Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Adam E. Flanders x
Clear All Modify Search
Restricted access

Dale M. Schaefer, Adam E. Flanders, Jewell L. Osterholm and Bruce E. Northrup

✓ Fifty-seven patients with acute cervical spine injuries and associated major neurological deficit were examined within 2 weeks of injury by magnetic resonance (MR) imaging. All patients had abnormal scans, indicating intramedullary lesions. This study was undertaken to determine if the early MR imaging pattern had a prognostic relationship to the eventual neurological outcome. Three different MR imaging patterns were observed in these patients: 21 patients had patterns characteristic of intramedullary hematoma (Group 1); 17 had intramedullary edema over more than one spinal segment, but no hemorrhage (Group 2); and 19 had restricted zones of intramedullary edema involving one spinal segment or less (Group 3).

The neurological state was determined using standard motor index scores at admission and at follow-up examination. Characteristically, the patients in Group 1 had admission motor scores significantly lower than the other two groups. At follow-up examination, the median percent motor recovery was 9% for Group 1, 41% for Group 2, and 72% for Group 3.

These studies suggest that the MR imaging pattern observed in the acutely injured human spinal cord has a prognostic significance in the final outcome of the motor system. It is only when an accurate prognosis can be given at the outset that useful treatment data might be collected for homogeneous injury groups, and accurately based long-term planning made for the best patient care.

Restricted access

George M. Ghobrial, Richard Dalyai, Adam E. Flanders and James Harrop

The authors describe a patient who presented with acute tetraparesis and a proposed acute traumatic spinal cord injury that was the result of nitrous oxide myelopathy. This 19-year-old man sustained a traumatic fall off a 6-ft high wall. His examination was consistent with a central cord syndrome with the addition of dorsal column impairment. Cervical MRI demonstrated an isolated dorsal column signal that was suggestive of a nontraumatic etiology. The patient's symptoms resolved entirely over the course of 48 hours.

Nitrous oxide abuse is increasing in prevalence. Its toxic side effects can mask vitamin B12 and folate deficiency and central cord syndrome. The patient's history and radiographic presentation are key to establishing a diagnosis.

Full access

Benjamin Zussman, Pascal Jabbour, Kiran Talekar, Richard Gorniak and Adam E. Flanders

Object

Although dynamic, first-pass cerebral CT perfusion is used in the evaluation of acute ischemic stroke, a lack of standardization restricts the value of this imaging modality in clinical decision-making. The purpose of this study was to comprehensively review the reported sources of variability and error in cerebral CT perfusion results.

Methods

A systematic literature review was conducted, 120 articles were reviewed, and 23 published original research articles were included. Sources of variability and error were thematically categorized and presented within the context of the 3 stages of a typical CT perfusion study: data acquisition, postprocessing, and results interpretation.

Results

Seven factors that caused variability were identified and described in detail: 1) contrast media, the iodinated compound injected intravascularly to permit imaging of the cerebral vessels; 2) data acquisition rate, the number of images obtained by CT scan per unit time; 3) user inputs, the subjective selections that operators make; 4) observer variation, the failure of operators to repeatedly measure a perfusion parameter with precision; 5) software operational mode, manual, semiautomatic, or automatic; 6) software design, the mathematical algorithms used to perform postprocessing; and 7) value type, absolute versus relative values.

Conclusions

Standardization at all 3 stages of the CT perfusion study cycle is warranted. At present, caution should be exercised when interpreting CT perfusion results as these values may vary considerably depending on a variety of factors. Future research is needed to define the role of CT perfusion in clinical decision-making for acute stroke patients and to determine the clinically acceptable limits of variability in CT perfusion results.

Full access

Arvind Rao, Ganesh Rao, David A. Gutman, Adam E. Flanders, Scott N. Hwang, Daniel L. Rubin, Rivka R. Colen, Pascal O. Zinn, Rajan Jain, Max Wintermark, Justin S. Kirby, C. Carl Jaffe, John Freymann and TCGA Glioma Phenotype Research Group

OBJECT

Individual MRI characteristics (e.g., volume) are routinely used to identify survival-associated phenotypes for glioblastoma (GBM). This study investigated whether combinations of MRI features can also stratify survival. Furthermore, the molecular differences between phenotype-induced groups were investigated.

METHODS

Ninety-two patients with imaging, molecular, and survival data from the TCGA (The Cancer Genome Atlas)-GBM collection were included in this study. For combinatorial phenotype analysis, hierarchical clustering was used. Groups were defined based on a cutpoint obtained via tree-based partitioning. Furthermore, differential expression analysis of microRNA (miRNA) and mRNA expression data was performed using GenePattern Suite. Functional analysis of the resulting genes and miRNAs was performed using Ingenuity Pathway Analysis. Pathway analysis was performed using Gene Set Enrichment Analysis.

RESULTS

Clustering analysis reveals that image-based grouping of the patients is driven by 3 features: volume-class, hemorrhage, and T1/FLAIR-envelope ratio. A combination of these features stratifies survival in a statistically significant manner. A cutpoint analysis yields a significant survival difference in the training set (median survival difference: 12 months, p = 0.004) as well as a validation set (p = 0.0001). Specifically, a low value for any of these 3 features indicates favorable survival characteristics. Differential expression analysis between cutpoint-induced groups suggests that several immune-associated (natural killer cell activity, T-cell lymphocyte differentiation) and metabolism-associated (mitochondrial activity, oxidative phosphorylation) pathways underlie the transition of this phenotype. Integrating data for mRNA and miRNA suggests the roles of several genes regulating proliferation and invasion.

CONCLUSIONS

A 3-way combination of MRI phenotypes may be capable of stratifying survival in GBM. Examination of molecular processes associated with groups created by this combinatorial phenotype suggests the role of biological processes associated with growth and invasion characteristics.

Restricted access

Nohra Chalouhi, Nikolaos Mouchtouris, Fadi Al Saiegh, Somnath Das, Ahmad Sweid, Adam E. Flanders, Robert M. Starke, Michael P. Baldassari, Stavropoula Tjoumakaris, Michael Reid Gooch, Syed Omar Shah, David Hasan, Nabeel Herial, Robin D’Ambrosio, Robert Rosenwasser and Pascal Jabbour

OBJECTIVE

MRI and MRA studies are routinely obtained to identify the etiology of intracerebral hemorrhage (ICH). The diagnostic yield of MRI/MRA in the setting of an acute ICH, however, remains unclear. The authors’ goal was to determine the utility of early MRI/MRA in detecting underlying structural lesions in ICH and to identify patients in whom additional imaging during hospitalization could safely be foregone.

METHODS

The authors reviewed data obtained in 400 patients with spontaneous ICH diagnosed on noncontrast head CT scans who underwent MRI/MRA between 2015 and 2017 at their institution. MRI/MRA studies were reviewed to identify underlying lesions, such as arteriovenous malformations, aneurysms, cavernous malformations, arteriovenous fistulas, tumors, sinus thrombosis, moyamoya disease, and abscesses.

RESULTS

The median patient age was 65 ± 15.8 years. Hypertension was the most common (72%) comorbidity. Structural abnormalities were detected on MRI/MRA in 12.5% of patients. Structural lesions were seen in 5.7% of patients with basal ganglia/thalamic ICH, 14.1% of those with lobar ICH, 20.4% of those with cerebellar ICH, and 27.8% of those with brainstem ICH. Notably, the diagnostic yield of MRI/MRA was 0% in patients > 65 years with a basal ganglia/thalamic hemorrhage and 0% in those > 85 years with any ICH location, whereas it was 37% in patients < 50 years and 23% in those < 65 years. Multivariate analysis showed that decreasing age, absence of hypertension, and non–basal ganglia/thalamic location were predictors of finding an underlying lesion.

CONCLUSIONS

The yield of MRI/MRA in ICH is highly variable, depending on patient age and hemorrhage location. The findings of this study do not support obtaining early MRI/MRA studies in patients ≥ 65 years with basal ganglia/thalamic ICH or in any ICH patients ≥ 85 years. In all other situations, early MRI/MRA remains valuable in ruling out underlying lesions.