Scoring flow restoration in cerebral angiograms after endovascular revascularization in acute ischemic stroke patients.

Endovascular revascularization techniques are increasingly used to treat arterial occlusions in patients with acute ischemic stroke. To monitor and communicate treatment results, a valid, reproducible, and clinically relevant, yet easy to use grading scheme of arterial recanalization and tissue reperfusion for digital subtraction angiography is needed. An ideal scoring system would consider the target arterial lesion, the perfusion deficit, and the collateral status before treatment and measure recanalization, reperfusion, early venous shunting, vasospasm, as well as distal embolization after flow restoration. Currently, a variety of different flow restoration scales are in use, including the Thrombolysis in Myocardial Infarction scoring system, the Thrombolysis in Cerebral Infarction score, and the Arterial Occlusive Lesion score, which describe the local recanalization result. These scores are not used homogeneously throughout the literature, are often modified and not fully documented, which make them inept to compare treatment effects across studies. In addition, none of these scores cover all of the above-mentioned aspects, nor are they able to describe satisfactorily all relevant angiographic findings, and data on their reliability and predictive power regarding clinical outcome are sparse. We aimed to review and illustrate the different revascularization scales, discuss their advantages and limitations as well as the available data regarding standardization, reliability testing, and outcome prediction. In addition, we give examples for the use of the scales and show potential pitfalls.

Central Review of Amyloid-Related Imaging Abnormalities in Two Phase III Clinical Trials of Bapineuzumab in Mild-To-Moderate Alzheimer's Disease Patients.

BACKGROUND: Amyloid-related imaging abnormalities (ARIA) consist of ARIA-E (with effusion or edema) and ARIA-H (hemosiderin deposits [HDs]). OBJECTIVES: To address accurate ascertainment of ARIA identification, a final magnetic resonance imaging (MRI) reading was performed on patients with mild-to-moderate Alzheimer's disease randomized to bapineuzumab IV or placebo during two Phase III trials (APOE ɛ4 allele carriers or noncarriers). METHODS: Final MRI central review consisted of a systematic sequential locked, adjudicated read in 1,331 APOE ɛ4 noncarriers and 1,121 carriers by independent neuroradiologists. Assessment of ARIA-E, ARIA-H, intracerebral hemorrhages, and age-related white matter changes is described. RESULTS: In the Final Read, treatment-emergent ARIA-E were identified in 242 patients including 76 additional cases not noted previously in real time. Overall, incidence proportion of ARIA-E was higher in carriers (active 21.2%; placebo 1.1%) than in noncarriers (pooled active 11.3%; placebo 0.6%), and was more often identified in homozygote APOE ɛ4 carriers than heterozygotes (34.5% versus 16.9%). Incidence rate of ARIA-E increased with increased dose in noncarriers. Frequency of ARIA-E first episodes was highest after the first and second bapineuzumab infusion and declined after repeated infusions. Incidence of total HDs <10 mm (cerebral microhemorrhages) was higher in active groups versus placebo. CONCLUSION: ARIA was detected more often on MRI scans when every scan was reviewed by trained neuroradiologists and results adjudicated. There was increased incidence of ARIA-E in bapineuzumab-treated carriers who had a microhemorrhage at baseline. ARIA-E was a risk factor for incident ARIA-H and late onset ARIA-E was milder radiologically. Age-related white matter changes did not progress during the study.

Instrument for measuring angles in spine radiographs.

This study describes an instrument that is simple to use when measuring angles in spine radiographs. Compared to the conventional method, measurements obtained with this instrument are reproducible and are less time-consuming.

Multispectral analysis of bone lesions in the hands of patients with rheumatoid arthritis.

Quantitative measures of rheumatoid arthritis (RA) disease progression can provide valuable tools for evaluation of new treatments during clinical trials. In this study, a novel multispectral (MS) MRI analysis method is presented to quantify changes in bone lesion volume (DeltaBLV) in the hands of RA patients. Image registration and MS analysis were employed to identify MS tissue class transitions between two serial MRI exams. DeltaBLV was determined from MS class transitions between two time points. The following three classifiers were investigated: (a) multivariate Gaussian (MVG), (b) k-nearest neighbor (k-NN), and (c) K-means (KM). Unlike supervised classifiers (MVG, k-NN), KM, an unsupervised classifier, does not require labeled training data, resulting in potentially greater clinical utility. All MS estimates of DeltaBLV were linearly correlated (r(p)) with manual estimates. KM and k-NN estimates also exhibited a significant rank-order correlation (r(s)) with manual estimates. For KM, r(p) = 0.94 p < 0.0001, r(s) = 0.76 p = 0.002; for k-NN, r(p) = 0.86 p = 0.0001, r(s) = 0.69 p = 0.009; and for MVG, r(p) = 0.84 p = 0.0003, r(s) = 0.49 p = 0.09. Temporal classification rates were as follows: for KM, 90.1%; for MVG, 89.5%; and for k-NN, 86.7%. KM matched the performance of k-NN, offering strong potential for use in multicenter clinical trials. This study demonstrates that MS tissue class transitions provide a quantitative measure of DeltaBLV.

Neuroradiological findings in vascular dementia.

INTRODUCTION: There are multiple diagnostic criteria for vascular dementia (VaD) that may define different populations. Utilizing the criteria of the National Institute of Neurological Disorders and Stroke and Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) has provided improved consistency in the diagnosis of VaD. The criteria include a table listing brain imaging lesions associated with VaD. METHODS: The different neuroradiological aspects of the criteria are reviewed based on the imaging data from an ongoing large-scale clinical trial testing a new treatment for VaD. The NINDS-AIREN criteria were applied by a centralized imaging rater to determine eligibility for enrollment in 1,202 patients using brain CT or MRI. RESULTS: Based on the above data set, the neuroradiological features that are associated with VaD and that can result from cerebral small-vessel disease with extensive leukoencephalopathy or lacunae (basal ganglia or frontal white matter), or may be the consequence of single strategically located infarcts or multiple infarcts in large-vessel territories, are illustrated. These features may also be the consequence of global cerebral hypoperfusion, intracerebral hemorrhage, or other mechanisms such as genetically determined arteriopathies. CONCLUSION: Neuroimaging confirmation of cerebrovascular disease in VaD provides information about the topography and severity of vascular lesions. Neuroimaging may also assist with the differential diagnosis of dementia associated with normal pressure hydrocephalus, chronic subdural hematoma, arteriovenous malformation or tumoral diseases.

Invasive central nervous system aspergillosis in bone marrow transplantation recipients: an overview.

Invasive central nervous system aspergillosis is being seen with an increased frequency, particularly due to the increased number of immunosuppressed patients. The major cause of invasive central nervous system aspergillosis is bone marrow transplantation. In most cases, aspergillosis develops in the paranasal sinuses and in the lungs, and secondarily spreads to the brain. Imaging of cerebral aspergillosis may present different patterns depending on the lesion's age and the immunologic status of the patient. Lesions of the spinal cord are far less common but has been encountered in our series. In this article we review the clinical and radiologic features of aspergillosis affecting the central nervous system in patients who underwent bone marrow transplantation. Different CT and MR patterns are presented, including pertinent clinical and pathologic material. Significant morbidity and mortality can be associated with this fungal infection, and it is therefore incumbent upon the radiologist to identify intracranial aspergillosis as early as possible so that appropriate therapy can be administered.

CT and MR imaging of central nervous system effects of therapy in patients treated for hematological malignancies.

The purpose of this article is to present the imaging appearance of central nervous system effects of therapy that may occur in patients treated for hematological malignancies. Imaging in these patients relates to complications of high-dose therapy, bone marrow transplantation, infections occurring in immunocompromised patients, central nervous system dysfunction due to failure of other organ systems, or cerebral hemorrhages due to platelet refractoriness. Rapid and accurate diagnosis is essential but often difficult, as neurological manifestations are rarely disease specific. Neurological imaging, in combination with electrophysiological studies as well as blood and cerebrospinal fluid investigations, may be helpful for diagnosing most of these complications, as well as in differentiating between the manifestations of the underlying disease and complications of the treatment.

Use of multispectral magnetic resonance imaging analysis to quantify erosive changes in the hands of patients with rheumatoid arthritis: short-term and long-term longitudinal studies.

OBJECTIVE: Magnetic resonance imaging (MRI) has been shown to be more sensitive than radiography for detecting bone erosions in rheumatoid arthritis (RA). Semiquantitative scoring based on visual image assessment has been introduced. However, there is considerable interest in true quantitative measures, particularly in the context of clinical trials designed to show differences between treatment groups. This study was undertaken to investigate the use of a new quantitative approach, multispectral (MS) image analysis, for assessing erosive change. METHODS: T1-weighted spin-echo (SE) and fat-suppressed gradient-echo (GE) sequences of metacarpophalangeal joints of the dominant hand were acquired at various time points throughout a 2-year period. MS analysis was applied to all images, resulting in segmentation into a generalized bone and a soft tissue class. Voxel changes from one to the other class identified apparent bone lesion volume change (Delta BLV). MR images were also visually scored for erosions (E score). All analyses were performed separately, on a per-joint basis, for short-term and long-term data sets. RESULTS: Analysis of variance with adjustment for individual effect revealed similar results in the short-term and the long-term studies, using either GE or SE images for visual assessment. Patients with an increase in E score on visual assessment had a significantly higher Delta BLV than those without. CONCLUSION: Temporal MS analysis of MRIs can be used to detect and quantify erosive changes in RA. This semiautomated method may be useful for demonstrating differences between treatment groups in clinical trials.

MR findings in knee osteoarthritis.

Knee osteoarthritis (OA) is a leading cause of disability. Recent advances in drug discovery techniques and improvements in understanding the pathophysiology of osteoarthritic disorders have resulted in an unprecedented number of new therapeutic agents. Of all imaging modalities, radiography has been the most widely used for the diagnosis and management of the progression of knee OA. Magnetic resonance imaging is a relatively recent technique and its applications to osteoarthritis have been limited. Compared with conventional radiography, MR imaging offers unparalleled discrimination among articular soft tissues by directly visualizing all components of the knee joint simultaneously and therefore allowing the knee joint to be evaluated as a whole organ. In this article we present the MR findings in knee OA including cartilage abnormalities, osteophytes, bone edema, subarticular cysts, bone attrition, meniscal tears, ligament abnormalities, synovial thickening, joint effusion, intra-articular loose bodies, and periarticular cysts.

Fixed-flexion radiography of the knee provides reproducible joint space width measurements in osteoarthritis.

The validity of a non-fluoroscopic fixed-flexion radiographic acquisition and analysis protocol for measurement of joint space width (JSW) in knee osteoarthritis is determined. A cross-sectional study of 165 patients with documented knee osteoarthritis participating in a multicenter, prospective study of chondroprotective agents was performed. All patients had posteroanterior, weight-bearing, fixed-flexion radiography with 10 degrees caudal beam angulation. A specially designed frame (SynaFlexer) was used to standardize the positioning. Minimum medial and lateral JSW were measured manually and twice by an automated analysis system to determine inter-technique and intra-reader concordance and reliability. A random subsample of 30 patients had repeat knee radiographs 2 weeks apart to estimate short-term reproducibility using automated analysis. Concordance between manual and automated medial JSW measurements was high (ICC=0.90); lateral compartment measurements showed somewhat less concordance (ICC=0.72). There was excellent concordance between repeated automated JSW measurements performed 6 months apart for the medial (ICC=0.94) and lateral (ICC=0.86) compartments. Short-term reproducibility for the subsample of 30 cases with repeat acquisitions demonstrated an average SD of 0.14 mm for medial JSW (CV=4.3%) and 0.23 mm for lateral JSW (CV=4.0%). Fixed-flexion radiography of the knee using a positioning device provides consistent, reliable and reproducible measurement of minimum JSW in knee osteoarthritis without the need for concurrent fluoroscopic guidance.