The ability of magnetic resonance black blood vessel wall imaging to evaluate blunt cerebrovascular injury following acute trauma.

BACKGROUND AND PURPOSE: Blunt cerebrovascular injury (BCVI) is associated with a significant risk of ischemic stroke when left untreated. Cross-sectional imaging is vital to early BCVI diagnosis and treatment; however, conventional luminal vessel imaging is limited in its ability to evaluate for vessel wall pathology. The purpose of this study is to evaluate the ability of vessel wall magnetic resonance imaging (VWI) to detect and evaluate BCVI in acutely injured trauma patients relative to neck computed tomographic angiography (CTA). MATERIALS AND METHODS: Trauma patients with suspected BCVI on initial neck CTA were prospectively recruited for VWI evaluation. Two neuroradiologists blinded to patient clinical history and CTA findings evaluated each artery independently on VWI and noted the presence and grade of BCVI. These results were subsequently compared to neck CTA findings relative to expert clinical consensus review. Interrater reliability of VWI for detecting BCVI was evaluated using a weighted Cohen κ-statistic. RESULTS: Ten trauma patients (40 cervical arteries) were prospectively evaluated using both CTA and VWI. Out of 18 vascular lesions identified as suspicious for BCVI on CTA, six lesions were determined to represent true BCVI by expert consensus review. There was almost perfect agreement between VWI and expert consensus regarding the presence and grade of BCVI (κ=0.82). This agreement increased when considering only low grade BCVI. There was only fair agreement between CTA and expert clinical consensus (κ=0.36). This agreement decreased when considering only low grade BCVI. CONCLUSIONS: VWI can potentially accurately identify and evaluate BCVI in acutely injured trauma patients with excellent inter-rater reliability.

Vessel wall MRI characteristics of endovascularly treated aneurysms: association with angiographic vasospasm.

OBJECTIVE: The aim of this paper was to evaluate the association between intracranial vessel wall MRI enhancement characteristics and the development of angiographic vasospasm in endovascularly treated aneurysm patients. METHODS: Consecutive cases of both ruptured and unruptured intracranial aneurysms that were treated endovascularly, followed by intracranial vessel wall MRI in the immediate postoperative period, were included. Two raters blinded to clinical data and follow-up imaging independently evaluated for the presence, pattern, and intensity of wall enhancement. Development of angiographic vasospasm was independently evaluated. Delayed cerebral ischemia; cerebral infarct; procedural details; and presence and grade of subarachnoid, parenchymal, and intraventricular hemorrhage were evaluated. Statistical associations were determined on a per-vessel segment and per-patient basis. RESULTS: Twenty-nine patients with 30 treated aneurysms (8 unruptured and 22 ruptured) were included in this study. Interobserver agreement was substantial for the presence of enhancement (κ = 0.67) and nearly perfect for distribution (κ = 0.87) and intensity (κ = 0.84) of wall enhancement. Patients with ruptured aneurysms had a significantly greater number of enhancing segments than those with unruptured aneurysms (29.9% vs 7.2%; OR 5.5, 95% CI 2.2-13.7). For ruptured cases, wall enhancement was significantly associated with subsequent angiographic vasospasm while controlling for grade of hemorrhage (adjusted OR 3.9, 95% CI 1.7-9.4). Vessel segments affected by balloon, stent, or flow-diverter use demonstrated greater enhancement than those not affected (OR 22.7, 95% CI 5.3-97.2 for ruptured; and OR 12.9, 95% CI 3.3-49.8 for unruptured). CONCLUSIONS: Vessel wall enhancement after endovascular treatment of ruptured aneurysms is associated with subsequent angiographic vasospasm.

Imaging spectrum of immunomodulating, chemotherapeutic and radiation therapy-related intracranial effects.

OBJECTIVE: A wide range of treatment-related side effects result in specific neurologic symptoms and signs and neuroimaging features. Even to the most seasoned neuroradiologist, elucidating therapy-related side effects from other common mimics can be challenging. We provide a pictorial survey of some common and uncommon medication-induced and therapy-related neuroimaging manifestations, discuss pathophysiology and common pitfalls in imaging and diagnosis. METHODS: A case-based review is utilized to depict scenarios on a routine basis in a general radiology or neuroradiology practice such as medication-induced posterior reversible encephalopathy syndrome to the more challenging cases of pseudoprogression and pseudoregression in temozolmide and bevacizumab therapy in gliobastoma treatment protocols. CONCLUSION: Knowledge of the treatment-induced imaging abnormalities is essential in the accurate interpretation and diagnosis from the most routine to most challenging of clinical situations. We provide a pictorial review for the radiologist to employ in order to be an invaluable provider to our clinical colleagues and patients.

Thorn in My Spine: A case of a retained intradural extramedullary foreign body.

Foreign bodies in the spine are most commonly traumatic and managed in an acute setting. A few case reports describe foreign bodies resulting in delayed neurologic dysfunction, most commonly iatrogenic or from penetrating injury. We present a 30-year old man with lower extremity weakness from an intradural extramedullary foreign body granuloma secondary to a thorn, which was initially thought to represent an aggressive malignant process with intra and extramedullary involvement on MR. Postoperatively, the patient endorsed a causative trauma several years prior. We also present a review of the few similar published cases as well as the described prototypical imaging features and pathologic process.