Norm of Hepatobiliary Scan (HIDA Scan)
Negative. Requires interpretation by a radiologist.
Normal anatomy and physiology of liver, spleen, and biliary tract as determined by a radiologist. Normal distribution of injectate: 86% in reticuloendothelial system (RES) of liver, 6% in spleen, 8% in RES of bone marrow.
Hepatobiliary (scan after IV injection of 99mTc-dimethylacetic acid): First-hour images show liver, cardiac, and vascular activity; gallbladder (GB) and common bile duct/bowel activity seen by 60 minutes. GB uptake should precede bowel visualization. An inflamed gallbladder will not take up radionuclide. In the presence of biliary tree obstruction, no radionuclide will be visualized beyond the point of obstruction.
Liver-spleen (scan after IV injection of technetium-99m radionuclide): Uniform uptake throughout liver and spleen. Decreased uptake, or “cold spots,” seen in areas with space-occupying lesions such as in Caroli's disease. Increased blood flow to the liver will be evidenced by increased radionuclide uptake, or “hot spots.”
Usage of Hepatobiliary Scan (HIDA Scan)
Used to visualize biliary tract and to detect acute acalculous, acute cholecystitis, calculous cholecystitis (caused by obstruction of cystic ducts), bronchobiliary fistulas, hepatocellular disease, gallbladder disease, jaundice, liver cancer, liver metastasis, obstruction, and perihepatic abscess; used to study biliary kinetics (biliary dyskinesia, gallbladder ejection fraction); evaluates patency of biliary system and cystic duct, including postsurgically, and nonspecifically demonstrates focal disease as “cold spots” of nonuptake of the radionuclide. Evaluation of pediatric jaundice (choledocho cyst; biliary atresia versus neonatal hepatitis); congenital bronchobiliary fistula; conditions causing increased flow to the liver will appear as “hot spots.”
Description of Hepatobiliary Scan (HIDA Scan)
The hepatobiliary scan is a radionuclide study that demonstrates hepatic parenchyma, extrahepatic bile ducts, gallbladder, and normal passage into the intestines as well as the position, size, and shape of the liver. Intravenously injected HIDA, a radionuclide, travels through the liver into the biliary system, enabling gamma camera imaging of the entire hepatobiliary system. The cells of the liver absorb the radionuclide within 30 minutes and can be observed on the scan before it is redeposited in the bloodstream and excreted. Dye is excreted in the bile, stored briefly in the gallbladder, and eliminated through the intestine, all within 4 hours. Failure of the dye to appear in the intestines is indicative of obstruction.
Professional Considerations of Hepatobiliary Scan (HIDA Scan)
Consent form IS required.
During pregnancy or breast-feeding; in children.
- Establish intravenous access.
- Have emergency equipment readily available.
- See Client and Family Teaching.
- Just before beginning the procedure, take a “time out” to verify the correct client, procedure, and site.
- The client is injected with radionuclide (usually 99mTc-IDA, the dose calculated by body weight) intravenously 30 minutes before the scan.
- Delay imaging for 6–48 hours after injection for clients known to have hepatocellular disease.
- The client is positioned supine on the scanning table during the scan.
- A gamma camera is placed over the right upper quadrant of the abdomen.
- Scintiphotos are obtained at 15, 30, 60, and 90 minutes after injection of the radiopharmaceutical.
- The procedure is repeated at 2–6 hours and 24 hours if obstruction is suspected or when the biliary system was not visualized.
- For 24 hours after the procedure, wear rubber gloves when discarding urine. Wash the gloved hands with soap and water before removing the gloves. Wash the hands again after the gloves have been removed.
Client and Family Teaching
- Fast from food and fluids for 4–6 hours before the scan.
- The scan takes 1.0–1.5 hours.
- Report any sensations that might indicate an allergic reaction such as itching or difficulty in breathing.
- Meticulously wash the hands with soap and water after each void for 24 hours after the procedure.
- Results are normally available from the physician within 24 hours.
Factors That Affect Results
- The scan must be performed promptly after the injection because radionuclides have a short transit time through the liver.
- Do not schedule any other radionuclear scans within 24 hours of this scan.
- If the client has just eaten, the gallbladder will be contracted and may not fill with HIDA, giving a false-positive study for acute cholecystitis. If the client has not eaten for many hours, the gallbladder may be full of bile or sludge and may not fill with HIDA, also giving a false-positive study.
- Total parenteral nutrition may also result in impaired visualization of the gallbladder.
- The presence of barium in the intestinal tract may inhibit gallbladder visualization.
- Health care professionals working in a nuclear medicine area must follow federal standards set by the Nuclear Regulatory Commission. These standards include precautions for handling the radioactive material and monitoring potential radiation exposure.