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R A Christensen

Publications and source records attributed to R A Christensen.

6 recordsLinked to original sources

Inadvertent ligation of the aberrant right hepatic duct at cholecystectomy: radiologic diagnosis and therapy.

Aberrant right hepatic ducts are the most common biliary tract anomaly and are particularly susceptible to injury at cholecystectomy because of their critical location. The authors report radiologic diagnosis and therapy in five cases of inadvertent ligation of this duct at cholecystectomy. The diagnosis was unsuspected prior to the radiologic studies in each patient. Four patients experienced recurrent cholangitis; one patient had chronic pain as the only symptom. Prior to diagnosis, the duration of symptoms ranged from 2 weeks to 126 months. Findings at ultrasound, computed tomography, and percutaneous transhepatic cholangiography with differential biliary pressures helped establish the diagnosis in each patient. Findings at endoscopic retrograde cholangiopancreatography were nondiagnostic in four patients. Percutaneous biliary drainage provided palliation of symptoms, improved each patient's condition prior to reconstructive surgery, and provided an intraoperative landmark for the surgeon. Two patients had associated bilomas, one of which was infected and was drained percutaneously. All patients survived and recovered without further complications.

Adult

Interventional ultrasound in the musculoskeletal system.

This article highlights the multiple applications of ultrasound as a guidance modality for interventional procedures in the musculoskeletal system. The percutaneous aspiration, drainage, and biopsy of musculoskeletal abscesses, masses, and focal muscular pathology in the extremities, trunk, and neck using ultrasound as the guidance system is described. Techniques for biopsy, fluid aspiration, catheter insertion, and needle visualization by ultrasound are discussed.

Abscess

Molecular evolution as a process of message refinement.

Amino acid sequences are often said to code for proteins. Taking that statement literally, we propose a methodology in which protein sequences appear as messages and as such are amenable to the techniques of signal analysis. Not only does this view of amino acid sequences as messages appear to be tenable, but the clarity of expression of these sequences seems to increase, i.e., the noisiness decreases, consonant with notions of ascendancy in the hierarchy of morphological taxonomy.

Amino Acid Sequence