E-Book, Englisch, 303 Seiten, ePub
Wolf / Grozdanovic / Albrecht Vascular Imaging
1. Auflage 2009
ISBN: 978-3-13-258107-4
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark
Direct Diagnosis in Radiology
E-Book, Englisch, 303 Seiten, ePub
ISBN: 978-3-13-258107-4
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark
Dx-Direct is a series of eleven Thieme books covering the main subspecialties in radiology. It includes all the cases you are most likely to see in your typical working day as a radiologist. For each condition or disease you will find the information you need -- with just the right level of detail.
Dx-Direct gets to the point: - Definitions, Epidemiology, Etiology, and Imaging Signs - Typical Presentation, Treatment Options, Course and Prognosis - Differential Diagnosis, Tips and Pitfalls, and Key References
...all combined with high-quality diagnostic images.
Whether you are a resident or a trainee, preparing for board examinations or just looking for a superbly organized reference: Dx-Direct is the high-yield choice for you!
The series covers the full spectrum of radiology subspecialties including:
- Brain
- Gastrointestinal
- Cardiac
- Breast
- Urogenital
- Spinal
- Head and Neck
- Musculoskeletal
- Pediatric
- Thoracic
- Vascular
Autoren/Hrsg.
Fachgebiete
Weitere Infos & Material
1 Brain
2 Spinal Canal
3 Head and Neck
4 Chest
5 Abdomen
6 Kidneys
7 Extremities
Epidemiology
Most common caroticobasilar anastomosis 0.1–0.2% of the population.
Etiology, pathophysiology, pathogenesis
Persistent fetal anastomosis between the internal carotid and basilar artery Anastomosis between the cavernous segment (C4 segment) of the internal carotid and basilar artery proximal to the origin of the posterior communicating artery In 25% of cases additional vascular anomalies are present Cerebral aneurysms are present in 10–15% of cases.
Modality of choice
DSA.
CT findings
Prominent artery between the internal carotid and basilar arteries.
CTA findings
Like CT Additional vascular anomalies may be present.
MRI and MRA findings
T1-weighted and T2-weighted images show the persistent trigeminal artery as a bandlike prepontine flow void between the internal carotid and basilar arteries MRA confirms the diagnosis.
DSA findings
The study demonstrates a primitive trigeminal artery supplying the distal vertebrobasilar system and the proximal hypoplastic basilar artery.
Typical presentation
Incidental finding.
Therapeutic options
Incidental finding without therapeutic relevance (unless additional vascular anomalies warranting treatment are present).
Course and prognosis
As an isolated finding, it has no clinical significance.
What does the clinician want to know?
Exclusion of additional vascular anomalies (aneurysms in 10–15% of cases).
Primitive trigeminal artery (arrow) on MR axial T2-weighted image (a), MRA–MIP (b), and DSA (c). Coiled aneurysm of the anterior communicating artery (c) asan incidental finding.
| – Second most common anastomosis between the internal carotid and basilar artery – Anastomosis at the C1–C2 level following the bony course of the hypoglossal nerve |
| – Very rare anastomosis between the internal carotid and basilar arteries – Courses through the internal auditory canal |
| – Anastomosis between the C2 and C3 segments of the internal carotid artery and the vertebral artery ( the basilar artery) at the level of C1–C2 |
The anomalous vessel can be misinterpreted as an aneurysm of the internal carotid artery It can be mistaken for another persistent carotid–basilar anastomosis.
Selected References
Athale SD, Jinkins JR. MRI of persistent trigeminal artery. J Comput Assist Tomogr 1993; 17: 551–554
Li MH et al. Persistent primitive trigeminal artery associated with aneurysm: Report of two cases and review of the literature. Acta Radiol 2004; 45: 664–668
Salas E et al. Persistent trigeminal artery: An anatomic study. Neurosurgery 1998; 43: 557–561
Epidemiology
Precise information is not available.
Etiology, pathophysiology, pathogenesis
Compression of a cranial nerve by a vascular loop in the cerebellopontine angle or the internal auditory canal Typically affects the trigeminal or facial nerve.
Modality of choice
High-resolution MRI.
CT findings
Usually normal Calcifying atherosclerosis can be associated with the disorder.
MRI findings
Thin-slice T2-weighted images Optimal imaging can be achieved using 3T-MRI.
– Trigeminal neuralgia is most commonly caused by vascular loops formed by the superior cerebellar artery, posterior inferior cerebellar artery, or vertebrobasilar artery, in that order of occurrence.
– Facial nerve palsy is more likely to be caused by a vascular loop originating from the anterior inferior cerebellar artery than the posterior inferior cerebellar artery or vertebral artery.
DSA
Angiography is usually not recommended as the topographic relation of vessel to nerve is not visualized.
Typical presentation
Trigeminal neuralgia Facial nerve palsy.
Therapeutic options
Surgical (Janetta procedure) or symptomatic medical treatment.
Course and prognosis
Postoperative long-term success rate is about 60% Postoperative complication rate is as high as 30%.
What does the clinician want to know?
Verify neurovascular coupling Clinical correlation Indication for treatment Follow-up examination.
Compressive neurovascular malformation Axial CISS sequence through the brainstem. Contact (arrow) between the trigeminal nerve and left superior cerebellar artery.
| – Usually in older patients with underlying atherosclerosis |
| – Characteristic tangle of vessels on MRI or early venous drainage |
| – Outpouching of the arterial wall on MRI or DSA |
Negative MRI findings do not exclude surgical exploration.
Selected References
Chun-Cheng Q et al. A single-blinded pilot study assessing neurovascular contact by using high-resolution MR imaging in patients with trigeminal neuralgia. Eur J Radiol Nov 20, 2007 [Epub ahead of print]
Chung SS et al. Microvascular decompression of the facial nerve for the treatment of hemifacial spasm: preoperative magnetic resonance imaging related to clinical outcomes. Acta Neurochir (Wien) 2000; 142: 901–906
Holley P et al. The contribution of “time-of-flight” MRI-angiography in the study of neurovascular interactions (hemifacial spasm and trigeminal neuralgia). J Neuroradiol 1996; 23: 149–156
Papanagiotou P et al. [Vascular anomalies of the cerebellopontine angle.] Radiologe 2006; 46: 216–223 [In German]
Epidemiology
Accounts for approximately 20% of all infratentorial and approximately 7% of all supratentorial vascular malformations Occasionally associated with cavernous malformations.
Etiology, pathophysiology, pathogenesis
Circumscribed clusters of dilated capillaries interspersed with normal brain tissue Predilection for the brainstem, especially the pons and the deep white matter of the cerebellum and cerebral hemispheres.
Modality of choice
MRI.
CT findings
Normal findings.
MRI findings
May appear as a hyperintense lesion on T2-weighted images Typically appears hypointense on T2*-weighted images Contrast-enhanced T1-weighted images show a brushlike pattern of enhancement Normal MRA findings.
DSA findings
Normal findings.
Typical presentation
Asymptomatic incidental finding.
Therapeutic options
No treatment is required.
Course and prognosis
No clinical significance.
What does the clinician want to know?
Rule out other lesions that enhance on T1-weighted sequences.
Capillary telangiectasia. Axial MR sequences through the brainstem; T2-weighted sequence (a), non-contrast T1-weighted sequence (b), and T1-weighted sequence with contrast (c). The telangiectasia appears hyperintense on the T2-weighted image (a, arrow), is not visualized on the T1-weighted sequence (b), and enhances homogeneously (c, arrow).
| – History – Usually marked enhancement on T1-weighted images after contrast administration |
| – Contrast pattern – Diffusion imaging, perfusion imaging, or MR spectroscopy may be indicated |
| – Multiple sites – Hemosiderin rim on T2*-weighted images |
| – Flow voids indicative of nidus on axial T2-weighted images – Angiography shows early venous drainage – Ectatic veins |
Can be misinterpreted as a metastasis, glioma, cavernous malformation, or AVM.
Selected References
Castillo M et al. MR imaging and histologic features of capillary...
