Table of Contents
Perspectives
Editorial
Health Care Reform Vignette
General Contents
- Nigrosome 1 Detection at 3T MRI for the Diagnosis of Early-Stage Idiopathic Parkinson Disease: Assessment of Diagnostic Accuracy and Agreement on Imaging Asymmetry and Clinical Laterality
Nigrosomes are calbindin-poor zones within the substantia nigra pars compacta, and are the primary subregion where dopaminergic cells are lost in Parkinson disease. High-resolution 3D multiecho imaging was performed at 3T in 13 healthy subjects and 24 patients with idiopathic Parkinson disease confirmed by 18F-FP-CIT PET. Diagnostic sensitivity, specificity, and accuracy of the nigrosome 1 detection at 3T MR imaging was 100%, 84.6%, and 94.6%, respectively. Further, the clinical laterality was in high concordance with the laterality of the nigrosome 1 detection.
- Ultra-High-Field MRI Visualization of Cortical Multiple Sclerosis Lesions with T2 and T2*: A Postmortem MRI and Histopathology Study
At 7T, 2D multiecho spin-echo T2WI and 3D gradient-echo T2*WI were acquired from 27 formalin-fixed coronal hemispheric brain sections of 15 patients and 4 healthy controls. Proteolipid-stained tissue sections were matched to the corresponding MR images, and lesions were manually scored on both MR imaging sequences and tissue sections. The T2WI sequence detected slightly more lesions than the T2*WI sequence (28% and 16%). When histopathologic information (type, location) was revealed to the reader, the sensitivity went up to 84%. Many lesions are still missed prospectively.
- The Contribution of Common Surgically Implanted Hardware to Functional MR Imaging Artifacts
The authors calculated the BOLD-dependent MR imaging artifact impact arising from surgically implanted hardware through a retrospective analysis of fMRIs acquired from 2006–2014. Mean artifact volume associated with intracranial hardware was 4.3 cubic centimeters. The mean artifact volume from extracranial hardware in patients with cerebrovascular disease was 28.4 cubic centimeters. Artifacts had no-to-mild effects on clinical interpretability in all patients with intracranial implants. Extracranial hardware artifacts had no-to-moderate impact on clinical interpretability. The exceptions to interpretability in the face of hardware were ventriculoperitoneal shunts, particularly those with programmable valves and siphon gauges, and large numbers of KLS-Martin maxDrive screws.
- Clinical and Imaging Follow-Up of Patients with Coiled Basilar Tip Aneurysms Up to 20 Years
Clinical follow-up of 144 of 154 patients who survived the admission period (January 1995–August 2006) was for a mean of 9.8 years. Aneurysm size of 15 mm was the most important independent predictor for retreatment. Nine rebleeds occurred in 106 patients who initially presented with SAH after a median follow-up of 8.3 years. Eight patients died of aneurysm-related adverse events: 3 of rebleed and 5 of progressive mass effect. Life-long MRA follow-up at yearly intervals is recommended.
- Carotid Webs and Recurrent Ischemic Strokes in the Era of CT Angiography
Carotid web was defined on CTA as a thin intraluminal filling defect along the posterior wall of the carotid bulb just beyond the carotid bifurcation on oblique sagittal section CTA that was seen as a septum on axial CTA. In the prospective series in this study, the mean age was 50 years, and 5 of 7 patients were women. Recurrent stroke was seen in 5 of 7. Histopathology suggested a high probability of fibromuscular dysplasia. In the retrospective series, carotid webs were seen in 7 of 576 patients. Carotid web may be an important cause of ischemic stroke in patients with otherwise no determined mechanism of stroke and may present a high risk of recurrent stroke.
- CT Metal Artifact Reduction in the Spine: Can an Iterative Reconstruction Technique Improve Visualization?
CT images were reconstructed by using weighted filtered back-projection and iterative metal artifact reduction. Two neuroradiologists evaluated images in the region of spinal hardware and assigned a score for the visualization of critical anatomic structures by using soft-tissue and bone windows. Using bone windows, they measured the length of the most pronounced linear artifacts. Visualization of critical soft-tissue anatomic structures was significantly improved by using iterative metal artifact reduction, but there was not a significant improvement in visualization of critical osseous structures. Routine generation of these iterative reconstructed images in addition to routine weighted filtered back-projection is recommended.
