TRANSRECTAL ULTRASONOGRAPHY OF THE LEFT ADRENAL GLAND IN HEALTHY HORSES

Little information is available on medical imaging of the adrenal glands in horses. We investigated the feasibility of transrectal ultrasonography to characterize the normal equine adrenal gland. Transrectal ultrasonography was performed in 25 healthy horses using a 7.5 MHz linear array probe at a displayed depth of 8 cm. Transrectal ultrasonography of the right adrenal gland was not feasible. For the left adrenal gland, the left kidney, the abdominal aorta, the left renal artery, the left renal vein, and the cranial mesenteric artery were used as landmarks. The size of the left adrenal gland was variable, but it generally appeared as a long, flat structure with a hyperechoic medulla surrounded by a hypoechoic cortex. The most cranial part of the gland could not be delineated appropriately in 11 horses (44%). The mean (±SD) thickness of the gland and medulla was 0.66±0.15 cm (n=25) and 0.28±0.09 cm (n=25) near the caudal pole, 0.87±0.25 cm (n=14) and 0.40±0.18 cm (n=12) near the cranial pole, and 0.89±0.18 cm (n=25) and 0.36±0.13 cm (n=25) in the middle of the gland, respectively. The mean (±SD) length of the entire adrenal gland and of the medulla was 6.22±0.77 cm (n=14) and 5.45±0.71 cm (n=6), respectively. Transrectal ultrasonography allowed adequate visualization of the left adrenal gland in horses.     

ULTRASONOGRAPHIC ASSESSMENT OF FRACTURE HEALING AFTER PLATE OSTEOSYNTHESIS

The goals of this study were to assess the ability of ultrasonography (US) to assess uncomplicated fracture healing and to establish normal images. Twenty-two dogs, ranging in age from 6 to 180 months were studied. Body weight ranged from 2.2 to 60 kg. All fractures were treated by plate osteosynthesis. US (B-mode and power Doppler) and radiography were performed until both were consistent with complete healing. B-mode US was performed in all dogs, and power Doppler US in 14. Fracture healing was judged to be complete based on US earlier than when based on radiography. The tissue immediately adjacent to the plate appeared vascularized on power Doppler images at a time when the tissue at the fracture site had a negative power Doppler exam. US appears useful for assessment of primary fracture healing and power Doppler was useful for detecting vascularization at the fracture site in nonhealed fractures. Power Doppler interrogation should be performed away from any metal implant, as a result from an interrogation adjacent to an implant will not reflect actual vascularization at the fracture site.     

Transaction Costs,Agglomeration Economies,and Industrial Location: A Comment

ABSTRACT This article comments on a recent contribution by Wood and Parr to Growth and Change. Wood and Parr apply the institutional–economic approach to agglomeration issues. After a sketch of the conceptual background, the present article discusses some concepts introduced by Wood and Parr, such as “transaction space” and the alleged relationship between space homogeneity and transaction cost. This is followed by critical remarks from the very same institutional–economic point of view. In the article, the conclusion is drawn that some limitations should be taken into account when applying the institutional perspective to agglomeration economics.     

POWER DOPPLER ASSESSMENT OF THE NEOVASCULARIZATION DURING UNCOMPLICATED FRACTURE HEALING OF LONG BONES IN DOGS AND CATS

The aims of this prospective study were to test the feasibility of assessing neovascularization with power Doppler ultrasonography and to investigate its usefulness to follow fracture healing of long bones in dogs and cats. A total of 51 patients (44 dogs and seven cats) were followed. Fracture types differed from simple to comminuted. Therapy ranged from external coaptation to plate osteosynthesis. Patients were followed with radiography, B-mode real time and power Doppler ultrasonography every 2-4 weeks until the fracture was healed. All fractures healed uneventfully. A semi-quantitative numerical score based on signal intensity, vessel area, and number of Doppler signals was assigned and the mean value was used to compare patients and examinations. Time postoperatively was divided into periods of 10 days. No Doppler signal was present during the first 10 days. The mean of the scores was highest between 11 and 20 days postoperatively and the median of the scores peaked between 21 and 30 days. A gradual decrease was seen thereafter. The mean of the scores was zero at 71-80 days and the median at 51-0 days postoperatively for the grouped results. In all positive power Doppler examinations, signals were present in and close to the callus. In seven patients (five dogs and two cats) signals were also present in the peripheral soft tissues in one of the follow up examinations. The normal healing process of fractured bones can be visualized using power Doppler ultrasonography and follows a distinctive time-dependent pattern.