Carotid near-occlusion can be identified with ultrasound by low flow velocity distal to the stenosis.

BACKGROUND: Most carotid near-occlusions are indistinguishable from conventional ≥ 50% stenosis on ultrasound, demonstrating high peak systolic velocity (PSV) in the stenosis. PURPOSE: To study whether the velocity distal to the stenosis can separate high PSV near-occlusion from conventional ≥ 50% stenosis. MATERIAL AND METHODS: We included patients with ≥ 50% carotid stenosis with high PSV (≥125 cm/s), examined with both computed tomography angiography (CTA) and ultrasound within 30 days, and a distal velocity measurement was performed. Based on CTA, cases were divided into three groups: conventional stenosis; near-occlusion without full collapse (NwoC; normal-appearing albeit small distal artery); and near-occlusion with full collapse (NwC; threadlike distal artery). Distal Doppler ultrasound flow velocities were compared between these groups. RESULTS: Sixty patients were included: 33 patients with conventional stenosis; 20 patients with NwoC; and seven patients with NwC. Mean distal PSV was 93, 63, and 21 cm/s ( P < 0.001) and mean distal end-diastolic velocity was 30, 24, and 5 cm/s ( P < 0.001), respectively. A distal PSV < 50 cm/s was 63% sensitive and 94% specific for separating both types of near-occlusion from conventional stenosis. CONCLUSION: In high PSV carotid stenoses, the distal velocity was lower in near-occlusions than conventional carotid stenosis. Distal velocities warrant further investigation in diagnostic studies.

Carotid near-occlusion frequently has high peak systolic velocity on Doppler ultrasound.

PURPOSE: Carotid near-occlusion is a tight atherosclerotic stenosis of the internal carotid artery (ICA) resulting in decrease in diameter of the vessel lumen distal to the stenosis. Near-occlusions can be classified as with or without full collapse, and may have high peak systolic velocity (PSV) across the stenosis, mimicking conventional > 50% carotid artery stenosis. We aimed to determine how frequently near-occlusions have high PSV in the stenosis and determine how accurately carotid Doppler ultrasound can distinguish high-velocity near-occlusion from conventional stenosis. METHODS: Included patients had near-occlusion or conventional stenosis with carotid ultrasound and CT angiogram (CTA) performed within 30 days of each other. CTA examinations were analyzed by two blinded expert readers. Velocities in the internal and common carotid arteries were recorded. Mean velocity, pulsatility index, and ratios were calculated, giving 12 Doppler parameters for analysis. RESULTS: Of 136 patients, 82 had conventional stenosis and 54 had near-occlusion on CTA. Of near-occlusions, 40 (74%) had high PSV (≥ 125 cm/s) across the stenosis. Ten Doppler parameters significantly differed between conventional stenosis and high-velocity near-occlusion groups. However, no parameter was highly sensitive and specific to separate the groups. CONCLUSION: Near-occlusions frequently have high PSV across the stenosis, particularly those without full collapse. Carotid Doppler ultrasound does not seem able to distinguish conventional stenosis from high-velocity near-occlusion. These findings question the use of ultrasound alone for preoperative imaging evaluation.

Imaging of the craniovertebral junction anomalies in children.

The craniovertebral junction (CVJ) is interposed between the unsegmented skull and the segmented spine; it is functionally unique as it allows the complex motion of the head. Because of its unique anatomy, numerous craniometric indices have been devised. Because of its complex embryology, different from that of the adjacent skull and spine, it is commonly the seat of malformations. Because of the mobility of the head, and its relative weight, the craniovertebral junction is vulnerable to trauma. Like the rest of the axial skeleton, it may be affected by many varieties of dysplasia. In addition, the bony craniovertebral junction contains the neural craniovertebral junction and its surrounding CSF: any bony instability or loss of the normal anatomic relationships may therefore compromise the neural axis. In addition, the obstruction of the meningeal spaces at this level can compromise the normal dynamics of the CSF and result in hydrocephalus and/or syringohydromyelia. To image the CVJ, plain X-rays are essentially useless. MR is optimal in depicting the soft tissues (including the neural axis) and the joints, as well as the bone itself. CT still may be important to better demonstrate the bony abnormalities.

Factors Determining the Clinical Complications of Radiosurgery for AVM.

PURPOSE: To identify the predictors of symptomatic post-radiation T2 signal change in patients with arteriovenous malformations (AVM) treated with radiosurgery. MATERIALS AND METHODS: The charts of 211 consecutive patients with arteriovenous malformations treated with either gamma knife radisurgery or linear accelerator radiosurgery between 2000-2009 were retrospectively reviewed. 168 patients had a minimum of 12 months of clinical and radiologic follow-up following the procedure and complete dosage data. Pretreatment characteristics and dosimetric variables were analyzed to identify predictors of adverse radiation effects. RESULTS: 141 patients had no clinical symptomatic complications. 21 patients had global or focal neurological deficits attributed to symptomatic edema. Variables associated with development of symptomatic edema included a non-hemorrhagic symptomatic presentation compared to presentation with hemorrhage, p=0.001; OR (95%CI) = 6.26 (1.99, 19.69); the presence of venous rerouting compared to the lack of venous rerouting, p=0.031; OR (95% CI) = 3.25 (1.20, 8.80); radiosurgery with GKS compared to linear accelerator radiosurgery p = 0.012; OR (95% CI) = 4.58 (1.28, 16.32); and the presence of more than one draining vein compared to a single draining vein p = 0.032; OR (95% CI) = 2.82 (1.06, 7.50). CONCLUSIONS: We postulated that the higher maximal doses used with gamma knife radiosurgery may be responsible for the greater number of adverse radiation effects with this modality compared to linear accelerator radiosurgery. We found that AVMs with greater venous complexity and therefore instability resulted in more adverse treatment outcomes, suggesting that AVM angioarchitecture should be considered when making treatment decisions.Facteurs en cause dans les complications cliniques de la radiochirurgie pour une malformation artérioveineuse.

Conventional MR Imaging in Trauma Management in Adults.

MR imaging has been shown to have higher sensitivity than computed tomography (CT) for traumatic intracranial soft tissue injuries as well as most cases of intracranial hemorrhage, thus making it a significant adjunct to CT in the management of traumatic brain injury, mostly in the subacute to chronic phase, but may also be of use in the acute phase, when there are persistent neurologic symptoms unexplained by prior imaging.

Antithrombotic choice in blunt cerebrovascular injuries: Experience at a tertiary trauma center, systematic review, and meta-analysis.

BACKGROUND: Blunt cerebrovascular injuries (BCVIs) may occur following trauma and lead to ischemic stroke if untreated. Antithrombotic therapy decreases this risk; however, the optimal agent has yet to be determined in this population. The aim of this study was to compare the risk-benefit profile of antiplatelet (AP) versus anticoagulant (AC) therapy in rates of ischemic stroke and hemorrhagic complications in BCVI patients. METHODS: We performed a retrospective review of BCVI patients at our tertiary care Trauma hospital from 2010 to 2015, and a systematic review and meta-analysis of the literature. The OVID Medline, Embase, Web of Science, and Cochrane Library databases were searched from inception to September 16, 2019. References of included publications were searched manually for other relevant articles. The search was limited to articles in humans, in patients 18 years or older, and in English. Studies that reported treatment-stratified clinical outcomes following AP or AC treatment in BCVI patients were included. Exclusion criteria included case reports, case series with n < 5, review articles, conference abstracts, animal studies, and non-peer-reviewed publications. Data were extracted from each study independently by two reviewers, including study design, country of origin, sex and age of patients, Injury Severity Score, Biffl grade, type of treatment, ischemic stroke rate, and hemorrhage rate. Pooled estimates using odds ratio (OR) were combined using a random-effects model using a Mantel-Hanzel weighting. The main outcome of interest was rate of ischemic stroke due to BCVI, and the secondary outcome was hemorrhage rate based on AC or AP treatment. RESULTS: In total, there were 2044 BCVI patients, as reported in the 22 studies in combination with our institutional data. The stroke rate was not significantly different between the two treatment groups (OR, 1.27; 95% confidence interval, 0.40-3.99); however, the hemorrhage rate was decreased in AP versus AC treated groups (OR, 0.38; 95% confidence interval, 0.15-1.00). CONCLUSION: Based on this meta-analysis, both AC and AP seem similarly effective in preventing ischemic stroke, but AP is better tolerated in the trauma population. This suggests that AP therapy may be preferred, but this should be further assessed with prospective randomized trials. LEVEL OF EVIDENCE: Review article, level II.

Incidence and Time of Onset of Osseous Pseudoprogression in Patients With Metastatic Spine Disease From Renal Cell or Prostate Carcinoma After Treatment With Stereotactic Body Radiation Therapy.

BACKGROUND: Tumor osseous pseudoprogression (PP), defined as an imaging-based transient increase in tumor size following treatment, was recently described in patients with spinal metastases following stereotactic body radiation therapy. Distinguishing PP from true tumor progression is critical. OBJECTIVE: To describe the incidence, time of onset, and time range of PP following stereotactic body radiation therapy in patients treated for spinal metastases from either prostate cancer (PC) or renal cell carcinoma (RCC), and associated predictive factors. METHODS: A retrospective study was conducted on our institution's cancer database from 2009 to 2015. Selection was based on single level, no prior radiation or surgery, ≥2 follow-up spine magnetic resonance imaging (MRI), and metastases arising from either PC or RCC. Gross tumor volume was contoured on pre- and up to 5 posttreatment MRIs. Patients were sorted into groups depending on gross tumor volume response: PP, non-PP, or progressive disease. Clinical and dosimetric variables were compared using either Fisher's exact test or Kruskal-Wallis analyses. RESULTS: Forty-three spinal segments from 31 patients were analyzed. RCC and PC patients showed similar incidence of PP (∼37%). Whether the primary was lytic or sclerotic was a significant predictive factor with more PP in the lytic group (P = .0208). There was a trend of earlier PP onset in RCC (within 6-18 mo) as compared to PC; however, PC segments showed more time-confined presentation of PP (9-12 mo). CONCLUSION: There was a higher incidence of PP in lytic compared to sclerotic primary tumor type. PP in spinal metastatic sites may have variable presentations depending on the primary cancer.

Incidence of Dural Venous Sinus Thrombosis in Patients with Glioblastoma and Its Implications.

OBJECTIVE: Glioblastoma (GBM) is associated with increased risk of developing dural venous sinus thrombosis (DVST), which often goes undiagnosed as symptoms are readily attributed to tumor. The purpose of this study was to investigate the incidence of DVST, potential predictive features on imaging, complications, its effect on survival, and time of greatest risk for developing DVST. METHODS: A retrospective search of patients with GBM who had surgery followed by chemotherapy and/or radiation therapy between 2009 and 2015 at our institution was performed. Magnetic resonance imaging studies of the brain were reviewed on volumetric postgadolinium T1-weighted sequences for DVST. Tumors were characterized using the Visually Accessible REMBRANDT (Repository for Molecular Brain Neoplasia Data) Images classification, and identified thromboses were tracked for propagation, regression, or resolution. Statistical analyses were directed at identifying clinical predictors and survival differences between the DVST and no-DVST groups. RESULTS: In total, 163 cases totaling 1637 scans, were reviewed; 12 patients (7.4%) developed DVST, of whom 11 presented with thrombus before any treatment. Tumor invasion of dural sinuses and greater T1/fluid-attenuated inversion recovery ratios were significantly associated with thrombus development (P = 0.02 and P = 0.02, respectively). In patients who developed DVST, thrombosis was more likely to develop ipsilateral to tumor side (P = 0.01) and was associated with a greater likelihood of developing extracranial venous thromboembolism (P = 0.012). There were no venous infarcts and no significant difference in survival between groups (P = 0.83). CONCLUSIONS: Patients with GBM have increased risk of developing DVST, independent of surgical treatment or chemoradiation. DVST presence does not affect survival. Tumor invasion of dural sinuses and greater T1/fluid-attenuated inversion recovery ratio on preoperative imaging were the most significant predictors of DVST development.