Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Neuroradiology: extra–axial and vascular
- Case 1 Isodense subdural hemorrhage
- Case 2 Non-aneurysmal perimesencephalic subarachnoid hemorrhage
- Case 3 Missed intracranial hemorrhage
- Case 4 Pseudo-subarachnoid hemorrhage
- Case 5 Arachnoid granulations
- Case 6 Ventricular enlargement
- Case 7 Blunt cerebrovascular injury
- Case 8 Internal carotid artery dissection presenting as subacute ischemic stroke
- Case 9 Mimics of dural venous sinus thrombosis
- Case 10 Pineal cyst
- Neuroradiology: intra-axial
- Neuroradiology: head and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Case 2 - Non-aneurysmal perimesencephalic subarachnoid hemorrhage
from Neuroradiology: extra–axial and vascular
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- List of contributors
- Preface
- Acknowledgments
- Section 1 Brain, head, and neck
- Neuroradiology: extra–axial and vascular
- Case 1 Isodense subdural hemorrhage
- Case 2 Non-aneurysmal perimesencephalic subarachnoid hemorrhage
- Case 3 Missed intracranial hemorrhage
- Case 4 Pseudo-subarachnoid hemorrhage
- Case 5 Arachnoid granulations
- Case 6 Ventricular enlargement
- Case 7 Blunt cerebrovascular injury
- Case 8 Internal carotid artery dissection presenting as subacute ischemic stroke
- Case 9 Mimics of dural venous sinus thrombosis
- Case 10 Pineal cyst
- Neuroradiology: intra-axial
- Neuroradiology: head and neck
- Section 2 Spine
- Section 3 Thorax
- Section 4 Cardiovascular
- Section 5 Abdomen
- Section 6 Pelvis
- Section 7 Musculoskeletal
- Section 8 Pediatrics
- Index
- References
Summary
Imaging description
Most cases of non-traumatic subarachnoid hemorrhage (SAH) are caused by aneurysm rupture. However, approximately 15% of patients will have no identifiable cause on CT angiography (CTA). In these patients, it is important to assess the pattern of SAH.
A subset of patients with CTA-negative SAH will have a pattern known as non-aneurysmal perimesencephalic subarachnoid hemorrhage (NAPH) (Figure 2.1). Criteria have been established for this, and include the following [1, 2]:
Subarachnoid hemorrhage within the perimesencephalic cisterns, centered anterior to the midbrain.
Possible extension into the posterior aspect of the anterior interhemispheric fissure, but not completely filling the anterior interhemispheric fissure.
Possible extension into the medial aspects of the Sylvian fissures, but no extension laterally within the fissures (Figure 2.2).
Possible small amounts of layering intraventricular hemorrhage sedimentation, but no frank intraventricular hemorrhage.
No intraparenchymal hemorrhage.
- Type
- Chapter
- Information
- Pearls and Pitfalls in Emergency RadiologyVariants and Other Difficult Diagnoses, pp. 5 - 7Publisher: Cambridge University PressPrint publication year: 2013