Quantitative T2 -mapping magnetic resonance imaging for assessment of muscle motor unit recruitment patterns.

INTRODUCTION: In this study, we aimed to determine whether muscle transverse relaxation time (T2 ) magnetic resonance (MR) mapping results correlate with motor unit loss, as defined by motor unit recruitment patterns on electromyography (EMG). METHODS: EMG and 3-Tesla MRI exams were acquired no more than 31 days apart in subjects referred for peripheral nerve MRI. Two musculoskeletal radiologists qualitatively graded T2 -weighted, fat-suppressed sequences for severity of muscle edema-like patterns and manually placed regions of interest within muscles to obtain T2 values from T2 -mapping sequences. Concordance was calculated between qualitative and quantitative MR grades and EMG recruitment categories (none, discrete, decreased) as well as interobserver agreement for both MR grades. RESULTS: Thirty-four muscles (21 abnormal, 13 control) were assessed in 13 subjects (5 females and 8 males; mean age, 46 years) with 14 EMG-MRI pairs. T2 -relaxation times were significantly (P < .001) increased in all EMG recruitment categories compared with control muscles. T2 differences were not significant between EMG grades of motor unit recruitment (P = .151-.702). T2 and EMG score concordance was acceptable (Harrell's concordance index [c index]: rater A, 0.71; 95% confidence interval [CI], 0.51-0.87; rater B, 0.77; 95% CI, 0.57-0.91). Qualitative MRI and EMG score concordance was poor to acceptable (c index: rater A, 0.60; 95% CI, 0.50-0.79; rater B, 0.72; 95% CI, 0.55-0.89). T2 values had moderate-to-substantial ability to distinguish between absent vs incomplete (ie, decreased or discrete) motor unit recruitment (c index: rater A, 0.78; 95% CI, 0.50-1.00; rater B, 0.86; 95% CI, 0.57-1.00). DISCUSSION: Quantitative T2 MR muscle mapping is a promising tool for noninvasive evaluation of the degree of motor unit recruitment loss.

The causes of medical malpractice suits against radiologists in the United States.

PURPOSE: To determine the most frequent causes of malpractice suits as derived from credentialing data of 8401 radiologists. MATERIALS AND METHODS: This study was approved by the Institutional Review Board of New Jersey Medical School. A total of 8401 radiologists in 47 states participating in the network of One-Call Medical, a broker for computed tomographic/magnetic resonance studies in workers' compensation cases, were required to provide their malpractice history as part of their credentialing application. Of these, 2624 (31%) radiologists had at least one claim in their career. In each enrollee's credentialing file, if there was a claim against the enrollee there was a narrative regarding each malpractice case from which, in most instances, a primary allegation could be discerned. Among the 4793 cases, an alleged cause could be derived from the narrative in 4043 (84%). Statistical analysis was performed with Stata 12 (2011; Stata, College Station, Tex) software. RESULTS: The most common general cause was error in diagnosis (14.83 claims per 1000 person-years [95% confidence interval {CI}: 14.19, 15.51]). In this category, breast cancer was the most frequently missed diagnosis (3.57 claims per 1000 person-years [95% CI: 3.26, 3.91]), followed by nonspinal fractures (2.49 claims per 1000 person-years [95% CI: 2.28, 2.72]), spinal fractures (1.32 claims per 1000 person-years [95% CI: 1.16, 1.49]), lung cancer (1.26 claims per 1000 person-years [95% CI: 1.11, 1.42]), and vascular disease (1.08 claims per 1000 person-years [95% CI: 0.93, 1.24]). The category next in frequency was procedural complications (1.76 claims per 1000 person-years [95% CI: 1.58, 1.96]), followed by inadequate communication with either patient (0.40 claim per 1000 person-years [95% CI: 0.32, 0.50]) or referrer (0.71 claim per 1000 person-years [95% CI: 0.60, 0.84]). Radiologists had only a peripheral role in 0.92 claim per 1000 person-years (95% CI: 0.77, 1.10). Failure to recommend additional testing was a rare cause (0.41 claim per 1000 person-years [95% CI: 0.34, 0.50]). CONCLUSION: Errors in diagnosis are, by far, the most common generic cause of malpractice suits against radiologists. In this category, breast cancer was the most frequently missed diagnosis, followed by nonvertebral fractures and spinal fractures. Failure to communicate and failure to recommend additional testing are both uncommon reasons for initiating a suit.

The demography of medical malpractice suits against radiologists.

PURPOSE: To delimit demographic characteristics of malpractice claims against radiologists in the United States by sex and location and to note the varying percentages of favorable outcomes and award amounts to plaintiffs by state. MATERIALS AND METHODS: This HIPAA-compliant study was institutional review board-approved. All radiologists enrolled in One-Call Medical, a specialized preferred provider organization, go through an initial and recurrent credentialing process, which records state of residence, age, sex, and malpractice history. For each radiologist, a record of unfavorable outcomes and payment awards is derived from narratives provided by the National Practitioner's Data Bank. All other suits are self-reported. Rates of malpractice claims per state were calculated with a zero-inflated negative binomial regression model allowing for differences in years at risk. Poisson regression was used to calculate the incidence rate ratio (IRR) for any payment as a result of a malpractice claim compared with the average of all 36 states, adjusted for sex. To determine the association of age, sex, and state with amount of payment, we used a general linear model assuming a gamma family distribution. RESULTS: In August 2010, 8401 radiologists from 47 states composed One-Call Medical's panel. During their careers, 30.9% (2600 of 8401) had been the subject of at least one malpractice claim. Median payment awards varied by 14-fold from Maine ($350 000) to Colorado ($24 105), while mean payments varied ninefold from Oregon ($715 707) to Nebraska ($74 373). Adjusted for age and state, radiologists in Alabama had the lowest rate of malpractice suits per 100 practice-years for men (0.95; 95% confidence interval [CI]; 0.73, 1.28) and women (0.70; 95% CI: 0.52, 0.96) compared with those in New York, who had the highest rate of suits for men (5.65; 95% CI: 5.09, 6.26) and women (4.13; 95% CI: 3.54, 4.80). Overall, male radiologists had a higher rate of being sued than did their female counterparts (IRR = 1.37; 95% CI: 1.20, 1.56). CONCLUSION: The likelihood of a radiologist being the defendant in at least one suit is 50% by age 60, yet the difference in frequency and average number of suits accrued varies widely by state of residence and sex. Among resolved suits, the percentage of cases in which payment was made to the plaintiff differs markedly by state, as do median and mean award amount. Men are more likely than women to be sued during the course of their careers.