Radioisotope study of the liver

Radioisotope study of liver function is carried out using compounds labeled with radioactive isotopes of iodine (J131 or J125). The most commonly used paint a Bengal rose labelled J131. The use of this drug significantly simplifies and accelerates the functional test. After intravenous administration of Bengal rose (5 - 10 mccoury) all subsequent measured using radiometric instruments type DSU-61 or UR, scintillation detectors which are above the ear or heart (removal of paint from the blood) and on the liver (to determine accumulation and excretion of paint).
Sometimes the third sensor monitor the admission of the drug through the bile ducts into the intestine. In healthy people the time of the cleansing blood from paint half (T 1/2 clearance) is equal to 8 minutes In the first minute after the introduction of paint see a sharp increase of the level of radioactivity above P. characterizing the state of the vascular bed. Subsequent slower rise of the curve (heptagram) reflects paint absorption of blood polygonal cells of P. the Maximum absorption at heptagram OK (according to some authors) occurs in 20-30-th minutes (Fig. 20). The breeding half of ink from P. the gallbladder varies between 60-115 minutes; after 24 hours in Petrograd remains no more than 2.5% of the administered drug.
When holangiogepatit the rate of accumulation and excretion of the drug from P. slows down. A day in the liver remains 10-18% of the maximum amount of radioactivity.

heptagram
Fig. 20. Heptagram healthy people.

Fig. 21. Heptagram patients with cirrhosis.

Based on the analysis of data on the rate of receipt of a preparation in P. and deducing from it a test with Bengal rose allows the differential diagnosis of jaundice different origin.
For jaundice hepatic origin characterized by normal absorption of Bengal rose liver dramatically slow removal of the gallbladder. Even after the function load (dacha 200 ml of milk for 40 minutes studies) the amount of radioactivity above the liver almost not changed. At jaundice hepatic origin functional load milk causes increased excretion of the drug in the intestines.
Acute obstruction of the bile ducts sharply slowing down the accumulation of the drug in Petrograd (T 1/2 clearance is increased to 60 minutes). After 24 hours in Petrograd there is a high level of radioactivity. Especially sharply heptagram varies with cirrhosis (Fig. 21). Curve is low, without the Express high and visible excretion. The paint in the liver can be detected after 48 and 72 hours.
In various pathological conditions associated with the change of the function P., increases the excretion of Bengal rose with urine. In particular, in viral hepatitis 1.5 hours with urine out of 9.2%, 24 hours 24,5% (OK, respectively 1.9% and 2,6%) of the drug. Radioisotope study of the function of P. it is possible to spend and children. Children entering 1-4 mccoury Bengal rose and within 3-6 days measure radioactivity urine and feces. In the case of partial blockage of the bile ducts within 24 hours excreted with faeces from 24 to 50% of the drug; if complete obstruction of the bile ducts Bengal rose excreted in the urine.
Of great importance in the diagnosis of diseases P. acquired scan (see), which provides graphic images (scans, Fig. 22) distribution of labelled compounds in the liver. Scanning is performed through special radiometric instruments (see Scanners). The most often used Bengal rose labelled J131 (150-200 mccoury), and colloidal gold Au198 (200-250 mccoury). When using Bengal rose can be performed only a one-time scan after 20-30 minutes after drug administration.
Application Au198 allows you to get re-scans for 72 hours. However, Au198 due to absorption by cells of the reticuloendothelial system is less effective in detecting diffuse lesions P., and, in addition, it creates a much greater exposure of the body. The location of tumor metastases in the letter seen by the light gaps in the scan, the places where radioactive connection is not absorbed cloth (Fig. 23). Cm. also Radioisotope diagnostics.

the scan of the liver
Fig. 22. Scanogram liver healthy person.

Fig. 23. The scan in the liver with multiple metastases.