Biliary and pancreatic ductal dilation in patients on methadone maintenance therapy.

PURPOSE: To determine whether the diameter of intrahepatic and extrahepatic bile ducts and pancreatic ducts in patients on methadone maintenance therapy is increased when compared with control subjects. METHODS: Between January 1, 2000 and March 15, 2013, a total of 97 patients (mean age 49.9, range 22-79, 65 male, 32 female) were identified who were receiving chronic methadone maintenance therapy (MMT) when they underwent imaging with abdominal MRI or a contrast-enhanced abdominopelvic CT. A group of 97 consecutive non-MMT control patients (mean age 51.4, range 21-86, 45 male, 52 female) who underwent imaging with abdominal MRI or contrast-enhanced abdominopelvic CT were identified. Patients with known pancreaticobiliary pathology that may confound biliary ductal measurements were excluded. Blinded interpretation was performed, documenting the diameters of the intrahepatic and extrahepatic bile ducts and pancreatic ducts. Descriptive statistics were performed. RESULTS: Patients on MMT demonstrated increased bile duct diameter, with an average increase in duct diameter of 2.39 mm for the common bile duct (p < 0.001; 95% CI 1.88-2.90 mm), 1.43 mm for the intrahepatic bile ducts (p < 0.001; 95% CI 1.12-1.74 mm), and 0.90 mm for the pancreatic duct (p < 0.001; 95% CI 0.64-1.16 mm). No statistically significant correlation was found between ductal diameters and the daily dose of methadone. CONCLUSION: Patients on methadone maintenance therapy demonstrate significantly increased intra- and extrahepatic bile duct and pancreatic duct diameter when compared with controls. There was no correlation between the dose of methadone and ductal diameter.

Tunable diacetylene polymerized shell microbubbles as ultrasound contrast agents.

Monodisperse gas microbubbles, encapsulated with a shell of photopolymerizable diacetylene lipids and phospholipids, were produced by microfluidic flow focusing, for use as ultrasound contrast agents. The stability of the polymerized shell microbubbles against both aggregation and gas dissolution under physiological conditions was studied. Polyethylene glycol (PEG) 5000, which was attached to the diacetylene lipids, was predicted by molecular theory to provide more steric hindrance against aggregation than PEG 2000, and this was confirmed experimentally. The polymerized shell microbubbles were found to have higher shell-resistance than nonpolymerizable shell microbubbles and commercially available microbubbles (Vevo MicroMarker). The acoustic stability under 7.5 MHz ultrasound insonation was significantly greater than that for the two comparison microbubbles. The acoustic stability was tunable by varying the amount of diacetylene lipid. Thus, our polymerized shell microbubbles are a promising platform for ultrasound contrast agents.

Changes in posture through the use of simple inclines with notebook computers placed on a standard desk.

This study evaluated the use of simple inclines as a portable peripheral for improving head and neck postures during notebook computer use on tables in portable environments such as hotel rooms, cafés, and airport lounges. A 3D motion analysis system measured head, neck and right upper extremity postures of 15 participants as they completed a 10 min computer task in six different configurations, all on a fixed height desk: no-incline, 12° incline, 25° incline, no-incline with external mouse, 25° incline with an external mouse, and a commercially available riser with external mouse and keyboard. After completion of the task, subjects rated the configuration for comfort and ease of use and indicated perceived discomfort in several body segments. Compared to the no-incline configuration, use of the 12° incline reduced forward head tilt and neck flexion while increasing wrist extension. The 25° incline further reduced head tilt and neck flexion while further increasing wrist extension. The 25° incline received the lowest comfort and ease of use ratings and the highest perceived discomfort score. For portable, temporary computing environments where internal input devices are used, users may find improved head and neck postures with acceptable wrist extension postures with the utilization of a 12° incline.

Notebook computer use on a desk, lap and lap support: effects on posture, performance and comfort.

This study quantified postures of users working on a notebook computer situated in their lap and tested the effect of using a device designed to increase the height of the notebook when placed on the lap. A motion analysis system measured head, neck and upper extremity postures of 15 adults as they worked on a notebook computer placed on a desk (DESK), the lap (LAP) and a commercially available lapdesk (LAPDESK). Compared with the DESK, the LAP increased downwards head tilt 6 degrees and wrist extension 8 degrees . Shoulder flexion and ulnar deviation decreased 13 degrees and 9 degrees , respectively. Compared with the LAP, the LAPDESK decreased downwards head tilt 4 degrees , neck flexion 2 degrees , and wrist extension 9 degrees. Users reported less discomfort and difficulty in the DESK configuration. Use of the lapdesk improved postures compared with the lap; however, all configurations resulted in high values of wrist extension, wrist deviation and downwards head tilt. STATEMENT OF RELEVANCE: This study quantifies postures of users working with a notebook computer in typical portable configurations. A better understanding of the postures assumed during notebook computer use can improve usage guidelines to reduce the risk of musculoskeletal injuries.

Accessibility of radiology equipment for patients with mobility disabilities.

OBJECTIVE: The purpose was to evaluate accessibility of typical radiology platforms by participants with mobility disabilities. BACKGROUND: These patients have difficulty using radiology equipment and have an increased risk of falling. METHODS: This field study evaluated three common types of radiology platforms - X ray, computed tomography (CT) scan, and fluoroscopy - by 20 patients/participants with mobility impairments who used walking aids. The participants were required to get onto the equipment, simulate a typical radiological procedure, and get off. Each participant then watched a video of his or her own session and answered questions. Four researchers independently reviewed the videotapes and identified accessibility and safety barriers. RESULTS: Overall, the CT scan platform was the easiest to use and the fluoroscopy platform the most difficult, primarily because of platform height differences. Sitting up on the Xray table was rated as difficult by most participants, primarily because of a lack of hand-holds and the surface pad not being fixed in place. Maintaining a position on the fluoroscopy platform while it rotated from horizontal to vertical was difficult and frightening for most participants. CONCLUSION: Some radiology platforms are difficult to use and are perceived to be less safe for patients with mobility disabilities. The interaction of patient disability and equipment design can impose substantial physical demands on medical personnel. Recommendations for improved design are provided to enhance radiology platform accessibility and safety. APPLICATION: The findings may be applicable to the design of a wide range of medical patient platforms.