UroTAC - uro-TAC

Generality

The uroTAC is the TAC with contrast medium that allows to analyze in detail the anatomy and function of the most important components of the urinary tract, namely: the kidneys, the bladder and the ureters.

Thanks to the potential of uroTAC, the radiologist is able to identify: kidney stones, bladder stones, urinary tract infections, cysts and tumors of one of the organs of the urinary tract, anatomical malformations of kidneys, ureters or bladder and, finally, the exact origin of symptoms for which a renal or bladder disorder is suspected.

The uroTAC provides a very specific preparation; among its preparatory norms, complete fasting is also included.

With a total duration of 10-15 minutes, the uroTAC requires maximum immobility on the part of the patient; the body's movements, in fact, can alter the accuracy of the images provided by the instrument, thus distorting the entire diagnostic examination.

The risks of uroTAC are related to the dose of ionizing radiation, to which the patient is exposed during the examination, and to the contrast medium, which in some individuals causes an allergic reaction.

Contraindicated in case of pregnancy, uroTAC supplies images of the urinary tract of excellent quality.

Short review of what the TAC is

TAC, or Computerized Axial Tomography, is a diagnostic procedure that uses ionizing radiation (X-rays) to create extremely detailed three-dimensional images of specific anatomical areas of the body (brain, bones, blood vessels, abdominal organs, thoracic organs, pathways respiratory, etc.).

The TAC equipment includes:

• The large donut-shaped scan unit, called a gantry . It is the radioactive source;
• The generator;
• The support on which to place the patient. Generally, it is a sliding bed;
• An electronic processor;
• A command console for displaying three-dimensional images;
• A system for recording the acquired data.

In addition to the conventional (or classical ) CT, there is also the CT with contrast medium : the contrast medium allows to obtain images richer in details than a particular organ or anatomical tissue.

The TAC is normally painless; it can be slightly painless, when intravenous injection of the contrast medium is expected.

Nevertheless, it is in any case among the minimally invasive procedures, since the dose of ionizing radiation to which the patient is exposed is considerable.

What is uroTAC?

The uroTAC is the diagnostic test that exploits the potential of the TAC with contrast medium, to visualize the urinary system, in particular the kidneys, the bladder and the ureters .

Similar to urography - but not exactly the same thing - uroTAC is a radiology procedure, just like the other types of CT scans.

The interpretation of uroTAC images is the responsibility of a radiologist, who, if necessary, will advise the patient to discuss what has emerged with a urinary tract specialist (a nephrologist or a urologist ).

The urinary system

• The kidneys are the main organs of the excretory system. In number of two, they reside in the abdominal cavity, on the sides of the last thoracic vertebrae and of the first lumbar vertebrae, they are symmetrical and possess a shape that resembles that of a bean.
• In number of two, the ureters are the ducts that connect the kidneys to the bladder. For the avoidance of doubt, it is specified that each ureter is independent of the other.
• The bladder is a small hollow muscular organ, which accumulates urine before urination.
• The urethra is the duct that serves to lead urine to the outside. In humans, it crosses the penis; in women, it is more and more short and flows into the vulva.

The contrast agent for urTAC

Generally, the contrast medium used for urotac is radioactive iodine based.

The radioactive iodine-based contrast media are also called iodinated contrast media .

Alternative ways of writing uroTAC

There are several ways to write uroTAC, including uro-TAC, uroTac and uro-Tac .

Indications

Thanks to the images of the urothac, the radiologist is able to analyze the anatomy of the kidneys, ureters and bladder, and to find out if the aforementioned organs are "working" well or if they are carriers of some anomaly or particular condition.

Going into more detail, the uroTAC represents an important useful tool to:

• Go back to the precise origin of symptoms, such as pain in the hips, pain in the lumbar area, haematuria, etc., which lead to thinking of a disease of the kidneys or a tract of the urinary tract;
• Diagnosing kidney stones (or kidney stones );
• Identify the presence of bladder stones (or bladder stones );
• Trace the signs of an ongoing urinary tract infection (eg, pyelonephritis);
• Diagnose a cyst or a tumor (both benign and malignant) against one of the organs of the urinary tract (eg: kidney cancer, kidney cyst, bladder cancer, etc.);
• Identify anatomical abnormalities that may affect one of the organs of the urinary tract.

Figure: pyelonephritis observed at the uroTAC

Preparation

The urobac requires special preparation, based on which the patient must:

• Communicate to the doctor who prescribes the examination if he suffers from some allergy, in particular iodine, that is the chemical element at the base of the contrast agents used for the procedure;
• If you are a woman, tell your doctor if you are pregnant or suspect you are pregnant ;
• Tell your doctor if you are taking any medications, such as metformin, NSAIDs, anti-rejection drugs (immunosuppressants) and / or antibiotics at that time.
• Inform your doctor of any illness suffered in the last period and if you suffer from some heart disease, diabetes, asthma and / or some kidney disease ;
• Tell your doctor if you are an organ transplant ;
• In the hours just before the exam, drink in abundance (at least 1 liter of water), so that the bladder is full at the time of the procedure;
• Take the exam without jewelry or clothing with metal parts, as these could interfere with the proper functioning of the diagnostic equipment.

  If the patient does not comply with this preoperative rule, he is invited to do so just before the procedure begins;

• Go to the full fasting exam for at least 6-8 hours. This means that, if the URTAC is held on the morning of a certain day, the last meal must be the dinner of the previous evening.

Procedure

First, at the invitation of a medical staff member, the patient must:

• Respond to a questionnaire related to your medical history,
• Undergo pressure and body temperature measurement,
• Wear a special coat instead of your clothes and finally
• Take off all the jewelery and other metal objects that it is wearing, for the reasons stated above.

Once all these operations have been completed, the patient is ready to take his seat on the sliding bed of the uroTAC, which serves, at a later time, to position him inside the so-called gantry (see figure).

To arrange themselves correctly on the couch, the patient can count on the help of a member of the medical staff (in general it is the same who, previously, has questioned him about the medical history, has measured pressure and temperature, etc.); during his placement, the one who helps him also reminds him how he must "behave" during the examination and the importance that his immobility has, when the instrument is in operation.

Once the patient is lying on his back or on his side and ready to be introduced into the gantry, the radiologist doctor intervenes, who, with the collaboration of a registered nurse, injects the contrast medium necessary for the uroTAC.

The injection of the contrast medium usually takes place in a vein in the arm or hand ; the contrast medium takes a few minutes to distribute itself, through the blood, in the various anatomical compartments to be analyzed.

After the time required for the contrast medium to reach the urinary tract, the patient can finally be introduced into the gantry and the phase dedicated to the creation of three-dimensional images begins.

The creation of the images is very noisy, so that often, together with the gown, the medical staff also provides the patient with ear plugs or headphones, to be worn before injection of the contrast medium.

Remember that, while the instrument is in operation, the entire medical staff leaves the room in which the patient and equipment reside and moves to an adjacent room, in which there are the gantry control console and the data recording system acquired. However, the patient is not really alone: ​​the room in which he is, in fact, is provided with a loudspeaker and a camera, through which he can communicate with the outside in case of sudden necessity.

After the collection of the images necessary for a detailed evaluation of the urinary tract, the radiologist declares the uroTAC concluded and starts the operations to extract the patient from the gantry, an extraction in which the "usual" member of the medical staff already intervened several times takes care of, in the previous phases.

Getting up from the couch and getting dressed, the patient is ready to go home and to his daily activities, unless otherwise indicated by the radiologist.

What feelings does the patient feel during the procedure?

The patient may experience some sort of discomfort when inserting the needle, for injection of the contrast medium.

Furthermore, after the injection it is very likely that, for a couple of minutes, you will notice a strange metallic taste in your mouth .

Patients who find it difficult to remain immobile may feel uncomfortable after a short time; however immobility is a fundamental condition for the success of the exam.

Important note on the immobility to which the patient must adhere: in some phases of the uroTAC, immobility also includes holding the breath for a few seconds, as even the slightest movements deriving from the respiratory act can distort the results.

Clearly, to indicate to the patient when to hold the breath is the medical staff, through the communication system present in the room where the exam is held.

How long is the uroTAC?

Generally, the uroTAC lasts 10-15 minutes at most.

On what occasions does the patient have to wait before returning home?

The radiologist may request the patient to stay further in the hospital center, where the uroTAC was held, in the event that the examination provided such unclear images as to make it necessary to repeat the entire procedure.

How to encourage the elimination of the contrast agent at the end of the uroTAC

To aid the elimination of the contrast agent from the body, radiologist doctors indicate that they drink a lot of water, starting immediately after the execution of the urTAC.

If the patient adheres to this indication, he eliminates the contrast agent from his body within 24 hours.

risks

The uroTAC has several risks; here is what these risks consist of:

• Patient exposure to a non-negligible dose of ionizing radiation . Ionizing radiations are a factor favoring the development of malignancies, both malignant and benign.

  Extent of risk? The dose of ionizing radiation emitted by an uroTAC is equivalent to 3 years of natural radioactivity. Comparing with a chest X-ray, this examination exposes the patient to a dose of ionizing radiation equal only to 10 days of natural radioactivity.

  With this, we do not want to demonize the uroTAC, but we just want to emphasize that its repetition is not recommended. There are alternative tests, which are also effective.

• Allergic reaction to contrast medium . It is a rare circumstance, which concerns only predisposed persons. Generally moderate and easily controlled with specific drugs, the most common symptoms of allergic reactions to the contrast medium are: hot flushes, nausea, strange tingling, hives and prolonged pain where there was an injection.

Contraindications

They certainly represent a contraindication to uroTAC: the state of pregnancy, the presence of an allergy towards the preparations that doctors must use during the examination (in particular contrast agent), obesity (the CT scan equipment are able to support people weighing no more than 150 kilograms) and the pharmacological assumptions that could interfere with the contrast medium (in these cases, the solution consists in temporarily interrupting these assumptions).

In some situations, claustrophobia could also become a contraindication to uroTAC.

Is breastfeeding a contraindication? How should a breastfeeding woman behave?

Breastfeeding is not a contraindication to uroTAC; however, for most doctors, it is not recommended in the first 24-48 hours following the exam.

Results

Depending on the severity of the patient's condition, uroTAC results may be available immediately or after a few days.

The main advantage of the uroTAC is that it provides very valuable information for a correct diagnosis.

Other advantages of uro TAC:

• It is painless, minimally invasive and very precise;
• Simultaneously shows the so-called soft tissues (nerves, muscles, ligaments, fat, blood vessels etc.) and the so-called hard tissues (bones and cartilages);
• Provides more detailed images of conventional X-rays;
• It is a short term exam;
• Identifies many morbid conditions;
• It is less sensitive to patient movement than nuclear magnetic resonance;
• Unlike nuclear magnetic resonance, it can be performed even if the patient has a metal prosthesis;
• It provides images in real time, so it can be exploited just before surgery;
• Given its extreme sensitivity, it may make it unnecessary to use exploratory surgery or a biopsy.