Formulary and Handbook: Nuclear Medicine

Gastrointestinal System

University of Iowa Hospitals and Clinics
Peer Review Status: Internally Reviewed

2. Procedure-No special patient preparation. Liver-spleen imagingshould be performed prior to G.l radiology procedures, as residualbarium in the colon may cause imaging artifacts.

3. Imaging time is 1-1.5 hours.

Hepatobiliary Imaging
1. An imaging procedure using Tc-99m mebrofenin to test for patencyof the cystic duct (acute cholecystitis) and to detect otherabnormalities in hepatobiliary function such as inadequategallbladder emptying, biliary dyskinesia, inadequate drainage througha biliary stent, or neonatal jaundice.

2. Procedure

a. Patient must be fasting (except for clear liquids) for at least 4 hours.

b. Imaging time is 60-90 minutes. Additional intermittent imaging may be required for as long as 24 hours.

c. If the gallbladder fails to visualize within 60 minutes in a patient suspected of cholecystitis, morphine may be administered intravenously to promote gallbladder filling. Requires approximately 30 minutes additional imaging time.

d. Sincalide may be administered to stimulate gallbladder contraction and emptying. Gallbladder emptying rate and ejection fractions may be quantitated. Requires approximately 30 minutes additional imaging time.

e. In the evaluation of neonatal jaundice, premedication with phenobarbital for 5 days may improve sensitivity/specificity of the examination. Consultation with the Nuclear Medicine physician is suggested for this clinical indication.

Imaging for Ectopic Gastric Mucosa
1. An imaging procedure using Tc-99m pertechnetate to detect thepresence and location of ectopic gastric mucosa.

2. Procedure

a. Patient should be fasting for 4 hours prior to imaging.

b. Imagh1g time is about 1 hour.

c. Pretreatment with cimetidine or glucagon may be desirable in selected cases.

Gastric Emptying Study
1. An imaging procedure to determine the rate of gastric emptying. Apreparation of scrambled eggs impregnated with Tc. 99m sulfur colloidis generally used as a marker of solid phase emptying. Tc-99m sulfurcolloid can also be mixed in water or infant formula to determineliquid phase emptying.

2. Adult procedure

a. Patient must be NPO for at least 6 hours prior to the examination.

b. Routine imaging time is 2-3 hours.

3. Procedure in diabetics

a. Patient must be NPO for 6 hours prior to examination unless special arrangements have been made.

b. Study is scheduled to start in the A.M. only unless special arrangements have been made.

c. Diabetics requiring insulin must have insulin dose modified (no regular insulin, reduced lente or NPH dose or reduced longer acting insulin dose) and l.V. access line in place prior to reporting for procedure.

d. Consultation with Nuclear Medicine staff is required.

e. Imaging time is 3 hours.

4. Pediatric procedure (ages 4-16)

a. Performed only by special arrangement with Pediatric Gastroenterology.

b. Patient must be NPO for at least 6 hours prior to the examination unless special arrangements have been made.

c. Routine imaging time is 2-3 hours

5. Pediatric procedure (infants)

a. Performed only in consultation with Pediatric Gastroenterology and Nuclear Medicine staff.

b. Study should be arranged to coincide with time of feeding.

c. Referring care area to place NG tube prior to scheduled exam.

d. Regularly scheduled feeding formula should come with patient.

e. Routine imaging time is 1-2 hours.

Gastroesophageal Reflux Study
1. An imaging procedure using Tc-99m sulfur colloid in water todetect gastroesophageal reflux.

2. Currently performed only after consultation with NuclearMedicine staff.

3. Patient must be NPO for a minimum of 6 hours prior to study,and preferably NPO overnight unless special arrangements have beenmade.

Imaging for Gastrointestinal Bleeding
1. An imaging procedure using Tc-99m labeled red blood cells todetermine the presence and site of gastrointestinal bleeding. Can beperformed to screen patients for angiography or to direct diagnosticstudies to the appropriate area of the abdomen. Study has poorsensitivity/specificity when bleeding site is proximal to theligament of Treitz.

2. Procedure

a. A blood sample (1-3 ml) is obtained from the patient and the red blood cells are labeled with Tc-99m in vitro and are then reinjected intravenously.

b. The initial imaging time is 60 minutes, but additional imaging (e.g., 1-2 hours) is often required.

c. Consultation with the Nuclear Medicine staff and possibly with radiology angiography staff is required to determine the type of study to be utilized.

Salivary Gland Imaging
1. An imaging procedure using Tc-99m pertechnetate to detectabnormalities in the salivary glands and their drainage.

2. Procedure

a. No special patient preparation.

b. The length of the study is approximately 1 hour.