Thirty percent of wrist fractures were not prospectively diagnosed on radiography, suggesting that CT should be considered after a negative radiographic finding if clinically warranted. The location of a dorsal scaphoid avulsion fracture emphasizes the need for specific radiographic views or cross-sectional imaging for diagnosis.

Sonication is a simple method for reducing the size of liposomes. We report the size distributions of liposomes as a function of sonication time using three different techniques. Liposomes, mildly sonicated for just 30 sec, had bimodal distributions when surface-weighted with modes at about 140 and 750 nm. With extended sonication, the size distribution remains bimodal but the average diameter of each population decreases and the smaller population becomes more numerous. Independent measurements of liposome size using Dynamic Light Scattering (DLS), transmission electron microscopy (TEM), and the nystatin/ergosterol fusion assay all gave consistent results. The bimodal distribution (even when number-weighted) differs from the Weibull distribution commonly observed for liposomes sonicated at high powers over long periods of time and suggests that a different mechanism may be involved in mild sonication. The observations are consistent with the following mechanism for decreasing liposome size. During ultrasonic irradiation, cavitation, caused by oscillating microbubbles, produces shear fields. Large liposomes that enter these fields form long tube-like appendages that can pinch-off into smaller liposomes. This proposed mechanism is consistent with colloidal theory and the observed behavior of liposomes in shear fields.

The 2010 RAD-AID Conference on International Radiology for Developing Countries was a multidisciplinary meeting to discuss data, experiences, and models pertaining to radiology in the developing world, where widespread shortages of imaging services reduce health care quality. The theme of this year’s conference was sustainability, with a focus on establishing and maintaining imaging services in resource-limited regions. Conference presenters and participants identified 4 important components of sustainability: (1) sustainable financing models for radiology development, (2) integration of radiology and public health, (3) sustainable clinical models and technology solutions for resource-limited regions, and (4) education and training of both developing and developed world health care personnel.

We present a case of bilateral retropharyngeal parathyroid hyperplasia detected with 4D-CT in a patient with persistent primary hyperparathyroidism and failed neck exploration. We discuss the embryologic basis of ectopic retropharyngeal parathyroid adenomas and hyperplasia and the utility of 4D-CT in their localization for surgical planning.