摘要:

Because radiation cell killing follows Poisson statistics, radiation dose response curves for tumors and normal tissue response are sigmoidal in shape. This shape implies that small errors in delivery of radiation dose can result in large changes in the probability of normal tissue necrosis or tumor control. Thus it is important for veterinarians involved with radiation oncology to be familiar with the basic aspects of radiation physics and dose calculation as they relate to radiation therapy. In this paper, we present a review of pertinent physics and treatment planning relative to orthovoltage and cobalt irradiation. The usefulness of radiation treatment planning computers is emphasized for improving the radiation oncologist's knowledge of dose distribution and selection of the optimum treatment plan.

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00776.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

A duplex ultrasound system incorporating a pulsed wave Doppler ultrasound probe with conventional B‐mode real‐time imaging was used to evaluate portal vein blood flow in eight normal dogs. Adequate visualization of the cranial abdominal vessels was obtained from the right lateral 11th or 12th intercostal space. Doppler spectral analysis showed non‐pulsatile flow with a wide range of linear flow velocities across the vessel lumen typical of laminar blood flow. Results for portal vein blood flows were 49.8 ± 13.5 ml/min/kg body weight (mean ± SD) with a range of 37.8 ‐ 76.8 ml/min/kg body weight. These values overestimate portal blood flow by approximately 2 times when compared with published studies using invasive techniques. This overestimation is primarily due to the use of the maximal flow velocity in the blood flow cal

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00777.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00778.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Carotid arteriography was performed in six normal goats. The same procedure was performed on these six and 112 other goats at various time intervals after placement of an arterial graft in one or both carotid arteries. An arterial catheter was introduced into the femoral artery and advanced to the origin of the brachiocephalic trunk with the aid of image‐intensified fluoroscopy. Hand‐injection of the contrast medium resulted in complete opacification of both common carotid arteries in normal animals. Opacification of one or both of the vertebral arteries was usually seen in the goats with prosthetic grafts. The left vertebral artery was seen more often than the right, and when both vertebral arteries were seen together, the left was often larger. This angiographic method proved to be reliable for opacifying both common carotid arteries from their origin on the brachiocephalic trunk to the cranial cervical region. No clinical problems were associated with either the catheterization procedure or with the permanent ligation of the catheterized femoral art

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00779.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

The ultrasonographic features of paraprostatic cysts in nine dogs are described along with historical, clinical, surgical and pathologic findings. Cysts occurred predominantly in older, large breed dogs (mean age 8 years, range 3–11 years). The most common presenting complaints were depression, inappetance, stranguria, tenesmus and bloody penile discharge. A palpable abdominal mass was the most common physical finding. Ultrasonographically, paraprostatic cysts were usually large anechoic structures; many contained internal septa. Moderately large anechoic cavities or cysts were also detected in the prostatic parenchyma of five dogs, and in two of these communication with the paraprostatic cyst was visualized. There were no clearly distinct ultrasonographic criteria to discriminate septic from nonseptic paraprostatic cyst

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00780.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Book‐Review in this article:Atlas of Diagnostic Radiology of the Horse, Part 1: Diseases of the Front Limb. Kees J. Dik and Ilona Gunnse

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1989.tb00781.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY