CAT Scan vs. CT Scan: Are They the Same Procedure?

CAT Scan vs. CT Scan:

What’s the Difference?

Medicine is a field with countless acronyms. Two that can be confusing are CAT scan and CT scan. Sometimes thought to be different types of diagnostic tests, they actually refer to the same X-ray procedure. CAT stands for “computed axial tomography” and CT is simply “computed tomography.” CAT scan was the first of the two terms to be used; CT scan has become more common in recent years. These two procedures are the same, though.

What is a CT Scan For?

A CT scan produces images using an X-ray tube that travels 360 degrees around your body. As it moves, it gathers information from multiple angles to create cross-sectional images.

Doctors order CT scans for a number of reasons, including to:

• Look for bone and joint problems such as complex fractures and tumors
• Detect masses and spots associated with conditions like heart disease, cancer and emphysema
• Locate clots, tumors, infection or fluid buildup
• Check for internal injuries and bleeding following a traumatic event like a car accident
• Provide information in preparation for a surgery, biopsy or other procedure
• Compare images taken over a period of time to gauge the effectiveness of a treatment such as the chemotherapy or radiation used to shrink a tumor

In some cases, what’s called a CT scan “with contrast” is needed. With this procedure, the technician performing the procedure inserts a catheter into one of your arms in order to administer a special dye called contrast material. This dye makes it easier for the scan to create a crisp image of tissues and organs that are less dense than bone and therefore may not show up as clearly.

The detail in a CT scan with contrast may make it the preferred approach over other imaging techniques in some instances. For example, a CT scan can provide better information on the bones of the spine than either a standard X-ray or an MRI (magnetic resonance imaging) scan, which is helpful when assessing conditions that affect the vertebrae and other bones.

There are some instances when a CT scan isn’t advisable. If you’re pregnant or think you may be pregnant, you should tell your doctor. There is also a weight limit for receiving a CT scan.

A CT Scan is a Pain-Free Procedure That Produces Crucial Images

Other than the poke if contrast material is needed, a CT scan is completely painless and provides your care team with critically important information on your condition. For many patients, the only unpleasant aspect of the scan is the feeling of being enclosed in the CT scan machine. However, that temporary discomfort is worth the valuable information the procedure produces.

At Baptist Health, the procedure takes place as follows:

• Preparation. How you prepare for your CT scan will depend on the type of scan performed. If your abdomen/pelvis, chest or head is being scanned with contrast, you may be instructed not to eat or drink for several hours prior to your exam. You may also have to drink a contrast medium or have it administered intravenously. If you’re having a head scan with no contrast, you can eat up until the time of the exam, and no liquid or intravenous contrast medium is required.
• Exam. A CT scan typically takes 15-30 minutes. A certified technologist helps you get positioned on the scan table, which is then moved into the machine. You’ll hear humming as the machine works and the table may move as different images are captured. You may also receive instructions, such as holding your breath for a short time, from the technologist, who observes the entire test and communicates with you through two-way microphones.
• Side effects. Depending on the type of exam, afterward, you may experience a metallic taste in your mouth (if contrast dye is used), fatigue, headache, weakness or constipation.
• Follow-up. After your exam, a radiologist (a doctor that specializes in imaging) reviews the images and sends a report to your physician who will discuss it with you at your next appointment.

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Learn more about CT scans available from Baptist Health, along with pre-and post-exam expectations.

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CT scan or CAT scan: How does it work?

A computerized tomography (CT) or computerized axial tomography (CAT) scan combines data from several X-rays to produce a detailed image of structures inside the body.

CT scans produce 2-dimensional images of a “slice” or section of the body, but the data can also be used to construct 3-dimensional images. A CT scan can be compared to looking at one slice of bread within a whole loaf.

CT scans are used in hospitals worldwide.

A CT scanner emits a series of narrow beams through the human body as it moves through an arc.

This is different from an X-ray machine, which sends just one radiation beam. The CT scan produces a more detailed final picture than an X-ray image.

The CT scanner’s X-ray detector can see hundreds of different levels of density. It can see tissues within a solid organ.

This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.

Sometimes, a contrast dye is used because it can help show certain structures more clearly.

For instance, if a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system.

If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessel images are the target, a contrast agent will be injected into the veins.

The accuracy and speed of CT scans may be improved with the application of spiral CT, a relatively new technology. The beam takes a spiral path during the scanning, so it gathers continuous data with no gaps between images.

CT is a useful tool for assisting diagnosis in medicine, but it is a source of ionizing radiation, and it can potentially cause cancer.

The National Cancer Institute advise patients to discuss the risks and benefits of CT scans with their doctors.

Share on PinterestA CT scan can detect abnormalities in the soft tissue.

It is useful for obtaining images of:

• soft tissues
• the pelvis
• blood vessels
• lungs
• brain
• abdomen
• bones

CT is often the preferred way of diagnosing many cancers, such as liver, lung, and pancreatic cancers.

The image allows a doctor to confirm the presence and location of a tumor, its size, and how much it has affected nearby tissue.

A scan of the head can provide important information about the brain, for instance, if there is any bleeding, swelling of the arteries, or a tumor.

A CT scan can reveal a tumor in the abdomen, and any swelling or inflammation in nearby internal organs. It can show any lacerations of the spleen, kidneys, or liver.

As a CT scan detects abnormal tissue, it is useful for planning areas for radiotherapy and biopsies, and it can provide valuable data on blood flow and other vascular conditions.

It can help a doctor assess bone diseases, bone density, and the state of the patient’s spine.

It can also provide vital data about injuries to a patient’s hands, feet, and other skeletal structures. Even small bones are clearly visible, as well as their surrounding tissue.

CT versus MRI

The main differences between CT and MRI are:

• A CT scan uses X-rays, but an MRI uses magnets and radio waves.
• Unlike an MRI, a CT scan does not show tendons and ligaments.
• MRI is better for examining the spinal cord.
• A CT scan is better suited to cancer, pneumonia, abnormal chest x-rays, bleeding in the brain, especially after an injury.
• A brain tumor is more clearly visible on MRI.
• A CT scan shows organ tear and organ injury more quickly, so it may be more suitable for trauma cases.
• Broken bones and vertebrae are more clearly visible on a CT scan.
• CT scans provide a better image of the lungs and organs in the chest cavity between the lungs.

The patient may need to abstain from food, and possibly drink, for a specific period before the scan.

On the day

In most places, the patient will need to undress, usually down to their underwear, and put on a gown that the health center will provide. Avoid wearing jewelry.

If the hospital does not provide a gown, the patient should wear loose-fitting clothes free of metal buttons and zippers.

Some patients may have to drink a contrast dye, or the dye may be given as an enema, or injected.This improves the picture of some blood vessels or tissues.

Any patient who has an allergy to contrast material should tell the doctor beforehand. Some medications can reduce allergic reactions to contrast materials.

As metal interferes with the workings of the CT scanner, the patient will need to remove all jewelry and metal fastenings.

During the scan

The patient will need to lie down on a motorized examination table that slides into a doughnut-shaped CT scanner machine.

In most cases, the patient will lie on their back, facing up. But, sometimes, they may need to lie facedown or sideways.

After one x-ray picture, the couch will move slightly, and then the machine will take another image, and so on. The patient needs to lie very still for the best results.

During the scan, everybody except for the patient will leave the room. An intercom will enable two-way communication between the radiographer and the patient.

If the patient is a child, a parent or adult might be allowed to stand or sit nearby, but they will have to wear a lead apron to prevent radiation exposure.

Share on PinterestThe doctor should explain why the scan is needed, any other options available, and the pros and cons of having a CT scan.

A CT scan involves a small, targeted dose of radiation.

These levels of radiation, even in people who have undergone several scans, has not proven to be harmful.

The chance of developing cancer as the result of a CT scan is thought to be less than 1 in 2,000.

The amount of radiation involved is estimated to be around the same as a person would be exposed to in a space of between several months and several years of natural exposure in the environment.

A scan is only given if there is a clear medical reason to do so. The results can lead to treatment for conditions that could otherwise be serious. When the decision is taken to perform a scan, doctors will ensure that the benefits outweigh any risk.

Problems that could possibly arise from radiation exposure include cancer and thyroid issues.

This is extremely unlikely in adults, and also unlikely in children. However, are more susceptible to the effects of radiation. This does not mean that health issues will result, but any CT scans should be noted on the child’s medical record.

In some cases, only a CT scan can show the required results. For some conditions, an ultrasound or MRI might be possible.

Can I have a CT scan if I am pregnant?

Any woman who suspects she may be pregnant should tell her doctor beforehand, because there is a risk that the x-rays could harm the fetus.

Citing the American College of Radiography, the American Pregnancy Association (APA) point out that “No single diagnostic x-ray has a radiation dose significant enough to cause adverse effects in a developing embryo or fetus.”

However, the APA notes that CT scans are not recommended for pregnant women, “Unless the benefits clearly outweigh the risk. ”

CT scans and breastfeeding

If a lactating, or breastfeeding, mother needs an iodinated intravenous dye for contrast, she should avoid breastfeeding for about 24 hours as may pass into the breast milk.

I have claustrophobia: Can I have a CT scan?

A patient who has claustrophobia should tell their doctor or radiographer beforehand. The patient may be given an injection or tablet to calm them down before the scan.

Your health care provider will usually be able to recommend a suitable facility for a scan. You can check if a radiologist is accredited by searching on the website of the American College of Radiology.

CT for animals in St. Petersburg

Accurate diagnosis in a few minutes

the animal may deteriorate rapidly.

CT provides a unique chance – in just a couple of minutes
using special protocols, we obtain comprehensive information about
condition of bones, central nervous system, internal organs, soft
tissues, vessels with minimal radiation exposure, we find out the cause of the disease
and immediately begin treatment.

CT scan at the PRIDE veterinary center is:

Accurate diagnosis

for one anesthesia

Only we do CT and MRI at the same time. No need for an accurate diagnosis
to go and overload the pet with drugs.

Animal research

weighing from 300 g to 120 kg

We select an individual level of radiation exposure for each pet.

Biopsy under

CT control

We immediately do a “targeted” biopsy of the area where the changes were found.

Research of any

difficulty level

Including contrast to improve diagnostic accuracy.

3D view

for more precision

Special protocols enable us to carry out complex examinations of the central
nervous system, blood vessels, internal organs.

Automatic

dose control

Independent of the area to be examined, via software
CARE Dose4D. Radiation exposure reduced by 68%.

Comfort during

examinations and after

Each examination is carried out with the participation of an anesthesiologist, he continuously monitors
the state of the animal.

Result control

after surgery

The doctor assesses how successful the operation was and plans further
treatment.

CT is indispensable in diagnosis:

Neoplasms – benign, malignant, metastases:

• Brain
• Internal organs: lungs, liver, pancreas, kidneys, spleen
• Bones
• Joints

Injuries – isolated and combined injuries:

• Spine
• Bones of the vault and base of the skull
• Chest
• Belly
• Limbs

Pathologies of the nervous system

• Strokes
• Post-traumatic hemorrhage
• Tumors
• Hydrocephalus
• Edema and atrophy of the brain
• Brain abscess
• Spinal cord compressions

Heart diseases

• Defects
• Camera extensions
• Scars after a heart attack
• Aneurysm
• Thrombus
• Tumors

Urological pathology

• Kidney and bladder stones
• Tumors of the genitourinary system
• Abnormalities of renal hypoplasia hydronephrosis, ectopic ureters

Vascular diseases

• Thrombosis
• Emboli
• Aneurysm
• Portosystemic shunts
• Development Options

Orthopedic diseases

• Fractures and fractures of bones
• Joint injuries
• Areas of bone destruction and sclerosis
• Herniated and protrusion of the intervertebral discs
• Arthritis and arthrosis

Anomalies of the body

• Malformations of the spine, joints, abdominal organs, urogenital
  systems

You are looking for answers to these questions:

X-ray

• Suitable for primary diagnosis
• Only gross deviations are visible in the images
• Displays an image in one plane
• In the images, the shadows of organs and tissues are superimposed on each other, slight
  changes are not visible.

CT

• Indispensable for a quick definitive diagnosis
• On the tomograms, lesions from 0.6 mm are visible
• Produces dozens of images in various planes and modes – for bones,
  soft tissues

• Duration of the procedure – several minutes
• Radiation exposure reduced by 68%
• Areas of the body not to be examined are covered with special screens
• For sedation during the study, use lower doses of drugs,
  than for operation

• To exclude contraindications, the animal is examined before the procedure
• The doctor constantly monitors the condition – conducts an examination before the procedure,
  administers medications and monitors the animal until waking up
• All manipulations are carried out quickly and accurately

Indications and contraindications

Indications:

• Polytrauma – head, chest, abdomen, spine, limbs,
• Suspicion:
• • hemorrhage
  • “acute abdomen”
  • neoplasm
  • thrombosis and thromboembolism
  • the presence of foreign bodies, including those not visible on radiographs,
• Search for neoplasm metastases
• Bone and joint deformities
• Movement disorder
• Planning for complex bone and joint surgery

Contraindications:

• Conditions where anesthesia is contraindicated
• Renal failure for contrast administration

CT in PRIDE in numbers

100%

reliability

Thanks to the new modern device SIEMENS SOMATOM Emotion, many years of
experience and high qualification of the radiologist.

Up to 20 minutes

per procedure

Depending on the weight of the animal and the area to be scanned

Lesions size

from 0.6 mm

And layered image of any part of the body

Price per CT for animals

90 190 9 500 ₽

9 0190 20 500 RUB

Specialized scientific and practical publications for veterinarians and students of veterinary universities.

Authors: Khatovich AR, veterinary surgeon. Azarova M.S., veterinarian of visual diagnostics. Veterinary clinic of Dr. Sotnikov, St. Petersburg.

Spontaneous pneumothorax is a relatively rare disease in dogs and cats. It occurs when air or gas enters the pleural space in the absence of a traumatic or iatrogenic cause. The most common source of air is damaged lung parenchyma. However, other sources of air can also be the trachea, bronchi, esophagus, or the development of an anaerobic infection in the pleural cavity.
Spontaneous pneumothorax is classified as primary or secondary based on the history of the disease, clinical features, and the ability to determine the underlying cause from the obtained history and imaging tests, such as chest x-ray, computed tomography (CT), or thoracoscopy.
Common causes of spontaneous pneumothorax in dogs include lung abscesses, heartworm disease, lung neoplasia, and bullous disease of the parenchyma and pleura.

According to many publications, bullous disease is the most common cause of spontaneous pneumothorax.

Bullae are accumulations of air in the layers of the visceral pleura, most often located at the tops or edges of the lungs (Figure 1). They form when air escapes from the lung parenchyma, travels to the periphery of the lobe, and becomes trapped between the layers of the visceral pleura. In general, bullae appear as small blisters or blisters on the surface of the lung that can be several centimeters in size. Other bullae are air-filled spaces in the lung parenchyma that result from destruction, expansion, and fusion of adjacent alveoli. They can vary in size, with some bullae being small (i.e., involving a few alveoli) and others being very large (involving most of the lung). The bullae are bounded by connective tissue septa in the lung and the inner layer of the visceral pleura.

Bullae are divided into three types depending on size and relationship with the surrounding tissue of the lung:

• Type 1. Thin bullae filled only with air from the inside and having little connection with the lung parenchyma. They are usually found at the edges of the lung and have outer walls that may be lined with mesothelial cells on the outer surface.
• Type 2 Bullae arising from the subpleural parenchyma and tightly associated with the rest of the lung parenchyma of an emphysematous lung. The inner part of the bullae is filled with emphysematous lung tissue, and the outer walls are formed by an intact pleura lined with mesothelial cells.
• Type 3 Bullae, which may be very large and contain emphysematous lung tissue extending deep into the lung parenchyma.

Secondary spontaneous pneumothorax due to bullous disease is more common in dogs than in cats at different ages. This disease has been described in animals with different forms of the chest and in different breeds of dogs (mestizo, golden retriever, German shepherd, husky, English setter, collie, Great Dane, etc.). In cats, bullae can also be found, but this disease is diagnosed much less frequently and is often an accidental finding when diagnosing some other pathology.
Photo 1. Apices of the lung (shaded box in the top picture). Lung vesicle (A), bulla type 1 (B), bulla type 2 (C), and bulla type 3 (D). Note the accumulation of air between the layers of the visceral pleura in the lung bladder and the various connections to the underlying lung parenchyma in Figures B, C, and D1.

The main clinical sign of this condition is intermittent or progressive dyspnea, which can be acute in some animals. Other clinical signs include apathy, anorexia, depression, cough, and exercise intolerance.
Physical examination may reveal varying degrees of tachycardia, tachypnea, rapid breathing, and the presence of respiratory distress. Conditionally, when trying to “free” or “open” the airways, the animal can take a forced posture, stretch its neck forward and widely place the chest limbs in the elbow joints. Auscultation of the chest may reveal a decrease in lung sounds on one or both sides. The results of general and biochemical blood tests are usually within the normal range.

Diagnostics

Radiography is an excellent method for accurately diagnosing spontaneous pneumothorax (Figure 2), although radiographic diagnosis of bullous emphysema, assessment of their location and number of lesions is less successful. In humans, the radiographic accuracy of detecting bullae ranges from 10 to 60.5%, in dogs – from 0 to 50%. Even when bullae are identified on radiographs, the severity of the lesions may be underestimated.
Foreign colleagues in the literature note that attempts to identify lesions by X-ray sometimes led to the choice of the wrong surgical approach due to underestimation of the number or location of lesions, especially in the right accessory lobe of the lung. In one of the publications8 it is mentioned that during the diagnosis of 12 dogs, X-rays failed to reveal 13 (!) Of the 17 affected lobes of the lungs.
Photo 2. Chest radiograph of a Siberian Husky dog, right lateral view. There is free air in the pleural cavity (arrows).

Computed tomography (CT) has the added benefit of being able to better differentiate lung anatomy and its relationship to lesions. In this regard, even in cases where lesions are clearly visible on radiographs, CT reveals more lesions, and with its help, their size, location and structure of the lung tissues surrounding the lesions are better determined (photos 3, 4).
Photo 3. CT scan of a cat. Multiple bullae are located diffusely in all lobes of the lungs. The radiograph of the same patient is shown in photo 8.

Photo 4. CT scan of a cat. Multiple bullae are located diffusely in all lobes of the lungs. The radiograph of the same patient is shown in photo 8.

Lesions can be single or multiple, unilateral or bilateral. It is also important to assess the severity of pneumothorax5 and the presence of atelectasis of the pulmonary lobes, pneumonia, pleurisy. When conducting contrast series in order to detect or exclude other pathologies of the chest organs, attention should be paid to the presence of necrotic processes in the lungs, arterial or venous pulmonary thrombi, neoplasms, lung abscesses, etc. Small and barely noticeable bullae (photo 6, 7) detected on CT are fixed as areas of the lung with a minimum density (less than 1000 HU) and distortion of the normal vascular pattern. In the presence of multiple cavity formations (thin-walled bullae), the density of the lung tissue will be reduced. The extreme degree of bullous emphysema may be called “honeycomb lung” (photo 8).
Thus, radiography is effective in detecting pneumothorax (Figure 2), but has low sensitivity in detecting bullae and cannot be used to evaluate and manage patients with spontaneous pneumothorax.
Photo 5. CT scan of a Siberian Husky dog ​​(photo 2 – radiograph of the same patient). A significant amount of free air in the pleural cavity. Bilateral tension pneumothorax.

Photo 6. CT scan of a Siberian Husky dog. Bullae were found along the periphery of the lungs (arrows). On the radiograph of the same dog, they are absent (photo 2)

Photo 7. CT scan of a Siberian Husky dog. Bullae were found along the periphery of the lungs (arrows). They are absent on the radiograph of the same dog (photo 2)

Photo 8. Chest radiographs of a cat showing multiple bullae of the lung parenchyma.

Although the results of CT do indeed agree well with the results of surgery, there have been cases in our practice and in published data when additional bullae were found during surgery. One possible reason for the absence of bullae on CT images may be the presence of a pneumothorax. With an increase in the degree of pneumothorax, an increase in atelectasis of the lung tissue and a focal decrease in the lungs are observed. This can make the bullae difficult to visualize and difficult to distinguish from the surrounding pleural air. Also, perforated bullae can appear as focal opacities of the alveolar type, therefore, it will be even more difficult to distinguish them from destroyed lung tissue using CT. Other potential reasons for the lack of visualization of bullae on CT may be the small size of the cavities and the insufficient spatial resolution of computed tomography.
It should be remembered that the formation of air pockets with pneumothorax can make it difficult to distinguish between subpleural bullae and free air. This can lead to a false positive CT diagnosis.
After a native CT scan, the pneumothorax should be corrected and the scan repeated, which may improve visualization of the affected lung lobes.

Treatment

Patient stabilization is of paramount importance, as spontaneous pneumothorax is a life-threatening condition due to reduced ventilation requirements.
As a rule, there are two options for long-term treatment (conservative and surgical). The underlying cause of spontaneous pneumothorax allows you to determine which option will be most appropriate for the patient.
In human medicine, this pathology is recognized as a chronic lung disease. In veterinary practice, this information is not confirmed in published sources due to the small number of studies and publications. But even if we do not keep this fact in mind, in the case of making a decision on the choice of treatment, it is very difficult to assume the likelihood of a relapse due to the lack of a unified approach and protocol in the treatment of the disease. Based on the described data, it can be concluded that an individual approach is required when making a decision.
Some recent publications3,8 have noted that pneumothorax persisted in all dogs despite conservative treatment lasting 1 to 5 days. Similar results were also found in two previous studies where pneumothorax persisted or recurred in 8 of 11 (73%) and 7 of 8 (88%) dogs with confirmed bullae after treatment with thoracocentesis or thoracic drainage. Based on these data, the authors of the article believe that conservative treatment should not be considered a reliable treatment for pneumothorax caused by bullous emphysema.
For dogs in which surgical treatment is not an option, long-term conservative management may eventually resolve the pneumothorax. However, this tactic should be coordinated with pet owners due to increased hospital stay and potential complications associated with repeat thoracocentesis or the length of the thoracic drain placement period. Ultimately, the decision regarding the duration of conservative treatment should be based on the severity of clinical manifestations, the rate of accumulation of air, the possibility of exclusion of the underlying lung disease and appropriate surgery, as well as postoperative treatment.

Thus, due to the lack of a single protocol and approach to the treatment of this pathology, foreign authors recommend surgical intervention as the preferred method of treating spontaneous pneumothorax. This recommendation is based on the higher overall success rate of this technique compared to conservative treatment, lower recurrence rate, and shorter hospital stay.

The surgical approach includes resection of the pulmonary bullae (Figure 9) with partial or complete lobectomy of the affected lung lobes. Currently, a median sternotomy is recommended, as this access allows a thorough examination of all intrathoracic structures. Lesions may be present in several lobes of the lungs, so each lobe must be carefully examined. Bullae usually appear as focal, translucent, blistering lesions at the lung margins, although they can be located anywhere in them. The size, number, and location of the lesions on each lobe determine the amount of lung tissue that needs to be removed. For dogs with lesions involving multiple lobes, it may not be possible to remove all lesions without significant reduction in lung volume.

Picture 9.

Sternotomy. After cutting the skin and superficial fascia, the bilateral sternal musculature is separated and separated from the sternum. The sternum is cut longitudinally with an oscillating saw (photo 10) or Liston’s bone cutters. For operations on small dogs, puppies and cats, a scalpel can be used. At the time of dilution of the sternum of the patient, it is necessary to provide artificial ventilation of the lungs with positive pressure. The edges of the incision should be covered with wet wipes soaked in warm saline. The Finochetto rib expander (Finochetto; Photo 11) can provide sufficient access to the lungs. Next, the chest is filled with warm saline and at the moment of inhalation of the animal, a search is made for a source of free air. Before closing the chest, fluid is removed by installing a thoracic drain. After combining the sternum, it is fixed (photo 12). To do this, the sternum is connected to the costal cartilage or a figure-eight wire suture is applied. In small patients, a non-absorbable or slowly absorbable USP size 0 to 2 suture can be used.
The sternal muscles and fascia are sutured in layers with continuous sutures (absorbable suture material). After that, a skin suture is applied.
Photo 10. Dissection of the sternum with an oscillating saw.

Photo 11.

Photo 12. Closure of the sternum with cerclage wire.

For partial lung lobectomy, the use of an automatic stapling device (like a stapler) is recommended because it is faster and has fewer complications than traditional suturing methods.
Video-assisted thoracoscopy (VATS; photo 13) has undeniable advantages over traditional surgical methods, since it is a minimally invasive method of surgical intervention. However, some studies2 show high conversion rates from thoracoscopy to median sternotomy due to the lack of a visible air source. This is dictated by the difficulty associated with attempting to immerse the lungs in saline in a closed chest. Because the saline in the dorsal thorax promotes buoyancy of the lungs, they move ventrally, leaving most of the parenchyma unsubmerged, especially during breathing. Thus, caution should be exercised when using an entirely thoracoscopy-based approach to treat spontaneous pneumothorax in dogs. The surgeon needs to have as much data as possible (obtained from CT studies) about the presence of possible lesions, but at the same time he should take into account that CT and thoracoscopy data can complement each other. Once the decision has been made to proceed with VATS surgery, the surgeon should be prepared to switch to a median sternotomy if lesions cannot be identified.
Photo 13. Thoracoscopic images: A – pulmonary bulla of the second type; B – pulmonary bulla of the first type.

Own clinical observations

Dog, Siberian Husky, 8 years old, female. The content of the animal is domestic, there is no history of sports activities. Two days before contacting our clinic, the owners noticed shortness of breath in their pet. Prior to this, they applied to a third-party clinic, where an x-ray was taken and pneumothorax was detected, after which 500 ml of free air from the chest was aspirated using thoracocentesis. On the day of contacting our clinic during a walk, the dog fell sharply and began to turn blue. The owners immediately contacted a nearby clinic, where they took 3 liters of free air on the left and 1.5 liters on the right, then the patient was urgently sent to our clinic for additional diagnostics.
Clinical and biochemical blood tests of the animal were within the normal range.
The patient underwent CT scan, which revealed areas of atelectasis of the caudal edge of the cranial lobe and the cranial edge of the middle lobe of the right lung, where a defect in the lung parenchyma, characteristic of fragments of a collapsed bulla, was determined. At the time of the CT scan, the patient was fitted with a thoracic drain to aspirate free air. During the next two days, there was no positive dynamics, free air continued to accumulate.
It was decided to perform a median sternotomy on the animal, during which a marginal bulla (photo 9) of the cranial lobe of the right lung was revealed. The thoracic drain was removed after 2 days. The patient has been observed for 8 months, no recurrence has been noted to date.

Dog, Siberian Husky, 3 years old, male. On the eve of the appointment at the clinic, the owners noticed shortness of breath in their pet, while he was active, slept peacefully at night, appetite and thirst were within normal limits, and there was no vomiting.
On radiographs (photo 2), free air was found in the pleural cavity. The patient underwent a CT examination and revealed subpleural bullae (photo 6, 7) of the cranial lobes of the lungs.
After CT scan, a bilateral thoracic drain was placed and more than 2300 ml of free air was removed. The owners of the animal, understanding all the possible complications and the likelihood of recurrence, categorically refused surgery, in connection with this they were taught how to use drains and remove air. The drains were removed after 2.5 weeks, pneumothorax resolved spontaneously. The patient has been observed for 7 months, no relapses have been noted to date.

References:

1. Spontaneous Pneumothorax Caused by Pulmonary Blebs and Bullae in 12 Dogs, J Am Anim Hosp Assoc, 2003.
2. Brad J. Case, Philipp D. Mayhew, Ameet Singh. Evaluation of Video-Assisted Thoracic Surgery for Treatment of Spontaneous Pneumothorax and Pulmonary Bullae in Dogs. Veterinary Surgery, 2015.
3. Sensitivity, positive predictive value, and interobserver variability of computed tomography in the diagnosis of bullae associated with spontaneous pneumothorax in dogs: 19cases (2003–2012), JAVMA, Vol 243, No. July 15, 2013.
4. Interpreting Small Animal Thoracic Radiographs, Procedures Pro / NAVC Clinician’s Brief / July 2010.
5. Peter Scrivani, DVM, DACVR Cornell University College of Veterinary Medicine. Pulmonary imaging: Getting the most information from thoracic radiographs. Ithaca, NY, 2013.
6. Pulmonary Patterns, VMA 976 (link)
7. Marie K. Holowaychuk, DVM. Pulmonary Contusions. November, 2006.
8. Au J. J., Weisman D. L., Stefanacci J. D. et al. Use of computed tomography for evaluation of lung lesions associated with spontaneous pneumothorax in dogs: 12 cases (1999–2002). JAVMA, Vol 228, No. 5, March 1, 2006.
9. Shebits H. Operative surgery of dogs and cats, 2010.
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