Emergency MRI utilization trends at a tertiary care academic medical center: baseline data.

RATIONALE AND OBJECTIVES: This study evaluates utilization trends of emergency department (ED)-ordered magnetic resonance imaging (MRI) examinations in an adult academic medical center over a 5-year period (2001-2005). MATERIALS AND METHODS: MRI examinations from the ED-ordering location were identified by searching the radiology information system (RIS). Overall MRI volume and ED patient encounters were also assessed during the same period. Each examination was assessed by type of examination, examination completion time, and primary and secondary clinical indications by reviewing the RIS and medical record. RESULTS: During the study period, 1,900 ED-ordered MRI examinations were performed on 1,020 patients. During the same period, 62,823 total MRI examinations were performed, and the total ED patient volume was 420,840. ED-ordered MRI volume increased 391% over the study period (125 to 614 examinations/year), whereas total MRI volume increased only 38.9% and ED patient volume in our institution actually decreased by -9%. MRI examinations of the brain, magnetic resonance angiography of the head and neck, and spinal MRI were the most commonly ordered tests. Clinical indications were analyzed. Peak times of ED-ordered examination completion were between 4:00 PM and 11:00 PM. A total of 15.5% of examinations required overtime or callback of MRI technologists for completion. CONCLUSIONS: Multiple reasons are suggested that may increase utilization (perceived need for diagnostic certainty, as well as medico-legal and patient-driven factors). Whether this increase in MRI utilization resulted in improved patient outcomes is unclear and should be studied further. Implications for radiologist coverage and resident training are discussed.

Prevalence and demographics of methicillin resistant Staphylococcus aureus in culturable skin and soft tissue infections in an urban emergency department.

BACKGROUND: The rising incidence of methicillin resistant Staph. aureus (MRSA) infections is a concern for emergency practitioners. While studies have examined MRSA in inpatients, few have focused on emergency department populations. We sought to describe predictors of MRSA skin infections in an emergency department population. METHODS: This was a prospective observational cohort study conducted over three months in 2005. A convenience sample of patients with culturable skin infections presenting to a busy, urban emergency department was enrolled. Demographic and risk factor information was collected by structured interview. The predictive value of each risk factor for MRSA, as identified by culture, was tested using univariable logistic regression, and a multivariable predictive model was developed. RESULTS: Patients were 43% black, 40% female and mean age was 39 years (SD 14 years). Of the 182 patients with cultures, prevalence of MRSA was 58% (95%CI 50% to 65%). Significant predictors of MRSA were youth, lower body mass index, sexual contact in the past month, presence of an abscess cavity, spontaneous infection, and incarceration. The multivariable model had a C-statistic of 0.73 (95%CI 0.67 to 0.79) with four significant variables: age, group living, abscess cavity, and sexual contact within one month. CONCLUSION: In this population of emergency department patients, MRSA skin infection was related to youth, recent sexual contact, presence of abscess, low body mass index, spontaneity of infection, incarceration or contact with an inmate, and group home living.