Linda Gray

Aspiration after stroke: Lesion analysis by brain MRI

Aspiration is a common problem following stroke, resulting in feeding difficulties and aspiration pneumonia. Despite past studies using clinical assessment and computed tomographic (CT) scans of the head, the correlation of stroke location with aspiration remains unclear. Since brain magnetic resonance imaging is more sensitive than CT for many stroke types, we have correlated MRI lesions with aspiration in patients who have sustained a stroke. We selected patients with acute stroke who underwent brain MRI and a swallowing evaluation. Aspiration was present in 21 of 38 patients (55%). Patients with just small vessel infarcts had a significantly lower occurrence of aspiration (3 of 14, 21%) compared to those with both large-and small-vessel infarcts (15 of 20, 75%, p=0.002). Multivariate analysis of several specific brain areas failed to identify a significant association between stroke location and the occurrence of aspiration. These findings suggest that patients who have experienced stroke should be individually evaluated for swallowing dysfunction regardless of stroke location or size, since even small-vessel strokes can be associated with aspiration in >20% of cases.

Assessment of aspiration risk in stroke patients with quantification of voluntary cough

Background: Dysphagia and subsequent aspiration are serious complications of acute stroke that may be related to an impaired cough reflex. It was hypothesized that aspirating stroke patients would have impaired objective measures of voluntary cough as compared with both nonstroke control subjects and nonaspirating stroke patients. Methods: Swallowing was evaluated by standard radiologic or endoscopic methods, and stroke patients were grouped by aspiration severity (severe, n = 11; mild, n = 17; no aspiration, n = 15). Airflow patterns and sound pressure level (SPL) of voluntary cough were measured in stroke patients and in a group of normal control subjects (n = 18). Initial stroke severity was determined retrospectively with the Canadian Neurological Scale. Results: All cough measures were altered in stroke patients as a group relative to nonstroke control subjects. Univariate analysis showed that peak flow of the inspiration phase (770.6 ± 80.6 versus 1,120.1 ± 148.4 mL/s), SPL (90.0 ± 3.1 versus 100.2 ± 1.6 dB), peak flow of the expulsive phase (875.1 ± 122.7 versus 1,884.1 ± 221.6 mL/s), expulsive phase rise time (0.34 ± 0.1 versus 0.09 ± 0.01 s), and cough volume acceleration (5.5 ± 1.3 versus 27.8 ± 3.9 mL/s/s) were significantly impaired in severe aspirators as compared with nonaspirators. Aspirating patients had more severe strokes than nonaspirators (mean Canadian Neurological Scale score 7.7 ± 0.7 versus 9.8 ± 0.3). Multivariate logistic regression found only expulsive phase rise time values during cough correlated with aspiration status. Conclusion: Objective analysis of cough may provide a noninvasive way to identify the aspiration risk of stroke patients.

Diagnosis of intracranial vasculitis: a multi-disciplinary approach.

Intracranial vasculitis, or primary angiitis of the central nervous system (PACNS), is an uncommon, often fatal disorder that frequently responds to aggressive immunosuppressive therapy. Magnetic resonance imaging (MRI), cerebral angiography, and brain biopsy are diagnostic modalities that vary in invasiveness and diagnostic accuracy. The purpose of this study was to determine whether certain clinical or radiologic features were predictive of a diagnostic biopsy. Thirty consecutive patients undergoing brain biopsy to “rule out vasculitis” were studied. Nine patients demonstrated granulomatous or lymphocytic vasculitis, 1 had lymphocytic vasculitis and encephalitis secondary to arbovirus infection, 5 had thickened vessels consistent with hypertensive changes, 5 had amyloid angiopathy and/or changes of Alzheimer disease, 5 demonstrated no pathologic abnormalities, and 1 each had acute infarct, vascular malformation, aneurysm, acellular fibrinoid necrosis, and demyelination. The spectrum of MRI and angiographic changes associated with PACNS were nonspecific, overlapping extensively with changes of chronic hypertension and amyloid deposition. The predictive values of brain biopsy (90–100%) were significantly higher than those of angiography (37–50%) or MRI (43–72%). In this study, morbidity associated with aggressive immunosuppression was significantly greater than that associated with cerebral angiography or brain biopsy. Thus, wedge biopsy of cortical and leptomeningeal tissues is central to the multi-disciplinary approach to a patient with clinical suspicion of PACNS.

Analysis of the anatomic changes of the aging facial skeleton using computer-assisted tomography.

Purpose: The bony skeleton serves as the scaffolding for the soft tissues of the face; however, age-related changes of bony morphology are not well defined. This study sought to compare the anatomic relationships of the facial skeleton and soft tissue structures between young and old men and women. Methods: A retrospective review of CT scans of 100 consecutive patients imaged at Duke University Medical Center between 2004 and 2007 was performed using the Vitrea software package. The study population included 25 younger women (aged 18–30 years), 25 younger men, 25 older women (aged 55–65 years), and 25 older men. Using a standardized reference line, the distances from the anterior corneal plane to the superior orbital rim, lateral orbital rim, lower eyelid fat pad, inferior orbital rim, anterior cheek mass, and pyriform aperture were measured. Three-dimensional bony reconstructions were used to record the angular measurements of 4 bony regions: glabellar, orbital, maxillary, and pyriform aperture. Results: The glabellar (p = 0.02), orbital (p = 0.0007), maxillary (p = 0.0001), and pyriform (p = 0.008) angles all decreased with age. The maxillary pyriform (p = 0.003) and infraorbital rim (p = 0.02) regressed with age. Anterior cheek mass became less prominent with age (p = 0.001), but the lower eyelid fat pad migrated anteriorly over time (p = 0.007). Conclusions: The facial skeleton appears to remodel throughout adulthood. Relative to the globe, the facial skeleton appears to rotate such that the frontal bone moves anteriorly and inferiorly while the maxilla moves posteriorly and superiorly. This rotation causes bony angles to become more acute and likely has an effect on the position of overlying soft tissues. These changes appear to be more dramatic in women.

The Consortium to Establish a Registry for Alzheimer's Disease (CERAD). Part III. Reliability of a standardized MRI evaluation of Alzheimer's disease

The Consortium to Establish a Registry for Alzheimers Disease (CERAD) has developed procedures for standardized imaging and reporting of magnetic resonance (MR) findings in Alzheimers disease (AD) for use by neuroradiologists in multiple medical centers using a variety of MR equipment and field strengths. After initial pretesting, we revised the protocol, expanded the summary rating scale to seven points, and added more illustrations. Fourteen participating neuroradiologists evaluated 28 MR scans of elderly patients, giving us the basis for judging interrater agreement. We obtained acceptable intraclass correlations (>0.79) for rating the size of the lateral and third ventricles and the temporal horn. Less satisfactory intraclass correlations occurred when rating other areas, including (1) global atrophy of the brain (0.70); (2) dilatation of the sulci of the temporal lobe (0.66); (3) frequency, location, and severity of white matter lesions (0.77); (4) sylvian fissure enlargement (0.70); and (5) cerebral sulcal dilatation (0.64). We also saw considerable variation in the reporting of cortical and lacunar infarcts. Despite careful design of the rating methodology and readings by experienced neuroradiologists, we did not find satisfactory interrater agreement for interpreting MR findings in elderly subjects. These findings may explain the difficulties encountered in applying similar subjective rating techniques that meet with success at one institution to multicenter studies. More objective and reproducible procedures are needed for interpretation of neuroimaging findings of AD in multicenter studies.

Intracerebral hemorrhage outcome: Apolipoprotein E genotype, hematoma, and edema volumes

Article abstract We investigated whether early hematoma or edema volumes could explain the adverse association between APOE ε4 and survival in intracerebral hemorrhage. Among 102 patients, ε4 carriers had a higher mortality rate than non–ε4 carriers (38 versus 24%, p = 0.05). Nonsurvivors had larger hematoma (75.5 cm3 versus 27.1 cm3, p < 0.001) and edema volumes (37.5 cm3 versus 17.1 cm3, p < 0.01), but these were not associated with ε4 after adjusting for race, age, and type of hemorrhage.

Stroke with negative brain magnetic resonance imaging.

Background and Purpose Magnetic resonance imaging (MRI) of the brain is replacing computed tomography in the diagnostic evaluation of acute ischeraic strokes. Past studies have suggested that MRI may not visualize all acute strokes, but few clinical details were included. To better understand the clinical characteristics of strokes not detected by MRI, we collected and reviewed case histories of several patients with acute stroke who had negative MRI scans. Methods Patients with a clinical diagnosis of stroke and negative brain MRI scans were ascertained from hospital records dating from 1989 to mid-1991. Patients with transient ischemic attacks, postictal paralysis, functional examinations, central nervous system infections, other nonstroke diagnoses, or equivocal findings were excluded. The MRI scans were performed with a GE Signa 1.5-T magnet in an axial plane (spin-echo repetition time/echo time: 500 msec/20 msec; 2,500 msec, 30 msec/80 msec). One patient received contrast material. Results We identified seven patients with clinically diagnosed ischemic stroke and negative brain MRI scan. Six of seven patients were scanned within 7 days of symptom onset and two patients within 24 hours. One patient was scanned 3 months after symptom onset The strokes not detected by MRI were clinically localized to the cortex (n=3), brain stem (n=3), and subcortical/lacunar area (n=1). One patient underwent two MRI scans, one with gadolinium. Conclusions These cases, while selected, illustrate some potential limitations of MRI for diagnosing stroke.

ACR Appropriateness Criteria® on Low Back Pain

Acute low back pain with or without radiculopathy is one of the most common health problems in the United States, with high annual costs of evaluation and treatment, not including lost productivity. Multiple reports show that uncomplicated acute low back pain or radiculopathy is a benign, self-limited condition that does not warrant any imaging studies. Guidelines for recognition of patients with more complicated status can be used to identify those who require further evaluation for suspicion of more serious problems and contribute to appropriate imaging utilization.

General competencies in radiology residency training: definitions, skills, education and assessment.

The Accreditation Council for Graduate Medical Education (ACGME) Outcome Project is a long-term initiative by which the ACGME is increasing emphasis on educational outcomes in the accreditation of residency education programs (http://www.acgme.org). The impetus for this project is a system of medical education that relies heavily on public funding and is therefore accountable to the public to meet public needs and prepare well-qualified new physicians as cost effectively as possible. The current model of accreditation focuses on the potential of a residency program to educate residents (ie, whether the program complies with the requirements, has established objectives and an organized curriculum, and evaluates the residents and itself). Examining structure and process, however, is not a direct way to measure the quality of a program’s educational outcomes. In future, accreditation will focus on a program’s actual accomplishments, through assessment of program outcomes (ie, whether residents achieve the stated learning objectives, whether the program provides evidence of this achievement, and whether it demonstrates continuous improvement in its educational process). The ACGME Outcome Project Advisory Committee identified six general competencies that were subsequently endorsed by the ACGME in February 1999: patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice. By July 2002 all Residency Review Committees (RRCs) must include minimum language regarding the general competencies and evaluation processes in their respective program requirements. A major activity of the Outcome Project was the identification and development of measurement tools for programs to use as part of an overall evaluation system. The ACGME and the American Board of Medical Specialties (ABMS) collaborated on developing a “Toolbox of Assessment Methods” (version 1.1, September 2000; ACGME/ABMS; http://www.acgme.org/outcome/assess /toolbox.asp). The Toolbox includes descriptions of instruments recommended for use by programs assessing the outcomes of their educational efforts, as well as information pertaining to the use, the psychometric qualities, and the feasibility and practicality of different assessment methods. A radiology “quadrad,” made up of representatives from the radiology RRC (including a resident member of the RRC), the American Board of Radiology (ABR), and the Association of Program Directors in Radiology (APDR), was formed in the spring of 2000 to interpret the six competencies as they relate to radiology. The Acad Radiol 2002; 9:721–726

Preoperative Transarterial Embolization of Spinal Column Neoplasms

PURPOSE To determine the safety and value of vertebral column embolization before surgical resection of vascular neoplastic disease. PATIENTS AND METHODS Thirty preoperative embolization procedures were performed in 20 patients with vascular neoplasms of the vertebral column (C-2 to sacrum). Fourteen patients had metastatic renal cell carcinoma. Distal embolic agents were used in 27 cases and were coupled with more proximal agents in six. Gelatin pledgets alone were used in three cases. Twenty-six of the 27 surgical procedures involved partial to complete tumor resection. RESULTS Seventy-two arteries were embolized (one to six per procedure). All surgical procedures were successful, and none were terminated because of blood loss. Massive blood loss occurred in one patient with paraganglioma, but embolization allowed complete vertebral resection at two levels. When this patient was excluded, blood loss ranged from 300 to 5,000 mL (mean, 1,871 mL). Transfusions required in 22 surgical procedures ranged from 1 to 10 units of packed red blood cells. Symptoms became worse after embolization in one case but improved with surgical decompression. CONCLUSION Embolization before surgery for spinal column neoplasms appears to safely and effectively limit blood loss.