Phantom-based standardization of CT angiography images for spot sign detection.

PURPOSE: The CT angiography (CTA) spot sign is a strong predictor of hematoma expansion in intracerebral hemorrhage (ICH). However, CTA parameters vary widely across centers and may negatively impact spot sign accuracy in predicting ICH expansion. We developed a CT iodine calibration phantom that was scanned at different institutions in a large multicenter ICH clinical trial to determine the effect of image standardization on spot sign detection and performance. METHODS: A custom phantom containing known concentrations of iodine was designed and scanned using the stroke CT protocol at each institution. Custom software was developed to read the CT volume datasets and calculate the Hounsfield unit as a function of iodine concentration for each phantom scan. CTA images obtained within 8 h from symptom onset were analyzed by two trained readers comparing the calibrated vs. uncalibrated density cutoffs for spot sign identification. ICH expansion was defined as hematoma volume growth >33%. RESULTS: A total of 90 subjects qualified for the study, of whom 17/83 (20.5%) experienced ICH expansion. The number of spot sign positive scans was higher in the calibrated analysis (67.8 vs 38.9% p < 0.001). All spot signs identified in the non-calibrated analysis remained positive after calibration. Calibrated CTA images had higher sensitivity for ICH expansion (76 vs 52%) but inferior specificity (35 vs 63%) compared with uncalibrated images. CONCLUSION: Normalization of CTA images using phantom data is a feasible strategy to obtain consistent image quantification for spot sign analysis across different sites and may improve sensitivity for identification of ICH expansion.

Neurohospitalists: an emerging subspecialty.

Akin to the rapid growth in hospitalist medicine seen in the prior decade, there has been a recent explosion in the need for neurohospitalists. Factors driving this demand include nationally mandated quality and safety measures, the increasing complexity and age of the hospitalized patient, and diminished training in diagnosis and management of neurological illnesses for internal medicine residents. The role of the neurohospitalist is varied and may include not only providing neurological care to hospitalized patients but also serving as a leader in an institution's push to meet quality and safety measures. Close collaboration with intensivists, vascular neurologists, and outpatient neurologists is both a challenge and essential for successful delivery of care both during hospitalization and after discharge. Future challenges facing neurohospitalists include defining its relationship to other fields, instituting a pathway for certification, and conducting research to guide the development of evidence-based practice and quality measures.

Enrollment of research subjects through telemedicine networks in a multicenter acute intracerebral hemorrhage clinical trial: design and methods.

BACKGROUND: Enrollment of subjects in acute stroke trials is often hindered by narrow timeframes, because a large proportion of patients arrive via transfers from outside facilities rather than primary arrival at the enrolling hospital. RATIONALE: Telemedicine networks have been increasingly used for provision of care for acute stroke patients at facilities outside of major academic centers. Treatment decisions made through telemedicine networks in patients with acute ischemic stroke have been shown to be safe, reliable, and effective. With the expanding use of this technology and the impediments to enrolling subjects into clinical trials, this approach can be applied successfully to the field of clinical research. METHODS AND CONCLUSIONS: The Antihypertensive Treatment of Acute Cerebral Hemorrhage II trial is a phase III randomized multicenter trial that has developed a protocol in collaboration with participating sites to implement the use of telemedicine networks for the enrollment of research subjects. The protocol describes the operating procedures and legal and Institutional Review Board perspectives for its implementation.

Enrollment of Research Subjects through Telemedicine Networks in a Multicenter Acute Intracerebral Hemorrhage Clinical Trial: Design and Methods.

BACKGROUND: Enrollment of subjects in acute stroke trials is often hindered by narrow timeframes, because a large proportion of patients arrive via transfers from outside facilities rather than primary arrival at the enrolling hospital. RATIONALE: Telemedicine networks have been increasingly utilized for provision of care for acute stroke patients at facilities outside of major academic centers. Treatment decisions made through Telemedicine networks in patients with acute ischemic stroke have been shown to be safe, reliable, and effective. With the expanding use of this technology and the impediments to enrolling subjects into clinical trials, this approach can be applied successfully to the field of clinical research. METHODS AND CONCLUSIONS: The antihypertensive treatment of acute cerebral hemorrhage II trial is a phase III randomized multicenter trial that has developed a protocol in collaboration with participating sites to implement the use of Telemedicine networks for the enrollment of research subjects. The protocol describes the operating procedures and legal and Institutional Review Board perspectives for its implementation.