摘要:

Diagnostic ultrasound, a non‐invasive mode for imaging soft tissues, requires for its use an understanding of sound and sound‐tissue interaction physics. Ultrasound frequencies from 1.0 to 10.0 MHz are created by electrical stimulation of piezoelectric crystals. These crystals are housed within transducers, which, when applied to the body surface with a coupling agent will produce sound waves, referred to as the sound beam, which are propagated through the soft tissues of the body. When the sound beam encounters tissue interfaces of differing acoustic impedance, a portion of the sound beam is reflected back to the transducer which also acts as a receiver. Echoes returning from soft tissue acoustic interfaces are converted to electrical impulses and displayed on an oscilloscope screen as a cross section of the tissue. Lower frequency sound beams penetrate further into soft tissue, but have poorer resolving capabilities, than higher frequency sound beams.A, B, and M‐modes are the three basic forms of ultrasound used in soft tissue imaging. A‐mode ultrasonic imaging is a one‐dimensional display of echo amplitudes versus distance. B‐mode ultrasonic imaging produces an accurate two‐dimensional cross sectional image of soft tissues. M‐mode ultrasonic imaging is an adaptation of B‐mode to evaluate moving structures of the heart.Fluid‐filled cystic structures have characteristic clear (anechoic) central areas with acoustic enhancement of the back wall of the cyst and deeper structures. Solid masses have echoes in their central portion with resultant poor accentuation of deeper structures.Application of ultrasound to animals requires hair removal since trapped air is a barrier to transmission of the sound beam. Gas‐filled bowel and bone are effective barriers to ultrasonic imaging because of their large acoustic impedance differences compared to soft tissues.The position of the focal point of a focused transducer relative to tissue interfaces is important to accurately depict tissue character. For example, the focal point of the transducer should be superficial to the back wall when scanning cystic structures. When solid lesions, such as liver metastases, are scanned a focal point that lies deep to the lesion should be selected in order to accentuate sound beam attenuation.Time‐gain compensation (TGC) settings are important to produce a balanced scan with equal echo production within like tissues throughout the depth of ultrasound tissue penetration. Initial TGC settings can be made from knowledge of the focal point of the particular transducer, but may have to be adjusted during scanning to produce a balanced image.Ultrasound is an attractive imaging modality in animals since it is noninvasive and presents no known hazard to

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01373.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

The production and identification of gray‐scale ultrasonic imaging artifacts and some basic principles of ultrasonic interpretation are reviewed, discussed, and demonstrated with canine ultrasonograms. Imaging artifacts produced by ultrasound matter interactions include:reverberations, shadowing, through transmission and refractive and reflective zones. Technical imaging artifacts discussed include: off‐normal incidence defects, echo displacement, and improper time gain compensation settings. Interpretation principles to distinguish mass lesions, cystic structures, and calculi within abdominal parenchymal organs are presen

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01374.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

Three horses with clinical signs compatible with pleural effusion were examined with diagnostic ultrasound. In one of the three horses, confirmed septic pleural effusion was monitored with ultrasound during a successful treatment regimen. Eficacy of thoracentesis and detection of recurrence of fluid were readily determined. In the second horse, diagnosis of diffuse pleural neoplasia (lymphosarcoma) was made. In the third horse presented for pleural effusion, the effusion was documented and concurrent ascites detected with ultrasound. Carcinomatosis was found at necropsy. Ultrasound examination proved to be a sensitive, noninvasive modality useful in diagnosis and treatment of pleural effusion.

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01375.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

B‐mode ultrasound was utilized to define the borders of the lungs and surrounding viscera in a normal horse. Characteristic reverberation artifacts produced by the air‐filled lung allowed accurate definition of the lung borders. The liver on the right and the spleen on the left were the predominant parenchymal organs identified. These two organs were seen adjacent to the lung and medial to the diaphragm. Recognition of the liver and spleen is important in evaluating equine pleural effus

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01376.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

This manuscript demonstrates that gray‐scale ultrasonography can be useful for the diagnosis of many canine abdominal disorders. It is safe, noninvasive, and requires minimal patient preparation. Size, shape, and location of abdominal organs can be determined readily. The unique physical properties of ultrasound allow detection and characterization of mass lesions and parenchymal pathology associated with abdominal organs. Ultrasonography can complement existing imaging modalities by adding information not obtainable by other methods. The effective use of ultrasound requires knowledge of its advantages, limitations, and how it complements other diagnostic procedures. The medical histories of four dogs were reported in order to illustrate proper application of ultrasound to clinical problems. Basic findings concerning ultrasound utilization for investigation of the liver, kidney, and caudal abdomen were discusse

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01377.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01378.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

ISSN:0196-3627    

DOI:10.1111/j.1740-8261.1981.tb01379.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY