Magnetic Resonance Imaging Availability Reduces Computed Tomography Use for Pediatric Appendicitis Diagnosis.

OBJECTIVES: To determine if introducing magnetic resonance imaging (MRI) as an imaging option for children with suspected appendicitis and an inconclusive ultrasound reduces computed tomography (CT) use. METHODS: This is a retrospective cohort study of patients aged 5 to 18 years who presented to a pediatric emergency department (ED) with suspected appendicitis. Rates of CT use 1 year before and 1 year after MRI availability are compared. Secondary outcomes include missed and negative appendectomies, imaging charges, time to antibiotics and surgery, time to radiology read, ED length of stay, and test characteristics of MRI and CT. RESULTS: Of the 981 patients screened, 499 patients met inclusion criteria. There was an absolute reduction of CT use of 25% from 38% in year 1 to 13% in year 2 (95% confidence interval, 18% to 33%). Advanced imaging charges were $371 higher in year 2 (MRI) than year 1 (CT), and median time to radiologist reads was longer in MRIs than CTs (129 versus 62 minutes; difference 53 minutes, 95% confidence interval, 23 to 74 minutes). All other secondary outcomes, including ED length of stay and test characteristics, were statistically similar. CONCLUSIONS: Introducing MRI for as an imaging option for children with suspected appendicitis and an inconclusive ultrasound markedly reduced CT use, but did result in a small increase in imaging charges and time to preliminary radiology read.

Primary Primitive Neuroectodermal Tumor Arising from an Ovarian Mature Cystic Teratoma in a 12-Year-Old Girl: A Case Report.

BACKGROUND: Ovarian mature cystic teratomas (MCTs) rarely transform to primary primitive neuroectodermal tumors. This case report offers evidence that MCTs might have undetected microfoci of malignant neural tumors. CASE: We describe the case of a 12-year-old girl who presented with right-sided abdominal pain and distention. Intraoperative findings revealed a right ovarian MCT. However, pathology showed a 0.5-cm focus of malignant neural tumor within the 11-cm MCT. SUMMARY AND CONCLUSION: This patient will need close follow-up with a multidisciplinary team because the clinical implications of this transformation has yet to be defined.

Evaluation of mulitprobe radiofrequency technology in a porcine model.

OBJECTIVE: We evaluated two new radiofrequency devices in an in vivo porcine model. MATERIALS AND METHODS: Multiprobe radiofrequency ablation (RFA) was used in a porcine model with an impedance-based algorithm in one experiment and clustered probes with and without switcher controllers in another; a Pringle maneuver was used with half of the ablations. RESULTS: The impedance experiment included 13 ablations, with a mean length of 7.0 cm and width of 2.9 cm (95% CI) and an average time of 596 s. Ablation volumes were significantly larger (54.1+/-11.7 cc(3) vs 34.9+/-4.8 cc(3), p<0.05) and ablation times were significantly shorter (359 s vs 834 s, p<0.05) for the Pringle group compared with the No Pringle group, respectively. The switcher controller experiment included 34 RFAs. Diameter (mm) (51.4 vs 40.3, p<0.0001), surface area (cm(2)) (22.4 vs 16.0, p<0.0002), and volume (cc) (66.1 vs 36.9, p<0.0001) were significantly larger for the combination probes with switcher controller compared with clustered probes, respectively. Ablation volumes for the Pringle vs No Pringle groups in the combination probes were 68.0 cc vs 64.3 cc and for the clustered probes 40.1 cc vs. 33.7 cc, respectively. CONCLUSION: Multiprobe ablations using RFA are promising technologies that need further study to evaluate their clinical utility.