Multislice computed tomography (CT) of the kidneys
A significant portion of all research in the branches of radiological diagnosis is necessary for patients of urological profile. Over the past 10 years, the development of methods of radiation diagnosis changed the approach to identifying pathology. MSCT of urinary system became the mandatory method of examination of patients with renal colic and purulent-destructive diseases, and the use of magnetic resonance imaging is now more aimed at diagnostics of diseases of organs of small pelvis.
The story of how CT became the leading method of diagnostics of urological diseases
Since that day, when CT began to be implemented in clinical practice, its diagnostic value for urology was obvious. By the end of 80-ies of the last century, CT became the standard for the diagnosis of kidney cancer. Gradually, it became inexpedient to the standard renal angiography in order to distinguish a cyst from a malignant tumor. Angiography has receded into the background and in the diagnosis of tumor thrombosis of the inferior Vena cava.
Kidney disease, for which effective multi-spiral computed tomography
MSCT is a particularly valuable study for the differential diagnosis of mass lesions kidney: cysts, tumors, arterio-venous malformations. The detection of certain types of tumors, it is necessary to assign a tumor stage that is also easy to do using multislice computed tomography. After surgery for excision of the tumor areas or complete removal of the kidney, CT helps to timely detect cancer recurrences. Injuries to the kidneys, occurrence of blood in urine, pyelonephritis and abscess of the kidney are also indications for the study.
Renal colic – this is also the occasion to assign the patient to the CT without intravenous contrast enhancement, since the function of the kidneys in this disease can be broken so that will bring the contrast agent from the body. MSCT urography visualizes the causes of ureteral obstruction and urine retention.
Contraindications to the study of the kidneys on the CT machine
MSCT is quite safe exploration. And, although it belongs to the methods of radiation diagnosis, improvement of tomography has allowed to reduce the individual dose exposure of the patient to an average of 4 to 8 mSv. Therefore, multislice computed tomography for medical reasons can be performed up to several times a year.
Absolute contraindications to the appointment of MSCT is pregnancy and infancy. Ionizing radiation may have adverse effects on the developing fetus or growing organism. However, such a study is done in cases when experts cannot find a more safe alternative method.
As for the CT with contrast, severe renal failure can become an insurmountable obstacle to the implementation of the survey. The fact is that for removing contrast agents from the body requires preserved renal function. It is estimated by such indicators as «creatinine serum». Creatinine serum 1.5 mg/DL or more 130 µm/l is a contraindication to the use of MSCT with contrast.
MSCT with contrast enhancement was also not conducted in the presence of severe allergic reactions to iodine-containing drugs in history (shock, cardiac respiratory or cardiac arrest, convulsions, collapse), severe bronchial asthma and hyperthyroidism.
How to prepare for multislice computed tomography and how goes the research?
Special training research is not required. It is carried out on an empty stomach, after at least three hours after a meal. Preparation is necessary only for patients with contraindications to administration of iodinated contrast agents: directly to the radiology Department where a premedication (antihistamines or glucocorticoids) to prevent the development of severe adverse reactions. In other cases, you just need to come to study on an empty stomach.
In the device CT the patient lies on his back with his hands up. Sometimes the specialist asks to hold the breath on the inhale – this is required for better visualization of certain areas.
Myths about the harmfulness of multislice computed tomography should be dispelled through the dissemination of scientific knowledge. The maximum allowable dose of the infamous exposure during the year — no more than 150 mSv in a year, the average radiation exposure from CT ranges from 4 to 8 mSv. It is easy to calculate that spending even a few CT examinations, standard chest x-rays and x-rays at the dentist – difficult to exceed the threshold of 150 mSv. And the failure of the multislice computed tomography can be fatal: after all, this is the leading method in the diagnosis of cancerous processes of the kidneys.