Neuroradiologists Compared with Non-Neuroradiologists in the Detection of New Multiple Sclerosis Plaques.

BACKGROUND AND PURPOSE: Multiple sclerosis monitoring is based on the detection of new lesions on brain MR imaging. Outside of study populations, MS imaging studies are reported by radiologists with varying expertise. The aim of this study was to investigate the accuracy of MS reporting performed by neuroradiologists (someone who had spent at least 1 year in neuroradiology subspecialty training) versus non-neuroradiologists. MATERIALS AND METHODS: Patients with ≥2 MS studies with 3T MR imaging that included a volumetric T2 FLAIR sequence performed between 2009 and 2011 inclusive were recruited into this study. The reports for these studies were analyzed for lesions detected, which were categorized as either progressed or stable. The results from a previous study using a semiautomated assistive software for lesion detection were used as the reference standard. RESULTS: There were 5 neuroradiologists and 5 non-neuroradiologists who reported all studies. In total, 159 comparison pairs (ie, 318 studies) met the selection criteria. Of these, 96 (60.4%) were reported by a neuroradiologist. Neuroradiologists had higher sensitivity (82% versus 42%), higher negative predictive value (89% versus 64%), and lower false-negative rate (18% versus 58%) compared with non-neuroradiologists. Both groups had a 100% positive predictive value. CONCLUSIONS: Neuroradiologists detect more new lesions than non-neuroradiologists in reading MR imaging for follow-up of MS. Assistive software that aids in the identification of new lesions has a beneficial effect for both neuroradiologists and non-neuroradiologists, though the effect is more profound in the non-neuroradiologist group.

Impact of increasing overnight intensive care unit registrar staffing on duration of intubation of elective cardiac surgery patients.

It is unclear whether increases to overnight junior medical staffing levels can improve ICU patient outcomes. We conducted a retrospective cohort study before and after the introduction of a third overnight ICU registrar at a 24-bed metropolitan ICU in February 2012. We hypothesised that this change would be associated with decreased intubation time for elective cardiac surgery patients and an increase in the proportion of these patients being extubated during the overnight period. All elective cardiac surgery patients were included from two temporally matched six-month periods (May to October) in 2011 and 2012. The primary outcome was median duration of intubation, and the secondary outcome was proportion of patients extubated during the 'overnight' period (2200 to 0700). A total of 142 and 188 patients were included in the control and intervention cohorts, respectively. Median (IQR) intubation time was 8.7 (6.6 to 14.5) hours in the control cohort and 8.2 (6.0 to 13.4) hours in the intervention cohort, with no significant difference between groups (P=0.40). The proportion of elective cardiac surgery patients extubated during the overnight period was similar, 54.2% in the control group compared to 50.0% in intervention group (P=0.45). In our unit, increasing overnight ICU registrar staffing levels was not associated with a significant reduction in duration of intubation for elective cardiac surgery patients or a reduction in the proportion of these patients extubated overnight. This is likely due to factors other than medical staffing levels influencing timing of extubation of these patients.

Improving Multiple Sclerosis Plaque Detection Using a Semiautomated Assistive Approach.

BACKGROUND AND PURPOSE: Treating MS with disease-modifying drugs relies on accurate MR imaging follow-up to determine the treatment effect. We aimed to develop and validate a semiautomated software platform to facilitate detection of new lesions and improved lesions. MATERIALS AND METHODS: We developed VisTarsier to assist manual comparison of volumetric FLAIR sequences by using interstudy registration, resectioning, and color-map overlays that highlight new lesions and improved lesions. Using the software, 2 neuroradiologists retrospectively assessed MR imaging MS comparison study pairs acquired between 2009 and 2011 (161 comparison study pairs met the study inclusion criteria). Lesion detection and reading times were recorded. We tested inter- and intraobserver agreement and comparison with original clinical reports. Feedback was obtained from referring neurologists to assess the potential clinical impact. RESULTS: More comparison study pairs with new lesions (reader 1, n = 60; reader 2, n = 62) and improved lesions (reader 1, n = 28; reader 2, n = 39) were recorded by using the software compared with original radiology reports (new lesions, n = 20; improved lesions, n = 5); the difference reached statistical significance (P < .001). Interobserver lesion number agreement was substantial (≥1 new lesion: κ = 0.87; 95% CI, 0.79-0.95; ≥1 improved lesion: κ = 0.72; 95% CI, 0.59-0.85), and overall interobserver lesion number correlation was good (Spearman ρ: new lesion = 0.910, improved lesion = 0.774). Intraobserver agreement was very good (new lesion: κ = 1.0, improved lesion: κ = 0.94; 95% CI, 0.82-1.00). Mean reporting times were <3 minutes. Neurologists indicated retrospective management alterations in 79% of comparative study pairs with newly detected lesion changes. CONCLUSIONS: Using software that highlights changes between study pairs can improve lesion detection. Neurologist feedback indicated a likely impact on management.

MRI grading versus histology: predicting survival of World Health Organization grade II-IV astrocytomas.

BACKGROUND AND PURPOSE: Histologic grading of intracranial astrocytomas is affected by sampling error and substantial inter- and intraobserver variability. We proposed that incorporating MR imaging into grading will predict patient survival more accurately than histopathology alone. MATERIALS AND METHODS: Patients with a new diagnosis of World Health Organization grades II-IV astrocytoma or mixed oligoastrocytoma diagnosed between September 2007 and December 2010 were identified. Two hundred forty-five patients met the inclusion criteria. Preoperative MRIs were independently reviewed by 2 readers blinded to the histologic grade, and an MR imaging grade was given. The MR imaging and histopathologic grades were compared with patient survival. RESULTS: Patients with grade II or III astrocytomas on histology but evidence of necrosis on MR imaging (consistent with a grade IV tumor) had significantly worse survival than patients with the same histology but no evidence of necrosis on MR imaging (P = .002 for grade II histology and P = .029 for grade III). Their survival was not significantly different from that in patients with grade IV tumors on histology (P = .164 and P = .385, respectively); this outcome suggests that all or most are likely to have truly been grade IV tumors. MR imaging evidence of necrosis was less frequent in grade II and III oligoastrocytomas, preventing adequate subgroup analysis. CONCLUSIONS: MR imaging can improve grading of intracranial astrocytomas by identifying patients suspected of being undergraded by histology, with high interobserver agreement. This finding has the potential to optimize patient management, for example, by encouraging more aggressive treatment earlier in the patient's course.