/7 weeks' GA, case 2 at 24 and 33 4/7 weeks' GA, and case 3 at 22 and 25 weeks' GA. Postnatal MRI was performed in case 2 at 6 months of life and case 3 at 1 day of life. Clinical follow-up occurred during the last 6 years.


RESULTS
In all of our cases, T2-W MR imaging demonstrated ballooned midline torcular Herophili with iso- to hypointense mass with or without focal eccentric area of greater hypointensity occupying the torcular Herophili with extension into the SSS. Case 3 had associated leptomeningeal dural vascular malformation overlying the left cerebral hemisphere with development of migrational disorder in the left cerebral hemisphere. Clinical outcome consisted of fetal demise in case 1, normal postnatal outcome in case 2 and severe brain damage with poor postnatal outcome in case 3.


CONCLUSIONS
Our findings of large iso-hypointense thrombus with or without a focal eccentric area more hypointense to thrombus in a dilated torcular Herophili with extension into the SSS on T2-W images corresponds to the majority of cases of this rare type of DST in the medical literature.
Department of Diagnostic Radiology and Nuclear Medicine Section of Neuroradiology, Rush Medical College and Rush University Medical Center, Chicago, IL 60612, USA. Sharon_E_Byrd@rush.edu
Sharon E
SE
Byrd
Jacques S
JS
Abramowicz
Paul
P
Kent
Robert E
RE
Kimura
Dean
D
Elias
Peter T
PT
Heydeman
D000328:Adult; D003287:Contrast Media; D003392:Cranial Sinuses / Q000002:abnormalities*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis*; D005865:Gestational Age; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives; D009942:Organometallic Compounds; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012189:Retrospective Studies; D012851:Sinus Thrombosis, Intracranial / Q000175:diagnosis*
D003287:Contrast Media; D009942:Organometallic Compounds; C064572:gadobenic acid; D008536:Meglumine