Normal MRI Report Including Angiography and Venography
A normal MRI with MR Angiography (MRA) and MR Venography (MRV) shows no pathological findings in the brain parenchyma, arterial structures, or venous structures.
Brain Parenchyma Findings (Normal MRI)
- Brain tissue: No evidence of infarction, hemorrhage, mass, or abnormal enhancement
- Ventricles: Normal size and configuration without displacement or enlargement
- Sulci and cisterns: Age-appropriate appearance without effacement
- Gray-white matter differentiation: Well-preserved
- Midline structures: No shift or herniation
- Posterior fossa structures: Cerebellum and brainstem appear normal
- Pituitary and parasellar regions: Normal size and signal intensity
- Cranial nerves: No abnormal enhancement or enlargement
- Sinuses: Clear paranasal sinuses without mucosal thickening or fluid levels
Arterial System Findings (Normal MRA)
- Circle of Willis: Complete and patent without aneurysm or vascular malformation 1
- Internal carotid arteries: Patent bilaterally without stenosis or dissection
- Anterior cerebral arteries: Normal caliber and course
- Middle cerebral arteries: Patent M1, M2, and M3 segments without occlusion
- Posterior cerebral arteries: Normal caliber and configuration
- Vertebral arteries: Patent bilaterally with normal course
- Basilar artery: Normal caliber without stenosis or dolichoectasia
- Communicating arteries: Patent anterior and posterior communicating arteries
Venous System Findings (Normal MRV)
- Superior sagittal sinus: Patent throughout its course without filling defects 2
- Transverse sinuses: Patent bilaterally without thrombosis (note: normal anatomic variation may include asymmetry)
- Sigmoid sinuses: Patent bilaterally
- Straight sinus: Patent without filling defects
- Internal cerebral veins: Normal caliber and signal
- Vein of Galen: Patent without dilatation
- Jugular bulbs and internal jugular veins: Patent bilaterally
- Cortical veins: Normal appearance without thrombosis
Technical Considerations
MRI sequences typically include:
- T1-weighted imaging
- T2-weighted imaging
- FLAIR (Fluid Attenuated Inversion Recovery)
- DWI (Diffusion-Weighted Imaging)
- SWI/GRE (Susceptibility-Weighted Imaging/Gradient-Recalled Echo) 1
MRA techniques typically include:
- 3D time-of-flight (TOF) for arterial evaluation 1
- Contrast-enhanced MRA may be used for better visualization
MRV techniques typically include:
- 2D time-of-flight for venous evaluation 1
- Phase-contrast imaging
- Contrast-enhanced MRV for improved visualization of venous structures
Important Considerations
MRI with MRA/MRV is the preferred imaging modality for comprehensive cerebrovascular evaluation, offering superior sensitivity for detecting early ischemic changes, vascular malformations, and venous thrombosis without radiation exposure 2
Normal anatomic variations that should not be confused with pathology:
- Asymmetric transverse sinuses (commonly the left is smaller than the right)
- Fenestrations in the anterior communicating artery
- Fetal origin of the posterior cerebral artery
- Hypoplastic A1 segment of the anterior cerebral artery
MRV is superior to CT venography for detecting cortical and deep venous thrombosis and provides better visualization of the superficial and deep venous systems 2
In cases where MRI/MRA/MRV cannot be performed (pacemaker, claustrophobia, etc.), CT with CT angiography and CT venography may be considered as alternative imaging modalities 2