Vet corner >> Recent Advancement in Diagnostics
Current diagnostic techniques in veterinary surgery:
Medical diagnostic technology has made rapid strides after the advent of computer. Many of the advances in human diagnostic medicines are translated into veterinary medicine in the developed countries. In brief, newer branches like Imaging, Radiodiagnosis, Telemedicine, Telesonography and Teleradiology have emerged. Broadly, the instrumentation /devices devised with the modern technology in the present digital age are listed below.
- Ultrasonography (USG)
- Computed Tomography (CT)
- Magnetic Resonance Imaging (MRI)
- Bone Scintigraphy
- Digital Substraction Angiography (DSA)
- Laparoscopy-Thoracoscope,Theloresectoscope, Rhinoscope, Otoscope etc
- Pulse Oximetry
All these imaging modalities have brought sea change in the diagnosis of a clinical case. Precise and an instant diagnosis of an intricate case can be made with their usage. The modalities which can be used under Indian conditions are:
- Image Intensifier T.V. system: Generally used
in orthopaedic surgery. This facilitates fracture repair using
a small incision thus achieving minimal invasive surgical manoeuvre.
IITV helps in X-ray imaging of the intra operative site for the
intra operative orthopaedic manipulations, and the same can be
stored for future reference purpose. This facilitates introduction
of Steinman pin giving a small incision.
- Ultrasound: In small animal and equine practice,
ultrasound is routinely used as a diagnostic aid. Applications
of ultrasound in ruminants have not been fully exploited, except
in pregnancy. There could be numerous organs which can be scanned
using an ultrasound scanner. Ultrasonography seems to have a promising
future in veterinary medicine, particularly for the assessment
of intra-periabdominal disease. Ultrasonography is viewed as the
single most versatile addition to the noninvasive and nonsurgical
armamentarium of the veterinary clinician since the advent of
fibre optic endoscope. Although other sophisticated imaging modalities
like CT and nuclear imaging can provide additional information,
the accessibility and cost effectiveness of these procedures do
not make these as promising as ultrasonography.
- Computed tomography: CT has been an extremely
significant development which has a unique cross sectional imaging
ability useful for the diagnosis of tumors, malformations, inflammation,
degenerative and vascular diseases and trauma. CT is a diagnostic
modality that is fundamentally different from X-ray method in
which an organ is scanned in successive layers by a narrow beam
of X-rays in such a way that the transmission of X-ray photons
across a particular layer can be measured and by means of a computer,
used to construct a picture of the internal structure.
- MRI: MRI is a highly sensitive and non invasive
technique providing accurate and detailed anatomic images with
good contrast and spatial resolution. However, in veterinary medicine
MRI is still in its infancy and its use is infrequent. To date,
MRI has been used in developed countries in clinical cases as
well as a research tool especially for CNS diseases in small animals.
MRI has a wide spectrum of application. It can be used for imaging
all body regions in small animals, but only the extremities and
the head can be imagined in large animals. It is useful in answering
many questions related to the musculoskeletal diseases in animals
such as understanding the pathogenesis of navicular disease, traumatic
arthritis and osteochondrosis in equines and wobbler syndrome
in dogs. The newer applications of MRI are Magnetic resonance
angiography(MRA) and MR spectroscopy. It is especially used to
differentiate an inflammatory process from a neoplastic mass,
tumors from peritumoral oedema. It is more specific and sensitive
in detecting localizing and differentiating osteomyelitis, cellulites
and abscess. However, its use is contraindicated in pregnancy.
- Nuclear scintigraphy: Nuclear scintigraphy
is a highly sensitive advanced procedure in which radioisotopes
are used to detect the functional abnormalities of the body system.
The interpretation is based on the appearance of the increased
(hotspots) or decreased (cold spots) radioactivity regions. For
eg. an active process is indicated by a hot spot while a dull
process like lack of perfusion is indicated by cold spot. Nuclear
scintigraphy has been used to detect functional disorders of the
kidney, liver, lungs, GI tract, thyroid gland and many other organs.
It is very useful in the diagnosis of occult lameness, lung perfusion
and ventilation and patency of the ureter in both large and small
animals. Also used for vertebral column imaging and monitoring
the progress of fracture healing and in tumor detection.
- DSA: DSA is a radiographic modality which
allows dynamic imaging of the vascular system following intravascular
injection of iodinated X-raycontrast media through the use of
image intensification, enhancement of the iodine signal and digital
processing of the image data. Temporal subtraction of the images
obtained during the first arterial phase of injection of the contrast
medium fromthe images obtained before and after contrast medium
administration yield images which are devoid of bone and soft
tissue. This imaging modality plays an important role in highlighting
the vascular pathologies like stenosis etc.
- Laparoscopy: Laparoscopy has been a valuable
diagnostic and therapeutic tool in human clinical medicine. Only
in the last 15 years, its use has been extensive in various animal
species for research and clinical diagnostic and therapeutic purposes.
Laparoscopic surgey offers significant advantages over open surgeries
in fields of cholecystotomy, appendicectomy, vagotomy, hernia
repair and adhesion release etc. For gynaecological problems like
ovarian cyst or in the case of oophorectomies and hysterectomies,
laparoscopic surgery (scarless surgery) is now considered a better
alternative in addition to laparoscopic sterilization. The most
advantageous characteristic of laparoscopy is that it allows direct
examination of abdominal cavity with only minimal and superficial
surgical intervention. Thoracoscopy has been employed in man for
the diagnosis and treatment of diseases of the pleura,Lung, mediastinum,
great vessels, pericardium and oesophagus. Visceral inspection
of the thoracic cavity by thoracoscopy has been used to provide
a more accurate diagnosis and prognosis in horses affected with
pleuropneumonia and other thoracic and oesophageal disorders.
Thoracoscopy allowsvisualization and biopsy of a large surface
of the lung and provides adequate specimen for histopathological
- Endoscopy: It is a minimal invasive diagnostic
modality which aids in a best way to document mucosal inflammation-
hyperemia, active bleeding, irregular mucosal surface, and facilitates
biopsy intubular organs like the GI tract, and repiratory and
the urogenital organ systems
- Pulse Oximetry: Pulse oximetry represents
the greatest advance in the patient monitoring. It has the unique
advantage of continuously monitoring the saturation of haemoglobin
with oxygen, easily and noninvasively, providing a measure of
cardio-respiratory function. The fundamental physical property
that allows the pulse oximeter to measure the oxygen saturation
of haemoglobin is that blood changes colour as haemoglobin absorbs
varying amounts of light dependent on it's saturation with oxygen.
Hence, pulse oximetry remains the standard of care during anaesthesia
as well as in the recovery room and intensive care unit.
To conclude, the advances in diagnostic technology in veterinary surgery is in infancy stage in India. An all out effort is required to introduce the basic imaging modality .
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